infectious disease

Wildfire Smoke And Dangerous Microbes | Earth Wise

February 12, 2021 By EarthWise Leave a Comment

The worsening severity of wildfires across the globe is a major public health concern. The pulmonary and cardiovascular consequences of wildfire smoke inhalation have been well researched and have been an increasing focus for officials in places like California, other western states, and Australia. More recently, another public health concern has emerged related to the fact that wildfire smoke can carry microbes that cause infectious diseases.

A new analysis, published in the journal Science, points out that the risk of potential infection from airborne microbes has not been the subject of much research.

The fungus coccidioides, for example, becomes airborne when soils are disturbed by fire. When this fungus is inhaled, it can cause Valley fever, an infection with flu-like symptoms that sometimes progresses to pneumonia or meningitis. Inhalation risk of these microbes is highest closest to fires, so coccidioidomycosis is listed as a professional risk for firefighters.

A recent study found an increase in cases of invasive mold infection, aspergilliosis, as well as cases of coccidioidomycosis at hospitals within 200 miles of major wildfires in California.

Wildfire smoke has been shown to carry airborne particles of fungal and bacterial cells, hitching a ride on water vapor or charred carbon, over thousands of miles. Some microbes in soil appear to be tolerant of or even thrive under high temperatures following wildfires.

A multidisciplinary research collaboration is needed to better understand the relationship between microbes, wildfire, and public health. Such knowledge is increasingly vital as severe wildfires become seasonal norms in parts of the world such as the United States and Australia.

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Wildfire Smoke Can Carry Dangerous Microbes Thousands of Miles, Scientists Warn

Photo, posted September 9, 2020, courtesy of Christopher Michel via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Livestock Expansion And Global Pandemics | Earth Wise

August 18, 2020 By EarthWise 1 Comment

The domestication of cows, pigs, chickens, and other animals as livestock for their meat, milk, and eggs was historically revolutionary. It boosted food security by giving people a readily-available means of feeding themselves as opposed to more traditional methods such as hunting and fishing.

But animal agriculture has plenty of drawbacks. The industrialization of animal agriculture has led to horrendous conditions. Animals are kept in huge quantities and packed together with little regard for their health and welfare. This approach to agriculture is simply designed to maximize production while minimizing costs.

With its chemical inputs and toxic outputs, intensive animal agriculture is also a major threat to the environment. In fact, it’s a major driver of habitat degradation and biodiversity loss all around the globe.

But it’s not just animals and the planet that pay a price. Humans have inherited several lethal pathogens from livestock over the years, including the influenza virus that likely jumped to humans from poultry.

According to a study recently published in Biological Conservation, there is a connection between the global increase in the emergence of infectious diseases and epidemics, the accelerated loss of biodiversity, and the expansion of livestock. In the study, the research team from the Institute of Evolution Sciences of Montpellier cross referenced databases on human and animal health, livestock expansion, and biodiversity loss between 1960-2019. The team found that the number of epidemics identified in humans increased in correlation with both biodiversity loss and livestock expansion.

In the era of COVID-19, it’s important to understand how global livestock expansion directly threatens both human health and the health of the planet.

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Livestock expansion is a factor in global pandemics

Photo, posted July 22, 2018, courtesy of Artem Beliakin via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Fighting Malaria With Gene-Drive Technology | Earth Wise

June 8, 2020 By EarthWise Leave a Comment

Malaria continues to be a major health hazard throughout the tropical and subtropical regions of the world. There were 228 million cases of malaria in 2018 and over 400,000 deaths.

Malaria is a mosquito-borne infectious disease spread by 40 of the world’s 3,500 mosquito species. So, efforts to control mosquito populations are the primary strategy to eradicate malaria.

A team led by Imperial College London has created a genetic modification that distorts the sex ratio of a population of Anopheles gambiae mosquitoes using “gene drive” technology. The modification works by using a DNA-cutting enzyme to destroy the X chromosome during the production of sperm, which leads to predominantly male offspring, since females require two X chromosomes. The modification is coupled to a gene drive to allow it to spread through a population in a very effective way. A gene drive is a genetic engineering technology that propagates a particular modification by assuring that a specific form of a gene (or allele) will be transmitted with far more than the natural 50% probability.

The result of this is that mosquitoes produce more male offspring, eventually leading to no females being born and a total collapse in the population. The mosquitoes studied are the main malaria vector in sub-Saharan Africa. The hope is that mosquitoes carrying a sex-distorter gene drive would be released in the future, spreading the male bias with local malaria-carrying populations and causing them to collapse. Only female mosquitoes bite and take blood meals. If the gene drive technology works in the field, it could be a game-changer in the fight to eliminate malaria.

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Malaria mosquitoes eliminated in lab by creating all-male populations

Photo, posted June 20, 2014, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Social And Ecological Underpinnings Of Infectious Disease

April 1, 2016 By WAMC WEB

When it comes to addressing infectious disease, we have a short attention span. Forces are mobilized when we’ve crossed a tipping point, and demobilized when the immediate threat has passed. In the case of Zika, the World Health Organization declared a public health emergency based on a strong association between Zika infection and microcephaly in newborns and a spike in Guillain-Barré syndrome.