Tropical disease

The Special Programme for Research and Training in Tropical Diseases (TDR) of the World Health Organization focuses on neglected infectious diseases that disproportionally affect poor and marginalized populations. The current disease portfolio includes the following ten: African trypanosomiasis Dengue fever Leishmaniasis Malaria Schistosomiasis Tuberculosis Chagas disease Leprosy Lympha ...

See also:

Tropical disease, Tropical disease - Diseases, Tropical disease - Relation of climate to tropical diseases

Read more here: » Tropical disease: Encyclopedia II - Tropical disease - Diseases

Schistosomiasis or bilharzia is a disease affecting many people in developing countries. It is also called snail fever but is not to be confused with swimmer's itch. In certain African communities the process of overcoming Schistosomiasis is an important rite of passage. Although it has a low mortality rate, schistosomiasis can be very debilitating. (Bilharzia, or bilharziosis, is a largely obsolete eponym, after Theodor Bilharz, who first described the cause of urinary schistosomiasis in 1851.) ...

Including:

• Schistosomiasis - Types
• Schistosomiasis - Geographical distribution and epidemiology
• Schistosomiasis - Life cycle
• Schistosomiasis - Pathology
• Schistosomiasis - Clinical features
• Schistosomiasis - Laboratory diagnosis
• Schistosomiasis - Treatment
• Schistosomiasis - Prevention and hygiene

Read more here: » Schistosomiasis: Encyclopedia - Schistosomiasis

Schistosomes have a typical trematode vertebrate-invertebrate lifecycle, with humans being the definitive host. The life cycles of all five human schistosomes are broadly similar: parasite eggs are released into the environment from infected individuals, rupturing on contact with fresh water to release the free-swimming miracidium. Miracidia infect fresh-water snails by penetrating the snail's foot. After infection, close to the site of penetration, the miracidium transforms into a primary (mother) sporocyst. Germ cells within the primary sp ...

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Schistosomiasis, Schistosomiasis - Types, Schistosomiasis - Geographical distribution and epidemiology, Schistosomiasis - Life cycle, Schistosomiasis - Pathology, Schistosomiasis - Clinical features, Schistosomiasis - Laboratory diagnosis, Schistosomiasis - Treatment, Schistosomiasis - Prevention and hygiene

Read more here: » Schistosomiasis: Encyclopedia II - Schistosomiasis - Life cycle

The disease was named after the Brazilian physician and infectologist Carlos Chagas, who first described it in 1909, but the disease was not seen as a major public health problem in humans until the 1960s. He discovered that the intestines of Triatomidae harbored a flagellate protozoan, a new species of the Trypanosoma genus, and was able to prove experimentally that it could be transmitted to marmoset monk ...

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Chagas disease, Chagas disease - History, Chagas disease - Epidemiology and geographical distribution, Chagas disease - Clinical manifestations, Chagas disease - Infection cycle, Chagas disease - Alternative infection mechanism, Chagas disease - Laboratory diagnosis, Chagas disease - Treatment, Chagas disease - Prevention, Chagas disease - Original publication, Chagas disease - Sources

Read more here: » Chagas disease: Encyclopedia II - Chagas disease - History

An infected triatomine insect vector takes a blood meal and releases trypomastigotes in its feces near the site of the bite wound. By scratching the site of the bite, the victim allows trypomastigotes to enter the host through the wound, or through intact mucosal membranes, such as the conjunctiva. Inside the host, the trypomastigotes invade cells, where they differentiate into intracellular amastigotes. The amastigotes multiply by binary fission and differentiate into trypomastigotes, and then are released into the circulation as bloodstrea ...

See also:

Chagas disease, Chagas disease - History, Chagas disease - Epidemiology and geographical distribution, Chagas disease - Clinical manifestations, Chagas disease - Infection cycle, Chagas disease - Alternative infection mechanism, Chagas disease - Laboratory diagnosis, Chagas disease - Treatment, Chagas disease - Prevention, Chagas disease - Original publication, Chagas disease - Sources

Read more here: » Chagas disease: Encyclopedia II - Chagas disease - Infection cycle

A reasonably effective vaccine was developed in Ribeirão Preto in the 1970s, using cellular and subcellular fractions of the parasite, but it was found economically unfeasible. More recently, the potential of DNA vaccines for immunotherapy of acute and chronic Chagas disease is being tested by several research groups. Prevention is centered on fighting the vector (Triatoma) by using sprays and paints containing insecticides (synthetic pyrethroids), and improving housing and sanitary conditions in the rural area. For urban dwel ...

