In the early years of 2022, malaria cases were taking place in the Ethiopian city of Dire Dawa, when more than 2,400 people fell ill. The spike in infections was the work of an invasive species of squash that is spreading across Africa, scientists report.
The discovery, which was presented in Seattle, in November, at the annual meeting of the American Society of Tropical Medicine and Hygiene, testifies that the vector of invasion of malaria outbreaks can act. Worryingly, the species can thrive in urban environments, potentially bringing the threat of malaria to many thousands more people across the continent.
Stephen’s elephant A mosquito in India and the Persian Gulf, where it is a major carrier Plasmodium parasites that cause malaria in humans (SN: 10/26/20). In Africa, it is the primary malaria vector Gambian elephant. A. Stephens in Djibouti in 2012 it was first reported on the African continent. Since then, the species has spread to other African countries such as Ethiopia, Somalia, and Nigeria.
It’s not clear what kind of burden malaria might throw on Africa, says Fitsum Girma Tadesse, a molecular biologist at the Armauer Hansen Research Institute in Addis Ababa, Ethiopia. Eighteen years after the mosquito’s arrival in Djibouti, the country reported a 40 percent increase in annual malaria cases, Tadesse says. But no one had connected himself A. Stephens to increase
So when malaria cases suddenly rose in Dire Dawa — from 27 cases to 260 in three weeks in early 2022 — Tadesse and his team jumped in to investigate.
The researchers studied 80 patients in the city who sought malaria treatment at a local or university clinic, as well as 210 patients who sought treatment for other reasons and family members of malaria patients. The team also surveyed the neighborhoods of the patients for the presence of mosquito adults and larvae within a 100-meter radius of families, or in the case of students who visited the clinic, dormitories.
The team found malaria patients primarily at water sources used by mosquito infestations A. Stephens. Families and dorms are located close to the water A. Stephens Larvae were 3.4 times as likely as those not close to such water sources to have a family member or dorm member test positive for malaria. Most of the adult mosquitoes the team caught — 97 percent — were invasive species, the only mosquito species the researchers found carrying them. Plasmodium parasites
A. Stephens “It prefers to generate water storage that is typically common in rapidly expanding urban settings,” Tadesse says. A native species of mosquito; A. gambiaeit tends to use natural water sources, such as small ponds, which are more common in rural areas, he adds. The concern then is that with expansion A. Stephens In the context of urbanization in Africa, the mosquito could use many new sources of water storage.
“This problem of malaria is expanding from a predominantly rural problem to an urban problem,” says Teun Bousema, an epidemiologist at Radboud University in Nijmegen, the Netherlands.
A 2020 study from another research group estimated that if the mosquito invasion were to spread widely across the continent, an additional 126 million people in cities could be at risk of contracting malaria.
“Propagation” Stephen’s elephant about the fact that this species has several characteristics that are difficult to control,” says Tanya Russell, a medical entomologist at James Cook University in Townsville, Australia, who was not involved in the study. Insects can not only lay their eggs in an almost readily available water source, but the eggs can also be dried for long periods of time. “This is very inappropriate for malaria carriers.”
Insecticide-treated bed netting and household residual insecticide spraying are the primary vector control approaches for malaria-carrying pumpkins, Russell says. But because A. Stephens It also bites outside, as a widespread mosquito blunts the effectiveness of these tools.
The next key step, Tadesse says, is intervention to reduce the transmission of the deadly parasites, including the larval stage of the mosquito, along with encouraging businesses and communities to cover safe water containers to prevent mosquitoes from laying eggs.
“The window of opportunity to do something about these species closes,” Bousema says. “Yes, I think this calls for very urgent action.”
#major #malaria #outbreak #Ethiopia #caused #invasion #Asian #mosquito