Search PubMed⌕ Search

Biomedical subjects

N Arunachalam

Publications and source records attributed to N Arunachalam.

33 records · Page 2Linked to original sources
PubMed1992

Observations on population density of Culex quinquefasciatus and transmission indices of Bancroftian filariasis during and after Integrated Vector Management strategy.

An Integrated Vector Management strategy, implemented as an alternative to the conventional control operations that include mainly chemical control in Pondicherry, South India, reduced very substantially the population density of Culex quinquefasciatus. This resulted in drastic decrease in the intensity of transmission of bancroftian filariasis transmitted by Culex quinquefasciatus and consequently the incidence of new infections in children of 0-5 age group was minimized. When the IVM strategy was withdrawn after five years of implementation and conventional control measures were re-adopted, resilience of Culex quinquefasciatus population was observed and human exposure to the risk of infection increased. The results suggest that maintenance of vector density at reduced levels for prolonged periods, is necessary to control infectious diseases like filariasis, which is difficult in the present day urban situations in developing countries. Hence the emphasis should be on chemotherapy to achieve control of lymphatic filariasis.

Animals↗
PubMed1991

Infectivity of a mermithid nematode Romanomermis iyengari (Welch) in different conductivity levels under laboratory and field conditions.

Infectivity of R. iyengari was examined by exposing mosquito (Culex quinquefasciatus) larvae to the preparasite at different conductivity levels. The preparasite infected 63.5, 30, 11, 1.5 and 0.5% of the mosquito larvae respectively at 2000, 2500, 3000, 3300 and 3600 mu ho/cm. Although, 62-69% of the preparasite survived at 4000-5400 mu ho/cm, it did not infect. Application of preparasite to tree-holes resulted in 53-63% infection of Aedes albopictus larvae initially. On 6th day the infection level was 40% which decreased further to 7% by 15th day. The infection reappeared on 38th day indicating that R. iyengari has not only infected mosquito larvae as soon as they were applied to tree-holes in which the conductivity was 600-2800 mu ho/cm but also got established there.

Animals↗
PubMed1990

Insecticidal activity of carbosulfan (OMS 3022) and pyraclofos (OMS 3040) against mosquitoes.

Carbosulfan (OMS 3022), a carbamate and pyraclofos (OMS 3040), an organophosphate were evaluated for their biological activity against vector mosquitoes, both in laboratory and field conditions. Carbosulfan (25% EC), was found to be active against adults and immatures of Culex quinquefasciatus, Anopheles stephensi and Aedes aegypti. The LD values for adults were 6.65, 5.19 and 8.35 micrograms/cm2 and LC 50values for immatures were 5.4 X 10(-5), 1.6 X 10(-4 and 5.4) X 10(-4) 50mg/1 respectively. Pyraclofos (50%) showed neither larvicidal nor adulticidal activities. The residual effect of carbosulfan (25% WP) on cement, thatch and mud surfaces at 400 mg (ai)/m2 lasted for 3, 16 and 21 weeks respectively. In the field, carbosulfan at 2.00 kg (ai)/ha resulted in complete control of C. quinquefasciatus larvae for a period of one week in cement tanks and less than a week in other polluted water bodies, such as cesspits, cesspools and drains. Pyraclofos was not effective at a dose of 2.00 kg (ai)/ha in any of the habitats.

Animals↗
PubMedDate not supplied

Efficacy of diethylcarbamazine-medicated salt for microfilaraemia of Brugia malayi.

BACKGROUND: Pilot studies in India and abroad have demonstrated the benefit of cooking salt fortified with diethylcarbamazine citrate (DEC) for the control of lymphatic filariasis. In India, DEC-medicated salt has been introduced on a commercial basis in the Cherthala region of Kerala, which is endemic for Brugia malayi (B. malayi). We studied the efficacy of DEC-medicated salt in the clearance of microfilaraemia of B. malayi. METHODS: Eighteen cases of microfilaraemia (11 men; 7 women) were selected; 14 in the experimental group (i.e. treated with 0.2% w/w DEC-medicated salt) and the rest as the control group who were given a placebo. The consumption of salt and the status of parasitaemia were monitored till all the microfilaria carriers became negative. RESULTS: There was a significant reduction in the density of microfilariae (intensity) among the treated individuals over a period of time. The duration required for the clearance of microfilariae ranged from 9 to 30 [mean (SD) 19.4 (1.7)] weeks. All microfilaraemics except one reported side-effects which were mild-to-moderate and persisted for a maximum period of one month. CONCLUSION: DEC-medicated salt effectively clears microfilariae within 30 weeks in parasitaemic individuals. No 'endemic normals' reported any side-effects, though these were common among the microfilaria carriers.

Animals↗