See also:

Chagas disease, Chagas disease - History, Chagas disease - Epidemiology and geographical distribution, Chagas disease - Clinical manifestations, Chagas disease - Infection cycle, Chagas disease - Alternative infection mechanism, Chagas disease - Laboratory diagnosis, Chagas disease - Treatment, Chagas disease - Prevention, Chagas disease - Original publication, Chagas disease - Sources

Read more here: » Chagas disease: Encyclopedia II - Chagas disease - Prevention

Anopheles is a genus of mosquito (Culicidae). There are approximately 400 Anopheles species, of which 30-40 transmit four different species of parasites of the genus Plasmodium. These are the cause of malaria, which affects humans in endemic areas. Anopheles gambiae is one of the best known, because of its predominant role in the transmission of the most dangerous malaria tropica (Plasmodium falciparum). Some species of Anopheles also can serve as the vectors for canine heartworm Dirofilari ...

Including:

• Anopheles - Life stages
• Anopheles - Eggs
• Anopheles - Larvae
• Anopheles - Pupas
• Anopheles - Adults
• Anopheles - Malaria transmission and control
• Anopheles - Preferred sources for blood meals
• Anopheles - Patterns of feeding and resting
• Anopheles - Insecticide resistance
• Anopheles - Susceptibility
• Anopheles - Habitat
• Anopheles - Source
• Anopheles - External links

Read more here: » Anopheles: Encyclopedia - Anopheles

The human disease occurs in two stages: the acute stage shortly after the infection. A local lesion (so called chagoma (see picture), palpebral edema) can appear at the site of inoculation. The acute phase is usually asymptomatic, but can present with manifestations that include fever, anorexia, lymphadenopathy, mild hepatosplenomegaly, and myocarditis. Some acute cases (10 to 20%) resolve over a period of 2 to 3 months into an asympto ...

See also:

Chagas disease, Chagas disease - History, Chagas disease - Epidemiology and geographical distribution, Chagas disease - Clinical manifestations, Chagas disease - Infection cycle, Chagas disease - Alternative infection mechanism, Chagas disease - Laboratory diagnosis, Chagas disease - Treatment, Chagas disease - Prevention, Chagas disease - Original publication, Chagas disease - Sources

Read more here: » Chagas disease: Encyclopedia II - Chagas disease - Clinical manifestations

The disease is found in tropical countries in Africa, Caribbean, eastern South America, east Asia and in the Middle East. Schistosoma mansoni is found in parts of South America and the Caribbean, Africa, and the Middle East; S. haematobium in Africa and the Middle East; and S. japonicum in the Far East. S. mekongi and S. intercalatum are found focally in Southeast Asia and central West Africa, respectively. An estimated 200 million people have the disease, 120 million symptomatic. A few countries hav ...

See also:

Schistosomiasis, Schistosomiasis - Types, Schistosomiasis - Geographical distribution and epidemiology, Schistosomiasis - Life cycle, Schistosomiasis - Pathology, Schistosomiasis - Clinical features, Schistosomiasis - Laboratory diagnosis, Schistosomiasis - Treatment, Schistosomiasis - Prevention and hygiene

Read more here: » Schistosomiasis: Encyclopedia II - Schistosomiasis - Geographical distribution and epidemiology

Medication for Chagas disease is usually only effective when given during the acute stage of infection. The drugs of choice are azole or nitroderivatives such as benznidazole [8] or nifurtimox (under an Investigational New Drug protocol from the CDC Drug Service), but resistance to these drugs has already been reported [9]. Furthermore, these agents are very toxic and have many adverse effects, and cannot be taken without medical supervision. A 10-year study of chronic administration of drugs in Brazil has revealed that these drugs are not t ...

