Lassa fever, like the infamous Ebola virus disease, is a form of viral hemorrhagic fever that causes fever and bleeding from body orifices.
The agent responsible for the transmission of this virus is a multimammate rat “Mastomys natalensis”. This rat transfers the virus by shedding its urine and feces on human foods and utensils. Infection with the disease can occur when food contaminated by these excreta is consumed by humans.
Infection can also occur when humans catch infected rats and prepare them as food or when humans inhale tiny particles in the air contaminated with feces or urine from infected rats.
Furthermore, although less frequently, human-to human transmission can occur through direct contact with body fluids (blood, saliva, mucus, etc) of infected individuals. Human-to-human transmission mostly occurs in healthcare settings, which puts healthcare workers at high risk of contracting the disease.
However, it is important to note that the disease is not transmitted through casual contacts such as hugging or shaking hands with infected individuals. The disease is also not believed to be spread by infected people who are yet to start showing symptoms of the disease.
Symptoms of Lassa fever start appearing 1 to 3 weeks after infection. In about 80 percent of cases, the symptoms are mild ranging from general malaise and weakness to headache. However, an estimated 20% of those infected develop serious symptoms that may require hospitalization. These symptoms are closely similar, although milder, to features of Ebola virus disease, and may include bleeding from gums, eyes, or nose; difficulty in breathing; vomiting; facial swelling; chest pain; back pain; abdominal pain; and shock. Neurological symptoms such as hearing loss, tremors, and encephalitis can also occur. Up to about 15% of those hospitalized for Lassa fever die of the disease, bringing the case fatality ratio of Lassa fever to about 1%.
Lassa fever can be treated effectively with an expensive antiviral drug called Ribavirin. However, simple hygienic practices can protect humans from contracting the disease from its rat vectors. These preventive measures include making our homes rodent proof by sealing all rodent holes keeping all utensils and food materials in rodent-proof containers, avoiding consumption of rats as food, isolating patients with symptoms of fever and bleeding, use of personal protective equipment by healthcare workers and relatives of patients infected by the disease, among others.
Mr Bako, a physician, is a doctoral student at Indiana University-Purdue University Indianapolis.