In Sudan, a woman walks for hours to get hold of a household item that for most in the West would be cheap to buy: a mosquito net treated with insecticide that could just be the difference between life and death for her family. Distributed for free by the WHO, these nets are an important step in preventing those most at risk from malaria from being bitten – but protecting people from the agents of the disease is a more difficult problem than even the widespread distribution of such aid can solve.
Image: James Gathany, CDC
Mosquito phase two: Mosquito larvae soon to become pupae.
Standing water is of course where the life cycle of the mosquito begins. Marshes, mangrove swamps, rice fields, grassy ditches, puddles and the edges of rivers and streams all provide this blood-sucker with environments in which the adult female can lay her eggs. In the space of just 5–14 days, the eggs hatch to become algae-feeding larvae, then develop into pupae – which like the larvae must come to the water’s surface often to breathe – before the adult mosquito emerges.
Image: Matthew Burrard-Lucas
Phase three becomes four: Mosquito hatching from pupal stage.
Adult mosquitoes typically mate within days after emerging from the pupal stage but females can live for up to two weeks. Though the female can feed on sugar sources for energy, she usually needs a blood meal for the development of her eggs. Once satisfied, she will rest for a few days while the blood is digested and eggs are developed before laying her eggs and seeking a new host. In that short interim period, she may well have become an infective vector for the lethal malaria parasite.