Link to Pubmed [PMID] – 29394367
J. Infect. Dis. 2018 Jan;
Background: Eliminating falciparum malaria in Cambodia is a top priority, requiring the implementation of novel tools and strategies to interrupt its transmission. To date, few data are available regarding the contributions to malaria transmission of symptomatic and asymptomatic carriers.
Methods: Direct-membrane and skin feeding assays (DMFA, SFA) were performed, using Anopheles minimus and An. dirus, to determine infectivity of symptomatic falciparum-infected patients and malaria asymptomatic carriers; a subset of the latter were followed for two months to assess their transmission potential.
Results: By microscopy and RT-PCR, P. falciparum gametocyte prevalence rates were, respectively, 19.3% (21/109) and 44% (47/109) on Day (D) 0 and 17.9% (5/28) and 89.3% (25/28) in recrudescent patients (Drec) (RT-PCR Drec vs. D0 P=0.0015). Falciparum malaria patient infectivity was low on D0, 6.2% (3/48), and Drec, 8.3% (1/12). DFMA and SFA gave similar results. None of the falciparum (0/19) and 3/28 P. vivax asymptomatic carriers were infectious to mosquitoes, including those that were followed up for two months. Overall, P. falciparum gametocytemias were low except in a few symptomatic carriers.
Conclusions: Only symptomatic falciparum malaria patients were infectious to mosquito vectors at baseline and recrudescence, highlighting the need to detect promptly and treat effectively P. falciparum patients.