A new and aggressive strain of HIV, which can develop into AIDS within three years of infection, has been discovered in Cuba . Researchers raise concerns that the strain’s accelerated progression is so rapid, that antiretroviral treatment may come too late . The study came in response to Cuban clinicians reporting an ‘increasing trend’ of rapid progression AIDS cases in Cuba and results were recently published in EBioMedicine on January 28, 2015 [1,2].
About HIV and AIDS
As the world’s leading infectious killer, ‘HIV’ stands for Human Immunodeficiency Virus. HIV attacks a person’s immune system, destroying what the body needs to fight off disease and infection [4,6]. The virus is transmitted through bodily fluids such as blood, semen, and breast milk and these fluids must come into contact with the mucous membrane, damaged tissue, or injected directly into a person’s bloodstream, in order for transmission to occur . Some of the earliest symptoms of HIV infection include: fever, swollen glands, sore throat, fatigue, and rash . However, many who are HIV positive may not immediately look or feel sick. During this stage -- clinical latency -- HIV reproduces at low levels, though remains very active within a person’s body . Treatments such as antiretroviral therapy (ART) have successfully helped manage HIV symptoms and has prolonged lives .
Over time, HIV can develop into AIDS -- Acquired Immunodeficiency Syndrome -- which is considered to be the final stage of HIV infection . While not everyone reaches the AIDS stage, those who do often have a certain number of opportunistic infections, cancer, or a low CD-4 cell count. It is the onset of these symptoms that indicates that the infected person has transitioned from the clinical latency stage to AIDS .
The Cuban Strain - CRF19
Typically, it takes HIV infection without treatment approximately five to ten years to advance to AIDS. Among patients included in the study in Cuba, the strain advanced significantly faster. According to the study, it was found that patients with the mutated strain developed AIDS within three years [1,2]. It is important to note that rapid progression of HIV to AIDS does happen -- individuals who contract HIV with an already suppressed immune system can have faster advancement to AIDS . That said, it is often a patient’s pre-existing immune system differences and not the HIV-subtype that contributes to AIDS development. However, in this study, the HIV variant seemed to play an imperative role in the rapid advancement .
Upon closer inspection, researchers found that the rapidly-advancing HIV patients were linked by their variant type of HIV. The new, variant-HIV was found to be a new recombinant subtype consisting of sub-types A, D, and G . This new combination has been named CRF19 .
A researcher on the study, Prof. Anne-Mieke Vandamme of Belgium University-Leuven, further explains how this particular variant accelerates the AIDS process:
“There are two types of co-receptors that HIV can use: CCR5 or CXCR4. And in the normal progression of the HIV to AIDS it often happens that the virus switches co-receptor. It almost always starts with using CCR5 and then it switches to CXCR4 after many years. And once it switches the progression to AIDS goes very fast” .
Researchers also suspect that the inclusion of sub-type D may also be the key in the aggressiveness of the CRF19 strain. HIV sub-type D “contains an enzyme that enables HIV to reproduce in greater numbers – and it takes proteins from other subtypes and uses them in new virus particles” .
The Burden of HIV/AIDS
On a global scale, 35 million people worldwide are currently living with HIV/AIDS . The greatest burden of the disease lies within low and middle income countries, specifically within sub-Saharan Africa . According to UNAIDS, there is approximately 16,000 people in Cuba currently living with HIV/AIDS . Of those infected, about 15,000 are adults aged 15 years and older .
More than 1.2 million people are currently living with HIV in the United States and 1 in 7 people do not know that they are infected . Approximately 25% of those who are acquiring new infections in the United States are between the ages of 13 and 24 years old -- those in this demographic also are usually unaware that they are infected and may pass on the virus to others unknowingly, perpetuating the transmission cycle .