Ebola hemorrhagic fever is caused by the Ebola virus. Ebola virus is a filovirus comprising five distinct species: Zaiire, Sudan, Cote d’Ivoire, Bundibugyo and Reston. Zaiire, Sudan and Bundibugyo species have caused higher fatality in Africa. The virus was first identified in regions of Sudan and Zaire in 1976 (Bowen et al. , 1977). According to the WHO, the Ebola virus infected 284 people in Sudan in 1976, causing 151 deaths and 318 cases and 280 deaths in the Democratic Republic of the Congo in 1977.
Yet another outbreak of Ebola was recorded in Sudan in 1979 which infected 33 cases resulting in 22 deaths. The rain forests of the African continent and areas of the Western Pacific are said to be the natural reservoir of the Ebola virus. Epidemics of Ebola have also been recorded in countries such as USA and Phillippines, Ebola hemorrhagic fever one of the most virulent viral diseases characterized by acute onset of fever, malaise, myalgia, headache, and pharyngitis followed by vomiting, diarrhea, maculopapular rash, limited renal and hepatic involvement and hemorrhagic diathesis (Beer et al., 1999).
Incubation period ranges between 2 – 21 days and case fatality rate vary from 50 – 90% (Bwaka et al. , 1999). Transmission of Ebola is mainly by direct contact with blood, body fluids and tissues of infected persons. Transmission has also occurred by handling sick or dead infected primates, forest antelope and fruit bats. There is no specific treatment and vaccine is yet unavailable for Ebola. The only treatment is general supportive therapy. Patients tend to get dehydrated easily.
An oral rehydration with electrolytes or intravenous fluids can be administered as substitutes. Leishmaniasis Leishmaniasesis are caused by flagellate protozoans belonging to the genus Leishmania. 20 species of Leishmania are pathogenic for humans and are generally transmitted by the bite of an insect vector, the phlebotomine sandfly. Sand flies while feeding on animal or human blood ingest a form of the parasite, which undergoes further transformation within the sandfly. Humans get infected by bite of this infected sandfly.
According to WHO worldwide prevalence of Leishmaniasis is approximately 12 million cases, case fatality of about 60 000. The phlebotomine sandfly, is native of inter-tropical and temperate regions. However Leishmaniases are spread cross large areas of Central and South America, Africa, Latin America, Central Asia, Middle East and the Mediterranean basin. Leishmaniasis is of four types. Cutaneous forms generally cause skin ulcers on exposed areas, such as the face, arms and legs.
Chronic lesions, those resembling lepromatous leprosy are produced in diffuse cutaneous leishmaniasis. In this case treatment is difficult. Mucocutaneous forms produce lesions that partially or totally destroy the mucous membranes lining the nose, mouth and throat. Cutaneous and mucocutaneous forms are prevalent in Central and South America such Bolivia, Brazil and Peru and are caused by L. mexicana and L. braziliensis species.
In South and Central Asia and Middle East, cutaneous Leishmaniasis is by L. tropica and L.major (Gonzalez et al. , 2008). Visceral Leishmaniasis is another form of Leishmaniasis also known as kala azar. Disease is characterized by high fever, substantial weight loss, swelling of the spleen and liver, and anaemia. This is mainly caused by L. donovani in Bangladesh, China, India, Nepal and Sudan by L. infantum in North Africa and southern Europe, and by L. chagasi in Latin America (Gonzalez et al. , 2008). Although scientists have tried their hands in bringing vaccines, vaccine for prevention of Leishmanisis is yet unavailable.
Recent research reveals that a 15 kD protein antigen derived from the salivary glands of the sandfly vector also could be protective when administered as a vaccine. However, this is still on the way. Giardiasis Giardia lamblia is a protozoan parasite, the life cycle of which has two forms: the trophozoite and the cyst. The cyst is the infectious form. In developing countries with poor sanitation and improper management of supplied water, Giardia (beaver fever) is an imp¬ortant unresolved health problem (Addiss et al., 1991).
The disease rate is higher in communities with presence of asymptomatic patients, who can be considered as the main source of infection through continuously excreting the cysts stages with their stools. According to Thompson et al. (1990), the prevalence of G. lamblia ranges from 2%–7% in industrialized countries and 20%–60% in developing countries.
Majority of infections are probably asymptomatic but in children they cause diarrhoea and intestinal irritation (Dubey et al., 2000), other symptoms include abdominal cramps, bloating, weight loss, and anorexia. When the illness is chronic, mal absorption of fat, lactose, vitamin A, and vitamin B occurs. Giardia is more common in children nevertheless in epidemic outbreaks all age groups become susceptible (Norhyati et al. , 1998). Faecal–oral route and direct person-to-per¬son spread is the primary mode of transmission. It is also associated with contaminated drinking water but also occasionally by recreational activity in still water (Thompson, 2001).
Antibiotics which are class agents of Nitroimidazoles, Quinacrine, Furazolidone, Benzimidazoles, Paromomycin, Bacitracin zinc are often recommended by doctors to treat Giardiasis. Nevertheless, healthy persons may recover without administration of any medication.
Works Cited
Addiss, D. G. et al. (1991). Evaluation of a commerc¬cially available enzyme-linked immunos¬sorbent assay for Giardia lamblia antigen in stool. Journal of clinical microbiology. 29(6), 1137–42. Beer,B. Kurth, R. Bukreyev, A. (1999). Characteristics of Filoviridae: Marburg and Ebola viruse. Naturwissenschaften. 86, 8-17