Fish can fight malaria mosquitoes

The fish consume the mosquito larvae

Kenyan researchers have hailed a humble fish as the latest weapon in the battle to curb the spread of malaria.

Nile tilapia, a fish more usually seen on Kenyan dinner tables, was introduced to several abandoned fishponds in the west of the country.

By consuming mosquito larvae it managed to reduce numbers of two of the main malarial mosquitoes by more than 94%.

The BMC Public Health study noted the fish could prove critical as mosquitoes are becoming resistant to pesticides.

Nile tilapia's taste for mosquitoes has been known since 1917 but this is the first time field data has been published detailing their use in mosquito control, the researchers from the International Centre of Insect Physiology and Ecology said.

Every 30 seconds

Malaria, spread by the single-celled parasite Plasmodium, is endemic in parts of Asia, Africa, and central and south America.

This method may well work in a defined area of water, but mosquitoes spread in all sorts of places - including small pools in the mud and puddles - where you obviously can't introduce fish Joanne Greenfield WHO

The organism is passed to humans through the bite of a mosquito. Each year it makes 300 million people ill and causes a million deaths worldwide.

Some 90% of cases are in sub-Saharan Africa, where a child dies of malaria every 30 seconds.

The authors suggested that for Kenyans, the fish could prove a win-win investment. In addition to limiting mosquito populations they could also be used for food, and even generate income, too.

Joanne Greenfield, malaria advisor for the World Health Organization in Kenya, was more circumspect, while describing the findings as "positive".

"This method may well work in a defined area of water, but mosquitoes spread in all sorts of places - including small pools in the mud and puddles - where you obviously can't introduce fish," she said. "It just wouldn't work for many areas."

But she added: "We recommend a spectrum of methods to combat malaria, and this could certainly be a useful tool."