Tropical diseases are
disease
A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...
s that are prevalent in or unique to
tropical
The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in
the Southern Hemisphere at S. The tropics are also referred to ...
and
subtropical
The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Geographical z ...
regions. The diseases are less prevalent in
temperate climate
In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout t ...
s, due in part to the occurrence of a cold
season
A season is a division of the year based on changes in weather, ecology, and the number of daylight hours in a given region. On Earth, seasons are the result of the axial parallelism of Earth's tilted orbit around the Sun. In temperate and pol ...
, which controls the insect population by forcing hibernation. However, many were present in northern Europe and northern America in the 17th and 18th centuries before modern understanding of disease causation. The initial impetus for
tropical medicine was to protect the health of colonial settlers, notably in India under the
British Raj
The British Raj (; from Hindi ''rāj'': kingdom, realm, state, or empire) was the rule of the British Crown on the Indian subcontinent;
*
* it is also called Crown rule in India,
*
*
*
*
or Direct rule in India,
* Quote: "Mill, who was himsel ...
. Insects such as mosquitoes and flies are by far the most common disease carrier, or
vector
Vector most often refers to:
*Euclidean vector, a quantity with a magnitude and a direction
*Vector (epidemiology), an agent that carries and transmits an infectious pathogen into another living organism
Vector may also refer to:
Mathematic ...
. These insects may carry a parasite, bacterium or virus that is infectious to humans and animals. Most often disease is transmitted by an insect bite, which causes transmission of the infectious agent through subcutaneous blood exchange. Vaccines are not available for most of the diseases listed here, and many do not have cures.
Human exploration of
tropical rainforest
Tropical rainforests are rainforests that occur in areas of tropical rainforest climate in which there is no dry season – all months have an average precipitation of at least 60 mm – and may also be referred to as ''lowland equatori ...
s,
deforestation
Deforestation or forest clearance is the removal of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. The most concentrated d ...
, rising
immigration
Immigration is the international movement of people to a destination country of which they are not natives or where they do not possess citizenship in order to settle as permanent residents or naturalized citizens. Commuters, tourists, and ...
and increased international air travel and other
tourism
Tourism is travel for pleasure or business; also the theory and practice of touring (disambiguation), touring, the business of attracting, accommodating, and entertaining tourists, and the business of operating tour (disambiguation), tours. Th ...
to tropical regions has led to an increased incidence of such diseases to non-tropical countries.
Health programmes
In 1975 the Special Programme for Research and Training in Tropical Diseases (TDR) was established to focus on
neglected infectious diseases which disproportionately affect poor and marginalized populations in developing regions of
Africa
Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...
,
Asia
Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...
,
Central America
Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. ...
and North
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...
. It was established at the
World Health Organization
The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level of h ...
, which is the executing agency, and is co-sponsored by the
United Nations Children's Fund
UNICEF (), originally called the United Nations International Children's Emergency Fund in full, now officially United Nations Children's Fund, is an agency of the United Nations responsible for providing humanitarian and developmental aid to ...
,
United Nations Development Programme
The United Nations Development Programme (UNDP)french: Programme des Nations unies pour le développement, PNUD is a United Nations agency tasked with helping countries eliminate poverty and achieve sustainable economic growth and human dev ...
, the
World Bank
The World Bank is an international financial institution that provides loans and grants to the governments of low- and middle-income countries for the purpose of pursuing capital projects. The World Bank is the collective name for the Interna ...
and the
World Health Organization
The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level of h ...
.
TDR's vision is to foster an effective global research effort on infectious
diseases of poverty
Diseases of poverty (also known as poverty-related diseases) are diseases that are more prevalent in low-income populations. They include infectious diseases, as well as diseases related to malnutrition and poor health behaviour. Poverty is one o ...
in which disease endemic countries play a pivotal role. It has a dual mission of developing new tools and strategies against these diseases, and to develop the research and leadership capacity in the countries where the diseases occur. The TDR secretariat is based in Geneva, Switzerland, but the work is conducted throughout the world through many partners and funded grants.
Some examples of work include helping to develop new treatments for diseases, such as ivermectin for onchocerciasis (river blindness); showing how packaging can improve use of artemesinin-combination treatment (ACT) for malaria; demonstrating the effectiveness of bednets to prevent mosquito bites and malaria; and documenting how community-based and community-led programmes increases distribution of multiple treatments
TDR history
The current TDR disease portfolio includes the following entries:
:
†
:
‡
Other neglected tropical diseases
Additional
neglected tropical diseases
Neglected tropical diseases (NTDs) are a diverse group of tropical disease, tropical infections that are common in low-income populations in Developing country, developing regions of Africa, Asia, and the Americas. They are caused by a variety ...
include:
Some tropical diseases are very rare, but may occur in sudden
epidemic
An epidemic (from Ancient Greek, Greek ἐπί ''epi'' "upon or above" and δῆμος ''demos'' "people") is the rapid spread of disease to a large number of patients among a given population within an area in a short period of time.
