Zika: A Bigger Threat to Pregnancy

Jul 17, 2018 | Natalia Ciesielska | Outbreak News

 

While first discovered in the African country of Uganda in 1947, Zika virus, carried by mosquitos and endemic in many tropical areas of the Americas, Asia and Africa was not well understood until its recent outbreaks in South America in 2015 and 2016 [2]. In adults, the virus causes mild symptoms including fever, rash, headache, joint and muscle pain and red eyes, however in many cases it is asymptomatic [6]. During the 2015 outbreak in Brazil, Zika brought great fear because little was known about its effects on the developing fetus and risk of microcephaly [3]. Microcephaly is a malformation making the perimeter of a developing fetus’s head smaller than normal, which can also lead to epilepsy and vision problems [6]. Between October 2015 and January 2016, approximately 4,000 babies were born with microcephaly in Brazil [1]. By June 2016, the World Health Organization (WHO) recommended people in affected areas to delay getting pregnant to avoid birth risks and defects [1].

 

Zika virus is now known for its cause of brain abnormalities in babies exposed in utero, called congenital Zika syndrome [6]. Microcephaly is the best known birth defect, but cases of it represent only a small proportion of children affected by the virus [4]. The disease can cause a series of complications during pregnancy besides microcephaly, including calcium deposits in the brain indicating brain damage, excess fluid in brain cavities and surrounding the brain, absent or poorly formed brain structures, abnormal eye development, hearing loss, and damage to the brain that affects the nerves, muscles or bones, such as clubfoot or inflexible joints [5]. The virus poses the greatest risks to the fetus early in the pregnancy and can even result in miscarriage [4]. It has been shown that the virus is able cross the placenta, which provides blood flow and nutrients to the fetus; damage to the placenta can lead to growth restriction and poor outcomes, either fetal growth restriction or fetal death [2].

 

According to more recent studies, the Zika virus’s ability to cause miscarriage poses a much greater threat to pregnancy than previously thought [2]. Researchers in Sao Paulo say that not only do women infected with Zika have higher rates of miscarriage, but also that Zika may be more likely to produce miscarriages than microcephaly [3]. Studies showed that in a sample of 125 women, Zika infections were linked to 10%-15% increased likelihood of miscarriage [1]. Another study in pregnant women showed that among infected women, 5% did not lead to full term pregnancy or had stillborn children [6], compared to 0.2% in non-infected women [3].

 

When Zika first appeared in Brazil in 2015, symptoms were mild and the outbreak was not of serious concern until months later, when babies began being born with abnormally small heads [3]. However, data from Brazil in 2016 suggests the country was also experiencing fewer live births around the same time [1]. Although Brazil’s decrease in birth rates could have been due to family planning, miscarriages from Zika infection could also have been to blame. It is hypothesized that Zika may have caused very early miscarriages in women before they even knew they were pregnant. It is possible that an increase of miscarriages was missed in the first wave of the Zika outbreaks due to women being asymptomatic or not knowing they were pregnant or had a miscarriage; all before Zika and its effects were brought to the public’s attention [3]. In fact, researchers later found a correlation between the drop in birth rates and the number of Zika cases recorded 40 weeks prior – 40 weeks being the average duration of a pregnancy [1].

 

In 2016, almost half of pregnant women infected with Zika in Rio de Janeiro experienced a serious complication such as a miscarriage or birth defect [4]. One study found that among women who were infected by the virus in their third trimester, 29% developed complications that affected their babies. In another study conducted by the Oswaldo Cruz Foundation in Rio de Janeiro, 55% of women infected in the first trimester experienced adverse outcomes that included miscarriage, calcifications in baby’s brain, microcephaly, and brain hemorrhages. Among women infected in the second trimester, 51% experienced the aforementioned adverse outcomes. Overall, of the infected pregnant women, 46% were affected, with 3.4% specifically experiencing cases of microcephaly in their infants. This indicates a very high risk of poor birth outcomes for infected pregnant women. Among women who did not test positive for Zika virus, only 11.5% had any adverse outcome [4].

 

While these statistics may be startling, it may still not be representative of the true proportion of affected cases in Brazil or South America. Babies who appear healthy and normal at birth may have brain damage and not show symptoms until they grow older [4]. Additionally, previous research on Zika only measured the number of miscarriages and stillbirths in women who showed signs/symptoms of infection [6]. Researchers know that about half of people who have Zika do not present with any symptoms, therefore, studies on pregnancy may not be taking into account a large percentage of infected people. It is also difficult to perform human studies that are representative of true rates of miscarriage because Brazil lacks strong public health surveillance systems. Women may also be underreporting miscarriages because they may not know they are pregnant or choose not to report their miscarriage for cultural or personal reasons, particularly due to the resemblance to induced abortions, which are still illegal in Brazil [3].

 

Studies in primates have shed some light on the mechanism of the virus as well as more plausible rates of miscarriage in Brazilian women infected with Zika. A study from California National Primate Research Center (CNPRC) collected data from various individual studies looking at Zika and vaccines, the virus’s effect on the placenta and pregnancy, and its progression in different monkey species [2]. Experiments showed that 26% of primates infected with Zika early during pregnancy, most of which were asymptomatic, suffered miscarriages or had stillborn young [6]. These rates are four times higher than those normally observed in non-infected monkeys. These studies are also evidence of pathological lesions in fetal and placental tissues causing fetal death. A lead author of the study expects the true rate of human miscarriages to be less than 26%, but still higher than what previous human studies have shown [2]. The advantage to research at NPRC labs is the ability to control timing and methods of infection in primates, which cannot be imitated in humans. Studies on Zika’s effect on pregnancy and birth outcomes in humans are very limiting and may underestimate true rates because it is difficult to identify asymptomatic cases, or identify women who themselves do not know are pregnant. Researchers studying primates found that the Zika virus infection (using strains from recent Asian and American outbreaks) affected the tissues connecting the mother to the developing monkey fetus, causing damage to the placenta, and cell death [2].

 

Studies both in humans and in primates provide important information to better understand the pregnancy and birth consequences caused by viruses such as Zika. Their data are essential both in identifying the source and mechanisms causing negative birth outcomes as well as in aiding in the prevention of maternal mortality around the world.

