Chauhdry Altaf  ( Armed Forces Institute of Transfusion )
Parvez Ahmed  ( Armed Forces Bone Marrow Transplant Centre )
Tanveer Ashraf  ( Combined Military Hospital )
Masood Anwar  ( Armed Forces Institute of Pathology )
Irfan Ahmed  ( Azad Kashmir Combined Military Hospital5, Muzaffarabad. )

Visceral leishmaniasis (VL) causes significant morbidity, mortality and burden on health care resources. It is a chronic inflammatory disorder, caused by Leishmania species which invades reticulo-endothelial system and is characterized by the pentad of chronic fever, wasting, marked hepatosplenomegaly, pancytopenia (especially, anaemia and thrombocytopenia) and hpergammaglobulinaemia.1 It is seen throughout the world, with half a million new cases occurring every year; 90% of these are in India, Bangladesh, Brazil, Nepal and Sudan, the areas where epidemics are quite common.2-5 This number is probably grossly under reported because of poor surveillance system. Moreover with the concomitant rise of HIV infection there is 100-1000 times increased risk of the disease in endemic areas.2

The vector, Phlebotomous and Lutzomyia sandflies6, take amastigotes from the host and transform these to promastigotes in the gut. There are certain parasitic and host factors like thermo-tropism, burden of parasites, production of lipopolysaccharides, glycoproteins and interferons that play their role in behaviour and outcome of the disease.1,7,8 The incubation period of disease is highly variable ranging from days to years and average time is 2-6 months.3,9

Main species that cause visceral leishmaniasis are Leishmania donovani, Leishmania infantum and Leishmania chagasi. Leishmania donovani is common in India, Bangladesh, Middle East and East Africa, with its reservoir in humans. It causes VL in older children (more than 5 years of age), frequently complicated by post Kalazar dermal Leishmaniasis and is associated with high incidence of resistance to antimony compounds. Leishmania infantum is seen in Mediterranean basin, China and Pakistan with its reservoir in dogs, foxes and jackals. It causes VL in younger children (below 5 years of age), post Leishmaniasis dermal lesions are rare, and resistance to antimony compounds is almost non existent.9-11 Leishmania chagasi is seen in Central and South America with its reservoir in dogs and foxes.
The antimonial compounds are the gold standard to treat visceral leishmaniasis; but recently there are reports of resistance of L. donovani to antimony and up to 65% primary resistance has been reported from some parts of India. All Leishmania species have similar morphological appearance under a light microscope. Although isoenzyme study is the reference method, clinical features and geographical distribution are also used to identify the species.9 This study was undertaken to see epidemiology and response to treatment in childhood VL in Muzaffarabad Azad Jammu and Kashmir. Based on epidemiological features plus treatment response an inference has been drawn about the species involved.

Children below 12 years of age who were admitted in paediatric ward of Azad Kashmir Combined Military Hospital Muzaffarabad from 1st January 1999 to 31st December 1999 were included in this study. All the patients had fever with visceromegaly and the diagnosis of visceral Lieshmaniasis was established by demonstrating parasites in bone marrow aspirate.

A proforma was designed and completed by interviewing the parents. The information recorded included profession, socioeconomic status, area of residence, and number of pet dogs kept in the house/farm. Temperature charts were reviewed and assessment of nutritional status performed by modified Gomez classification.12

Two-ml EDTA blood was analyzed on automatic haematology analyzer (Abacus-16 parameter). Bone marrow aspiration was done from tibial tuberosity and posterior iliac spine. Slides were stained with Leishman and brilliant cresyl blue using methods described by Dacie and Lewis.13

The patients received intramuscular elemental antimony (Glucantime-Rhone-Poulenc, 20 mg of elemental antimony in 75 mg of melgumine antimoniate salt) in a dose of 6 mg/Kg/day for initial 3 days and later the dose was increased to 20 mg/Kg/day for a total duration of 21 days. The patients were discharged from the hospital once they became afebrile and remaining treatment was completed in OPD.

The resolution of fever after the start of treatment was taken as the response criterion. This outcome measure was grouped into excellent (fever settling within 7 days), satisfactory (fever settling in 8-10 days) and resistant (fever not settling in 10 days). The probability of existence of L. infantum was inferred on the basis of age of affected children, seasonal variation, and absence of resistance to antimonial compounds.

Statistical Package for Social Sciences (SPSS) computer software was used to enter and analyse the data. Wilcoxon Signed Rank Test-2 tailed (Z-test) was applied to find significance of outcome measures.