Epidemics ...
s, such as the
Ebola
Ebola, also known as Ebola virus disease (EVD) and Ebola hemorrhagic fever (EHF), is a viral hemorrhagic fever in humans and other primates, caused by ebolaviruses. Symptoms typically start anywhere between two days and three weeks after becom ...
hemorrhagic fever,
Lassa fever
Lassa fever, also known as Lassa hemorrhagic fever (LHF), is a type of viral hemorrhagic fever caused by the Lassa virus. Many of those infected by the virus do not develop symptoms. When symptoms occur they typically include fever, weakness, h ...
and the
Marburg virus
Marburg virus (MARV) is a hemorrhagic fever virus of the ''Filoviridae'' family of viruses and a member of the species '' Marburg marburgvirus'', genus ''Marburgvirus''. It causes Marburg virus disease in primates, a form of viral hemorrhagic f ...
. There are hundreds of different tropical diseases which are less known or rarer, but that, nonetheless, have importance for
public health
Public health is "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals". Analyzing the det ...
.
Relation of climate to tropical diseases
The so-called "exotic" diseases in the tropics have long been noted both by travelers, explorers, etc., as well as by physicians. One obvious reason is that the hot climate present during all the year and the larger volume of
rain
Rain is water droplets that have condensed from atmospheric water vapor and then fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides water f ...
s directly affect the formation of breeding grounds, the larger number and variety of
natural reservoir
In infectious disease ecology and epidemiology, a natural reservoir, also known as a disease reservoir or a reservoir of infection, is the population of organisms or the specific environment in which an infectious pathogen naturally lives and rep ...
s and animal diseases that can be transmitted to humans (
zoonosis
A zoonosis (; plural zoonoses) or zoonotic disease is an infectious disease of humans caused by a pathogen (an infectious agent, such as a bacterium, virus, parasite or prion) that has jumped from a non-human (usually a vertebrate) to a human. ...
), the largest number of possible
insect
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...
vectors of diseases. It is possible also that higher temperatures may favor the replication of pathogenic agents both inside and outside biological organisms. Socio-economic factors may be also in operation, since most of the poorest nations of the world are in the tropics. Tropical countries like
Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
, which have improved their socio-economic situation and invested in
hygiene
Hygiene is a series of practices performed to preserve health.
According to the World Health Organization (WHO), "Hygiene refers to conditions and practices that help to maintain health and prevent the spread of diseases." Personal hygiene refer ...
,
public health
Public health is "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals". Analyzing the det ...
and the combat of transmissible diseases have achieved dramatic results in relation to the elimination or decrease of many
endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...
tropical diseases in their territory.
Climate change
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...
,
global warming
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...
caused by the
greenhouse effect
The greenhouse effect is a process that occurs when energy from a planet's host star goes through the planet's atmosphere and heats the planet's surface, but greenhouse gases in the atmosphere prevent some of the heat from returning directly ...
, and the resulting increase in global
temperature
Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measured with a thermometer.
Thermometers are calibrated in various temperature scales that historically have relied o ...
s, are possibly causing tropical diseases and vectors to spread to higher altitudes in mountainous regions, and to higher latitudes that were previously spared, such as the
Southern United States
The Southern United States (sometimes Dixie, also referred to as the Southern States, the American South, the Southland, or simply the South) is a geographic and cultural region of the United States of America. It is between the Atlantic Ocean ...
, the Mediterranean area, etc. For example, in the Monteverde cloud forest of Costa Rica, global warming enabled Chytridiomycosis, a tropical disease, to flourish and thus force into decline amphibian populations of the Monteverde Harlequin frog. Here, global warming raised the heights of orographic cloud formation, and thus produced cloud cover that would facilitate optimum growth conditions for the implicated pathogen, B. dendrobatidis.
Prevention and treatment
Vector-borne diseases
Vectors are living organisms that pass disease between humans or from animal to human. The vector carrying the highest number of diseases is the mosquito, which is responsible for the tropical diseases dengue and malaria. Many different approaches have been taken to treat and prevent these diseases. NIH-funded research has produced genetically modify mosquitoes that are unable to spread diseases such as malaria. An issue with this approach is global accessibility to genetic engineering technology; Approximately 50% of scientists in the field do not have access to information on genetically modified mosquito trials being conducted.
