Humans are the only natural host of pinworms, and there currently is no confirmed pinworm reservoir. However, in 2004, Chan et. al documented the existence of pinworm and Trichinella in cockroaches from hospitals and grade schools in Hawaii. While cockroaches are known carriers of bacteria and fungi that produce disease in humans, the link between cockroaches and pathogenic helminths has not yet been elucidated, and this was the first report of pinworm infestation in naturally occurring cockroaches.
In 2005, Tatfeng et. al isolated pinworm ova from cockroaches (Diploptera punctata), as well as the ova, cysts, oocysts, and mature parasites of several other parasites. This team trapped 234 cockroaches from areas in and around households in Ekpoma, Africa. The cockroaches were placed in containers of formol saline, which were then shaken vigorously to detach the parasites from the insects. The fluid was then spun and examined under a microscope.
The findings from both studies have great public health implications. Cockroaches are ubiquitous, and both studies detected pinworm in cockroaches taken from human-occupied settings. If they are indeed reservoirs for pinworms, control of cockroach populations and limiting contact with cockroaches could possibly greatly minimize not only the spread of pinworm infection, but of many other infectious diseases as well.