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The Half-Century View

By Clive Shiff

I started work on mosquitoes in 1959 in Northern Rhodesia (now Zambia).

It was my first job out of university, with a master’s degree in medical entomology. After a year I was transferred south to what is now Zimbabwe where two decades earlier, H.S. Leeson had shown that the mosquito population moved upriver each rainy season, and from there spread into farmlands.

So we studied the distribution of mosquitoes, and we found that if you spray all the houses on either side of the rivers, the mosquitoes didn’t do well. With this “barrier spraying,” we were able to prevent the surge upriver.

I spent a lot of time collecting mosquitoes. We’d hang over cliffs and collect mosquitoes from the river below with a large ladle—and then suddenly the head of something not very nice nearby would 
pop up. There were a lot of water snakes in the river.

The work was systematic and thorough, and supervision was necessary to ensure that the spraying actually happened. But it worked very well. Rhodesia had a very effective mosquito control program, and the number of cases annually were in the hundreds, instead of the tens of thousands.

We have learned that fighting malaria is a long and hard process requiring simple strategies based on good surveillance, careful planning and supervision of the work, and dedicated epidemiologists to help find the outbreak centers.