Manmade Triggers Behind the Zika Virus

by Katy Schaefer

It seems that every year has its own health crisis. In the past ten years, we have seen panic from SARS, Mad Cow Disease, Bird and Swine Flu just to name a few.This year seems to be the year of the Zika Virus. Although the disease changes all the time, the panic is always the same. People want to know where it comes from, how it can be treated, and how it can be transmitted. But these aren’t the questions we should be asking. What we really need to know is what is causing the disease and is there a way we can make ourselves less susceptible to it? Recently scientists have been looking into the rising rates of diseases like Zika and Malaria and have found a surprising result. We might be doing this to ourselves, here’s how.

The first confirmed case of the Zika virus came out of Brazil in May of 2015. It is passed through mosquito bites and common symptoms include fever, rash, joint pain, and conjunctivitis. Hospitalization is uncommon, but there is currently no cure and there were reported links between the disease and birth defects in children born to infected mothers. However, most cases of Zika have been sprouting up primarily in South America, the Caribbean, and Africa. Researchers want to know why here, and why now? It is becoming clear that human intervention in the natural environment is impacting not only the viruses that infect our communities, but the insects that spread them.

The Aedes aegypti mosquito, also infamously known for spreading diseases like dengue and yellow fever, is also carrying and spreading Zika. This particular mosquito thrives in unique environments. “It doesn’t live in the ground, or in swamps, or any other kinds of places where you would normally find mosquitoes… So humans have created an environment for it to proliferate, by having all of these water containing containers around, and the mosquito has adapted so well…it’s really kind of a human parasite. It’s like the cockroach of the mosquito world” said Durland Fish, professor of microbial diseases at Yale University. Namely, they survive in tires, cans, and plastic containers. These are symptoms of not only poverty, but environmental degradation. However, the poor aren’t the only people being affected. The mosquitos can live in flower pots or water collected on a pool cover. Of course there are other factors that contribute to the spread of diseases like this, such as planes that can carry people and their diseases across oceans. Poverty that limits peoples ability to prevent and treat illness in a timely fashion to keep it from disseminating. But it’s more about the fact that while these factors have been discussed very openly, the environmental causes have been neglected.

An often looked over cause is the building of dams. While there have been widespread complaints about the ways damming a river might effect its ecosystem, with regards to the spread of disease, it is most problematic in that it brings people and disease together. Schitsomiasis is spread by parasite crying snails that live in freshwater. The Schistosomiasis outbreak in Ghana was catastrophic and widely blamed on the emergence of a dam. “More than 200 million people are infected worldwide. In terms of impact, this disease is second only to malaria as the most devastating parasitic disease. Schistosomiasis is considered one of the Neglected Tropical Diseases (NTDs)” (http://www.cdc.gov/parasites/schistosomiasis/). Malaria alone is responsible for 1.1 million deaths per year and the building of dams only exacerbate the issue. Because the water is still and calm once it has been dammed, it acts as a habitat for the mosquitos.

Another trigger for the spread of diseases like Zika has been the rampant cutting down of forests. The removal of trees that used to act as a sort of barrier between people, animals, and insects. With the massive removal of these trees, the way that we interact with these living creatures is changing, and making humans more susceptible to disease. “In Malaysian Borneo over the past few years, scientists started to suspect that’s what was happening when they noticed an uptick in a form of malaria, caused by the parasite Plasmodium knowlesi, historically found mainly in macaques. In the last decade, research has shown that P. knowlesi has become the leading cause of human malaria in the region” (Chelsea Harvey). Although the parasite is found in macaques, it is still passed by mosquitos that live on, or near them. Scientists concluded that it was an environmental disturbance that brought people and these parasites together. And indeed it was, “forest clearing and development are actually causing people and mosquitoes and macaques to be in much closer contact than before” said Kimberly Fornace, research fellow at the London School of Hygiene and Tropical Medicine. Because of something called the “edge effect”, when ecosystems experience a high level of change at the edges of the habitat, these are also the most critically challenged areas when it comes to the spread of disease, where people and macaques come into contact. Additionally, the fact that these deforested areas tend to be hotter is affecting the spread of these diseases. Because they lack the cooling benefit of the trees, certain parts of the mosquito life cycle have been changing. In particular, the blood feeding and egg laying cycle of female Anopheles gambiae is shortened by up to 52%, greatly affecting the overall population of the insect.

