Symptoms+and+Disease+Progression-+Lassa+Fever

While 80% of cases are asymptomatic, 20% of victims experience severe effects from the illness. After contracting the virus, the incubation period for the disease is between six to 21 days, the typical time it takes for a host to feel symptoms. The virus usually spreads to every tissue of the human body, starting with the mucosal membranes, lungs, urinary tract, and intestines, and then progresses to the vascular and nervous systems, including the brain.

The virus can produce a multitude of symptoms and affect a wide range of organs. The first set of symptoms can include fever, conjunctivitis, facial swelling, naseau, bloody vomiting and diarrhea, hepatitis (inflammation of the liver), high or low blood pressure, coughing, sore throat, retrosternal pain (chest wall pain), and back pain. In severe cases, the disease can cause mucosal bleeding, encephalitis and meningitis (swelling of the brain and spinal cord), and seizures. The illness is also known to cause many neurological effects even after the disease is treated, such as tremors and hearing loss.

Due to the wide range and non-specificity of the symptoms, diagnosis can be difficult and the disease is often mistaken for other hemorrhagic fevers such as Ebola, Marburg, and Malaria.