Your neighbour's cows could raise your malaria risk: Study finds

Did you know that you could own no cattle at all and still face a higher risk of malaria simply because someone down the road keeps a herd?

That is the surprising finding of a new study from Kwale County, one that is prompting scientists to rethink a long-standing assumption about the relationship between livestock and malaria.

Researchers from ISGlobal and the Kenya Medical Research Institute (Kemri) set out to determine whether keeping cattle protects people from malaria or actually increases their risk. For years, studies have largely asked a straightforward question: does this household own cattle or not?

This study took a different approach.

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Instead of looking only at household ownership, researchers mapped the locations of cattle around each home. For every child tested for malaria, they drew concentric circles of varying sizes around the child's home and counted all the cattle within each radius regardless of who owned them. This meant that a child whose family kept no cattle could still be exposed to animals belonging to neighbours.

The results were striking. Simply owning cattle was not significantly associated with a child's malaria risk. However, when researchers counted cattle across the wider area, the picture changed.

Children living in areas with a higher density of cattle had a 63 per cent higher chance of testing positive for malaria within 400 metres of their homes.