Kala-azar epidemic in Varanasi district, India.

Research Kala-azar epidemic in Varanasi district, India R. Kumar,1 P. Kumar,1 R.K. Chowdhary,2 K. Pai,3 C.P. Mishra,4 K. Kumar,5 H.P. Pandey,6 V.P. Singh,7 & S. Sundar 8 Reports at the Sir Sunder Lal Hospital, Banaras Hindu University, of a large number of kala-azar cases from one particular village in Varanasi district, Uttar Pradesh, led us to carry out an epidemiological study of the situation using standard techniques. The overall prevalence and case fatality of the disease were 12.9% and 10.5%, respectively. A history of fever and hepatosplenomegaly was noted for all the cases. The case definition was the presence of parasites in bone marrow or splenic aspirate smears. The disease was more prevalent among adults, but occurred also among children. However, there was no clear linear relationship between the prevalence of the disease and age group. Kala- azar occurred among males and females, and its prevalence did not correlate significantly with income. Since the disease vector continues to be present in the study area, the health authorities should take strong steps to control the disease. Voir page 373 le re´sume´ en franc¸ais. En la pa´gina 373 figura un resumen en espan˜ol. Introduction Leishmania spp., the etiological agent of kala-azar (leishmaniasis), was first recognized in India in 1903 (1). Kala-azar is still present in the country and remains endemic in eastern India, predominantly in Bihar State, where occasional epidemics occur (2, 3). In the last two decades, sporadic cases have been reported from the eastern districts of Uttar Pradesh (4, 5). In 1994, at the Sir Sunder Lal Hospital, Banaras Hindu University, Varanasi, which serves the health needs of the population in eastern Uttar Pradesh and Bihar State, an unusually large number of kala-azar patients were observed to have come from one particular village, Pandit Ka Purva, situated across the river Ganges in Varanasi district. We therefore carried out a study to discover the epidemiological characteristics of the kala-azar outbreak in that village. Study area and methods Varanasi district (total population, ca. 3.5 million) is situated on the plains of the Indo-Gangetic river belt and lies on both banks of the river Ganges. There are three distinct seasons (winter, summer, and mon- soon). The soil is alluvial and the rural population is engaged mostly in agriculture; cattle and cattle sheds are very common. The region is also well known for the internationally important silk-weaving industry, and migrants from the adjoining states of Bihar, Madhya Pradesh and West Bengal have settled here for employment. The rural study village of Pandit Ka Purva, situated 8 km from the Niyamtabad Community Development block in Varanasi district, had a population of 518. A door-to-door survey of all families in Pandit Ka Purva was carried out in November and December 1995, using a pre- designed and pre-tested proforma. Suspected cases of kala-azar were referred to the Sir Sunder Lal Hospital for parasitological confirmation of the diagnosis. The patients were also questioned about their movements between districts in the state in previous years. Patients were considered to be suffering from kala-azar if they had had fever (for more than 2 months) and hepatosplenomegaly. The presence of parasites in splenic and bone marrow aspirates was confirmed by culture and Giemsa staining. 1 Senior Research Fellow, Department of Biochemistry, Faculty of Science, Banaras Hindu University, Varanasi, India. 2 Resident, Department of Preventive and Social Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India. 3 Immunobiologist, Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India. 4 Lecturer, Department of Preventive and Social Medicine, Institute of Medical Sciences, Varanasi, India. 5 Medical Officer, Department of Medicine, Institute of Medical Sciences, Varanasi, India. 6 Reader, Department of Biochemistry, Faculty of Science, Banaras Hindu University, Varanasi, India. 7 Professor and Director, Department of Medicine, Institute of Medical Sciences, Varanasi, India. 