Mapping of risk prone areas of kala-azar (Visceral leishmaniasis) in parts of Bihar State, India: an RS and GIS approach.

BACKGROUND & OBJECTIVES: The kala-azar fever (Visceral leishmaniasis) is continuing unabated in India for over a century, now being largely confined to the eastern part of India mainly in Bihar state and to some extent in its bordering states like West Bengal and Uttar Pradesh. Two study sites namely Patepur block in Vaishali district with high endemicity in northern part and Lohardagga block in Lohardagga district with absolute non-endemicity in southern part of Bihar were selected for the study with the following objectives : (i) to study the macro-ecosystem in relation to distribution of vector -Phlebotomus argentipes; (ii) to identify/map the risk prone areas or villages in a block for quick remedial measures; and (iii) to make use of satellite remote sensing and GIS to demonstrate the utility for rapid assessment of landuse/landcover and their relation with the incidence of kalaazar leading to the mapping of risk prone areas. METHODS: Indian Remote Sensing (IRS)-1D LISS III satellite data for the periods of March and November 2000 were analysed in Silicon graphic image processing system using ERDAS software. False color composites (FCC) were generated and landuse/landcover was assessed using Maximum likelihood supervised classification techniques based on ground truth training sets. During the study the GIS functions are used to quantify the remotely sensed landscape proportions of 5 km2 buffer surrounding each known group of villages of high occurrence of sandflies in endemic and nonendemic study sites. Instead of traditional ground based survey methods to vector surveillance, the present study used a combination of remote sensing (RS) and geographical information system (GIS) approach to develop landscape predictors of sandfly abundance-an indicator of human vector contact and as a measure of risk prone areas. RESULTS: Statistical analysis using the remotely sensed landscape variables showed that rural villages surrounded by higher proportion of transitional swamps with soft stemmed edible plants and banana, sugarcane plantations had higher sandfly abundance and would, therefore, be at higher risk prone areas for man-vector contact. INTERPRETATION & CONCLUSION: The present study clearly brought out the usefulness of satellite remote sensing technology in generating the crucial information on spatial distribution of landuse/landcover classes with special emphasis on indicator landcover classes thereby helping in prioritising the area to identify risk prone areas of kala-azar through GIS application tools.

Epidemiological, microbiological & electron microscopic study of a cholera outbreak in a Kolkata slum community.

BACKGROUND & OBJECTIVE: Epidemics of cholera caused by Vibrio cholerae O1 or O139 have been reported from different parts of India. Factors such as unsafe water supply, poor environmental sanitation, indiscriminate defaecation and lack of personal hygiene are mainly responsible for continued transmission of this disease. We report here epidemiological and microbiological findings of a localized outbreak of cholera, which occurred during March and April 2004 in the eastern part of Kolkata city. METHODS: The affected slum area has a population of 4409, predominantly muslims. Patients suffering from acute watery diarrhoea attended the health outposts organized by National Institute of Cholera and Enteric Diseases, Kolkata and International Vaccine Institute, South Korea as part of a routine surveillance programme at the locality as well as the emergency medical camp organized by the Kolkata Municipal Corporation. Stool and water samples were collected and tested for diarrhoeagenic pathogens in the laboratory. Bacteriophages specific for V. cholerae were isolates and studied electron microscopically for morphology. RESULTS: A total of 89 diarrhoea cases were reported giving an attack rate of 2 per cent. V. cholerae O1 biotype ElTor, serotype Ogawa was isolated as a sole pathogen from 15 (15.8%) of 89 stool samples screened. Water samples (2 from tube wells, 3 from municipal taps and 1 from well) showed presence of coliform bacilli with high MPN (Most Probable Number) count. Bacteriophages specific to V. cholerae were isolated from 2 of 6 water samples examined. A leakage was detected in the main pipeline supplying drinking water to that area. INTERPRETATION & CONCLUSION: The outbreak was caused by V. cholerae O1 (Ogawa) biotype ElTor. The presence of phages in the water samples was an additional indicator for V. cholerae contamination in this community. Occurrences of such outbreaks support vaccination against cholera as an alternative strategy.

Primary cutaneous nocardiosis: a case study and review.

BACKGROUND: Primary cutaneous nocardiosis is an uncommon entity. It usually occurs among immunocompetent but occupationally predisposed individuals. AIM: To study clinical profile of patients with primary cutaneous nocardiosis in a tertiary care hospital and to review the literature. METHODS: The records of 10 cases of primary cutaneous nocardiosis were analyzed for clinical pattern, site of involvement with cultural study and response to treatment. RESULTS: All the patients were agricultural workers (nine male) except one housewife. The commonest clinical type was mycetoma. Unusual sites like the scalp and back were involved in two cases. Culture was positive in six cases with N. brasiliensis being commonest organism. N. nova which was previously unreported cause of lymphocutaneous nocardiosis, was noted in one patient, who had associated HIV infection. All the patients responded to cotrimaxazole. CONCLUSION: Mycetoma is the commonest form of primary cutaneous nocardiosis and responds well to cotrimoxazole.

Inflammatory cutaneous metastasis as a presenting feature of bronchogenic carcinoma.

