Drug Prevents Malaria in High-Risk Region

NIH | SEPTEMBER 30, 2014

Malaria is caused by the Plasmodium parasite, which is transmitted to people through mosquitoes. More than 40% of the world’s population lives in at-risk regions. Malaria affects about 300-500 million people each year. Most cases can be successfully treated, but nearly 1 million still die of the disease every year, including about 800,000 children under age 5 in Sub-Saharan Africa.

Anopheles Freeborni Mosquito Pumping Blood. Image courtesy of CDC

Researchers have been developing vaccines and other preventive strategies to combat malaria. In addition to insecticide-treated bed nets, certain drugs can help prevent malaria in infants during the rainy season. However, they aren’t recommended in areas with a high risk of malaria year round and with high rates of drug resistance.

A team at the University of California, San Francisco, led by Dr. Grant Dorsey and colleagues in Kampala, Uganda, compared drugs to prevent infant malaria in areas with a high risk year round and high rates of drug resistance.

The team enrolled 400 infants in eastern Uganda. At 6 months of age, the children were randomly divided into 4 groups. They received either current preventative treatments—the antifolate drugs sulfadoxine-pyrimethamine (SP) monthly or trimethoprim-sulfamethoxozole (TS) daily, or a new combination drug called dihydroartemisinin-piperaquine (DP) once daily for 3 consecutive days each month. A fourth control group received the current standard of care, with no preventive drugs.

The drugs were administered by the families and recorded in a diary. Infants were routinely monitored at clinics. Families were also encouraged to take the children to the clinic any time they were ill. All families were given insecticide-treated bed nets and encouraged to use them. Treatments stopped at 24 months of age, and most children (340) were followed until age 3.

The researchers found that DP provided the most protection, with children in the DP group 58% less likely to develop malaria than those in the control group. TS treatment was moderately protective (28%), but SP treatment wasn't significantly different from the non-treatment group (7%).There were 3.02 malaria episodes per person year in the DP group, 5.21 for the TS group, 6.73 for the SP group, and 6.95 for the control group. There were no significant side effects from the drugs. In addition, after the interventions stopped, the rates of malaria in the groups were similar over the next year.

Notably, tests performed on the day malaria was diagnosed suggested that a complete dose of DP hadn’t been given to the infant in the previous month in half the malaria cases. These findings suggest that DP is a promising long-term preventative treatment for malaria in infants. However, ensuring proper dosing may be a challenge. Further studies will also be needed to clarify the long-term safety and efficacy of DP treatment.

YOU MAY ALSO LIKE

Surprising enzymes discovered in giant ocean viruses

Results of a new study led by researchers at the Woods Hole Oceanographic Institution and Swansea University Medical School increase our knowledge of viruses -- in the sea and on land -- and their potential to cause life-threatening illnesses.

Researchers Discover Microplastics in 100 Percent of People Studied

In the first study of its kind, Austrian researchers have tracked the movement of microplastics into human beings. The results show that the plastic that is a ubiquitous element of human life is now also a constant element in the human body.

Interplay between mitochondria and the nucleus may have implications for changing cell’s ‘batteries’

Mitochondria, the ‘batteries’ that produce our energy, interact with the cell’s nucleus in subtle ways previously unseen in humans.

TRAPPIST-1 is Older Than Our Solar System

Scientists now have a good estimate for the age of one of the most intriguing planetary systems discovered to date -- TRAPPIST-1, a system of seven Earth-size worlds orbiting an ultra-cool dwarf star about 40 light-years away.

Previously unknown mechanism causes increased forest water use

Researchers have discovered a previously unknown mechanism that causes increased water use in forests, advancing our understanding of forest water cycles and highlighting threats to plants from water stress, as happens from acid rain.

Born during a drought: Bad news for baboons

After the plains of southern Kenya experienced a severe drought in 2009 that took a terrible toll on wildlife, researchers looked at how 50 wild baboons coped with the drought, and whether the conditions they faced in infancy played a role.