Differential diagnosis

There are several other diseases that mimic VL and overlap epidemiologically with VL.

Malaria: Malaria, also a protozoan disease, caused by plasmodium may present in acute form with fever, splenomegaly and anemia. It can also cause several other complications. The diagnosis is established by peripheral blood microscopy demonstrating the plasmodium species. The geographic distribution overlaps with that of VL in Ethiopia. Residents of malaria endemic areas face repeated infections and develop a chronic form called hyperreactive malarial splenomegaly. This may result from chronic stimulation of the immune system by the malaria infection. This also mimics VL and is a common differential diagnosis that can be diagnosed only after exclusion of other diseases.

Hepatosplenic schistosomiasis: This presents with portal hypertension, huge splenomegaly and cachexia. Pancytopenia is common as a result of the hypersplenism. The stool microscopy may show Schistosoma eggs. Ultrasound examination of the abdomen is very important for diagnosis that shows periportal fibrosis.

Typhoid fever: H igh grade fever, headache, abdominal pain with constipation or diarrhea are the common manifestations. Hepatosplenomegaly may occur. Diagnosis is established by demonstration of the salmonella in culture which can be from blood, stool or urine.

Tuberculosis: is a common disease among the socioeconomically poor population groups similar to that of VL. While the pulmonary form with chronic cough is common, extrapulmonary and disseminated form of tuberculosis are also common. Clinical presentation is with chronic fever and other signs and symptoms are related to the organ system affected.

Infective endocarditis: has a wide range of signs and symptoms among which are fever, splenomegaly, anemia, petechial rash. Hepatomegaly and peripheral edema occur due to the congestive heart failure. Diagnosis requires echocardiography and repeated blood culture.

Hematological malignancies such as acute and chronic leukemia present with splenomegaly and bleeding tendencies. Patients with hematological malignancies are immune suppressed and can have superinfections. Some of the clinical manifestations overlap with VL. Peripheral blood count, differential count and morphology are important to distinguish the two and further classify the type of leukemia. 

References:
Guidelines for diagnosis, treatment and prevention of leishmaniasis in Ethiopia, 2^nd Ed. June 2013