An elderly man with a long history of smoking presented with an excruciatingly painful mass of short duration on the left side of the neck, without any systemic complaint. Clinical and radiological examination revealed left upper lobe consolidation which was proved to be secondary to bronchogenic carcinoma. Histopathological findings from a skin biopsy from the neck mass were consistent with inflammatory cutaneous metastasis. Interestingly, this was the presenting feature of the underlying malignancy in this patient. This pattern of cutaneous metastasis has rarely been reported in association with bronchogenic carcinoma.

Greither's disease.

A 14-year-old girl with diffuse palmoplantar keratoderma with hyperhidrosis and progressive extension of keratoderma to the dorsum of the hands and feet is reported. The inheritance pattern was autosomal dominant.

The genus Malassezia and human disease.

Sabouraud's Pityrosporum is now recognized as Malassezia. With taxonomic revision of the genus, newer species have been included. The role of this member of the normal human skin flora in different cutaneous and systemic disorders is becoming clearer. The immunological responses it induces in the human body are conflicting and their relevance to clinical features is yet to be explored.

Koebner phenomenon in PLEVA.

Koebner phenomenon has been described in relation to many immunological, inflammatory and infectious dermatoses since the time of its first description. We report a man with pityriasis lichenoides et varioliformis acuta showing Koebner phenomenon.

Serious cutaneous adverse drug reactions: pathomechanisms and their implications to treatment.

Severe cutaneous adverse drug reactions pose diagnostic and therapeutic challenges to the medical community. Understanding the pathomechanisms can prevent their onset and improve their management, while timely and judicious intervention can reduce their mortality.

A prospective study of phage types & biotypes of Salmonella enterica serotype Typhi isolated from hospitalized children in Kolkata, India.

BACKGROUND & OBJECTIVES: Kolkata and its suburbs in eastern India faced an epidemic of typhoid fever in 1990. A prospective, hospital and laboratory based study over a period of 12 yr (1990-2001), on the phage typing and biotyping pattern of Salmonella enterica serotype Typhi was carried out, to see if there has been a change. METHODS: A total of 338 S. enterica serotype Typhi isolates from 1491 blood samples were phage typed and biotyped. The mean age of isolation was calculated. RESULTS: The age distribution of subjects (neonates to 12 yr) has been analysed. Of the 338 (22.7%) isolates obtained, eight different S. enterica serotype Typhi phage types were detected. Biotype I (95.8%) was more prevalent as compared to biotype II (4.1%). Phage type E1 was the commonest phage type in Kolkata and its suburbs. INTERPRETATION & CONCLUSION: The mean age at isolation was found to be 6.7 +/- 3.3 yr. Biotype I was predominant and it was of interest that all strains of phage type E1 belonged to biotype I.

Vectorial efficacy of Phlebotomus argentipes in Kala-azar endemic foci of Bihar (India) under natural and artificial conditions.

Ability of Phlebotomus argentipes to acquire Leishmania donovani the causative agent of Indian Kala-azar was evaluated in the laboratory. Flies were fed artificially on infected blood suspensions, using a chick-skin-membrane feeding apparatus, and naturally on Leishmania donovani infected mice. In addition flies collected from different endemic areas were dissected and examined for natural infection. Flies fed on infected mice showed significantly higher feeding rate (14.4%, p < 0.01) compared to that of other experiments (9%, 8.75%) but the percentage of infection was very low (2.43%). No Chi-square comparison was made between infection rate and feeding rate because of low value in infection rate (less than 5). Flies dissected for natural infection showed only 0.1% infection. Not much difference was observed in the intensity of Leishmania donovani infection in the mid gut of sandflies examined from any of these experiments. These observations have confirmed that Phlebotomus argentipes has ability to acquire infection and it provides the final piece of evidence that Phlebotomus argentipes is the vector of Leishmania donovani in Bihar State.

An entomological field evaluation of larval biology of sandfly in Kala-azar endemic focus of Bihar--exploration of larval control tool.

Knowing the exact breeding places inside the habitat is very important to plan the larval control strategy. Information regarding larval biology in relation to different seasons will be more useful to organize insecticide spray schedule at a particular month of maximum immature density to bring down the adult sandfly density. In the present study, maximum number of soil samples were found positive in the month of January and minimum in the month of September. Maximum positive soil samples were collected from cattle sheds, minimum in mixed dwellings and in case of human dwellings all soil samples were negative. Comparison of two methods for the isolation of immature stages showed that direct microscopic observation is superior to sugar flotation technique.

Field trial of an ecological approach for the control of Phlebotomus argentipes using mud & lime plaster.

A pilot study for the control of Ph. argentipes, a known vector of kala-azar in India, was carried out using an ecological approach. Of the 15 houses selected for the study 10, including the cattle sheds and latrines, were plastered with a mixture of mud and lime, up to a height of 1.22 m taking care to seal all cracks and crevices. The remaining five houses were left unplastered and were considered as control areas. The pre-treatment and post-treatment resting densities of the sandfly were monitored both in treated and untreated houses. A sudden drop in the sandfly density was noticed in the treated houses, whereas there was no significant reduction in the check houses, suggesting an effective control.