Leishmania donovani - Clinical manifestations, Complications, Prognosis, PKDL

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

Visceral leishmaniasis (VL)

Syndromes of visceral leishmaniasis caused by Leishmania donovani include:

• fever

• hepatosplenomegaly

• hematological anomalies

• weight loss

• hypergammaglobulinemia

• leishmanoma

• other features

Fever

• 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

Hepatosplenomegaly

• 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

Hematological anomalies

• 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

Hypergammaglobulinemia

• 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

Leishmanoma

• 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

Other features

• 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

Leishmaniasis in HIV of Leishmania donovani

• 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 Leishmania donovani

• 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

Prognosis of Leishmania donovani

• 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

Post kala-zar dermal leishaniasis (PKDL) of Leishmania donovani

• 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