Leishmania donovani - Clinical manifestations, Complications, Prognosis, PKDL

Last Modified: December 15, 2022

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Clinical manifestations of Leishmania donovani

Leishmania donovani causes clinical manifestations such as visceral leishmaniasis, which is a serious and often fatal infection
the incubation period of visceral leishmaniasis is usually 3-6 months but can even range from months to years
the onset of the disease may be gradual or sudden, the sudden onset usually occurs in individuals traveling from non-endemic to endemic areas

Syndromes of visceral leishmaniasis caused by Leishmania donovani include:

typically remittent fever is the first symptom of Leishmania donovani infection
described as a double rise in 24 hours
fever is accompanied by sweating and chills and less commonly by rigor, malaise
period of pyrexia (increased body temperature) is followed by a period of apyrexia (absence or intermission of fever)
fever is not usually continuous

splenomegaly caused by Leishmania donovani is the distinguishing feature of this infection
the spleen becomes non-tender, soft, and enlarged to such an extent by the third month that it occupies the entire left side of the abdomen
the liver is soft with a smooth surface and a sharp edge but is less conspicuous
due to splenomegaly and hepatomegaly, the abdomen is protuberant

normocytic normochromic anemia is a usual occurrence in leishmaniasis caused by Leishmania donovani
anemia is caused by numerous factors such as
increased hemolysis
hemorrhage
haemodilution
replacement of bone marrow with infected macrophages
splenic sequestration of red cells
another characteristic of leishmaniasis is leucopenia which is a low white blood cell count and may go as low as 1000/mm3
leucopenia is caused by
autoimmune mechanism
increased margination
splenic sequestration
other conditions such as epistaxis and petechiae are caused by thrombocytopenia which in turn is caused by the destruction of platelets

in the sera of patients with leishmaniasis, hypergammaglobulinemia, rheumatoid factors, and circulating immune complexes are present
immune complex-glomerulonephritis and interstitial nephritis are also present in this condition

mostly in the African continent, leishmanoma primarily occurs
leishmanoma is a primary cutaneous lesion
manifests as a nodule in the skin after 1-3 weeks of infection and measures 2.5 cm to 4 cm
not seen in Indian leishmaniasis

as leishmaniasis caused by Leishmania donovani progresses in untreated cases, the skin becomes dry, thin, and scaly, the hairs are dull, and thin and fall while the nails turn brittle
due to hypopigmentation of the skin, especially greying and darkening of the hands, feet, abdomen, and around the mouth, the disease is called black fever or kala-azar
other late manifestations include epistaxis, petechiae, gingival bleeding, peripheral edema, and ecchymoses
lymphadenopathy is seen in Chinese and African forms but not in Indian forms of leishmaniasis

the absence of hepatosplenomegaly
more involvement in the respiratory and gastrointestinal system
other syndromes include pleural effusion, odynophagia, and ulcers and masses in the gastrointestinal tract

complications of leishmaniasis caused by Leishmania donovani include pneumonia, tuberculosis, dysentery, and uncontrolled hemorrhage
less frequent complications involved include Glomerulonephritis and cirrhosis
death may result from immunosuppression, uncontrolled severe hemorrhage from the gastrointestinal tract, or secondary infection such as pneumonia, septicemia, dysentery, or tuberculosis

if treated early with specific treatments, the cure rate (prognosis) is more than 90%
in untreated cases, death occurs within 3 months to 20 months and varies according to the age of the patient- 40% to 90% in adults, 75% to 85% in children

after completion of treatment, Post kala-zar dermal leishaniasis (PKDL) may occur which is characterized by non-ulcerative lesions of the skin
occurs in 10% of Indian kala-zar cases after a latent period of 2 years to 20 years and 3% in African leishmaniasis cases after a few months
Post kala-zar dermal leishaniasis (PKDL) also involves multiple, hypopigmented, erythematous macules mostly in the neck and trunk region
in such cases caused by Leishmania donovani, the patients act as reservoirs