Other prevention methods include:
* Draining wetlands to reduce populations of
insect
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...
s and other
vector
Vector most often refers to:
*Euclidean vector, a quantity with a magnitude and a direction
*Vector (epidemiology), an agent that carries and transmits an infectious pathogen into another living organism
Vector may also refer to:
Mathematic ...
s, or introducing natural predators of the vectors.
* The application of
insecticide
Insecticides are substances used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. Insecticides are used in agriculture, medicine, industry and by consumers. Insecticides are claimed to b ...
s and/or
insect repellent
An insect repellent (also commonly called "bug spray") is a substance applied to skin, clothing, or other surfaces to discourage insects (and arthropods in general) from landing or climbing on that surface. Insect repellents help prevent and cont ...
s) to strategic surfaces such as clothing, skin, buildings, insect habitats, and
bed net
A mosquito net is a type of meshed curtain that is circumferentially draped over a bed or a sleeping area, to offer the sleeper barrier protection against bites and stings from mosquitos, flies, and other pest insects, and thus against the di ...
s.
* The use of a
mosquito net
A mosquito net is a type of meshed curtain that is circumferentially draped over a bed or a sleeping area, to offer the sleeper barrier protection against bites and stings from mosquitos, flies, and other pest insects, and thus against the di ...
over a bed (also known as a "bed net") to reduce nighttime transmission, since certain species of tropical
mosquito
Mosquitoes (or mosquitos) are members of a group of almost 3,600 species of small flies within the family Culicidae (from the Latin ''culex'' meaning " gnat"). The word "mosquito" (formed by ''mosca'' and diminutive ''-ito'') is Spanish for "li ...
es feed mainly at night.
Sexually transmitted diseases
Sexually transmitted infections (STIs), also referred to as sexually transmitted diseases (STDs) and the older term venereal diseases, are infections that are spread by sexual activity, especially vaginal intercourse, anal sex, and oral sex ...
Both pharmacologic pre-exposure prophylaxis (to prevent disease before exposure to the environment and/or vector) and pharmacologic post-exposure prophylaxis (to prevent disease after exposure to the environment and/or vector) are used to prevent and treat
HIV
The human immunodeficiency viruses (HIV) are two species of ''Lentivirus'' (a subgroup of retrovirus) that infect humans. Over time, they cause acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the immune ...
Community approaches
Assisting with economic development in endemic regions can contribute to prevention and treatment of tropical diseases. For example,
microloan
:''This article is specific to small loans, often provided in a pooled manner. For direct payments to individuals for specific projects, see Micropatronage. For financial services to the poor, see Microfinance. For small payments, see Micropay ...
s enable communities to invest in health programs that lead to more effective disease treatment and prevention technology.
Educational campaigns can aid in the prevention of various diseases. Educating children about how diseases spread and how they can be prevented has proven to be effective in practicing preventative measures.
Educational campaigns can yield significant benefits at low costs.
Other approaches
* Use of
water well
A well is an excavation or structure created in the ground by digging, driving, or drilling to access liquid resources, usually water. The oldest and most common kind of well is a water well, to access groundwater in underground aquifers. Th ...
s, and/or
water filtration
A water filter removes impurities by lowering contamination of water using a fine physical barrier, a chemical process, or a biological process. Filters cleanse water to different extents, for purposes such as: providing agricultural irrigation ...
,
water filter
A water filter removes impurities by lowering contamination of water using a fine physical barrier, a chemical process, or a biological process. Filters cleanse water to different extents, for purposes such as: providing agricultural irrigation ...
s, or
water treatment
Water treatment is any process that improves the Water quality, quality of water to make it appropriate for a specific end-use. The end use may be drinking water, drinking, industrial water supply, irrigation, river flow maintenance, water recrea ...
with water tablets to produce drinking water free of parasites.
*
Sanitation
Sanitation refers to public health conditions related to clean drinking water and treatment and disposal of human excreta and sewage. Preventing human contact with feces is part of sanitation, as is hand washing with soap. Sanitation systems ...
to prevent transmission through human waste.