During the study period 3520 children were admitted in paediatric ward of Combined Military Hospital Muzaffarabad Azad Jammu and Kashmir. Out of these 61 (1.73%) were diagnosed as VL. There were 40 males and 21 females (2:1). The median age was 18 months (range 9-60 months). The age distribution is shown in figure I. Only 13 children had normal nutritional status while 48 (79%) had malnutrition. The distribution of patients according to nutritional status is given in figure 2. Fifty six (92%) cases belonged to rural areas. Fifty cases (82%) were admitted during non-winter season (March-October) whereas 11 (18%) reported in winter season (November-February). Month wise distribution of the cases is given in figure 3. All the patients kept at least one pet dog in their house while 14 had two and one had three dogs. Agriculture was the predominant (92%) profession among the parents of affected children, followed by public service (5%) and business (3%). The median and mean body temperatures of the patients at presentation were 103°F and 102.8°F (SD+1.1) respectively. Following treatment, the fever settled after mean duration of 5.7 days (SD+1.8). There was significant (P = 0.000) difference between pre treatment and post treatment outcome measures. Fifty two cases (85.3%) had

[(0)]

Figure 1. Age distribution of patients (n=61).

excellent and 9 (14.8%) satisfactory response to treatment with fever settling in 7 and in 8-10 days respectively. In all 61 patients fever settled within 9 days and none of the patients had resistance to antimonial compounds. One patient relapsed due to poor treatment compliance in OPD but responded to same treatment as indoor. Two patients died in this series. One of these had severe thrombocytopenia at diagnosis and died of cerebral bleeding even before the start of treatment while second died on second day of treatment due to cardiac arrest most likely because of drug toxicity.

[(1)]

Figure 2. Nutritional status of patients according to modified Gomez classification (n=61).

Note: For purpose of this classification the 50th percentile on weight for age chart is taken is standard (or 100%) and weight of patient is expressed as percentage of this standard. It is taken as normal if weight of patient is 81-100% of this standard. First, second and third degree malnutrition is present if weight is 71-80%, 61-70% and <60% respectively.

[(2)]

Figure 3. Month wise distribution of cases (n=61).

The magnitude of problem of childhood visceral leishmaniasis in our set up is obvious from diagnosis of 61 cases (frequency of 1.73% among paediatric hospital admissions) during study period. To the best of our knowledge no prevalence study on VL has been carried out in this area. The reservoir of parasite in Azad Jammu and Kashmir is reportedly in dogs14 and presence of dogs in every house in this study supports this observation.

The median age of the patients in our study was 18 months (range 9-60), a feature of L. infantum. Although slight male preponderance has been reported9,10 in the literature but predominance of males in our study could also be due to gender bias in the male dominant society. More than 80% of the patients were diagnosed in non-winter season. Similar seasonal variation of the disease in Gizan, Saudi Arabia has been reported.15 This could be due to increased exposure to sandfly during summer, besides being a feature of L. infantum. Another contributing factor could be the relatively easy access to Muzaffarabad city in summer.

Following treatment the fever settled after mean duration of 5.7 days (SD+1.8). In a study by Al-Orainey et al15 the fever settled within first week of treatment in 96.7% patients. Fifty two cases (85%) in our study had excellent response and in 7 (11.4%) the response was satisfactory. Two patients died; one before the start of treatment and the other on second day of treatment. Cardiac toxicity is an established side effect of antimony compounds and baseline echocardiography is advised before the start of this treatment. In 59 patients fever settled within 9 days and none of the patient had resistance to antimonial compounds. Jurayyan et al16 have also reported excellent response of the disease to antimony compounds. The younger age group, seasonal variation and absence of resistance to antimony indicates that visceral leishmaniasis in Azad Jammu and Kashmir is most likely due to L. infantum and not due to L. donovani. This is in contrast to common belief among health professionals, that as in India, L. donovani causes visceral leishmaniasis in our region. Use of the term leishmania donovani bodies (LD bodies) in reports of bone marrow aspirates supports this notion. Rab et al17,18 using indirect fluorescence and isoenzyme techniques have identified L. infantum in patients of VL AJK and Northern areas.14,17,18

A shortcoming of this study is that microbiological and serological techniques could not be employed to identify the species.

The study concluded that childhood VL is quite common in Azad Jammu and Kashmir. It affects children below five years of age with seasonal variation and has excellent therapeutic response to antimony compounds. These findings suggest that childhood VL in the area is caused by L infantum and not by L donovani. This inference however, needs confirmation by isoenzyme studies.

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