Society is shaped in big part on the inherent nature of humans to stay healthy, survive, and live longer. Nowadays, in developed countries the leading causes of death and disability are cancer, diabetes, and cardiovascular diseases. Therefore, people start to take action to prevent such conditions by exercising regularly, eating healthier diets, and avoiding cancer causing agents. Another example on how disease and health shaped society was during the 1980’s; the spread of HIV/AIDS and other venereal diseases generated a great stigma and discrimination towards homosexuals, drug users, and sex workers. Years later, improvements in education and the increased use of prophylactics allowed for contingency, mainly in developed countries, of HIV.
There are also diseases that trap society in a circle of disease and poverty, these are the neglected tropical diseases (NTDs). The name NTD is given by the fact that this group of infectious diseases afflict one billion people in the tropical regions which include East and South Asia, Africa, and Latin America (http://www.cdc.gov/globalhealth/ntd/diseases/ntd-worldmap-static.html) especially in rural communities away from big cities where most of healthcare is focused. NTDs include helminth, protozoan, bacterial, and viral infections; out of which ascariasis, hookworm infection, trichuriasis, schistosomiasis, and dengue are the top most prevalent ones. These different infectious diseases share a geographic overlap as well as impact the health and socioeconomic status of the regions where endemic. The characteristic features of NTDs is that they have a high morbidity but low mortality, are linked to affecting the “world’s poorest people”, cause disability and disfigurement, and promote poverty. As the majority of NTDs are caused by parasitic organisms, hence the high morbidity low mortality of this diseases due to parasites having tremendously evolved to survive as long as possible inside their host, but I will continue on this topic on parasitism for a later time. When comparing NTDs to other infectious diseases such as HIV or malaria, NTDs may not seem as devastating as they truly are. In fact, about 1 million people die every year form HIV/AIDS while only around 550, 000 people die annually from a NTD, thus further diminishing the importance of NTDs. However, when considering the number of life years lost to disability caused by the disease, NTDs are of enormous public health concern. Because of the life years lost to disease, NTDs have adverse socioeconomic effects in that they bury the affected region in a state of poverty and disease. For example, hookworm infection and schistosomiasis are known to cause iron deficiency anemia, a condition which severely weakens the affected person. This weakened health status leads to reduced cognitive ability and poor school performance in children, as well as reduced workforce productivity. Another example is the disease filariasis, which in some cases leads to elephantiasis, a disfiguring condition which limits a person’s ability to move and therefore to work. Onchocerciasis and trachoma diminish visibility leading to complete blindness thus incapacitating a person from their normal activities. These diseases go even deeper as they also impact the psychological state of the afflicted person.
While this groups of diseases may sound exotic, ancient, or even “dirty”, the fact is that they exist and affect almost one third of the world population living in already precarious conditions. A great deal of effort has been implemented in containing and preventing NTDs. In fact, vector control using insecticides, improved sanitation and hygiene, mass drug administration, and public health are measures that have already taken place in NTD prevalent regions, yet these diseases continue to be a major health concern and socioeconomic burden in the affected regions. Of course there is no single measure that will stop the spread of these diseases. A successful approach will require to combine all current prevention methods as well as novel approaches such as vaccination and improved drug therapies.
The main 17 NTDs:
- Ascariasis
- Hookworm
- Trichuriasis
- Schistosomiasis
- Lymphatic filariasis
- Onchocerciasis
- Food-borne trematodiasis
- Cysticercosis
- Echinococcosis
- Chagas disease
- African trypanosomiasis
- Trachoma
- Buruli ulcer
- Leprosy
- Yaws
- Dengue
- Rabies
To learn more please visit: http://www.who.int/neglected_diseases/diseases/en/
Parasites and Us 