 

Sources:

[1] Baranuik, Chris. “Zika Outbreak May Have Led to Fewer Births in Rio De Janeiro.” New Scientist, New Scientist, 24 Apr. 2017, www.newscientist.com/article/2128642-zika-outbreak-may-have-led-to-fewer....

[2] Barncard, Chris. “Zika Virus Infection May Multiply Risk of Miscarriage, Stillbirth.” News, University of Wisconsin-Madison, 2 July 2018, news.wisc.edu/zika-virus-infection-may-multiply-risk-of-miscarriage-stillbirth/.

[3] Beaubien, Jason. “Did Zika Cause More Miscarriages Than Microcephaly?” NPR, NPR, 10 Nov. 2017, www.npr.org/sections/goatsandsoda/2017/11/10/563364000/did-zika-cause-mo....

[4] Vogel, Gretchen. “First Hard Look at Zika Pregnancies Finds Nearly Half Result in Miscarriage or Birth Defects.” Science | AAAS, American Association for the Advancement of Science, 13 Dec. 2016, www.sciencemag.org/news/2016/12/first-hard-look-zika-pregnancies-finds-n....

[5] “Zika and Pregnancy.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 26 June 2018, www.cdc.gov/pregnancy/zika/data/pregnancy-outcomes.html.

[6] “Zika Causes More Abortions than Doctors Thought, Research Shows.” O Globo, gda, 2 July 2018, oglobo.globo.com/sociedade/saude/zika-causa-mais-abortos-do-que-medicos-pensavam-mostra-pesquisa-22843698.

Lyme Disease Vaccine Candidate VLA15 Advances Through Phase 1 Trials

Jul 16, 2018 | Emily Wolfson | Research & Policy

 

Valneva, a French biotech company focused on developing vaccines, has announced it has obtained successful Phase 1 results for its Lyme disease vaccine candidate, VLA15 [1]. The Food and Drug Administration (FDA) approved a Fast Track designation for VLA15 in 2017 due to the increasing severity of Lyme disease. Therefore, the vaccine candidate will be given priority at every step of the licensing process [2]. Phase 1 of the clinical trial aimed to evaluate the safety and tolerability of VLA15. It is expected to enter Phase 2 clinical development by the end of 2018, to test efficacy of the vaccine [1].

 

Lyme disease is a vector-borne disease spread by ticks carrying the bacterium Borrelia burgdorferi [3]. Unlike many bacterial infections, it is found in the body’s tissues rather than circulating in the blood, making it more difficult to detect and treat [2]. Symptoms include fever, headache, fatigue and skin rash, all of which can usually be treated with antibiotics. If left untreated, the infection can spread to the heart and the central nervous system. Lyme disease is considered the most common vector-borne disease in the Northern Hemisphere and the burden of the disease is growing each year. The World Health Organization (WHO) estimates that there are 532,125 cases in the world annually [4].

 

The VLA15 vaccine targets the outer surface protein A (OspA) of Borrelia burgdorferi. It confers protection by creating antibodies that prevent Borrelia from migrating from the tick to the human after a bite occurs [1]. VLA15 protects against the majority of human pathogenic Borrelia species. The target population includes individuals over two years of age living in endemic areas or those planning to travel to endemic areas. Study subjects in the Phase 1 trial were given the vaccine three times, each one month apart. This is the likely number of doses that will be needed to confer immunity, pending the remaining trials[1].

 

To date, there has only been one other licensed Lyme disease vaccine on the market, from 1998 to 2002. This vaccine, called LYMERix, was given in a three-dose series and was 78% effective in protecting against infection after all three doses [5]. Shortly after the vaccine arrived on the market, several reports were made of serious adverse events, as well as cases of arthritis believed to be caused by the vaccine. Simultaneously, many people were growing suspicious of vaccines, particularly fueled by the now-retracted Lancet study that falsely claimed that the measles, mumps and rubella (MMR) vaccine was linked to autism [6]. The cases of arthritis combined with anti-vaccine media and lawsuits caused the vaccine to be withdrawn from the market. Though official safety data did not show a difference in chronic arthritis between those who received the vaccine and those who did not, public concern ultimately carried the most weight [5].

 

Until now, there have been no other attempts to develop a new human Lyme disease vaccine, in part due to this failure of LYMERix in the eyes of the public. More than a decade after the first and only vaccine was withdrawn from the market, Valneva has placed priority on the increasing incidence of Lyme disease in the United States and worldwide, in the face of the modern anti-vaccine movement.

 

 

Sources:

[1] http://www.valneva.com/en/rd/vla15

[2] https://www.healthline.com/health-news/how-vaccine-fears-helped-kill-the...

[3] http://www.who.int/ith/diseases/lyme/en/

[4] http://www.who.int/vector-control/burden_vector-borne_diseases.pdf

[5] https://www.historyofvaccines.org/content/articles/history-lyme-disease-vaccine

[6] https://www.vox.com/science-and-health/2018/5/7/17314716/lyme-disease-va...

 

Shedding Light on NTDs: Guinea Worm Disease

Jul 12, 2018 | Lauren Goodwin | Outbreak News

 

Historically referred to as “little dragons”, this week’s NTD is Guinea worm disease. Guinea worm is caused by a parasitic worm that causes severe pain and blisters in those it infects. It is a disease that has been around for as long as time. Mummies from ancient Egypt have been discovered to carry the worms and in the Book of Numbers, the “fiery serpents” infecting the Israelites is believed to have been Guinea worms [1]. Muslim pilgrims participating in the hajj suffered from infections on the way to Medina, giving the infectious disease its Latin name, Dracunculus medinensis, or “Little dragon of Medina” [1]. Even more fascinating, many believe that the symbol of medicine, snakes coiled around a staff, represents the ancient treatment for the disease documented on the Ebers papyrus from approximately 1500 BC that is still utilized today [1, 2].

 

Guinea worm disease is caused by the ingestion of contaminated water containing microscopic water fleas called copepods that carry the Guinea worm larvae [3]. It is typically contracted from drinking stagnant water from a pond or water source.  Once digested, the larvae are released in the digestive tract and enter the body cavity, where the larvae develop into adult worms that can reach two to three feet in length over a period of 10 to 14 months [3]. When the female worm is ready to release larvae, it moves to the surface of the skin and creates a painful blister, often on the leg or foot [3]. Most often, once the blister forms, people submerge the blister in water, as it greatly relieves the burning pain. However, doing so signals the worm to release larvae into the water source, thus contaminating the water supply and perpetuating their life cycle [3]. Whenever the worm comes in contact with water, the female worm can release millions of immature larvae [3]. Humans typically are infected with one worm, but they can be infected with multiple worms at the same time if there is a higher prevalence of the parasite in their local area [4].

