Resistência in vitro de cepas do Plasmodium falciparum isoladas no sul do estado do Pará, em diferentes períodos: emergência de casos de multirresistência

Abstract

The responses of Plasmodium falciparum to antimalarial drugs were evaluated through the in vitro test using blood sample collected from patients of 7 municipalities of the south of Pará State. Sixty nine microtests for chloroquine and mefloquine, 62 for amodiaquine and 61 for quinine were performed. The results showed a high resistance for chloroquine (71%), a relatively low resistance level for amodiaquine (25.8%) and little resistance to quinine (8.2%). For mefloquine 100% of sensitivity was found.

Antimalarial drug susceptibility testing of Plasmodium falciparum in Brazil using a radioisotope method

“…Malaria prevalence in Brazil has increased three times during the past and quinine in those studies were too low, leading to overestimation of the resistance percentages (Alecrim 1986, Di Santi et al 1988) When adequate "cut off" limits are employed, taking together in vivo and in vitro data, parasite resistance has been observed at levels greater than 70% to chloroquine, greater than 60% to sulfadoxine-pyrimethamine, lower than 20% to quinine and almost none to mefloquine (Boulos et al 1986, Alecrim 1986, Di Santi et al 1988, Kremsner et al 1989, Souza 1992, Couto et al 1993. As in vitro evaluations of P. falciparum sensitivity have not been performed since the 80's (Di Santi et al 1988, Kremsner et al 1989, and considering that radioisotopic methods had not been used, except in one occasion (Zalis et al 1998), we decided to verify the patterns of resistance in a typical endemic area of the Brazilian Amazon region.…”