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| Author(s): |
Mônica da Silva Nunes
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI) |
| Defense date: | 2008-10-15 |
| Examining board members: |
Marcelo Urbano Ferreira;
Alejandro Miguel Katzin;
Delsio Natal;
Paulo Eduardo Martins Ribolla;
Guilherme Loureiro Werneck
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| Advisor: | Marcelo Urbano Ferreira; Irene da Silva Soares |
| Abstract | |
Here a cohort study in a frontier settlement in Acre, Brazil, where 509 subjects contributed 489.7 person-years of follow-up, is described. Incidence rates for Plasmodium vivax and Plasmodium falciparum malaria were 30.0/100 and 16.3/100 person-years at risk, respectively. Malaria morbidity was strongly associated with land clearing and farming, and decreased after 5 years of local residence. Besides, there was significant spatial clustering of vivax and falciparum malaria in areas of recent occupation. No significant association was found between FcgRIIa allotype, Duffy promoter type or presence of antibodies against PvMSP-1 and malaria in the follow-up. Humoral and cellular responses were more common against the C- and N-terminal portions of PvMSP-1 respectively, but did not match the PvMSP-1 variants found in infecting parasites. The clinical spectrum of malaria episodes varied widely; while headache, fever and myalgia were the most frequent symptoms, 29.4% of the episodes were asymptomatic. The results show that clinical immunity is acquired under low malaria transmission and environmental changes occurring in the settlements perpetuate malaria transmission. These findings are of utmost importance for malaria control in the Amazon. (AU) | |