Oesophagostomum natural history, complications and prognosis
|
Oesophagostomum Microchapters |
|
Diagnosis |
|---|
|
Treatment |
|
Case Studies |
|
Oesophagostomum natural history, complications and prognosis On the Web |
|
American Roentgen Ray Society Images of Oesophagostomum natural history, complications and prognosis |
|
FDA onOesophagostomum natural history, complications and prognosis |
|
CDC on Oesophagostomum natural history, complications and prognosis |
|
on Oesophagostomum natural history, complications and prognosis |
|
Risk calculators and risk factors for Oesophagostomum natural history, complications and prognosis |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Please help WikiDoc by adding more content here. It's easy! Click here to learn about editing.
Natural History
Transmission
Transmission of Oesophagostomum is believed to be oral-fecal for both humans and animals, largely because percutaneous infection with Oesophagostomum has never been reported.[1] It is unclear whether or not parasite transmission is specifically waterborne, foodborne, or both. Regardless, introduction of the stage three infective larvae is necessary for human infection. Much about the biological mechanism of transmission is still unknown, and current knowledge of oral-fecal transmission mechanisms does not explain why Oesophagostomum are mostly localized to Northern Togo and Ghana. It is possible that there are behavioral factors or unique soil conditions that facilitate larval development and are not found outside the current endemic areas.[2] Oesophagostomiasis is generally classified as a zoonotic disease, which is an infectious disease that can be transmitted between animals and humans. This has been called into question recently, as recent research has found that human-to-human transmission is possible.
Reservoir
Oesophagostomum are carried predominantly by non-humans, infecting cattle, sheep, goats, wild pigs, and primates. Humans are largely presumed to be an accidental host, as they are not suitable for completion of the Oesophagostomum development; however, the extreme localization of oesophagostomiasis to northern Togo and Ghana in Africa suggests the possibility that the Oesophagostomum is increasingly exhibiting preference for human hosts.[3]
Until recently it was believed that primates were the main reservoirs of human-infecting Oesophagostomum in northern Togo and Ghana, as these particular species have a considerable concentration in non-human primate reservoirs. A 2005 study done by van Lieshout and de Grujiter found that O. bifurcum in humans from northern Ghana is distinct from the O. bifurcum found in olive baboons and mona monkeys outside the endemic area. They used species-specific PCR and microscopy to establish the identification of two separate species of O. bifurcum. [4] These results are significant, as they necessitate further research to determine the definitive reservoirs of human-infecting O. bifurcum. Oesophagostomiasis has no vector.[5]
Incubation Period
The life-cycle of Oesophagostomum can usually be completed in less than 60 days.[6] When the eggs are passed into the feces to the outside environment, they hatch into stage one larve. The stage two larve then molt twice, developing into infective stage three larva in 6–7 days. These stage three larvae can survive extended periods of desiccation by shrinking within their sheaths.
References
- ↑ Ziem, J.B. “Controlling human oesophagostomiasis in northern Ghana.” (Doctoral thesis) Leiden University. 2006.<https://openaccess.leidenuniv.nl/dspace/handle/1887/4917?mode=more>.
- ↑ Ziem, J.B. “Controlling human oesophagostomiasis in northern Ghana.” (Doctoral thesis) Leiden University. 2006. <https://openaccess.leidenuniv.nl/dspace/handle/1887/4917?mode=more>.
- ↑ Gasser, R B, J M de Gruijter, and A M Polderman. “Insights into the epidemiology and genetic make-up of Oesophagostomum bifurcum from human and non-human primates using molecular tools.” Parasitology 132.Pt 4 (2006): 453-60.
- ↑ van Lieshout, Lisette et al. “Oesophagostomum bifurcum in non-human primates is not a potential reservoir for human infection in Ghana.” Tropical Medicine & International Health: TM & IH 10.12 (2005): 1315-20.
- ↑ “GIDEON Infectious Diseases - Diseases.” GIDEON Infectious Disease Database. 5 Feb 2009.<http://web.gideononline.com/web/epidemiology/index.php?gdn_form=ZGlzZWFzZT0xMTY1MA==>.
- ↑ Ziem, J.B. “Controlling human oesophagostomiasis in northern Ghana.” (Doctoral thesis) Leiden University. 2006. <https://openaccess.leidenuniv.nl/dspace/handle/1887/4917?mode=more>.