Some 60 percent of the diseases that affect people spend part of their life cycle in wild and domestic animals.The research work is urgent — land development is rapidly taking place across regions with high biodiversity, and the greater the number of species, the greater the number of diseases, scientists say.Flowing water is dammed up, deliberately and inadvertently, and pools.
Some 60 percent of the diseases that affect people spend part of their life cycle in wild and domestic animals.The research work is urgent — land development is rapidly taking place across regions with high biodiversity, and the greater the number of species, the greater the number of diseases, scientists say.Tags: Amway India Business PlanGreat Gatsby And The American Dream EssayEssays On Tolerance Is The Strength Of SocietyAdmission Essays NursingEssays On Cars HistoryRationale For DissertationDream In My Life EssayArchaeology Dissertation Ideas
In response to a push to use bed nets to prevent nighttime bites in malaria-prone regions of the world, for example, researchers are seeing a change in the time of day mosquitoes bite — many now target their human quarry in the hours before bed.
A study by Vittor and others found that one malaria-carrying mosquito species, in 2006.
The most recent example came to light this month in the , with researchers documenting a steep rise in human malaria cases in a region of Malaysian Borneo undergoing rapid deforestation.
This form of the disease was once found mainly in primates called macaques, and scientists from the London School of Tropical Medicine and Hygiene wondered why there was a sudden spike in human cases.
As agriculture replaces forest, “re-growth of low lying vegetation provides a much more suitable environment” for the mosquitoes that carry the malaria parasite, Vittor says.
The link between deforestation and increases in malaria has been known for some time, but research in the last two decades has filled in many of the details.“The species that survive and become dominant, for reasons that are not well understood, almost always transmit malaria better than the species that had been most abundant in the intact forests,” write Eric Chivian and Aaron Bernstein, public health experts at Harvard Medical School, in their book .“This has been observed essentially everywhere malaria occurs.” Mosquitoes can adapt fairly quickly to environmental change.Deforestation creates other conditions conducive to mosquito breeding.Leaves that once made streams and ponds high in tannins disappear, which lowers the acidity and makes the water more turbid, both of which favor the breeding of some species of mosquito over others.“In the forest, we found almost no breeding whatsoever, and no biting by the adult mosquitoes,” Vittor said.That’s probably because the ecology of the deforested landscape — short vegetation and deep water — favored their breeding, and they need human blood to grow their eggs.The types of mosquitoes that do well in this radically altered ecosystem are more “vector competent,” which means their systems are particularly good at manufacturing a lot of the pathogen that causes malaria.A study in Brazil, published in the in 2010, found that clearing four percent of the forest resulted in a nearly 50-percent increase in human malaria cases.The Zika virus, for example, which is believed to be causing microencephaly, or smaller than normal heads, in newborns in Latin America, emerged from the Zika forest of Uganda in the 1940s.Dengue, Chikungunya, yellow fever, and some other mosquito-borne pathogens likely also came out of the forests of Africa. What research is demonstrating is that because of a complex chain of ecological changes, the risk of disease outbreaks, especially those carried by some mosquitoes, can be greatly magnified after forests are cleared for agriculture and roads.