 

Treatment for Guinea worm disease is not comfortable. With no preventative vaccine or drug to treat the disease, the only option is to take a small stick or gauze and slowly pull the worm out of the wound [3]. It can only be pulled out a few centimeters a day to avoid tearing of the worm, so the process typically takes a few weeks to remove the worm completely [3]. Antibiotic ointment is typically applied to the wound to prevent secondary bacterial infection, which is very common in rural regions of Africa where there is limited access to healthcare and sanitation[3].

 

Infection with Guinea worm disease can be debilitating. This often means they are unable to work due to the pain caused by the worm, leaving their families to struggle, thus continuing a cycle of poverty. The Center for Disease Control  (CDC), in association with organizations like the Carter Center and World Health Organization (WHO), have worked tirelessly to educate those most at risk and have provided tools for filtering drinking water to drastically reduce the incidence of Guinea worm disease. In 1986, 20 countries globally had a combined 3.5 million cases a year and 120 million people were at risk for the disease [5]. Due to eradication and elimination efforts, there were only 25 new cases worldwide in 2016, coming from Chad, Ethiopia and South Sudan [5]. In March 2016, 198 countries, territories and areas representing WHO Member States were declared free from Guinea worm disease transmission [5]. It is expected that Guinea worm disease will be the first disease to be eradicated using core public health practices, including surveillance, case containment and simple interventions, without the use of vaccines or medicines [5].  The eradication campaign has prevented at least 80 million cases of Guinea worm disease since its inception [6].

 

Disease elimination and eradication can be incredibly complex and time-consuming, requiring a multidisciplinary approach to stop the spread of disease. To understand this process, we must first understand basic epidemiologic principles. Elimination refers to incidence of a disease or infections associated to a disease being reduced to zero in a specific geographic region [7]. For example, poliomyelitis has been eliminated in the United States, however, you can still find cases around the globe. Eradication refers to the permanent global reduction of a specific disease agent to zero [7]. The only infectious disease that has been completely eradicated is smallpox, which was declared to be eradicated in 1980 after an extensive campaign led by the World Health Organization [8].

 

There are many biologic and technical characteristics of infectious diseases that make them more or less likely to reach eradication [7]. However, these factors can be boiled down to three simple traits: there is an effective treatment for the disease; there are tools that are both appropriately specific and sensitive to detect disease; and humans are essential for the infectious agent to complete its life cycle and are the only reservoir for it [7]. Simply put, if humans are the only species to carry the disease, it is much more feasible to eradicate. The ultimate goal of public health is disease elimination and eradication, which requires directed efforts of the public health community and government organizations in order to effectively prevent and treat disease to avoid transmission.

 

Seven diseases are currently targeted by the International Task Force for Disease Eradication, including Guinea worm, lymphatic filariasis, measles, mumps, rubella, poliomyelitis and cysticercosis [9]. However, now that Guinea worm infections in both domestic and wild dogs have been confirmed, the possibility that it can be truly eradicated is no longer certain, putting thirty-two years of dedicated efforts at risk [10]. Last year, over 800 cases of Guinea worm occurred in dogs along the Chari River, compared to thirty human cases in 2017 [10]. It is still unclear how the dogs are contracting the larvae, though the CDC does not suspect that it is from drinking water [3]. One hypothesis is that the dogs are eating aquatic animals, like frogs or fish, that have consumed copepods that carry the Guinea worm larvae [3]. Luckily, there is no sign of dog to human transmission yet, but the dogs can transmit the parasitic worm to water sources, where humans are most susceptible to contracting the parasite [10].

 

With this new knowledge that humans are not the only species at risk for infection of Guinea worm, the eradication process has become more challenging. However, this has not deterred public health officials from taking every step necessary to contain the infections and prevent the spread to humans. Infections in dogs have been a bump in the road, but the public health community has and will remain steadfast in their efforts to make sure those most at risk are cared for.

 

 

 

 

Sources:

[1] http://phenomena.nationalgeographic.com/2013/01/24/the-guinea-worm-a-fond-obituary/

[2] https://www.florenceinferno.com/rod-of-asclepius-and-caduceus-symbols/

[3] https://www.cdc.gov/parasites/guineaworm/gen_info/faqs.html

[4] https://www.cartercenter.org/news/documents/doc1308.html

[5] https://www.cdc.gov/parasites/guineaworm/gwep.html

[6] https://www.cartercenter.org/health/guinea_worm/index.html

[7] https://www.cdc.gov/mmwr/preview/mmwrhtml/su48a7.htm

[8] http://www.who.int/csr/disease/smallpox/en/

[9] https://www.cartercenter.org/resources/pdfs/news/health_publications/itfde/updated_disease_candidate_table.pdf

[10] https://www.nytimes.com/2018/06/18/health/guinea-worms-dogs-chad.html

 

 

 

What You Might Have Missed in History Class: Black Death is Still Here and Closer Than You May Think

Jun 29, 2018 | Lauren Goodwin | Outbreak News

 

 

In case you haven’t been in a history class in a while, let’s set a scene for you. The year is 1347 and you are at the Messina port in Sicily. Twelve ships just arrived from the Black Sea and you excitedly go to the port to greet them. To your horror, when the ships arrive, most of the passengers were gravely ill or already deceased and were covered with black boils on the skin. Almost immediately the port commanders required the ships to leave but is too late. The lethal pathogen that annihilated the ships has already been transmitted to those waiting on the shore. Seemingly overnight, people who were otherwise healthy were contracting the disease and dying quickly thereafter. Over the next five years, this mysterious disease would kill an estimated 25 million people across Europe, killing one-third of the continent’s population [1]. It wasn’t until years later that it would be called the Black Death.

