Abstract:
Despite the annual implementation of a robust and extensive indoor residual spraying
programme against malaria vectors in Limpopo Province (South Africa), significant transmission
continues and is a serious impediment to South Africa’s malaria elimination objectives. In order to gain
a better understanding regarding possible causes of this residual malaria, we conducted a literature
review of the historical species composition and abundance of malaria vector mosquitoes in the
Limpopo River Valley region of the Vhembe District, northern Limpopo Province, the region with the
highest remaining annual malaria cases in South Africa. In addition, mosquito surveys were carried
out in the same region between October 2017 and October 2018. A total of 2225 adult mosquitoes
were collected using CO2-baited tent and light traps, human landing catches and cow-baited traps.
Of the 1443 Anopheles collected, 516 were members of the An. gambiae complex and 511 An. funestus
group. In the malaria endemic rural areas outside the Kruger National Park, one specimen each of
An. gambiae s.s. and An. funestus and only three of An. arabiensis were collected. The latter species was
abundant at a remote hot spring in the neighboring Kruger National Park. Eighteen other species
of Anopheles were collected. Our survey results support the historical findings that An. arabiensis,
the species widely held to be the prime malaria vector in South Africa, is a rare species in the malaria
endemic Limpopo River Valley. The implications of the mosquito surveys for malaria transmission,
elimination and vector control in northern Limpopo Province and neighboring regions are discussed.