8 Professor, Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi–221005, India. Requests for reprints should be sent to Professor S. Sundar at this address. Reprint No. 5786 371Bulletin of the World Health Organization, 1999, 77 (5) # World Health Organization 1999 Results The findings of the door-to-door survey in Pandit Ka Purva village are given in Table 1. Of the total of 518 persons surveyed, 67 (39 males and 28 females) showed typical clinical and parasitological features of kala-azar, including 7 who died. The overall pre- valence and case-fatality rate were 12.9% and 10.5%, respectively. Fever occurred mostly in September and October after the monsoon had ended. All the cases had a history of fever and splenomegaly and most had thrombocytopenia in the range 60 000– 100 000 per mm3. Leukocyte counts ranged between 4000 and 7000 per mm3. None of the cases had lymphadenopathy. All 67 patients were treated with sodium stibogluconate (20 mg per kg per day intravenously for 30 days) (data not shown); 60 (89.6%) of them improved and 7 (10.5%) died from concurrent infection or advanced disease. The age distribution of kala-azar cases showed significant differences, being highest among the 45–54-year age group, followed by those >55 years, and lowest in the age group <5 years (Table 1). The prevalence of kala-azar was lower among literate persons, but the differences were not statistically significant (Table 2). The prevalence of the disease was highest among males whose primary occupation was in agriculture; a similar trend was observed among women who worked in agriculture and weaving (Table 3). The income of the study subjects did not vary markedly and the distribution of cases among different income categories was not statistically significant (Table 4). Discussion During the past few years, an increasing number of cases of kala-azar have been reported in various parts of India. Some of these could have been due to migration of cases from Bihar. The detection of a large number of clinically and parasitologically positive kala-azar cases in the present study may be due to a population influx from adjoining areas or to active disease transmission, or both. The reported annual incidence of kala-azar in India (ca. 20 000 Table 1. Age distribution of kala-azar cases in Pandit Ka Purva village, Varanasi district, Uttar Pradesh, India Age group No. of subjects No. of casesb (years)a surveyed <5 76 2 ( 2.6) 6–14 149 17 (11.4) 15–24 94 11 (11.7) 25–34 94 13 (13.8) 35–44 47 6 (12.8) 45–54 25 12 (48.0) >55 33 6 (18.2) All groups 518 67 (12.9) a w2 test = 23.32, degree of freedom = 6, P <0.001. b Figures in parentheses are the prevalence per 100. Table 2. Distribution of kala-azar cases, by sex and literacy status, Pandit Ka Purva village, Varanasi district, Uttar Pradesh, India Characteristic n No. of Prevalence Z P- value cases (per 100) Sex Male 266 39 14.7 1.21 > 0.05 Female 252 28 11.1 Literacy Males Literate 56 5 8.9 1.59 > 0.05 Illiterate 210 34 16.2 Females Literate 44 4 9.1 0.50 > 0.05 Illiterate 208 24 11.5 Table 3. Distribution of kala-azar cases, by sex and occupation, Pandit Ka Purva village, Uttar Pradesh, India Occupation Males Females Total No. No. Prevalence No. No. Prevalence No. No. Prevalence surveyed +ve (per 100) surveyed +ve (per 100) surveyed +ve (per 100) Agriculture 19 8 42.1 18 4 22.2 37 12 32.4 Weaver 200 24 12.0 186 20 10.8 386 44 11.4 Small 23 5 21.7 24 3 12.5 47 8 17.0 business Service 20 1 5.0 19 1 5.3 39 2 5.1 Other 4 1 25.0 5 0 0 9 1 11.1 (e.g. painter, rickshaw puller, mason) Total 266 39 14.7 252 28 11.1 518 67 12.9 Research 372 Bulletin of the World Health Organization, 1999, 77 (5) cases) may represent only a fraction of the real number. Since we found no evidence for population movements in the study village, the cases must have been due to a high level of disease transmission. Our survey showed that kala-azar was verging on epidemic proportions. The appearance of such an epidemic is serious because of the risk of spread to other areas of Uttar Pradesh. We found a higher disease prevalence among adults, but children were also affected. Rai & Sehgal (4) reported leishmaniasis cases among all age groups, including under-1-year-olds, but the majority of their cases were in children and young adults (aged 5– 30 years). No direct relationship between the occurrence of kala-azar and age group was observed, but the higher prevalence among males may be