Diagnosis

A range of laboratory investigations are performed to diagnose the disease and assess its course and complications. An ELISA test for antigen and IgM antibodies give 88% sensitivity and 90% specificity for the presence of the infection. Other laboratory findings in Lassa fever include lymphopenia (low white blood cell count), thrombocytopenia (low platelets), and elevated aspartate aminotransferase levels in the blood. Lassa fever can also be found in cerebrospinal fluid. In West Africa, where Lassa is most prevalent, it is difficult for doctors to diagnose due to the absence of proper equipment to perform tests. In cases with abdominal pain, diagnoses in countries where Lassa is endemic are often made for other illnesses, such as appendicitis and intussusception, delaying treatment with ribavirin.