Climate and Health

Although global warming may bring some localized benefits, such as fewer winter deaths in temperate climates and increased food production in certain areas, the overall health effects of a changing climate are likely to be overwhelmingly negative. Climate change affects social and environmental determinants of health like clean air, safe drinking water, sufficient food and secure shelter. Moreover, extreme high air temperatures contribute directly to deaths from cardiovascular and respiratory disease, particularly among elderly people. In the heat wave of summer 2003 in Europe for example, more than 70 000 excess deaths were recorded (UNEP, 2004, March). Noticeably high temperatures also raise the levels of ozone and other pollutants in the air that exacerbate cardiovascular and respiratory disease.

Globally, the number of reported weather-related natural disasters has more than tripled since the 1960s. Every year, these disasters result in over 60 000 deaths, mainly in developing countries (WHO, 2017, July). Relating to the rising sea levels and increasingly extreme weather events particularly will destroy homes, medical facilities and other essential services. More than half of the world’s population lives within 60 km of the sea (Creel, 2003, September). And people may be forced to move, which in turn heightens the risk of a range of health effects, from mental disorders to communicable diseases. Increasingly variable rainfall patterns are likely to affect the supply of fresh water. A lack of safe water can compromise hygiene and increase the risk of diarrheal disease, which kills thousands children aged less than 5 years, every year. In extreme cases, water scarcity leads to drought and famine.

Floods are also increasing in frequency and intensity, and the frequency and intensity of extreme precipitation is expected to continue to increase throughout the current century. Floods contaminate freshwater supplies, heighten the risk of water-borne diseases, and create breeding grounds for disease-carrying insects such as mosquitoes. They also cause drownings and physical injuries, damage homes and disrupt the supply of medical and health services.

In addition, climatic conditions strongly affect water-borne diseases and diseases transmitted through insects, snails or other cold blooded animals. Changes in climate are likely to lengthen the transmission seasons of important vector-borne diseases and to alter their geographic range. For example, climate change is projected to widen significantly the area of China where the snail-borne disease schistosomiasis occurs (WHO, 2009). Malaria is strongly influenced by climate. Transmitted by Anopheles mosquitoes, malaria kills over 400 000 people every year – mainly African children under 5 years old (WHO, 2017, April).

To sum up, climate change normally affect all populations, but some are more vulnerable than others. People living in small island developing states and other coastal regions, megacities, and mountainous and polar regions are particularly vulnerable. Children, in particular, children living in poor countries that are among the most vulnerable to the resulting health risks and will be exposed longer to the health consequences.


Ottmar Edenhofer, R. P.-M. (2014). Summary SPM for Policymakers.

UNEP. (2004, March). Impacts of Summer 2003 heat wave in Europe. Environment Alert Bulletin.

Organization, W. H. (2017, July). Climate change and health. Media centre.

Creel, L. (2003, September). Ripple Effects: Population and Coastal Regions. Population Reference Bureau.

WHO. (2009). Climate change and health. WHO representative office China.

WHO. (2017, April). Malaria. Media Centre.

Travel Health – Leishmaniasis

There are dozens of countries in the old world and the new where you could get this disfiguring and potentially fatal disease. However in the past 2 decades most of the press has been on soldiers returning from the Middle East with this disease.

Leishmaniasis is not a single disease, but a group of syndromes due to a variety of species of this parasite. The affect different populations and are related to a characteristic vector, the sandfly.

The disease can range from asymptomatic infections to those causing significant illness and death. Disease can appear on a spectrum from a single skin ulcer to destructive lesions of the face to terminal organ disease.

Leishmaniasis is found in 88 countries worldwide and is broken down between Old World and New World.
Old World leishmaniasis is primarily found in parts of Asia, East and North Africa, Soouthern Europe and the Middle East.

New World leishmaniasis occurs from northern Mexico to northern Argentina, with rare cases reported in parts of Texas and Oklahoma. In South America it is not found in Chile or Uruguay.

Leishmaniasis in the US is typically indicative of immigration and travel.

The vector for this parasite is a phlebotomine sandfly. There are a few different species implicated depending on the part of the world.

Sandflies are very small (about 1/3 the size of a mosquito) and make no noise when flying. There bites can sometimes be painless; because of these reasons, many people have no idea they were bitten.

Even one bite of a sandfly can transmit disease, so travelers on short trips can still get infected.

When the female sandfly takes a blood meal it injects the parasite into the wound. Macrophages pick up the parasite and here they multiply until the cell bursts from overcrowding. The parasite goes on to infect more macrophages.

Some of these cells get carried to organs of the body including the liver, spleen and the bone marrow.

There are several species of Leishmania that cause disease in humans. The most common are Leishmania donovani (kala-azar), L. tropica (Baghdad boil), and L. braziliensis (espundia).