 

What you probably did not take out of that lesson is that the plague is still present today. In fact, the United States has a reported average of seven cases of plague a year, typically in the grassland regions of the western United States. While the last documented outbreak of pneumonic plague was documented in 1924, on June 12, 2018, the Central District Health Department reported a confirmed case of bubonic plague in an adolescent boy [2]. It is believed that he contracted the disease at his home in Idaho or from a recent trip to Oregon through a flea bite, but thankfully he is currently recovering at home after seeking medical attention [2, 3].  Around the globe, bubonic plague can be found in South America, Africa and Asia, most notably in Madagascar, where there was an estimated 2,348 cases of pneumonic and bubonic plague from August to November 2017 [4].

 

The bacteria that causes the plague, Yersinia pestis, is found in rats and fleas and often cycles between the two [3]. When a person is bit by an infected flea or comes in contact with body fluids of an infected rodent, the bacteria can be transmitted to them [3]. Human-to-human transmission occurs when an infected person releases infected droplets into the environment when coughing [3]. Plague infection presents in three forms: bubonic, septicemic and pneumonic.  All three forms of the plague have common symptoms of fever, chills and weakness. The bubonic plague, also known as the “Black Death”, involves sudden onset of common symptoms, plus characteristic swollen lymph nodes [5]. Septicemic plague has additional symptoms including abdominal pain, bleeding into the skin and organ and tissue death, especially in the fingers, toes and nose [5]. Pneumonic plague causes rapid pneumonia and can sometimes develop from untreated bubonic and septicemic plagues [5]. Pneumonic plague is the most severe form of plague and is the only form that can spread from person-to-person through droplet transmission [5].

 

However, we do not need to worry about the Black Death coming on a 14th-century scale just yet. The main difference between the 14th century plague and today is how the advancement of public health impacts its transmission. Surveillance and control measures from organizations like the Center for Disease Control and Prevention (CDC) and the World Health Organization (WHO), allow for possible outbreaks to be recognized and infected animals to be identified to limit human exposure to plague. The differences in basic living conditions and sanitation alone provide a barrier that can drastically reduce plague transmission. The improvement of medical technology, including antibiotics, give those who are infected today a chance to be cured. Water is cleaner and in many regions of the world, there is less contact with flea-carrying rodents. It does require us to be vigilant, however, because we always have the risk of the plague spreading if pneumonic plague goes undiagnosed and untreated. In order to avoid future outbreaks, it is imperative that we limit contact with possible carriers of disease and seek medical attention as soon as symptoms develop to ensure that history does not repeat itself.

 

 

 

 

Sources:

[1] https://www.history.com/topics/black-death

[2] http://www.cdhd.idaho.gov/dac-hot-topics.php

[3] https://www.cdc.gov/plague/transmission/index.html

[4] http://www.who.int/csr/don/27-november-2017-plague-madagascar/en/

[5] https://www.cdc.gov/plague/symptoms/index.html

 

 

 

Epidemic of Typhoid Fever in El Salvador

Jun 28, 2018 | Tianyuan Hu and Emily Cohn | Outbreak News

 

An outbreak of typhoid fever has been reported in El Salvador, with 644 suspected cases from January to the end of May, according to the Minister of Public Health, Violeta Menjívar. The case rate is high across the country, affecting 26 municipalities, including the capital city, San Salvador. Typhoid fever cases increased dramatically this year, compared to the 340 typhoid fever cases reported during the same time period from January to May 2017. El Salvador health authorities have begun monitoring the situation to reduce the spread of disease. [1]

 

Typhoid fever, more commonly known as typhoid, is a bacterial disease with an estimated 20 million cases and 222,000 fatalities worldwide each year [2]. The causal agent of typhoid is Salmonella Typhi, or Salmonella enterica serotype Typhi, which is a bacterium that breeds in human blood and the intestinal tract. Because severity of illness varies, mild typhoid fever is typically not characterized by its symptoms due to the similarity with other febrile diseases, such as prolonged fever, fatigue, headache, loss of appetite, weakness, abdominal pain, and constipation or diarrhea. Therefore, a blood test is the only reliable way to diagnosis typhoid fever by identifying the presence of Salmonella Typhi.

 

Salmonella Typhi lives only in humans [3]. The bacteria can be transmitted from both active patients and recovered patients. Although symptoms disappear, the agent is still carried by those that have recovered, and can contaminate food and water through feces [4]. Poor sanitation, handling food without washing hands, and lack of clean drinking water, all significantly contribute to typhoid fever outbreaks among poor communities, where children are one of the most vulnerable populations.

 

Fortunately, typhoid fever is preventable and treatable. People can reduce their risk of exposure by washing hands, consuming thoroughly-cooked food and drinking boiled water in the areas with high prevalence of disease. Additionally, vaccination is also available for prevention; however, it is not 100% effective and cannot provide lifelong immunity [2]. According to World Health Organization (WHO), the single-shot injectable Vi capsular polysaccharide vaccine (ViCPS) has estimated 72% protective efficacy in the first 1.5 years in the high-risk areas, and revaccination is recommended every three years [5]. For the oral Ty21a vaccine, revaccination is recommended every five years by US Center for Disease Control and Prevention (CDC) [6]. For local health authorities, providing adequate sanitation, offering health education and improving the public health surveillance system are compelling and necessary strategies to control the typhoid fever epidemic.

 

Typhoid fever is often treated with antibiotics and supportive care. Antibiotics, such as ampicillin, chloramphenicol, trimethoprim/sulfamethoxazole, amoxicillin, and ciprofloxacin, have historically been used for typhoid fever treatment. With supportive care, the proper antimicrobial therapy decreases mortality rates to around 1% [7]. However, as antibiotic resistance becomes a growing global issue, most medicines mentioned above are no longer used as first-line treatment for typhoid [8]. Instead, ceftriaxone or azithromycin are recommended for people who are infected with multidrug-resistant typhoid [9]. With limited antibiotic options available, and high selective pressure on S. Typhi, experts are concerned that one more genetic mutation may create an antibiotic resistant typhoid fever which will be untreatable in areas like Southeast Asia and parts of Africa [10].

 

 

 

 

 

Sources:

[1] http://outbreaknewstoday.com/el-salvador-reports-increase-in-typhoid-fev...