See also:

Chagas disease, Chagas disease - History, Chagas disease - Epidemiology and geographical distribution, Chagas disease - Clinical manifestations, Chagas disease - Infection cycle, Chagas disease - Alternative infection mechanism, Chagas disease - Laboratory diagnosis, Chagas disease - Treatment, Chagas disease - Prevention, Chagas disease - Original publication, Chagas disease - Sources

Read more here: » Chagas disease: Encyclopedia II - Chagas disease - Treatment

Chagas disease currently affects 16-18 million people, killing around 20,000 people annually and with some 100 million at risk of acquiring the disease. Chronic Chagas disease remains a major health problem in many Latin American countries, despite the effectiveness of hygienic and preventive measures, such as eliminating the transmitting insects, which have reduced to zero new infections in at least two countries of the region. With increased population movements, however, the possibility of transmission by blood transfusion has become more ...

See also:

Chagas disease, Chagas disease - History, Chagas disease - Epidemiology and geographical distribution, Chagas disease - Clinical manifestations, Chagas disease - Infection cycle, Chagas disease - Alternative infection mechanism, Chagas disease - Laboratory diagnosis, Chagas disease - Treatment, Chagas disease - Prevention, Chagas disease - Original publication, Chagas disease - Sources

Read more here: » Chagas disease: Encyclopedia II - Chagas disease - Epidemiology and geographical distribution

Microscopic identification of eggs in stool or urine is the most practical method for diagnosis. The stool exam is the more common of the two. For the measurement of eggs in the feces of presenting patients the scientific unit used is epg or eggs per gram. Stool examination should be performed when infection with S. mansoni or S. japonicum is suspected, and urine examination should be performed if S. haematobium is suspected. Eggs can be present in the stool in infections with all Schistosoma species. The e ...

See also:

Schistosomiasis, Schistosomiasis - Types, Schistosomiasis - Geographical distribution and epidemiology, Schistosomiasis - Life cycle, Schistosomiasis - Pathology, Schistosomiasis - Clinical features, Schistosomiasis - Laboratory diagnosis, Schistosomiasis - Treatment, Schistosomiasis - Prevention and hygiene

Read more here: » Schistosomiasis: Encyclopedia II - Schistosomiasis - Laboratory diagnosis

Many infections are asymptomatic. Acute schistosomiasis (Katayama's fever) may occur weeks after the initial infection, especially by S. mansoni and S. japonicum. Manifestations include: Abdominal pain Cough Diarrhea Eosinophilia Fever Fatigue Hepatosplenomegaly Occasionally central nervous system lesions occur: cerebral granulomatous disease may be caused by ectopic S. japonicum eggs in the brain, and granulomatous lesions around ectopic eg ...

See also:

Schistosomiasis, Schistosomiasis - Types, Schistosomiasis - Geographical distribution and epidemiology, Schistosomiasis - Life cycle, Schistosomiasis - Pathology, Schistosomiasis - Clinical features, Schistosomiasis - Laboratory diagnosis, Schistosomiasis - Treatment, Schistosomiasis - Prevention and hygiene

Read more here: » Schistosomiasis: Encyclopedia II - Schistosomiasis - Clinical features

The main focus of prevention is eliminating the water-borne snails which are natural reservoirs for the disease. This is usually done by identifying bodies of water, such as lakes, ponds, etc., which are infested, forbidding or warning against swimming and adding acrolein, copper sulfate, etc., to the water in order to kill the snails. In 1989, Aklilu Lemma and Legesse Wolde-Yohannes received the Right Livelihood Award for their research on the sapindus-Plant (Phytolacca d ...

See also:

Schistosomiasis, Schistosomiasis - Types, Schistosomiasis - Geographical distribution and epidemiology, Schistosomiasis - Life cycle, Schistosomiasis - Pathology, Schistosomiasis - Clinical features, Schistosomiasis - Laboratory diagnosis, Schistosomiasis - Treatment, Schistosomiasis - Prevention and hygiene

Read more here: » Schistosomiasis: Encyclopedia II - Schistosomiasis - Prevention and hygiene

Schistosomiasis is readily treated using a single oral megadose of the drug Praziquantel. Whilst Praziquantel is safe and highly effective in curing an infected patient, it does not prevent re-infection by cercariae and is thus not an optimum treatment for people living in endemic areas. As with other major parasitic diseases, there is ongoing and extensive research into developing a vaccine that will prevent the paras ...

