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Biomedical subjects

M Warren

Publications and source records attributed to M Warren.

At least 109 records · Page 6Linked to original sources
PubMed1975

Natural infections of Anopheles albimanus with Plasmodium in a small malaria focus.

Entomologic surveys conducted in a small village in an area of known high malaria transmission in El Salvador yielded a high rate of infection in Anopheles albimanus collected inside houses in which cases of malaria had occurred. Of 324 specimens dissected, 12 were found to harbor sporozoites or oocysts. This is in contrast to prior reports of extremely low infection rates in collections of this species from malarious areas, and suggests that under some circumstances A. albimanus does meet the criteria of an effective malaria vector.

Anopheles↗
PubMed1975

The seroepidemiology of malaria in Middle America. I. Longitudinal studies on populations in a low incidence area of El Salvador.

Serologic profiles were established using the indirect fluorescent antibody test in a longitudinal study of six villages in an interior area of El Salvador. Positive serologic responses as well as active cases found through the voluntary collaborator posts occurred primarily in adult males, suggesting that much of the malaria experience in the study area resulted from exposure of this segment of the population in more malarious areas where they traveled to engage in temporary agricultural labor. Malaria incidence was generally low but transmission potential apparently varied markedly even over relatively small distances. Serologic profiles reflected the malaria experience in the population sampled, but many localities were widely dispersed and samples taken from village centers were found in some cases not to be representative of the entire locality population in terms of malaria exposure. The indirect fluorescent antibody technique was found to reflect the malaria experience in the population segments examined. When these data were correlated with the surveillance data from the voluntary collaborator posts, the epidemiology of malaria in the study area was more thoroughly understood.

Adolescent↗
PubMed1975

The seroepidemiology of malaria in Middle America. II. Studies on the Pacific coast of Costa Rica.

Serologic studies for malaria using the indirect fluorescent antibody technique suggest that active transmission is either absent or very low in 6 villages on the Pacific side of Costa Rica. Positive titers (1:20 or higher) were seen in the under-15-year age group in three of the study localities, but only 5 such responses were encountered among 249 people examined in this age range. In the adults (15 years and over) from the same 3 villages there were 68 positive titers among 161 examined. There were 43 positive responses in 189 adults from the remaining 3 villages where none of 307 persons under 15 years of age showed a titer of 1:20 or higher to any of the 3 malaria antigens tested (Plasmodium falciparum, P. vivax and P. malariae). These data suggest that the positive responses in the latter villages are more likely to be associated with old or imported cases than with current local transmission. Serologic responses of 1:80 or higher to the P. falciparum antigen suggested the continued presence of this parasite in the population in spite of the paucity of positive blood smears with this species in recent years. Positive titers with the P. malariae antigen suggest that this parasite is probably still present in the area. Such serologic studies help to indicate areas where malaria transmission is active and provide information on parasite reservoirs in particular populations.

Adolescent↗