[2] http://www.who.int/immunization/diseases/typhoid/en/

[3] http://www.who.int/mediacentre/factsheets/typhoid/en/

[4] https://www.cdc.gov/typhoid-fever/symptoms.html

[5] http://www.who.int/ith/vaccines/typhoidfever/en/

[6] https://www.cdc.gov/typhoid-fever/typhoid-vaccination.html

[7] https://web.archive.org/web/20111102190825/http://www.who.int/vaccine_re...

[8] http://mbio.asm.org/content/9/1/e00105-18.full

[9]http://cochranelibrary-wiley.com/doi/10.1002/14651858.CD004530.pub4/abst...

[10] https://www.nytimes.com/2018/04/13/health/drug-resistant-typhoid-epidemi...

The Future of Healthcare is Robots

Jun 26, 2018 | Natalia Ciesielska | Research & Policy

 

Imagine a future where advanced technology can improve healthcare and medicine by providing faster, easier and more accurate diagnoses [6]. The field of artificial intelligence (AI), which is currently being led by some of the biggest technology companies and startups, enables machines and robots to be intelligent and perform complex tasks, whereas humans and other animals naturally demonstrate intelligence. Medical facilities are constantly looking for innovative approaches to increase treatment efficiency and to improve their quality of care and outcomes. AI, combined with machine learning and predictive analytics, can help speed drug discovery time, provide virtual assistance to patients, and diagnose ailments by processing medical images [3]. The market for AI will become especially popular when healthcare switches to a value-based reimbursement style [6], if the values of the Affordable Care Act can be salvaged from the current political climate, where providers are paid based on the quality of care they provide rather than the time spent or number of patients seen.

 

So far, AI has produced some promising inventions to aid in the treatment and detection of chronic disease. For example, a tool called Cognitive Cloud, developed by CognitiveScale - a company based in Austin, TX, can help detect chronic disease in patients [6]. There is also potential for AI to be able to look at medical records and predict outcomes a few months into the future, providing an opportunity for better preventative strategies [3]. For example, New York University is developing a software that can accurately predict the onset of diseases such as Type 2 diabetes, heart or kidney failure and stroke [3]. Furthermore, Boston-based startup FDNA uses facial recognition technology to match with a database associated with over 8,000 rare diseases and genetic disorders, and shares the data to medical centers in 129 countries via the Face2Gene application [3]. Lab-based research in California research havehas been able to detect cardiac arrhythmia with 97% accuracy on Apple Watch users with the AI-based Cariogram application, allowing for early treatment options and helping to avoid strokes [3]. However, some possible challenges to the use of AI in the medical field exist around the integration of medical records with data from smart watch technologies, such as Apple Watch or FitBit, largely because of difficulties in access and use due to privacy and regulations [3].

 

Today, with innumerable innovations occurring daily, it is difficult for doctors to stay updated with the latest medical knowledge, technology and techniques [6]. One of the most challenging problems for doctors is finding the right clinical trial for a patient if a large number of options are available. AI opens up new possibilities for personalized medicine by being adaptive to an individual’s genetics and being able to search through clinical research at a speed impossible by humans [3]. For example, an AI tool called IBM Watson can read through hundreds of clinical trial protocol to find the right one for a particular patient and inform the doctor [6]. Similarly, to treat cancer effectively, doctors must identify molecularly distinct cancer subtypes, potential targets and drug combinations, which requires high quality analysis of very specific data [5]. Having electronic medical records and molecular diagnostics presents AI the opportunity to filter through the data and rapidly determine the best personalized cancer treatment option.

 

Another example of AI used to detect cancer is the Magnetic Resonance Imaging (MRI) and Ultrasound Robotic Assisted Biopsy (MURAB) project [1]. This developing technology will make it possible to make more precise and effective biopsies to diagnose cancer. The project will create a robot that will scan a patient’s body using a combination of MRI and ultrasound technology. Currently, cancer screening techniques provide a false negative rate of 10-20%, informing patients that they do not have cancer, when in fact, they do. The new MURAB robot will enhance patient comfort and quality of care as it will only take 15-20 minutes instead of the standard 45-60 minute MRI scan time; it will also have the potential to identify early-stage signs of cancer. The major benefit of this project is that it will be able to use highly accurate MRI technology without high costs [1]. Google’s DeepMind division uses a similar AI tool to help doctors analyze tissue samples to determine the likelihood that cancers will spread along with developing the best radiotherapy treatments [3].

 

Although AI may not necessarily be able to find a cure, it can help make correct diagnoses faster as well as understand people’s behaviors and habits [3]. Its use to analyze an individual’s mental health provides an opportunity for early screening and detection of mental illnesses. Research by Florida State University’s Jessica Ribeiro found that AI can predict with 80 to 90% accuracy whether someone will attempt suicide in the next two years [3]. Facebook also uses AI as part of a test project to prevent suicides by analyzing the content of social network posts [3]. Similarly, scientists from Harvard and the University of Vermont developed a tool that enables computers to learn and identify signs of depression by studying Instagram posts [3].

 

Taken beyond the doctors’ office, AI technology can be used to help patient recovery as well as be used in therapy. AI can be designed to encourage patients to meet their wellness goals and to adhere to treatment and medications. For example, Welltok’s Cafewell Concierge app based on Watson, offers customized health solutions to patients [6]. Even therapeutic animal robots are being developed using AI to help patients in long-term care or with chronic diseases such as Alzheimer’s to recover [6]. These pet robots can help stimulate brain function in patients to improve cognition, thus improving the quality of their lives.

 

The use of AI can also be applied to infectious diseases and outbreaks. In the case of vector control, a predictive real-time response using AI would be more effective in preventing outbreaks compared to a passive response [4]. Most countries worldwide have many good measures for vector prevention including fumigation, larvicides and genetically modified mosquitoes; these measures would be effective in prevention only by knowing where and when the next outbreak were to occur.

 

Using vectors as an example, Asia spends over US$300 million a year on mosquito control [4]. Dengue, a mosquito-borne viral infection that can lead to hospitalization, is particularly common across Asia. Artificial Intelligence in Medical Epidemiology (AIME) program system is reportedly able to detect dengue outbreaks by analyzing medical data, databases and variables influencing the spread of disease in real time [2]. AIME cross-references data, searching through approximately 90 databases and taking into account 276 variables that influence the spread of dengue. The system analyzes data provided by doctors and databases containing all known cases of dengue disease [2]. AIME considers factors and variables such as wind speed, local roof architecture, water accumulation and population density, that can be used to predict the next dengue outbreak [4]. It is capable of detecting dengue outbreaks up to three months in advance and detects the location of the outbreak exactly within a 400-meter radius [2]. It also provides outbreak responders with the most effective intervention for the particular area, such as fogging mosquitoes or removing breeding sites [4]. The program’s designers believe it is over 80% reliable and accurate in predicting dengue outbreaks [2]. Since January 2018, the Malaysian state of Penang has been using the program and it is also being tested in several cities in Asia and South America.