* Development and use of
vaccine
A vaccine is a biological Dosage form, preparation that provides active acquired immunity to a particular infectious disease, infectious or cancer, malignant disease. The safety and effectiveness of vaccines has been widely studied and verifie ...
s to promote disease
immunity
Immunity may refer to:
Medicine
* Immunity (medical), resistance of an organism to infection or disease
* ''Immunity'' (journal), a scientific journal published by Cell Press
Biology
* Immune system
Engineering
* Radiofrequence immunity desc ...
.
* Pharmacologic treatment (to treat disease after infection or infestation).
See also
*
Hospital for Tropical Diseases
The Hospital for Tropical Diseases (HTD) is a specialist tropical disease hospital located in London, United Kingdom. It is part of the University College London Hospitals NHS Foundation Trust and is closely associated with University College Lo ...
*
Tropical medicine
*
Infectious disease
An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable dise ...
*
Neglected diseases
*
List of epidemics
This is a list of the largest known epidemics and pandemics caused by an infectious disease. Widespread non-communicable diseases such as cardiovascular disease and cancer are not included. An epidemic is the rapid spread of disease to a large nu ...
*
Waterborne diseases
Waterborne diseases are conditions (meaning adverse effects on human health, such as death, disability, illness or disorders) caused by pathogenic micro-organisms that are transmitted in water. These diseases can be spread while bathing, washing ...
*
Globalization and disease
Globalization, the flow of information, goods, capital, and people across political and geographic boundaries, allows infectious diseases to rapidly spread around the world, while also allowing the alleviation of factors such as hunger and poverty ...
References
Further reading
Books
TDR at a glance - fostering an effective global research effort on diseases of povertyLe TDR en un coup d’oeilLe TDR en un coup d’oeil - favoriser un eff ort mondial de recherche eff icace sur les maladies liées à la pauvretéTDR annual report - 2009Monitoring and evaluation tool kit for indoor residual sprayingIndicators for monitoring and evaluation of the kala-azar elimination programmeMalaria Rapid Diagnostic Test Performance - results of WHO product testing of malaria RDTs: Round 2- 2009Quality Practices in Basic Biomedical Research (QPBR) training manual: TrainerQuality Practices in Basic Biomedical Research (QPBR) training manual: TraineeProgress and prospects for the use of genetically modified mosquitoes to inhibit disease transmissionUse of Influenza Rapid Diagnostic TestsManson's Tropical DiseasesMandell's Principles and Practice of Infectious Diseaseso
this site
Journals
*
Japanese Journal of Tropical Medicine and Hygiene
The ''Japanese Journal of Tropical Medicine and Hygiene'' ( ja, Nippon Nettai Igakkai zasshi, print , electronic ) is a Japanese medical journal. It was established in 1973 and changed its name to ''Tropical Medicine and Health'' in 2004. Originall ...
Tropical Medicine and International Health*
ttp://www.scielo.br/scielo.php?script=sci_serial&lng=en&pid=0036-4665 Revista do Instituto de Medicina Tropical de São PauloRevista da Sociedade Brasileira de Medicina TropicalJournal of Venomous Animals and Toxins including Tropical Diseases
Websites
Special Programme for Research and Training in Tropical Diseases -TDR*
GIDEON-Global Infectious Disease Epidemiology Network
External links
WHO Neglected Tropical DiseasesWHO Operational research in tropical and other communicable diseases*
European Bioinformatics Institute
The European Bioinformatics Institute (EMBL-EBI) is an Intergovernmental Organization (IGO) which, as part of the European Molecular Biology Laboratory (EMBL) family, focuses on research and services in bioinformatics. It is located on the Well ...
open source drug discoveryDrugs for Neglected Diseases InitiativeTropical diseasesfrom Maya Paradise, The Guatemala Information Web Site
American Society for Tropical Medicine and HygieneU.S.
Food and Drug Administration
The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respon ...
Travelers' Health- National Center for Infectious Diseases -
Centers for Disease Control and Prevention
The Centers for Disease Control and Prevention (CDC) is the national public health agency of the United States. It is a United States federal agency, under the Department of Health and Human Services, and is headquartered in Atlanta, Georgi ...
Tropicology Library In Portuguese.
'Conquest and Disease or Colonisation and Health' lecture by Professor Frank Cox on the history of tropical disease, given at
Gresham College
Gresham College is an institution of higher learning located at Barnard's Inn Hall off Holborn in Central London, England. It does not enroll students or award degrees. It was founded in 1596 under the will of Sir Thomas Gresham, and hosts ove ...
, 17 September 2007 (available for download as video and audio files, as well as a text file).
*
{{DEFAULTSORT:Tropical Disease
Infectious diseases
Global health