Lastly, climate change has been influencing the survivable temperatures globally, broadening the regions that these mosquitos can live in. “Globally, temperature increases of 2-3ºC would increase the number of people who, in climatic terms, are at risk of malaria by around 3- 5%, i.e. several hundred million,” concludes the WHO. “Further, the seasonal duration of malaria would increase in many currently endemic areas.” Beyond this, mosquitos reproduce more quickly, and bite more frequently in the heat.

It is clear that there is a relationship between the environment and the spread of diseases like Schitsomiasis, Zika, and Malaria. The rising temperatures have expanded the regions that mosquitos are able to occupy. the damming of rivers has created massive pools of still water that not only attract mosquitoes, but bring parasite infected snails to the people that swim in it. Yet, it is still one of the least talked about factors in the spread of disease. It has become clear that we need to think about disease from a more ecological standpoint. Rather than rushing into the vaccination process, we should think more critically about the environmental factors that could be preventative. With these diseases in particular, it all comes down to the mosquitos, and treating them is just about as important as treating the people.

 

LINKS: https://www.washingtonpost.com/news/energy-environment/wp/2016/02/03/the-hidden-environmental-factors-behind-the-spread-of-zika-and-other-deadly-diseases/

https://www.washingtonpost.com/news/energy-environment/wp/2015/12/21/by-cutting-down-forests-humans-may-be-giving-themselves-malaria/?tid=a_inl

http://www.cdc.gov/zika/geo/index.html

Gruesome Virus attacks Sea Turtles in Florida

by Pushan Hinduja

Climate change and pollution around the world are causing marine mammals to see an increase in illness and disease. More specifically, Lorraine Chow, discusses a rising number of sea turtles affected by fibropapillomatosis (FP), a disease similar to herpes, in the waters around Florida. Chow believes that the possible culprits for the observed rise in affected turtles are increased pollution and the warming of the waters. Between 2012 and 2014, the Turtle Hospital rescue and rehab facility based in the Florida-Keys has seen an increase in the number of turtles admitted, from 56 to almost 100. FP is a virus that primarily causes tumors to grow on the exterior of a turtle’s body. In some cases, however, FP can cause tumors so large that they prevent a turtle from being able to swim, see, or avoid predators. The hospital tries its best to find turtles and cut off the tumor growths with a carbon dioxide laser, however the process and sheer volume they are dealing with doesn’t make it easy. Although the survival rate after the surgery is almost 90 percent, some surgeries can take almost “half a year,” given the huge number of tumors some turtles can have; additionally, because many turtles are already sick, only one in five actually gets to return to the wild after the surgical procedure. Continue reading

Improving Food Yield in Africa

by Tyler Dean

According to an article in Appropriate Technology in 2014, climate change is predicted to increase the number of malnourished people in Sub-Saharan Africa by nearly forty percent by 2050, from the current 22 million, to 355 million. In East and Central Africa, suitable areas for growing beans could decline up to eighty percent, while areas suitable for growing bananas could decline twenty-five percent. In aggregate, climate change will severely lower crop yields by adversely affecting the length of the growing season and rainfall. It is crucial for African farmers to switch to “climate- smart agriculture”(CSA). CSA will increase resilience by allowing farmers to adapt to climate change and reduce their greenhouse gas emissions. The government has implemented monitored subsidy programs, consultants and aggregators in order to improve production and instill confidence in Africa’s farmers. Continue reading

Using Cloud Computing to Monitor Climate Change

by Tyler Dean

The department of Biomedical Engineering at the Adhiyamaan College of Engineering has proposed a system that provides monitoring benefits to a large number of users by deploying a collection of observed data over a long period of time. The system uses a combination of advanced technologies to collect comprehensible environmental data that can be accessed from any location online. The system requires sensors for air pollution, temperature and humidity of a selected place. The data acquisition system acquires the data of temperature, humidity, pollution of air including Illumination, dust, carbon dioxide, ultraviolet, wind direction, wind speed, air pressure and the altitude from remote sensing areas .The system can be used for intrusion detection, used to remotely monitor the conditions of a place, to determine the habitat of a place and to field conditions to specify which cultivation is suitable for a region. Continue reading