 

Something to consider, however, is that AI systems such as AIME can work efficiently, but become complicated as people and the environment react to the information provided and start taking preventative measures [4]. When the environment reacts, all the factors and variables used to predict outbreaks change and must be adjusted; the years spent studying intricate relationships at a time when outbreaks were not actively prevented are not representative of the present and must be updated and refined [4].

 

 

 

 

Sources:

[1] “About MURAB · Murab.” Murab, European Commission, 2018, www.murabproject.eu/about-murab/.

[2] “Artificial Intelligence: Tool with the Potential to Detect Dengue Outbreaks Three Months in Advance.” Newsroom Allianz Worldwide Partners Business Insights, Allianz Partners, 2 June 2018, allianzpartners-bi.com/news/artificial-intelligence-tool-with-the-potential-to-detect-dengue-outbreaks-three-months-in-advance-f7eb-333d4.html.

[3] “Experts See Advances in AI Helping Diagnose, Find Cures for Hard-to-Treat Diseases.” HPN Online, KSR Publishing Inc., 6 June 2017, www.hpnonline.com/experts-see-advances-ai-helping-diagnose-find-cures-ha....

[4] Irwin, Aisling. “This AI Tool Could Detect Dengue Outbreaks 3 Months in Advance.” The Next Web, MaxCDN, 16 May 2018, thenextweb.com/syndication/2018/05/16/this-ai-tool-could-detect-dengue-outbreaks-3-months-in-advance/.

[5] Tenenbaum, Jay M., and Jeff Shrager. “Cancer: A Computational Disease That AI Can Cure.”Association for the Advancement of Artificial Intelligence, 2011, www.aaai.org/ojs/index.php/aimagazine/article/view/2345.

[6] Thoggy, Arina. “Can Artificial Intelligence Diagnose and Cure Diseases?” Big Data  Made Simple, Crayon Data, 30 Nov. 2017, bigdata-madesimple.com/can-artificial-intelligence-diagnose-and-cure-diseases/.

Outbreak of Rift Valley Fever in Kenya

Jun 25, 2018 | Lindsay Bonesteel | Outbreak News

 

Since the beginning of June, Kenya has been experiencing an outbreak of Rift Valley Fever (RVF) with 26 reported human cases and six deaths [1]. The first human case of RVF was laboratory-confirmed on June 7, 2018 [2]. This is the first RVF outbreak in Kenya since a 2006-2007 outbreak killed 234 people [3]. As of June 16th, twenty-four cases, and all six deaths, have been reported in Wajir County, with the remaining two cases occurring in Marsabit County [1]. Additionally, an estimated 50 animals, primarily camels and sheep, have died from RVF since the beginning of June [3].

 

Rift Valley Fever, which most commonly occurs in livestock, including sheep, goats, cattle, and camels, can be transmitted to humans in a few different ways [5,6]. Most human cases of RVF are the result of contact with the blood or tissue of an infected animal, often through slaughtering, butchering or veterinary procedures [6]. RVF can also be transmitted through the bite of an infected mosquito. However, there is no record of human-to-human transmission of RVF. 

 

Most people who contract RVF experience mild symptoms, including fever, headache, and muscle and joint pain, typically lasting between two and seven days [6,7]. However, a small percentage of people will develop more severe symptoms. Approximately 0.5% to 2% of patients will develop ocular disease [6]. While it is rare to die of this form of the disease, 50% of patients who develop lesions in the macula of the eye will experience permanent vision loss. Two other serious forms of the disease include encephalitis and hemorrhagic fever, with each affecting less than 1% of patients [7]. Symptoms of the encephalitic form include severe headaches, hallucinations, lethargy, disorientation, and coma [6]. Most RVF fatalities are the result of the hemorrhagic fever form. These patients usually develop symptoms within two to four days of the onset of the disease. The earliest symptom is usually jaundice, and may be followed by vomiting blood, blood in feces, bleeding from the nose and gums, and a purpuric rash. The case-fatality ratio for this form of the disease is 50%, with death occurring within three to six days after developing symptoms. There is no specific treatment for RVF.

 

Outbreaks of RVF most often occur after a period of heavy rainfall, which allows mosquito populations to thrive [8]. The earliest evidence of an outbreak in animals is usually a large number of abortions in domesticated animals [6]. For infected sheep, the rate of abortion is nearly 100%. RVF also has a high mortality rate in young animals [6,8]. Animal vaccination can be used to control the disease before an outbreak occurs. However, a vaccination campaign is not recommended during an outbreak, as this could worsen the outbreak if proper procedure is not followed [6]. A human RVF vaccine has been developed, but it is not licensed or available commercially [6].

 

The Kenyan government has implemented several measures in an effort to control the current outbreak. Four isolation centers have been set up in infected areas, and vector control measures are in place, including insecticide spraying [1,2]. Additionally, the slaughter of uninspected animals has been banned in Wajir County [2]. The Ministry of Health urges Kenyans to remain on alert and report to a health facility if they suspect they may have the disease.

 

 

 

Sources:

[1] http://www.who.int/csr/don/18-june-2018-rift-valley-fever-kenya/en/

[2] http://www.health.go.ke/press-release-on-disease-outbreak-situation-in-k...

[3] https://www.reuters.com/article/us-kenya-health/kenyan-official-says-fiv...

