Since the beginning of 2012, the West African nation of Nigeria has been battling Lassa fever. The disease has reached 12 states and killed 40 people.
397 suspected cases have been recorded in the states of Borno, Gombe, Yobe, Taraba, Plateau, Nasarawa, Ebonyi, Edo, Ondo, Ribers, Anambra and Lagos; however, only 87 of those cases have been confirmed.
Last week, the Nigerian federal government created the Lassa Fever Rapid Response Committee, whose goal is to control and prevent the spread of the disease. Public health officials have also asked Nigerians to stop burning bushes as this drives rats out of the bush and into nearby houses.
Lassa fever is a zoonotic virus, transmitted when a human comes into contact with an infected rat’s feces, urine, or the bodily fluids of an infected human. The Mastomys rat carries the virus. These rats breed frequently and bear many offspring, increasing the potential for spread of the virus from rats to humans. Further, these rats are often found in human homes. Transmission through contaminated food is common, as the rats can leave excretions in food stores.
While in some cases, the infection has no noticeable impact; it is, in other cases, fatal. The CDC estimates that in 20 percent of Lassa cases, patients suffer a “severe multisystem disease” and the case-fatality rate has reached as high as 50 percent.
Symptoms show up anytime between one and three weeks after infection. According to the CDC, symptoms of Lassa are varied and include fever, abdominal pain, vomiting, diarrhea, facial swelling, protein in the urine, encephalitis, and mucosal bleeding.
Lassa fever is treated with an antiviral drug called Ribavirin. In addition, doctors caring for Lassa fever patients should monitor fluid, electrolyte and oxygen levels.
The virus was discovered in 1969, when two nurses in the Nigerian town of Lassa died of a mysterious hemorrhagic fever. The virus is endemic to many parts of West Africa including Nigeria, Sierra Leone, Guinea and Liberia.