After getting bitten by a sandfly, disease may manifest itself from a week to many months later.

It starts out as a papule that enlarges to an ulcer. The ulcer can give the appearance of a volcano crater. Lesions may appear singly or multiple; many heal spontaneously within weeks to months to years.

Certain species (L. braziliensis) can disseminate to the mucosal areas of the face and mouth and cause very destructive and disfiguring disease (espundia) that appears similar to leprosy.

Kala-azar, an Indian name given to systemic type of the disease due to the grayish appearance of the body, can result in enlarged spleen and liver, diarrhea, emaciation, weakness and death.

Laboratory diagnosis I usually based on stained microscopic examination of the infected tissue. More specialized techniques like culture, molecular techniques and antibody detection are available but are not available in most diagnostic laboratories.

If you get leishmaniasis, your doctor should consult the Centers for Disease Control and Prevention (CDC) for treatment guidelines.

So you plan to travel to a part of the world where leishmaniasis is endemic, what can you do to prevent the horrible disease?

There is not a vaccine available to prevent leishmaniasis. The best way is to avoid sandfly bites. The CDC recommends the following:

Avoid outdoor activities, especially from dusk to dawn, when sand flies generally are the most active.

When outdoors (or in unprotected quarters):
o Minimize the amount of exposed skin. To the extent that is tolerable in the climate, wear long-sleeved shirts, long pants, and socks; and tuck your shirt into your pants.
o Apply insect repellent to exposed (uncovered) skin and under the ends of sleeves and pant legs. Follow the instructions on the label of the repellent. The most effective repellents are those that contain the chemical DEET (N,N-diethylmetatoluamide).

When indoors:
o Stay in well-screened or air-conditioned areas.
o Keep in mind that sand flies are much smaller than mosquitoes and therefore can get through smaller holes.
o Spray living/sleeping areas with an insecticide to kill insects.
o If you are not sleeping in a well-screened or air-conditioned area, use a bed net and tuck it under your mattress. If possible, use a bed net that has been soaked in or sprayed with a pyrethroid-containing insecticide (permethrin or deltamethrin). The same treatment can be applied to screens, curtains, sheets, and clothing (clothing should be retreated after five washings).

Effects of Global Warming on Health

A report of the effects of global warming on health published by WHO, has estimated around one million fifty thousand deaths every year due to global warming. Further it declared that each year five million people are suffering from health problems and diseases caused for this climate change. The rising concern over this matter has led many scientists and researchers to take a deeper look and prepare a plan to save human civilization from this onslaught.

Global warming has caused changes in temperature, ocean current flow, sea level, ecosystem, economy, agriculture, industry, settlements and related to all these – the health and living. Warmer world has created congenial atmosphere for the breeding and life expanse of various virus, bacteria and carriers of infectious diseases. Few evidences of global warming leaving negative effects on human health are:

– The vectors distribution of infectious diseases have been altered and increased.

– Heat wave resulted causing deaths.

– The seasonal distribution of few species of allergenic pollen has been changed.

– Various extreme conditions of global warming like droughts, heat and cold wave, storm, flood, fire will increase the death tolls as well as injuries and diseases.

– Malnutrition and disordered development of children.

– It will cause increase of malaria, diarrhea, cholera, dengue, encephalitis and other diseases.

– There will be constant rising rate of mortality due to ground level ozone related diseases as well as high cardio respiratory morbidity.

Thus it will affect human health in two major ways – with extreme weather condition and with rising infectious diseases. IPCC in a study of one of the most global warming affected area of Illinois, Chicago, has provided an apprehensive report that by 2020 extreme climate condition like heat wave will raise the climate average deaths to 400 and to 497 by 2050 from the present average of 191. European heat wave of 2003 is an example of its severity. Heat waves will even cause cardio respiratory complications resulting to high rate of deaths.

The results of ill health due to climate change and infectious diseases are already evident. Houston as well as many tropical countries are experiencing frequent outbreak of malaria, dengue and other encephalitis diseases. Even colder regions like Michigan, New Jersey, New York, Queens are severely suffering from malaria since 1990 as a result of global warming. McAllen of Texas also suffered a dengue epidemic in 1995. Florida, New Orleans, Arizona, Mississippi, Texas, Colorado, and California – all are experiencing encephalitis epidemic for global warming since 1987. According to IPCC, 65% of world population will suffer from high risk of infectious diseases in near future. The risk itself will be increased by 20%, only as a result of global warming.

Facing such an impending calamity due to climate change, the requirement of proper planning and organized adaptation to new and changing condition has received a new dimension. Along with urgent and basic adaptation practices to fight the immediate effects, a longer planning and elaborate gradual methodology are also necessary to address the severity of future conditions resulted from this. A participatory approach to the holistic development of human health is expected to sober down the effects of global warming on health to some extent.