Sandfly survey in Nainital and Almora districts of Uttaranchal with particular reference to Phlebotomus argentipes, vector of kala-azar.

Kala-azar continues to pose a major public health problem in Bihar, West Bengal and parts of eastern Uttar Pradesh in India causing great deal of morbidity and mortality. During 1998, several kala-azar cases from Sub-Himalayan region were treated in Delhi hospitals. And a suspected focus of kala-azar was subsequently reported from this area. Therefore a preliminary sandfly survey was carried out during October, 1999 in 18 randomly selected villages at different altitudes in Nainital & Almora districts of Kumaon region Uttaranchal. The surveys revealed relative preponderance of vector sandfly Ph. argentipes as 77%; mainly confined to cattlesheds and mixed dwellings in the villages at an altitude ranging from 350-960 metres main sea level. The other sandfly species encountered were: Ph. papatasi 6.9%, Ph. major 2.9% and 13.2% Sergentomyia spp. 17.4% Ph. argentipes reacted positive with human antisera and 82.6% with bovine but none reacted with goat, pig dog and bird antisera indicating that Ph. argentipes in the area is mainly zoophilic. Ph. argentipes was found to be highly susceptible to DDT; mortality ranging from 98-100%.

Japanese Encephalitis epidemic in Anantapur district, Andhra Pradesh (October-November, 1999).

Epidemic of Japanese Encephalitis has occurred in Andhra Pradesh during October-November, 1999 affecting 15 out of 23 districts. In total, 873 cases with 178 deaths have been recorded up to the day 29.11.99. The epidemiological investigation has been done in Anantapur district in western Andhra Pradesh, where the outbreak has started in the third week of October. In the district 47 PHC have been affected. On an average 4.5 per cent of 3175 villages have been affected. Average number of cases per affected village have been 1.5. Rural population has been primarily affected. Age groups 1-14 years including infants have been affected but nearly 86.8% of cases have been among 1-9 year age group. The overall case fatality rate has been 18.4 per cent. Clinical features have been high fever, headache, altered sensorium, convulsions and coma. A marked seasonal onset of a few cases per village and 93.75 per cent of human serum samples collected from hospitalised cases showed the evidence of J.E. virus infection indicating that the present outbreak was due to JE virus. High density of Culex vishnui complex mosquitoes has been observed in the area. All the environmental and ecological conditions, temperature, rainfall and relative humidity have been in favour of JE transmission. Analysis of the data for the last 10 years showed that the human JE cases occurred in Anantapur in September-October months, which shifted to October-November, 99. Prolonged draught conditions were observed till October. Possibly the delayed monsoon and congenial atmospheric conditions after monsoon were favourable to the vector species for extra-human cycle of transmission in 1999. Low level transmission leading to small number of cases continued during the succeeding years every September-October till the present epidemic. In all 24 PHCs and urban towns were identified with 212 cases and 39 deaths till 29.11.99.

Ecological observations on the anopheline mosquitoes of Jalpaiguri Duars, West Bengal.

A nine month entomological study was conducted from August 1989 to April 1990 in Jalpaiguri duars of West Bengal where malaria has been persistent problem. Amongst the anopheline fauna three vector species were recorded; An. minimus was the principal vector supported by A. dirus during the rainy months and An. fluviatilis in dry months. All the three vectors were found in close association with human orbit and An. minimums was found to be primarily a domestic vector. The primary role of An. minimus in the transmission of malaria in the region has been highlighted. Observations on seasonal variation, biting preferences, and biting time and vector infection rates were recorded.

Visceral leishmaniasis control in India through primary health care system--a successful experiment of district level planning.

A model district action plan for control of Visceral Leishmaniasis a serious public health problem in north-east Bihar was developed in late 1989 and implemented in 1992 in district Vaishali. A two years implementation resulted in decline in cases and deaths due to Visceral Leishmaniasis to the extent of 65.32% and 46.51% respectively in 1993 as compared to 1992 and 41.13% and 44.93% respectively in 1994 as compared to 1993 with an overall decrease of 79.58% in case and 70.54% in deaths in 1994 as compared to 1992. The implementation of action plan not only established declining trends in morbidity and mortality due to Visceral Leishmaniasis in the district but also successfully contained the cases unresponsive to first line treatment with Sodium Stibogluconate by reducing the prevalence of such cases from 12.42% in 1992 to 8.59% in 1994. Various components of the action plan, implementation strategy and consequent impact on disease situation are presented in this paper.

Kala-azar in Ballia district, Uttar Pradesh.

Door to door search during 1991 in 85 villages in Ballia district of Uttar Pradesh revealed 29 sporadic cases of Kala-azar in four villages. Epidemiological investigations indicated indigenous transmission in Phulwaria village (PHC: Dubhar) with 25 cases while the remaining three villages showed four imported cases from the endemic states. No kala-azar cases had been reported in Ballia between 1947 and the present investigation. Phlebotomus arqentipes, the known vector of kala-azar in India, was encountered in 10 PHCs including the four villages having kala-azar cases. Regular vigilance in Ballia and the neighbouring districts in Uttar Pradesh bordering Bihar is suggested in view of indigenous transmission detected in one village with multiple infection in families. The presence of high vector density, ambient environmental factors and absence of regular residual insecticidal spray warrant constant surveillance in Kala-Azar prone areas in Uttar Pradesh.