A Dissertation Submitted in Partial Fulfillment of the Requirement for the Degree of
Master of Science in Public Health Research of the Nelson Mandela African Institution
of Science and Technology
Residents of malaria-endemic communities spend several hours outdoors performing
different activities such as cooking, story-telling or eating; thereby exposing themselves to
potentially-infectious mosquitoes. This compromises indoor interventions, notably longlasting
insecticide-treated nets (LLINs) and indoor residual spraying (IRS). This study
characterized common peri-domestic spaces in rural south-eastern Tanzania, and assessed
protective efficacies of transluthrin-treated chairs and hessian ribbons against mosquitoes.
Two hundred households were surveyed, and their most-used peri-domestic spaces physically
characterized. Protective efficacies of these two prototyped interventions were tested outdoor
in 28 households in dry and wet seasons, using volunteer-occupied exposure-free double net
traps. Center for Diseases Control and Prevention miniature light traps (CDC-LT) were used
to estimate host-seeking mosquito densities within outdoor kitchens. Field-collected
Anopheles arabiensis and Anopheles funestus mosquitoes were exposed underneath the chairs
to estimate 24h-mortality. Approximately half (52%) of houses had verandas. Aside from
these verandas, most houses also had peri-domestic spaces where residents stayed most times
(67% of houses with verandas and 94% of non-veranda houses). Transfluthrin-treated chairs
reduced outdoor-biting An. arabiensis densities by 70-85
% while transfluthrin-treated hessian
ribbons caused 77-81% reduction in the general peri-domestic area. Field-collected An.
arabiensis (99.4%) and An. funestus (100%) exposed under transfluthrin-treated chairs died.
Most houses had actively-used peri-domestic spaces where exposure to mosquitoes occurred.
The transfluthrin-treated chairs and ribbons reduced outdoor-biting malaria vectors in these
peri-domestic spaces, and also elicited significant mortality among pyrethroid-resistant fieldcaught
malaria vectors. These two new prototypes, if developed further, may constitute new
options for complementing LLINs and IRS with outdoor protection against malaria and other
mosquito-borne pathogens in areas where peri-domestic human activities are common.