[4] http://apps.who.int/iris/bitstream/handle/10665/272848/OEW24-815062018.pdf

[5] https://www.cdc.gov/vhf/rvf/index.html

[6] http://www.who.int/news-room/fact-sheets/detail/rift-valley-fever

[7] https://www.cdc.gov/vhf/rvf/symptoms/index.html

[8] http://www.oie.int/doc/ged/D13962.PDF

Shedding Light on NTDs: Onchocerciasis / River Blindness

Jun 25, 2018 | Lauren Goodwin | Outbreak News

 

As we officially reach the one-month mark of our summer series, “Shedding Light on NTDs”, we hope you are gaining insight and increasing your awareness about diseases that are affecting the most vulnerable populations around the globe. This week, we are going to be discussing Onchocerciasis, a neglected tropical disease commonly referred to as “River Blindness”. The disease is caused by a parasitic worm, Onchocerca volvulus, which is spread through the bite of the Simulium blackfly [1]. The disease’s name comes from the flowing rivers that serve as breeding grounds for the blackfly and from the ultimate blindness that arises from an untreated infection.

 

Humans contract the parasite when the fly bites and deposits infective larvae into the skin [2]. As the human body reacts to the parasite, nodules form around the larvae, which protects them from host responses [2]. The larvae complete their life cycle in the human body, maturing into worms that can produce thousands of new larvae daily [2]. Shockingly, adult worms can survive for up to 15 years in the human body [2]. As larvae move through the body, host responses react to their presence and cause inflammation, rashes and discomfort [2]. When the larvae reach the eye and optic nerve, severe damage can occur. Initially, lesions on the cornea can occur, but are reversible with treatment. However, inflammation around the optic nerve, caused by death of larvae, can cause peripheral vision loss and may lead to blindness [2].

 

Transmission of River Blindness usually does not occur from a single blackfly bite; more often it requires numerous bites. However, for those living in the rural communities where blackfly exposure is high, there is a great risk of disease without proper protection from blackflies. Worldwide, 120 million people are at risk of contracting Onchocerciasis, and 99% of those infected live in 31 African countries [3]. In 1975, the Onchocerciasis Control Programme (OCP) in West Africa was created and they were able to effectively eliminate the disease in 10 of the 11 countries that it operated in through mass administration of medication and health education [4]. Furthermore, through the vigilant work of the World Health Organization (WHO), OCP and their partners, between 2013 and 2016, four countries were verified free of River Blindness, including Guatemala, Colombia, Ecuador and Mexico [3].

 

Blindness due to Onchocerciasis is the fourth leading preventable cause of blindness around the world, after cataract, glaucoma and trachoma [4]. This blindness furthers the cycle of poverty as those who are affected are often not able to work, creating a social stigma against their condition and their status in the community. Additionally, social isolation is not uncommon amongst those with severe skin scarring from nodules and inflammation due to the stigma associated with deformities caused by infection [4]. The only way to help the communities most affected by the disease is through targeted efforts for insect control and effective medical treatments.

 

On June 13th, 2018, the United States Food and Drug Administration (FDA) approved moxidectin as the first new drug in over twenty years for the treatment of River Blindness [5, 6]. This monumental decision is a game-changer for how the public health community works to eliminate the disease and gives new hope for future drugs aiming to treat neglected tropical diseases. The only drug currently in use is Ivermectin, which has greatly reduced the disease’s presence in endemic regions but is not effective enough to reduce the global burden of River Blindness [6]. Public health officials are optimistic that this new drug will bring us one step closer to eliminating River Blindness once and for all.

 

 

Sources:

[1] https://www.cdc.gov/parasites/onchocerciasis/gen_info/faqs.html

[2] https://www.cdc.gov/parasites/onchocerciasis/disease.html

[3] http://www.who.int/onchocerciasis/en/

[4] http://www.who.int/apoc/onchocerciasis/disease/en/

[5] https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&applno=210867

[6] http://www.who.int/tdr/news/2018/moxidectin-approved-as-treatment-for-river-blindness/en/

Shedding Light on NTDs: Chagas

Jun 20, 2018 | Lauren Goodwin | Outbreak News

 

Welcome back to “Shedding Light on NTDs”! This week, we are looking at Chagas disease, also known as American trypanosomiasis, which is a parasitic disease that is only found in the North and South America. The disease is spread through triatomine bugs, most commonly referred to as kissing bugs, due to its tendency to take blood meals on the face of animals. It is a vector predominately prevalent in Central and South America but is increasingly found in the United States and globally.

 

The Trypanosoma cruzi parasite lives in the digestive system of kissing bugs and is spread through their bite. During the night, the bugs often bite and feed on the faces of humans and other animals, giving them their distinct name as a kissing bug. After finishing its blood meal, the bug may defecate in or around the open wound. The parasite is able to enter the host organism as the host unknowingly scratches the wound or rubs their eyes, pushing the feces into their blood stream [1]. The parasite can be transmitted to humans and animals, including dogs, non-human primates, opossums, woodrats, armadillos, coyotes, mice, raccoons, skunks, and foxes [2].

 

In humans, Chagas disease exists in two phases: acute and chronic. The acute phase typically goes unnoticed because it is either symptom-free or has very mild symptoms, including fever, fatigue, body aches, headaches and rash [1]. The most noticeable marker of acute disease is called Romaña’s sign, which includes swelling of the eyelid where the bug typically bites. Most acute symptoms resolve on their own within a few weeks or with antibiotic treatment [1].  Approximately 30% of Chagas cases develop into the chronic disease phase if untreated, though researchers are still investigating why most cases lie dormant while the remaining develop into severe disease [1, 2]. The chronic phase can stay latent in the body for years or even decades, which leads to difficulty in effectively diagnosing the disease unless you are specifically looking for it. If the chronic phase develops into symptoms, it is characterized by cardiac and intestinal complications, including cardiomyopathy, cardiac arrest or enlarged colon and esophagus [1]. Untreated, Chagas disease can be fatal [1].

 

Chagas disease is often overlooked because of its vague clinical presentation. In its acute phase, the symptoms of infection could be confused with many other illnesses. Conditions like fever and fatigue are associated with hundreds of other conditions, so the likelihood of recognizing Chagas without an obvious bite wound can be difficult. Furthermore, when a person presents with cardiomyopathy or other heart-related illnesses, physicians rightly treat the issue at hand rather than running immediately the diagnostics for identifying the chronic phase of a tropical disease. Taking the non-disease-specific symptoms of Chagas disease into consideration with its long periods of latency in the body, it is not surprising that it can be overlooked if a physician is not specifically testing for Chagas.

