Indian journal of malariology最新文献

A field trial in Beel Akbarpur village, Dadri PHC, District Ghaziabad (U.P.) was carried out to test the impact of burning neem oil in kerosene lamp from dusk-to-dawn in living rooms on vector populations and incidence of malaria. Results revealed that burning 1% neem oil in kerosene lamps resulted in the deviation of An. culicifacies from living rooms to cattlesheds. This was also reflected when malaria incidence was compared in experimental and control villages. Cases/000 and Pf/000 were 1.03 and 0.0 in experimental village as against 9.6 and 4.3 in control village. Discontinuation of burning 1% neem oil in kerosene lamp resulted in recurrence of An. culicifacies in living rooms and increase in malaria incidence in experimental village.

Insect growth regulators (IGRs) namely, Isopropyl (E-E)-(RS)-11-methoxy-3,7,11-trimethyldodeca-2, 4-dinoate (Methoprene) and 1-(4-cyclophenyl)-3-(2,6-diflerobenzoyl) urea (Diflubenzuron) were evaluated against mosquito larvae in laboratory as well as in different breeding habitats in Tezpur, Assam. LC90 values of diflubenzuron against Culex quinquefasciatus and Aedes albopictus were 0.0022 and 0.0027 ppm respectively, while it was 0.0027 and 0.0022 ppm respectively in case of methoprene. However, LC50 values of both the IGRs were almost same in case of Ae. albopictus and Cx. quinquefasciatus (varies between 0.0009 and 0.0011 ppm). In case of methoprene, maximum mortality was observed in pupal stage though the exposure was given in all the cases to the III instar larvae. Field trials were conducted in cemented drains, small ponds and ditches. At 0.2 ppm (0.020 kg/ha) both diflubenzuron and methoprene were found to eliminate 92-96 per cent Culex and Anopheles larvae. Methoprene and diflubenzuron were found equally effective for control of mosquito breeding in different breeding habitats and provide better efficacy than conventional larvicides and biocides.

To determine the sibling species composition of An. subpictus complex in Sri Lanka polytene chromosomes of ovarian nurse cells were examined. Samples of An. subpictus s.l. were collected from 65 of the 73 Health Areas surveyed. Of 3095 ovaries collected 869 polytene chromosomes preparation were identified as sibling species A and 77 B. Species B was present only in coastal localities of the Island whereas species A was found both in coastal and inland areas with predominance in inland areas. This is the first report on the occurrence of two sibling species of An. subpictus in Sri Lanka. Some biological characteristics of coastal and inland populations such as susceptibility to different insecticides, human blood index and human biting rates are discussed.

Hepatocytes from bonet monkey (Macaca radiata) obtained by perfusion of a liver biopsy were infected in-vitro with Plasmodium cynomolgi bastianellii sporozoites raised in Anopheles stephensi. The development of exoerythrocytic (EE) stages was seen under phase contrast microscope and by Giemsa staining. Multinucleated EE-stages were seen in the cultured hepatocytes on day 7-8 post-sporozoite inoculation.

Ovarian polytene chromosomes of Anopheles culicifacies collected from different climatic and eco-epidemiological localities were examined to study the composition and distribution of sibling species in Sri Lanka. During the study period 4328 ovaries were prepared for examination, of which 1937 were suitable for the reading of polytene chromosomes. Among these 458 specimens were identified as belonging to species B based on diagnostic inversion on x-chromosome and 1479 definitively were identified as sibling species B on the basis of x-chromosome and chromosome arm-2 inversion. Other sibling species were not encountered among the specimens identified from 31 Health Areas during the study period. The occurrence of sibling species B of An. culicifacies in Sri Lanka is confirmed but no evidence of other sibling species (A, C or D) was found.

Mosquito breeding in relation to aquatic vegetation and certain physico-chemical parameters was studied in rice fields of Kheda district in central Gujarat. A total of 14 anopheline and 15 culicine species were encountered in close association with different types of aquatic vegetation in different proportions. Among anophelines, Anopheles annularis, An. nigerrimus, An. subpictus and An. tessellatus were of general distribution and were found associated with each aquatic vegetation. An. culicifacies showed poor association with most of the aquatic weeds. Maximum number of anophelines were found associated with algae. Culex vishnui sub-group predominated among culicines and showed frequent association with Ceratophyllum, Hydrilla and algae. Physico-chemical parameters also exerted some impact on mosquito larval population.