Climate Change and Its Effect on Human Health.

by Tyler Dean

Anththropogenic greenhouse gas emissions are leading to climate changes in temperature, precipitation, humidity and/or wind patterns(Natural clmate forcing also contribute to this). Climate changes yeild environmental effects that cause adaptation and health effects. The environtmental effects include: change in frequency, severity and geography of extreme weather events, ecosystem changes on land and sea that effect numerous species, rises in sea level that cause storm surges and salination of costal land and freshwater, and environmental degradation on land, costal ecosystems and fisheries. The health effects include: thermal stress that causes deaths, illness and injury from floods, storms, cyclones and bush fires (thermal stresses also effect food yields), microbial proliferation that leads to food poisoning and unsafe drinking water, increase in vector-pathogen-
host relations and in infectious disease geography/seasonality, impaired crops, livestock and fisheries yield that leads to impaired nutrition, health, survival and loss of livelihood that leads to poverty and adverse health such as mental health, infectious diseases, malnutrition and other physical risks. The easiest to define climate-health relationships are related to heat waves. The harder to define climate-health relationships are from “changes in regional food yields, disruption of fisheries, loss of livelihoods, and population displacement (because of sea-level rise, water shortages, etc).” The results from this research on climate change and its effect on future human health represent an imperative contribution to international and national policy debates. 

McMichael, AJ & Woodruff, RE Climate Change and Human Health: Present and Future Risks Lancet 367.68079-3 (2006): 859-69.

http://www.sciencedirect.com/science/artic.le/pii/S0140673606680793

Extreme Temperatures Increase the Incidence of Tuberculosis in Japan

by Allison Hu

Tuberculosis (TB) is a major global public health problem – it affects millions of people annually and ranks as the second leading cause of death from an infectious disease worldwide (World Health Organization (WHO) 2013) (Onozuka et al. 2014). The WHO estimated that there were 8.6 million new TB cases and 1.3 million TB deaths in 2012. The worldwide TB incidence rates peaked in 2004 and have decreased at a rate of less than 1 % per year since then. Thus, the overall worldwide burden continues to rise as a result of the rapid growth of the world population. TB is a leading cause of death in people in the most economically productive age groups. Furthermore, with growing concerns about global climate change, many studies have focused on associations between weather variability and the fluctuations of infectious diseases and have suggested that weather factors play an important role in their incidence, indicating the possibility of multiple functional pathways. Continue reading

Drought Impacts on Children’s Respiratory Health in the Brazilian Amazon

by Allison Hu

Drought conditions in Amazonia are associated with increased fire incidence, enhancing aerosol emissions with degradation in air quality. On average, the Brazilian Amazon experiences extreme flood or drought once every ten years (Smith et al. 2014). However, in 2005 and 2010, only a five-year period, two mega droughts have occurred in the Amazon. Although the 2005 drought was the first in 100 years, the second drought occurred only five years later in 2010. Environmental impacts of drought include tree mortality from water deficits and social impacts include lack of food, lack of medical supplies, isolation of communities, and even health problems. Health issues arise because during droughts, wind erosion in deforested areas causes soil particles and microbes to be blow into the air, creating and exacerbating respiratory problems and triggering allergies. Furthermore, droughts have a positive correlation with fire incidences – in Amazonia, droughts can lead to over 30% increase in fire occurrence. This too leads to more hazardous health issues as smoke from fires tends to carry fine Particulate Matter particles (PM2.5), that when inhaled, may reach deep into the lungs, causing irritation of the throat, lungs, and eyes. The primary location for fires within the Amazon is centered around the southern and eastern periphery where 85% of fires occur, emitting as much as 300-600 mg/m3 of PM10 per 24 hours and up to 400 mg/ m3 of PM2.5 per 24 hours during the dry season (Smith et al.). Measurements carried out in southern Amazonia demonstrated that exposure to PM2.5 have positive associations with children’s respiratory health. This increase of 10 mg/m3 PM2.5 has shown simultaneous correlation with a 5.6% and 2.9% increase in outpatients in Rio Branco, Acre State, and Alta Floresta, Mato Grosso State, respectively. Continue reading