Medical geography is an important sphere of research that researches the impact of climate, water, and environment in the whole on an individual’s health. This field of science helps to make prognosis of the diseases spread implementing geographic techniques into the study of human health around the world. As a result, scientists of medical geography create geographic maps, showing the dispersion of diseases or even websites of traveler`s health helping tourists to be aware of the human illness development, and to take measures in order to prevent it.

Scientists distinguish three groups among major types of diseases: 1) infectious diseases caused by parasites (e.g. malaria); 2) chronic or degenerative diseases, causing long-term deterioration of the human body (e.g. cancer, heart disease); 3) genetic or inherited diseases (e.g. hemophilia, sickle-cell anemia, lactose intolerance, etc.).

Diseases transmitted by insects (ticks, mosquitoes, fleas, black flies, and sandflies) or house pets, snails or larger animals that carry protozoa, bacteria and viruses, are called vectored. Diseases carried from one host to the next one without any intermediate host (some touching, exhaling air, etc.) are said to be non-vectored. Disease organisms are also transmitted by non-biological or vehicle vectors (soil, water, food, and feces). The most frightening disease in the group of vehicle-vectored diseases is Cholera caused by the bacteria Vibrio cholera that exists naturally in rivers, estuaries, seas, and coastal waters. Transmission occurs while a person consumes contaminated water or food.

Cholera occurred in India until the beginning of the nineteenth century, and during the nineteenth century six cholera pandemics (epidemics of global proportions) spread through the Indian subcontinent. During these pandemics cholera spread to China, East Africa, Mediterranean Europe, Japan, and America.

After being absent for a century, on January 1991 cholera reemerged in the Western Hemisphere in Peru. The sea current El-Ni?o Southern Oscillation brought warmer water to the Peruvian waters, coupled with plankton blooms and amplified the pollution of the bacteria Vibrio cholera in the water with decreasing salinity.

Another geographical factor that caused the distribution of the disease is that the coastal area of Peru is deserted, and rivers that flow down from the Andes Mountains make oases with stagnant water. High population densities and water problems are favorable for the spread of bacteria. In addition, this water is used for irrigation by the farmers or, when water is scarce, sewage is used to fertilize fields, due to the farmers’ need to grow the kind of crops in a short period of time. As a result, they have high cash yields and at the same time contaminated food. Some experts have also blamed the large fishing industry of Peru, particularly seafood (fish, crab meat, etc.) infected with disease organisms.

Cholera is characterized by sudden onset, profuse painless watery stools, occasional vomiting, and if untreated, rapid dehydration (loss of skin plasticity, fast heart beat, low blood pressure, sunken eyes, and rapid weight loss), circulatory collapse, and death. In severe cases, mortality amount is 50 per cent. In 1992, the epidemic spread to 21 countries in South America. According to the Pan American Health Organization (PAHO) report, by the end of 1992, 391,000 cases of cholera and 4002 deaths were fixed in South America. In 1992, statistics reports about further 339,000 cases and 2321 deaths spreading over South America.

This disease is associated with poverty, deficit of pure water, poor sanitation and bad hygiene. Without proper human hygiene, filtration and chlorination of water supplies cholera can be a serious problem. In some countries, the peak of cholera is combined with the summer rains, when water sources are over contaminated.

The example of cholera in Peru in 1991 makes it obvious that, in addition to the environment, some socioeconomics factors make good conditions for epidemic increase. Thus, the overcrowding of the shanty towns and poor infrastructure leads to problems with the sick people transportation to hospitals, and disease diagnostic. Moreover, high level of inflation and unemployment, terrorism, political unrest effect on taking control measures and appropriate treatment with sick population.

As a result, the epidemic has disrupted the social and economic structure of Peru and caused panic among the population. According to the information of World Health Organization, the cholera outbreak in Peru in 1991 costs the country 770 million of dollars due to food trade embargoes and restricting on tourism.

In countries where people live on less than one dollar a day they cannot afford to use a water filter or fuel wood for boiling it and use contaminated water sources for bathing, drinking, and cooking. Therefore, some regions of the world (especially in South and Central Africa) have annual outbreaks of cholera.

In countries disposed to cholera outbreaks, government should take prevention and control measures, implement disease-control programs, control oral rehydration therapy program, invest into an epidemic field investigation service, and laboratory resources. Sanitation and drinking waters should be improved in poor countries. Among the modern instruments of fighting with this infection are water purification, oral rehydration therapy, prescription of antibiotics and the employment of cholera oral vaccines.

Nevertheless, cholera remains being the disease of hot temperature, because colder temperature causes the dormancy of the bacteria. It can be predicted, that global warming, due to changes in the balance between salt and fresh water, may cause next explosions of cholera in the Bay of Bengal, Indonesia, Egypt, Thailand, Mozambique and Nigeria.

Conclusion is based on medical geography researches, relied on the statistical modeling of spatial distribution of diseases and their diffusion in time and space. Health geography is both retrospective and perspective. As an old disease, almost forgotten, reemerged with new risks, influenced by climate changes, changes in a human lifestyle, urbanization, different genetic transformations and mutations, parasitic transformation, health geography with its analyses becomes relevant to promote health and provide care for the disease. Also, it integrates techniques of physical, biological, social sciences combined with spatial analyses while studying cultural-environmental interactions important to disease etiology. Thus, medical geography is interdisciplinary and holistic study of human health remains important and prominent today.

About the author: Jim Baker is a bachelor in English philology and literature at Oregon University. He is currently working as one of the best writers at the article writing He also studies feminine psychology