Background: Most studies that assess efficacy of antimalarial drugs focus on the outcome of clinical treatment. However, community surveys of surrogate indicators are often more practical and can provide a wider view of possible changes in drug response, but it has not been clear whether assessment of parasite isolates from patients and asymptomatic individuals are directly comparable. In the present work, we have compared the prevalence of molecular markers associated with resistance to sulfadoxine-pyrimethamine in parasites isolated from asymptomatic and symptomatic individuals.