Population Booms Result In Parasite Abundance

Environmental changes, impacted largely by human population growth, could be directly resulting in a massive spike in diseases caused by parasitic flatworms, a new study suggests. This is alarming news, as recent reports indicate that the world population is living longer and growing quickly.

The study, published in Trends in Parasitology, details how researchers from the National Museum of Natural History assessed anthropogenic changes in Africa's Lake Malaŵi, determining the driving forces behind a remarkable increase in urogenital schistosomiasis cases in the region.

According to the World Health Organization (WHO), an estimated 249 million people required preventative treatment for shistomsomiasis back in 2012. However, only a fifth of that population was treated after becoming infected with the disease. This is largely because the disease - which is caused by parasitic worms - is most common in remote and poor regions with limited access to adequate medical care.

Smithsonian researchers estimate that recently, the number of people infected is rising, with at least 600 million people facing a considerable risk of contracting the disease annually. According to a Smithsonian press release, around Africa's Lake Malaŵi alone, 73 percent of villagers and 94 percent of schoolchildren have reportedly become infected with the parasite-borne disease, suggesting an alarming spike in the parasite population

Examining environmental changes around the region, the researchers determined that increased agricultural activates in the area have lead to an influx of soil erosion, creating ideal nutrient-rich sandy sediments along shorelines that the parasites thrive in.

The agricultural changes occurred as the region's number of people have doubled in the last thirty years. In fact, a WHO report indicates that recent global gains in life expectancy were largely driven by child survival in third-world regions such as sub-Saharan Africa.

"An important reason why global life expectancy has improved so much is that fewer children are dying before their fifth birthday," Dr Margaret Chan, WHO Director-General, said in a recent news release.

Overfishing to feed these growing numbers has also led to a massive decline in the disease-causing worm's few natural predators.

Study lead Bert Van Bocxlaer explained that increased population numbers for both people and the parasite means a sudden and great need for prevention programs in the region.

"Decreasing the transmission of this infectious disease will require an integrated control program for schistosomiasis, including community-based health education with efforts toward more sustainable resource use," he said in a statement.

The study was published in Trends in Parasitology, on May 20.