The epidemiology of malaria in an epidemic area of the Peruvian Amazon.

Abstract

Abstract. A longitudinal study of malariometric indicators and their association with potential risk factors was conducted during August 1997-July 1998 at Padre Cocha, a village of 1,400 residents in the Peruvian Amazon. The incidence of Plasmodium falciparum infections during the study year was 166/1,000 persons; that of P. vivax was 826/1,000 persons. The mean duration of symptoms prior to diagnosis was 2 days; presenting geometric mean parasite densities were 3,976 parasites/l for P. falciparum infections and 2,282 parasites/l for P. vivax. There were no malaria-associated deaths. Consistent with the epidemic nature of malaria in the area, the incidence of both parasite species increased with age and there were no age-specific differences in mean parasite densities. No specific occupational risks for malaria were identified. Activities significantly associated with malaria risk reflected local vector behavior and included strolling outdoors after 6:00 PM and arising before 6:00 AM for adults, and attending evening church services for children.

High prevalence of malaria infection in Amazonas state, Venezuela

“…SA et al (2005) after studying 1933 malaria cases found no association with age or gender and malaria infection, but there was an association between infection and the cultural activities of the people outside their homes in peak hours of vector activity, which facilitated exposition to infection 36 . In our study we did not find any statistically significant association between malaria infection and epidemiological factors such as gender and occupation, demonstrating that they are not risk factors in these populations, even though occupation has been related to malaria incidence in other populations, due to the increase of exposition to the vector of people with certain activities 32 . In Rondonia State, Brazil, transmission appears to be related predominantely to occupation and to extra-domiciliary infection 10 .…”

Dynamics of Malaria Drug Resistance Patterns in the Amazon Basin Region following Changes in Peruvian National Treatment Policy for Uncomplicated Malaria

“…The 2006-to-2007 study samples came from Iquitos, while the 1999 study samples were from Padre Cocha and Caballococha. The village of Padre Cocha is located on the Nanay River, approximately 5 km (10 min by boat) from Iquitos, with a population of 1,400 and relatively low levels of migration in and out of the village (26) (Fig. 1).…”

“…The 1999 isolates were collected during an in vivo efficacy trial for SP (approval no. MCMR-RCQ-HR 70-1n from the Walter Reed Army Institute of Research) that contributed to the removal of this combination therapy from Peruvian Ministry of Health clinics (13,26; D. J. Bacon et al, unpublished data). The 2006 and 2007 malaria isolates were collected as part of an ongoing febrile surveillance protocol (approval no.…”

Determinants of Anopheles Seasonal Distribution Patterns Across a Forest to Periurban Gradient near Iquitos, Peru

“…3,4 Concomitant with this increase in the 1990s was a change in the predominant causative agent of malaria from Plasmodium vivax to P. falciparum and the appearance of Anopheles darlingi Root as the primary vector, which was associated with these changes and increases of malaria in the Department of Loreto. 3,[5][6][7] Although reasons for the changes in malaria transmission have not been clearly established, inadequate healthcare services, delayed diagnostics, poor housing, climate events (i.e., El Niñ o), inadequate vector control programs, banned use of dichlorodiphenyltrichloroethane (DDT), habitat modifications because of agriculture and deforestation, and reintroduction, reemergence, or expansion of An.…”