RESUMEN
Indoor residual spraying with DDT was the principle method by which malaria transmission was eradicated or greatly reduced in many countries between the late 1940s and 1970s. Since then, decreasing use of DDT has been associated with a resurgence of malaria in India, Sri Lanka, former Soviet Central Asia, Zanzibar, Venezuela and several other Latin American countries. In India and Zanzibar, DDT resistance in vectors, as well as a decline in spray coverage, are probable causes of reduced effectiveness of DDT in recent decades. In southern Europe, eradication of malaria transmission was achieved by DDT spraying in the 1940s and 50s and eradication has been sustained by adequate treatment of imported human malaria cases. In the highlands of Madagascar and South Africa, recent reversion to DDT spraying has been successful in stemming resurgences of malaria. Continued use of DDT for vector control, but not for agriculture, is approved by the Stockholm Convention on Persistent Organic Pollutants. DDE residues in breast milk have been associated with DDT anti-malaria spraying in South Africa, but it is not known whether this is harmful. A claimed association of DDE residues with breast cancer have not been substantiated. There is a recent report of association of DDE residues with probability of premature birth; the possible relevance of this to anti-malarial use of DDT should be investigated. In Colombia, testing of the DDT stockpile for suspensibility, DDT resistance in Anopheles darlingi and investigation of the present affordability of widespread spraying with DDT, compared with alternative chemicals, are recommended.
Asunto(s)
DDT , Insectos Vectores , Malaria , Contaminación del Aire InteriorRESUMEN
Objective To detect circumsporozoite protein (CSP) in anopheline vectors from south Yunnan and to evaluate ELISA in the detection. \ Methods\ Salivary glands of the anopheline mosquitoes were taken for finding sporozoites by microscopy and part of the glands was used for detecting CSP by ELISA. An. minimus was experimentally infected by blood from vivax malaria patient (with Plasmodium vivax) and examined for sporozoites and CSP. Eight species of anopheline mosquitoes were caught in the field and examined. Monoclonal antibodies to P.falciparum (Pf2A10) and P.vivax (Pv210, Pv247) were used in ELISA for detecting CSP. \ Results\ Sporozoites were found in the salivary glands of 27 out of 36 An. minimus experimentally infected (75^0%), 29 were ELISA CSP positives (80^6%), and 26 of the 27 mosquitoes showed Pv210 CSP positive. Among \{1 010\} parous anopheline mosquitoes from the field, 7 were found sporozoite positive (0^69%), 8 were ELISA CSP positive (0^79%), and 6 of the 7 mosquitoes showed CSP positive. Of \{4 675\} wild mosquitoes in 8 anopheline species with different ages, 11 were found CSP positive (0^24%) including An.minimus, An.sinensis and An.maculatus with a positive rate of 0^20%, 0^24% and 0^39% respectively.Among the 11 mosquitoes, 9 were Pv210 positive and 2 were Pf2A10 positive. Conclusion CSP detection by ELISA is a useful method to monitor the malaria transmission capacity of anopheline vectors.