 

The US Center for Disease Control and Prevention (CDC) estimates that over eight million people in the Americas are infected with Chagas disease and most of them are unaware of their condition [1]. Most cases occur in rural regions of Mexico, Central and South America, but there are cases that occur in the United States, particularly in Texas, California, Arizona and New Mexico and states along the southern border [1]. Research conducted by Texas A&M University showed that kissing bugs are found in 28 states in the United States and approximately 50% carry the Trypanosoma cruzi parasite [3]. Interestingly, veterinarians in southern Texas have seen an increase in Chagas disease in dogs. This increase in the number of infected dogs should act as a sentinel surveillance indicator - it would not be surprising if there is an increase in human cases over time as exposure to kissing bugs changes. The burden of Chagas disease in the United States is still relatively unknown. There are estimates between 300,000 and up to eight million, in the case of the CDC, however there is no consistent reporting system for the disease [4]. Some states, like Texas, have made Chagas disease a reportable disease, but it is still largely unreported and untested across the country [4]. Globally, the most recently reported Chagas outbreak occurred in Venezuela in April 2018, presumably through oral transmission of the parasite [5]. There were 45 suspected cases of acute Chagas disease and five reported fatalities in the village Puerto Nuevo, Libertador [5].

 

The best way to prevent Chagas transmission is through vector control, however, once again we are faced with the reality that those most impacted by the disease have little control over their living environment. In the remote rural regions of Central and South America, families live in homes that provide the perfect breeding grounds and entry points for kissing bugs. Dark, damp spaces give the bugs plenty of places to hide and at night, families that co-sleep give the bugs plenty of options to continue feeding in one space, as the bugs are attracted to carbon dioxide and heat [2]. Additionally, the bugs can fly longer distances, which gives them plenty of opportunities to spread and create new colonies that can spread disease. Furthermore, the best treatment for Chagas disease requires early detection and medical access. With limited healthcare access, a person who has little to no symptoms is not going to seek care if it requires extensive travel and is financially impractical, especially if the symptoms are mild or only last a short time.

 

Chagas is also difficult to control because of the wide range of species that contract the parasite. This creates a cycle where animals and kissing bugs continually spread the parasite, making it difficult to eradicate. Luckily, there are many Chagas vaccines in development, which provide a new hope for controlling the disease and its spread. The World Health Organization (WHO), in partnership with many influential global organizations, released the London Declaration on Neglect Tropical Diseases, which aims to control or eliminate NTDs and to provide treatment to as many people as possible if they are infected [6]. For Chagas, their goal is to control the disease and its spread by 2020, while being realistic that elimination will take a greater amount of time to adequately control the spread of Chagas to all animals [6].

 

 

Sources:

[1] https://www.cdc.gov/parasites/chagas/gen_info/detailed.html

[2] http://kissingbug.tamu.edu/

[3] http://www.kristv.com/story/38369673/uptick-in-chagas-disease-in-south-texas

[4] http://kissingbug.tamu.edu/FAQ/

[5] http://outbreaknewstoday.com/chagas-outbreak-kills-five-sickens-dozens-tachira-venezuela-44325/

[6] http://unitingtocombatntds.org/ntds/chagas-disease/

 

 

Update from Venezuela: First Polio Outbreak in Nearly 30 Years

Jun 14, 2018 | Emily Wolfson | Outbreak News

 

One confirmed case and three suspected cases of polio have been reported in Venezuela, the first cases to emerge since polio was eradicated from the country in 1989. There has been laboratory confirmation that a two-year-old child has developed the disease. The Venezuelan Society for Public Health has reported that three additional children are suffering from acute flaccid paralysis and are suspected to have polio as well.  All four children are living in the community of La Playita del Volcán, in the remote eastern state of Delta Amacuro [1].

 

Polio, short for poliomyelitis, is a debilitating and highly infectious disease caused by the poliovirus, which occurs predominantly in young children. It is spread through the fecal-oral route, and can cause symptoms such as fever, fatigue, headache, vomiting, and pain in the limbs. In severe cases, the virus can invade the nervous system, causing paralysis. According to the World Health Organization (WHO), one in 200 polio infections leads to irreversible paralysis [2].

 

There is no cure for polio but it can be prevented with a vaccine, of which there are two varieties. Inactivated polio vaccine (IPV) is an intramuscular shot given in the arm or leg. The other option, oral polio vaccine (OPV) is used widely due to its low cost and ease of administration. In order to be most effective, children should get four doses of the vaccine [3]. None of the confirmed or suspected cases in the Delta Amacuro region had been vaccinated.

 

This outbreak of polio comes at a highly unstable time for Venezuela. The country is in the midst of a public health crisis, with outbreaks of measles, malaria, diphtheria and tuberculosis, a result of the political and socioeconomic turmoil which began in 2012. There has been a complete breakdown in infrastructure, with shortages of food, water, electricity and medical supplies [4].

 

Delta Amacuro is one of the poorest states in Venezuela, with most of its population having to travel several hours by boat to reach the closest medical center. According to a local source, the community in Delta Amacuro is apathetic to the outbreak of polio. Many think of it as equivalent to a disease like malaria, unaware of the gravity of its symptoms [5].  Delta Amacuro is also the state with the largest coverage gap for all types of immunizations. The polio vaccine coverage in the region was only at 67 percent at the time the cases were reported [1].

 

Low vaccine coverage is also a growing nationwide issue. According to Manuela Bolivar, a member of parliament in Venezuela, “the government is not approving the money for the vaccines” [1]. Low vaccination rates are partially to blame for a resurgence of diphtheria and measles in the country, in addition to polio [5]. Long before this humanitarian crisis in Venezuela, the country was a leader in Latin America for its free immunization programs. Now, many hospitals in the country do not have any type of vaccine available. In order to contain the polio outbreak, the government will have to act quickly to immunize its population and improve overall health and living conditions.

 

Sources:

[1] https://www.telegraph.co.uk/news/2018/06/10/venezuela-hit-first-case-polio-since-1989-country-falls-deeper/

[2] http://www.who.int/en/news-room/fact-sheets/detail/poliomyelitis

[3] https://www.cdc.gov/vaccines/vpd/polio/index.html

[4] https://wwwnc.cdc.gov/travel/notices/warning/health-infrastructure-breakdown-venezuela

[5] https://www.cnn.com/2018/06/11/health/venezuela-polio-who/index.html

 

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