Pity the poor mosquito. It gets the blame for spreading wretched diseases like malaria, dengue and chikungunya, when parasites and viruses really cause disease. The infectious agents are catching a ride in the mosquito’s stomach and glands. When the mosquito settles down for a blood meal, that’s when diseases swoop in to do their damage.

Ronald Ross, a 19th-century British scientist, figured out how the malaria parasite travels through mosquitoes to humans while working for the Indian Medical Service in the 1890s. He won the Nobel Prize for his achievement.

Almost 130 years later, malaria, one of the most serious mosquito-borne diseases, still kills an estimated 600,000 people a year, most of them African children whose small bodies are less able to battle the parasite.

Worldwide, close to 200 million fall ill from malaria each year, a disease rate that takes a toll on productivity and economic stability in the regions where it occurs.

The President’s Malaria Initiative (PMI) is the leading U.S. program to combat the disease.

Launched in 2005 to target malaria in the most vulnerable countries, PMI is devoted to expanding three significant counter-disease measures: distribution of medication and insecticide-treated bed nets and insecticide spraying of indoor living areas.

Since PMI began, more than 102 million nets and 318 million lifesaving anti-malarial treatments have been distributed.

These gains are an important step forward for people who live in malaria-prone areas, as efforts to further reduce the disease risk continue. Even travelers have a chance of exposure in these regions and need to take precautions.

(Illustrations by Doug Thompson / State Dept.)