See also:

Schistosomiasis, Schistosomiasis - Types, Schistosomiasis - Geographical distribution and epidemiology, Schistosomiasis - Life cycle, Schistosomiasis - Pathology, Schistosomiasis - Clinical features, Schistosomiasis - Laboratory diagnosis, Schistosomiasis - Treatment, Schistosomiasis - Prevention and hygiene

Read more here: » Schistosomiasis: Encyclopedia II - Schistosomiasis - Treatment

The first epidemics occurred almost simultaneously, in Asia, Africa, and North America in the 1780s. The disease was identified and named in 1779. A global pandemic began in Southeast Asia in the 1950s and by 1975 DHF had become a leading cause of death among children in many countries in that region. Epidemic dengue has become more common since the 1980s - by the late 1990s, dengue was the most important mosquito-borne viral disease affecting humans after malaria, there being around 40 million cases of dengue fever and several hundred thous ...

See also:

Dengue fever, Dengue fever - Signs and symptoms, Dengue fever - Diagnosis, Dengue fever - Treatment, Dengue fever - Epidemiology, Dengue fever - Prevention, Dengue fever - Potential antiviral approaches, Dengue fever - Recent outbreaks

Read more here: » Dengue fever: Encyclopedia II - Dengue fever - Epidemiology

Like all mosquitoes, anophelines go through four stages in their life cycle: egg, larva, pupa, and adult. The first three stages are aquatic and last 5-14 days, depending on the species and the ambient temperature. The adult stage is when the female Anopheles mosquito acts as malaria vector. The adult females can live up to a month (or more in captivity) but most probably do not live more than 1-2 weeks in nature. < ...

See also:

Anopheles, Anopheles - Life stages, Anopheles - Eggs, Anopheles - Larvae, Anopheles - Pupas, Anopheles - Adults, Anopheles - Malaria transmission and control, Anopheles - Preferred sources for blood meals, Anopheles - Patterns of feeding and resting, Anopheles - Insecticide resistance, Anopheles - Susceptibility, Anopheles - Habitat, Anopheles - Source, Anopheles - External links

Read more here: » Anopheles: Encyclopedia II - Anopheles - Life stages

Recent dengue outbreaks in South East Asia: Philippines (January - October 2005) 21,537 cases with 280 dead. Thailand (May 2005) 7200 infected. At least 12 dead. Indonesia (2004) 80,000 infected with 800 deaths. Malaysia (January 2005), 33,203 cases. Singapore (2005), At least 13 deaths, (2004), 9460 cases, (2003), 4788 cases. As of September 2005, Singapore reported a significant rise in the number of dengue cases - about 9000 in the year to date so far, about double the rate fo ...

See also:

Dengue fever, Dengue fever - Signs and symptoms, Dengue fever - Diagnosis, Dengue fever - Treatment, Dengue fever - Epidemiology, Dengue fever - Prevention, Dengue fever - Potential antiviral approaches, Dengue fever - Recent outbreaks

Read more here: » Dengue fever: Encyclopedia II - Dengue fever - Recent outbreaks

In cell culture experiments Morpholino antisense oligos have shown specific activity against Dengue virus [2] . In 2002 the Swiss pharma company Novartis and the Singapore Economic Development board created the Novartis Institute for Tropical Diseases (NITD). NITD is a public-private partnership that researches neglected tropical disease. NITD's dengue unit is researching anti-viral drug discovery to treat or prevent dengue fever. ...

See also:

Dengue fever, Dengue fever - Signs and symptoms, Dengue fever - Diagnosis, Dengue fever - Treatment, Dengue fever - Epidemiology, Dengue fever - Prevention, Dengue fever - Potential antiviral approaches, Dengue fever - Recent outbreaks

Read more here: » Dengue fever: Encyclopedia II - Dengue fever - Potential antiviral approaches

The diagnosis of dengue is usually made clinically. The classic picture is high fever with no localising source of infection, a petechial rash with thrombocytopenia and relative leukopenia. Serology and PCR (polymerase chain reaction) studies are available to confirm the diagnosis of dengue if clinically indicated. ...

See also:

Dengue fever, Dengue fever - Signs and symptoms, Dengue fever - Diagnosis, Dengue fever - Treatment, Dengue fever - Epidemiology, Dengue fever - Prevention, Dengue fever - Potential antiviral approaches, Dengue fever - Recent outbreaks

Read more here: » Dengue fever: Encyclopedia II - Dengue fever - Diagnosis