Contact must then be transferred to the mouth and swallowed. It is especially prevalent amongst those in regular contact with bodies of fresh water including recreational water such as swimming pools. Other potential sources include insufficiently treated water supplies, contaminated food, or exposure to feces. The high resistance of Cryptosporidium oocysts to disinfectants such as chlorine bleach enables them to survive for long periods and still remain infective. Some outbreaks have happened in day care related to diaper changes.The following groups have an elevated risk of being exposed to Cryptosporidium:
Child care workers
Parents of infected children
People who take care of other people with cryptosporidiosis
International travelers
Backpackers, hikers, and campers who drink unfiltered, untreated water
People, including swimmers, who swallow water from contaminated sources
People who handle infected cattle
People exposed to human feces through sexual contactCases of cryptosporidiosis can occur even in cities that have a properly de-contaminated water supply. In a city with clean water, it may be that cases of cryptosporidiosis have other origins. Testing of water, as well as epidemiological study, are necessary to determine the sources of specific infections. Cryptosporidium is causing serious illness  more frequently in immunocompromised than in apparently healthy individuals. It may chronically sicken some children, as well as adults who are exposed and immunocompromised. A subset of the immunocompromised population is people with AIDS. Some sexual behaviors can transmit the parasite directly. Life cycle
Cryptosporidium spp. exist as multiple cell types which correspond to different stages in an infection (e.g., a sexual and asexual stage).
Tuberculosis verrucosa cutis is a rash of small, red papular nodules in the skin that may appear 2–4 weeks after inoculation by Mycobacterium tuberculosis in a previously infected and immunocompetent individual. It is also known as "prosectors wart" because it was a common occupational disease of prosectors, the preparers of dissections and autopsies. Reinfection by tuberculosis via the skin, therefore, can result from accidental exposure to human tuberculous tissue in physicians, pathologists and laboratory workers; or to tissues of other infected animals, in veterinarians, butchers, etc. TVC is one of the many forms of cutaneous tuberculosis, such as the tuberculous chancre (which results from the cutaneous inoculation in immunocompetent people without previous exposure), and the reactivation cutaneous tuberculosis (the most common form, which appears in previously infected patients). Other forms of cutaneous tuberculosis are: lupus vulgaris, scrofuloderma, lichen scrofulosorum, erythema induratum and the papulonecrotic tuberculid. It was described by René Laennec in 1826. Signs and symptoms
Because the TVCs entry point usually is the site of a trauma, wound or puncture in the skin (during an autopsy, for example), the most frequent site for the wart are the hands. But it can occur anywhere in the skin, such as in the sole of the feet, in the anus, and, in the case of children from developing countries, in the buttocks and knees.