Diseases likely to be exacerbated by El Niño

Changes in climate and rainfall patterns triggered by El Niño have even affected hunting regimes for certain animals that favor the transmission and spread of infectious diseases in Latin America and the Caribbean. Polycystic echinococcosis can be fatal in the Amazon, a new study finds. (Read an inconvenient truth about the Fukushima Daiichi nuclear power plant dump)

Experts say El Niño and its climate change have affected incidence and distribution, especially of diseases transmitted by vectors such as rodents, mosquitoes and ticks.

El Niño and his temper

El Niño is characterized by warming waters in the central and eastern equatorial Pacific Ocean, causing winds to weaken and large amounts of hot water to stop circulating, releasing more heat into the atmosphere and favoring rainfall in the region. region. Meanwhile, in other regions, it also triggers drought.

Although it formed in the Pacific Ocean, it affects climates around the world. “In Latin America, El Niño has led to increased temperatures and rainfall along the Pacific coast, southern and southeastern Brazil, and northern Argentina, while causing drought in Central America, parts of the Caribbean, and northern South America,” noted. Christovam Barcellos, Department of Information and Health, Osvaldo Cruz Foundation (Fiocruz), Brazil.

These changes affect the incidence of infectious diseases, adds Paulo Altaso of the Institute of Physics at the University of São Paulo in Brazil. However, he noted that it’s hard to tell which ones will stand out because the weather isn’t the only factor. “Health risks associated with El Niño vary by region, country and time of year,” he told CNN Science Development Network.

In addition to the direct effects of climate on health, the study also identified indirect factors.Most recently published work on Proceedings of the National Academy of Sciences found in section Pan-Amazon El Niño can interfere with hunting patterns of certain animals by indigenous and rural populations, favoring the transmission and spread of polycystic echinococcosis.

This Neglected Disease Is Caused by a Worm Echinococcus Vogeliusually infecting cotton bales (Paka Rabbit) and agouti (Arthrin), are often hunted in the area.

Hunters often discard raw offal in the environment or use it as food for domestic dogs, “which can become infected and excrete eggs in their feces, contaminating soil, food and water for human consumption,” says the biologist Leandro Siqueira de Souza explains. From the Fiocruz Foundation, which studies the disease in northern Brazil.

The international study analyzed more than 400 cases of polycystic echinococcosis in the region and data on hunting activity recorded in 55 regions over the past 55 years.

Adrià San José of the Barcelona Institute for Global Health (ISGlobal) said: “In some areas, the drought caused by this phenomenon may affect fisheries, forcing locals to hunt pacas and agouti, thereby Increased risk of Vogelial contamination.”), Spain, one of the authors of the article.

“The Brazilian state of Aca and Peru are the areas with the greatest potential for parasite transmission,” another author of the study, ISGlobal’s Xavier Rodó, told SciDev.Net.

More parasites, viruses, bacteria and mosquitoes

El Niño also produces heavy rainfall and flooding, and increases water-related diseases such as schistosomiasis, hepatitis A and diarrheal diseases.

“In urban slums, these events can trigger outbreaks of leptospirosis due to poor garbage collection and poor drainage,” Creuza Rachel Vicente from the Department of Social Medicine at the Federal University of Espírito Santo told Brazil’s SciDev.Net.

These rainfalls lead to the formation of ponds where Aedes aegypti mosquitoes grow, the cause of dengue, Zika and chikungunya. “In dengue, warmer temperatures increase the rate at which the virus replicates (causes the disease), and it also increases the rate at which the vector survives, reproduces and bites,” said Rachel Lowe, a researcher at the London School of Hygiene and Tropical Medicine. , in U.K.

The incidence of dengue fever has increased significantly over the past two decades. In 2000, 505,000 cases were registered around the world, but in the first half of 2023, more than 3 million cases were registered in the Americas alone, surpassing the 2.8 million in 2022.

Brazil has more than 2.3 million cases, followed by Peru (more than 215,000) and Bolivia (more than 133,000). In Argentina, where the dengue fever epidemic is most severe, the latest epidemiological report shows that dengue fever has caused 66 deaths and more than 129,000 confirmed cases.

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