|Written by Dr.Md.Redwanul Huq (Masum)|
|Sunday, 15 January 2012 16:12|
Leishmaniasis is a type of parasitic infection which is caused by unicellular flagellate intracellular protozoa named Leishmania species.
Classification of leishmaniasis:
Leishmaniasis is classified as following-
- Visceral Leishmaniasis (Kala-Azar)
- Cutaneous Leishmaniasis
- Mucosal Leishmaniasis
Moreover, there are Post Kala-Azar Leishmanial syndromes-
1. Post Kala-Azar Dermal Leishmaniasis (PKDL)- consists of
- Depigmented macules in trunk and extremities
- Erythematous pathes in cheek, chin & nose
- Yellowish pink nodules in nose, tongue & face
2. Post Kala-Azar Mucosal Leishmaniasis (PKML)
3. Post Kala-Azar laryngitis
4. Post Kala-Azar conjunctivitis/ blepheritis
5. Post Kala-Azar colitis
6. Post Kala-Azar Anterior uveitis.
Visceral Leishmaniasis (Kala-Azar)
Human, dog, fox, rodent, carnivores.
Vector of kala-azar:
Infected sand fly (Phlebotomus argentipes).
Mode of transmission:
1. Bite of infected sand fly.
2. Blood transfusion.
3. Transplacental transmission.
- Address: Patient usually resides in endemic area (like Gajipur, Valuca, Mymensing, Trishal, Jamalpur, Norshingdi, Pabna in Bangladesh)
- Dwelling house: Usually made of mud and may have cracks. May have cattle house near the dwelling house
- Less or no use of mosquito net / curtain
- Family history of kala-azar may be positive
- May travel to endemic areas.
- Low grade intermittent fever with typically double peak rise within 24 hours
- Weight loss with good appetite
- Nasal bleeding
- Abdominal pain or discomfort
- Fever – present
- Anaemia- present (Cardinal feature)
- Splenomegaly – present (Cardinal feature)
- Hepatomegaly- present
- Hyperpigmentation specially in face
- Enlarged lymph node (very rare)
- May also have-
- Phychiatric illness.
- TC, DC- Leucopenia (due to neutropenia and eosinopenia) with relative lymphocytosis and increased monocyte. If TC is repeated , there is progressive leucopenia with progressive granulocytopenia.
- Hb%- Decreased. If repeated there is progressive anemia
- ESR- Increased
- Total platelet count- Thrombocytopenia (Average – 1,00,000/µl)
- PBF- Normocytic normochromic
- Serum iron and folate – normal
- Reticulocyte count- normal
- Albumin:Globulin- Altered
- PT and APTT- Usually normal until late
- Serological or immunological tests (Indirect evidence of the parasite)-
i) Aldehyde test (AT) :
- A bed side supportive test which becomes positive after 2-3 months from infection, if positive within 2-20 min of test- Strongly positive, if within 2 hours- Moderately positive, if within 24 hours- Mildly positive.
- Aldehyde test reverts to negative after 6 months from cure
- It is falsely positive in Tuberculosis, Leprosy, SLE, Leukemia,Multiple myeloma etc
ii) Direct agglutination test (DAT) : A bed side diagnostic test which-
- becomes positive within 2-4 weeks of infection
- will remain positive for many years after infection
- may be falsely positive in TB, leprosy, HBV infection
iii) Immuno chromatographic test (ICT) : It is an Antibody based where Antigen is looked for
iv) RK 39 Antibody based test
v) Complement fixation test (CFT) – done with W.K.K Antigen
vi) Immuno fluorescent antibody test (IFAT)
vii) Enzyme linked immunosorbent assay (ELISA)
viii) Polemerase chain reaction (PCR)
11. Detection of parasite in tissue smear (Direct evidence of the parasite)-
- Presence of Leishmania donovani (LD) bodies (amastigotes) in following tissue smears:Spleen (95-97%), liver(75-90%), bone marrow (55-70%), lymph node(55-70%),Buffy coat (70%)
- Culture of tissue smear in Nove-Nicole-Mc Neal (NNN) media- takes 2-3 wks to grow
12. Following investigations are done prior to treatment-
- ECG- To exclude cardiac arrhythmia
- CXR (P/A)- To exclude Pneumonia, Pulmonary TB.
- Liver function test is also done in visceral leishmaniasis– To exclude hepatic impairment.
Treatment for kala-azar:
1. Proper nutrition should be ensured
2. Intercurrent infection(s) should be treated
3. Ferrous sulphate, folic acid or blood transfusion should be given according to Hb level.
4. Inj. Vitamin K should be given IV – if there is hemorrhage.
Treatment- A ( For Kala-azar):
Sodium antimony gluconate (SAG)-100 mg/ml is given IV or IM at a dose of 20 mg/kg/day for 20 days. Maximum daily adult does should not exceed 850 mg (8.5 ml). This treatment is contraindicated if the patient has severe renal, cardiac or hepatic impairments.
Treatment- B [For Kala-azar Treatment failure (KATF)]:
Step 1– Pentamidine (isoethionate)-50 mg/ml is given deep IM at a dose of 4 mg/kg three times a week for 5 wks(i.e.15 injections).This treatment is contraindicated if the patient has severe renal impairment.
Step 2- On the 6th week i.e. after completion of pentamidine course, treatment should be continued with SAG daily for 30 days as per treatment – A.
Treatment- C (For Post Kala-azar Dermal Leishmaniasis):
SAG should be given at a dose of 20 mg/kg /day for 20 days according to treatment-A. This treatment-A cycle is repeated for 6 times. Between each treatment cycle there will be a 10 days interval.
Treatment of relapse of Kala-azar:
SAG should be given at a dose of 20 mg/kg /day for double duration of treatment – A i.e. for 40 days.
Treatment of resistent Kala-azar:
Amphotericin-B is used.
Prognosis and response to treatment:
Clinical parameters of Prognosis and response to treatment:
1. Increased well being
2. Progressive remission of fever
3. Increased body weight
4. Regression of spleen size- occurs within 6 months- 1 year.
Laboratory parameters of Prognosis and response to treatment:
1. Hb%- Increased
2. S. Albumin- Increased, Albumin:Globulin- becomes normal
3. Platelet count- becomes normal.