Once hatched, the larvae then lacerate the skin with their mouthparts, causing open sores. Once the skin has been breached, the larvae then tunnel through the sores into the hosts subcutaneous tissue, causing deep and irritating lesions highly subject to infection. After about the second day, bacterial infection is likely and, if left untreated, causes bacterial bloodstream infections or sepsis. This leads to anorexia and weakness and is generally fatal if untreated. Human vectors
There are three main fly families causing economically important myiasis in livestock and also, occasionally, in humans:
Calliphoridae (blowflies)
Some examples include Calliphora vomitoria and Calliphora vicina
Oestridae (botflies)
Sarcophagidae (fleshflies) Sarcophaga barbata are usually found in dead and rotting meat and animal excrement, which are prime environments for them. This is because their larvae are facultative parasites, as they feed on organic tissue and use the hosts oxygen reserve.Other families occasionally involved are:
Anisopodidae
Piophilidae
Stratiomyidae
Syrphidae

Specific myiasis
Caused by flies that need a host for larval development
Dermatobia hominis (human botfly)
Cordylobia anthropophaga (tumbu fly)
Oestrus ovis (sheep botfly)
Hypoderma spp. (cattle botflies or ox warbles)
Gasterophilus spp. (horse botfly)
Cochliomyia hominivorax (new world screwworm fly)
Chrysomya bezziana (old world screwworm fly)
Auchmeromyia senegalensis (Congo floor maggot)
Cuterebra spp. (rodent and rabbit botfly)

Semispecific myiasis
Caused by flies that usually lay their eggs in decaying animal or vegetable matter, but that can develop in a host if open wounds or sores are present
Lucilia spp. (green-bottle fly)
Cochliomyia spp. (screw-worm fly)
Phormia spp. (black-bottle fly)
Calliphora spp. (blue-bottle fly)
Sarcophaga spp.
Factitious disorder imposed on another
Factitious disorder imposed on another, previously Munchausen syndrome by proxy, is the involuntary use of another individual to play the patient role. For example, false symptoms are produced in children by the caregivers or parents, to produce the appearance of illness, or they may give misleading medical histories about their children. The parent may falsify the childs medical history or tamper with laboratory tests to make the child appear sick. Occasionally, in Munchausen by proxy, the caregiver actually injures the child or makes them sick to ensure that the child is treated. For instance, a father whose son has celiac disease might knowingly introduce gluten into the diet. Such parents may be validated by the attention that they receive from having a sick child. Ganser syndrome
Ganser syndrome was once considered a separate factitious disorder, but is now considered a dissociative disorder. It is a disorder of extreme stress or an organic condition. The patient experiences approximation or giving absurd answers to simple questions. The syndrome is sometimes diagnosed as merely malingering—however, it is more often defined as a factitious disorder. This has been seen in prisoners following solitary confinement, and the symptoms are consistent in different prisons, though the patients do not know one another.Symptoms include a clouding of consciousness, somatic conversion symptoms, confusion, stress, loss of personal identity, echolalia, and echopraxia. Individuals also give approximate answers to simple questions such as, "How many legs on a cat?" "Three"; "Whats the day after Wednesday?" "Friday"; and so on.