Dr Rajkumar Singh
A lot of research has been done on the effects of climate change on infectious diseases which showed its several negative impacts on human health system. It not only increases existing inequalities but also enhances the chances or likelihood of being certain new kinds of infectious diseases, posing a fresh challenge for the health system of a nation and the globe as well. Among the infectious diseases, some like malaria and dengue are directly affected by the climate change with extreme weather conditions and higher temperature. However, once control of any disease is no guarantee that it would not repeat in future, and normally, it repeats with some changed features, which brings for us and the health system new challenges to face and solve it. Climate change and human health: Extreme nature of weather , either hot or cold, compels our body temperature to adjust anyhow. The body feels a lot of difficulty in regulating its internal system as these differences in body’s internal settings and external environment directly impact cardiovascular and respiratory diseases. In particular, the respiratory diseases need quality air and as air quality becomes poor due to climate change. Climate change produces higher concentration of CO2, higher temperature and changes in precipitation. In addition, climate change affects vector-borne diseases by way of survival, distribution and behaviour of vectors such as mosquitoes, ticks and rodents. These vectors carry with them viruses, bacteria and protozoa and also transfer them from one person to another. The vectors and pathogens are also competent to adapt themselves by climate fluctuations posing various challenges in terms of shifting and expanding their geographical locations. Vector-borne diseases are important because they have played a significant role in shaping the rise and fall of human civilizations all over the world. Thus, up and down in the climate is directly related to our existence and development of human history.
Changes in climate increase the global temperature and the record keeping of its fluctuating started in the US in the year 1895 and then onwards it increased from 1.3 Fahrenheit to 1.9 Fahrenheit. Later on, decades before in 1988, the World Health Organisation and United Nations Environment Programme established an Intergovernmental Panel on Climate Change to study further and know the relations between the climate change and human health. The IPCC, in its report submitted later, mentioned the potential health risks associated with the changes in climate. Thereafter, dozens of study have been conducted on global, regional and national levels to know more detail and understand the relationship between the climate and health. Virus-related diseases: There are two important diseases — Dengue and Ebola — coincide with climate change. Dengue is a potential virus transmitted by mosquitoes called Aedes Aegypti and first detected in the year 1943. It is deadly enough and has affected the people all over the world, especially those living in the warmer climate. It is also of two kinds-mild and severe. Mild symptoms of the disease include vomiting, rash, high fever, joint pain, eye pain, while in severe cases fever raises high and even causes death. The rising case of Dengue is closely related to the greenhouse gases and increase if earth’s temperature. The rising temperature normally affects the regions which are near the sea coast or water. Nearby waters absorb a lot of energy from the sun and release it in the form of vaporisation which causes heavy rain in the surrounding areas. The vaporisation brings further climate change, high raining seasons, temperature and humidity. All these circumstances are favourable for increasing the population of mosquitoes and ultimately for transmission of Dengue virus to people.
Next to Dengue, Ebola is the most fatal virus disease with about 40% death rate. It starts from the flu or cold caused by virus and soon took the form of global issue. Many researches and advances studies showed that deforestation in linked to the uptick in Ebola. In fact, the virus of this disease is commonly found in animals of the wild and due to large scale cutting of trees these animals began to come in contact of humans. The virus of Ebola transmits in human body when exposed to infected human fluids. The virus can also spread to another human when come in direct contact with the virus hosts blood, vomit, or feces. Wild animals also come in contact with human due to the drought and changing pattern of rainfall in the region. Many international organisations like WHO, the World Bank Group, Economic Community of West African States and World Food Programme are helping the Ebola victims by cash and kind. Several countries are also helping each other through sending doctors and other health workers. Other dangers ahead: In recent decades, several studies have indicated that due to climate change and rising temperature of the earth is associated with changes in the epidemiology of infectious diseases in future. In this warning there is a strong possibility of emerging the previously known or unknown infectious diseases because of warmer climates which needs in human an advanced immunity, which the latter lacks in general. Climate changes at large scale have given a chance to fungal diseases to emerge and re-emerge in the days to come. Although the humanity has faced several and fatal viral and other infectious diseases, there is no guarantee for the success in future. Every disease when comes brings new challenges for health workers and science community as well. It’s a wake up call for all of us to be prepared and take necessary steps in right direction.
— The writer is Professor and Head, P G Department of Political Science, Bihar, India.
