Researchers from the Burnet Institute and the University of Melbourne believe the discovery could enhance the hopes of survival in the 85 million pregnancies exposed to malaria globally every year.
Philippe Boeuf, the lead researcher on the study, said that placental malaria is a major cause of low birth weight, which is a major risk factor in 80 per cent of neonatal deaths.
Children born at a low weight are also at a higher risk of intellectual development issues and are more susceptible to chronic diseases such as diabetes in adulthood.
“Before now, no one understood the link between being infected with malaria in pregnancy and having an increased risk of delivering a low birth weight baby,” Boeuf said in a media release on Wednesday.
“But we’ve identified the first mechanism that links the two, and this gives us the opportunity to try to improve fetal growth, and therefore, birth weight.
“Because low birth weight is the main cause of neonatal death, if we improve the birth weight, this could have a significant impact on neonatal survival, and allow a healthier adult life.”
The researchers discovered that inflammation caused by malaria disrupts the mTOR signalling pathway which impairs the placenta’s capacity to deliver amino acids, a major factor in foetal growth, to the foetus.
The discovery of mTOR inhibition gives scientists the opportunity to supplement the pathway, restroing its activity to normal, Boeuf said.
“There have been quite a few trials of nutritional supplementation of malaria-exposed pregnant women that had relatively modest impact on birth weight. We think that’s because those interventions haven’t been targeted specifically at mTOR,” Boeuf said.
“The view of most of these interventions has been, well, these women and/or their fetuses are not getting enough nutrients, therefore if we give mothers dietary supplements, that should improve birth weight, but results have largely been inconsistent.
“The approach we are taking is, OK, we know that mTOR inhibition appears to be a driver of low birthweight, so let’s research ways to activate mTOR, and those that show any effect, we’ll take further and hopefully to implementation.”
Malaria is a mosquito-borne infectious disease affecting humans and other animals caused by parasitic protozoans (a group of single-celled microorganisms) belonging to the Plasmodium type. Malaria causes symptoms that typically include fever, fatigue, vomiting, and headaches. In severe cases it can cause yellow skin, seizures, coma, or death. Symptoms usually begin ten to fifteen days after being bitten. If not properly treated, people may have recurrences of the disease months later. In those who have recently survived an infection, reinfection usually causes milder symptoms. This partial resistance disappears over months to years if the person has no continuing exposure to malaria.
The disease is most commonly transmitted by an infected female Anopheles mosquito. The mosquito bite introduces the parasites from the mosquito’s saliva into a person’s blood. The parasites travel to the liver where they mature and reproduce. Five species of Plasmodium can infect and be spread by humans. Most deaths are caused by P. falciparum because P. vivax, P. ovale, and P. malariae generally cause a milder form of malaria. The species P. knowlesi rarely causes disease in humans. Malaria is typically diagnosed by the microscopic examination of blood using blood films, or with antigen-based rapid diagnostic tests. Methods that use the polymerase chain reaction to detect the parasite’s DNA have been developed, but are not widely used in areas where malaria is common due to their cost and complexity.
The risk of disease can be reduced by preventing mosquito bites through the use of mosquito nets and insect repellents, or with mosquito control measures such as spraying insecticides and draining standing water. Several medications are available to prevent malaria in travellers to areas where the disease is common. Occasional doses of the combination medication sulfadoxine/pyrimethamine are recommended in infants and after the first trimester of pregnancy in areas with high rates of malaria. Despite a need, no effective vaccine exists, although efforts to develop one are ongoing. The recommended treatment for malaria is a combination of antimalarial medications that includes an artemisinin. The second medication may be either mefloquine, lumefantrine, or sulfadoxine/pyrimethamine. Quinine along with doxycycline may be used if an artemisinin is not available. It is recommended that in areas where the disease is common, malaria is confirmed if possible before treatment is started due to concerns of increasing drug resistance. Resistance among the parasites has developed to several antimalarial medications; for example, chloroquine-resistant P. falciparum has spread to most malarial areas, and resistance to artemisinin has become a problem in some parts of Southeast Asia.
The disease is widespread in the tropical and subtropical regions that exist in a broad band around the equator. This includes much of Sub-Saharan Africa, Asia, and Latin America. In 2015, there were 214 million cases of malaria worldwide resulting in an estimated 438,000 deaths, 90% of which occurred in Africa. Rates of disease have decreased from 2000 to 2015 by 37%, but increased from 2014 during which there were 198 million cases. Malaria is commonly associated with poverty and has a major negative effect on economic development. In Africa, it is estimated to result in losses of US$12 billion a year due to increased healthcare costs, lost ability to work, and negative effects on tourism