due to the greater exposure of men to the vector, because of their clothing and habits. The occurrence of fewer cases among literate persons may be related to their use of protective measures, such as mosquito nets. The distributions of the disease by occupation and income in the study area were similar to the findings reported by Rai & Sehgal (4). The disease vector of kala-azar (female Phlebo- tomus argentipes) occurs in large numbers in the alluvial plains of Uttar Pradesh. In view of the outbreak of kala-azar in Pandit Ka Purva, it is essential for the health authorities to take immediate measures to control the epidemic and prevent its spread to neighbouring villages. The control of kala-azar ultimately rests on the development of much shorter treatment courses, greatly improved diagnostic methods, and close cooperation between universi- ties, public health agencies, and the government. n Acknowledgements We are indebted to the Department of Biotechnol- ogy, Government of India, New Delhi, for providing funds for carrying out this study. Ramesh Kumar and Pramod Kumar were recipients of senior research fellowships from the University Grants Commission, New Delhi. We thank the members of the Art & Photo section, Institute of Medical Sciences, Banaras Hindu University, Varanasi, for their help and the headman of Pandit Ka Purva village, Mr Ram Doe Patel, for his cooperation during the study. Re´sume´ Epide´mie de kala-azar dans le district de Be´nare`s (Inde) Ayant eu connaissance, par le Sir Sunder Lal Hospital (Universite´ Banaras Hindu), de l’existence de nombreux cas de kala-azar dans un village du district de Be´nare`s (Etat de l’Uttar Pradesh), nous avons entrepris une e´tude e´pide´miologique en utilisant les me´thodes habituelles. La pre´valence globale et le taux de le´talite´ de la maladie se situaient respectivement a` 12,9 et 10,5%. On a releve´ des ante´ce´dents de fie`vre et d’he´patosple´nome´galie chez tous les malades. Les cas ont e´te´ de´finis par la pre´sence de parasites dans des frottis de moelle osseuse et de biopsies sple´niques. La maladie a surtout frappe´ les adultes, mais des enfants ont e´galement e´te´ atteints. On n’a toutefois pas constate´ de relation line´aire nette entre la pre´valence de la maladie et la classe d’aˆge. Le kala- azar a se´vi parmi des sujets illettre´s de sexe masculin, mais il n’y avait pas de corre´lation significative avec le niveau de revenu. Comme le vecteur est toujours pre´sent dans la zone e´tudie´e, il convient que les autorite´s sanitaires prennent des mesures rigoureuses pour circonscrire la maladie. Resumen Epidemia de kala-azar en el distrito de Varanasi (India) En el Hospital Sir Sunder Lal, de la Universidad Hindu´ de Banaras, se detecto´ un elevado nu´mero de casos de kala-azar procedentes de Uttar Pradesh, aldea del distrito de Varanasi. Ese hecho nos llevo´ a realizar un estudio epidemiolo´gico de la situacio´n mediante te´cnicas normalizadas. La prevalencia global y la tasa de letalidad eran del 12.9% y el 10.5%, respectivamente. En todos los casos existı´a una historia de fiebre y hepatoespleno- megalia. Los casos se definı´an por la presencia de para´sitos en los frotis de los aspirados de me´dula o´sea o de bazo. La enfermedad era ma´s frecuente en los adultos, pero se daba tambie´n entre los nin˜os. Sin embargo, no existı´a una relacio´n lineal clara entre la prevalencia de la enfermedad y el grupo de edad. El kala- azar afectaba sobre todo a varones y a personas analfabetas, pero no se observo´ una correlacio´n significativa entre su prevalencia y los ingresos. Dado que el vector de la enfermedad no ha desaparecido de la zona estudiada, las autoridades sanitarias deberı´an tomar medidas ene´rgicas para combatir esa dolencia. Table 4. Distribution of kala-azar cases, by monthly per capita income, Pandit Ka Purva village, Uttar Pradesh, India Monthly income No. surveyed No. positive for Prevalence (Rs)a kala-azar (per 100) 100–200 148 19 12.8 201–300 230 32 13.9 301–400 90 11 12.2 >400 50 5 10 Total 518 67 12.9 a w2 test = 1.1051, degree of freedom = 3, P >0.05. Kala-azar epidemic in Varanasi district, India 373Bulletin of the World Health Organization, 1999, 77 (5) References 1. Leishman WB. 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