Why treat for pinworms?
Pinworms have been a problem at Case for many years. They do not generally cause clinical disease and infection is not detected until we go looking for it, so the question as to why pinworms should be treated is extremely valid. The following top ten reasons to eliminate pinworms are provided!
Reason 1: Pinworms interfere with research
As most investigators will agree, experimental models are susceptible to perturbation from many sources. The fewer variables that are introduced into the colony by infectious agents, the more likely results will remain consistent, predictable and comparable between institutions and research projects. A number of references are included FYI. The banner on this page shows histologic sections of pinworms in the cecum of mice unexpectedly found during histological analysis of an experimental mouse.
Reason 2: Pinworms impede collaborations
Most institutions across the country report pinworm infection in some or all of their colonies and most seek to prevent the introduction of new infections. The presence of pinworms in the facility is often used as reason to prevent animals from being shipped even if health history in the room is negative. Institutions will often request rederivation or prohibit animals from pinworm positive colonies from being shipped.
Reason 3: Pinworms jeopardize funding
In some cases, grants are awarded based on the availability of adequate Specific Pathogen Free (SPF) colonies in the institution. Pinworms are one of the Specific Pathogens that are universally excluded from SPF colonies. The lack of sufficient facilities has been sited as the reason funding opportunities have been missed.
Reason 4: Pinworms jeopardize publication
Many journals now require that a statement be made describing the condition of the animal facilities and the health status of experimental animals. SPF is the standard throughout the scientific community.
Reason 5: Pinworms jeopardize other animals in the colony
Although we work very hard to isolate clean and dirty animals, the presence of dirty animals on campus and specifically those infected with pinworms pose a threat to immunodeficient or compromised animals on campus.
Reason 6: Pinworm eggs are very hard to eliminate
Pinworm eggs are very resistant to neutralization by most common disinfection procedures. The eggs persist in the environment for up to eight weeks. The treatment regimen used to treat the parasite covers an 8 week period so that all susceptible animals are treated while the pinworm eggs are given time to be inactivated.
Reason 7: Treatment reduces egg burden
Fenbendazole impregnated feed (150 ppm) is the preferred treatment for pinworms. As soon as infected animals begin consuming the feed, eggs produced by the pinworm female are inactivated. This effectively and immediately reduces the pinworm egg burden in the facility.
Reason 8: Treatment is relatively innocuous
Although the introduction of fenbendazole treated feed represents an additional experimental variable, the treatment has few demonstrated side effects. The treatment has been in widespread use for a number of years in the research community. We have used it here for a number of years with few reported side effects. The drug is administered in very low quantities and is poorly absorbed from the GI tract. Side effects of treatment and the mechanism of action of the compound are described in on the Fenbendazole Information Page.
Reason 9: Animals from many sources are being relocated
Animals from a number of areas are being moved and consolidated in preparation for the upcoming renovation project. We are doing a great deal of testing of many animals however, as a precaution, we believe that treatment is indicated in persistently infected colonies. Infection has persisted in the Yellow (D) and Gray (E) hallways for a number of years. All of these animals will have to be relocated so in order to protect the integrity of new established housing locations, we are seeking to eliminate the infection in the area.
Reason 10: Microisolators are in place throughout the operation
Now that we have placed all rodents in microisolators, we have the opportunity to eliminate infected animals and keep them clean. Microisolator technique, like everything in life, is not perfect but it does an excellent job of containing and reducing infection. The microisolator is an integral part of the future of disease control and its introduction will enable us to enter a new era of cleanliness throughout the operation. |
