THE FLIES THAT CAUSE MYIASIS IN MAN 141 



California. Neotropical Region: Mexico, Ba.ja California, Guatemala, Panama, 

 Canal Zone, Bermuda, Bahama Islands. Cuba, Jamaica. Haiti, Dominican Re- 

 public, Puerto Rico, Virgin Islands, St. Kitts, St. Vincent, Antigua. Martinique, 

 Barbados, Grenada, Trinidad, Colombia, Galapagos Islands, Ecuador, Venezuela, 

 British Guiana, Brazil, Ascension Island, Peru. Paraguay, Uruguay. Chile, Argen- 

 tina, Patagonia. Palaearctic Region : Iceland, Ireland, Scotland, England, Spain, 

 France, Netherlands, Switzerland, Italy. Corsica, Sardinia, Norway, Sweden, 

 Finland, Lapland (Swedish), Denmark, Germany, Poland, Czechoslovakia. 

 Austria, Hungary. Yugoslavia, Rumania, Greece, European Turkey, Russia. 

 Transcaspia, Azores, Canary Islands. Madeira. Morocco, Algeria, Tunisia, Libia, 

 Egypt, Dodecanese, Syria, Palestine, Iraq, Siberia (Tomsk), China (Shantung), 

 Manchuria, Chosen, Japan. Oriental Region: India, Ceylon, Malaya. Taiwan, 

 Philippine Islands. Sumatra, Borneo, Java. Ethiopian Region : Gold Coast, 

 Nigeria. Sudan. Eritrea. Uganda. Kenya, Tanganyika, Zanzibar, Nyasaland, 

 Mozambique, Rhodesia, South-West Africa, South Africa (Natal), Seychelles, 

 Admirantes, Coetivy and Cargados Islands. Rodriquez. Australian Region: 

 Western Australia, Northern Territory, South Australia, Queensland, New 

 South Wales. Victoria, New Zealand, New Caledonia. New Hebrides (Espiritu 

 Santo Island). Guam. Samoa, Fiji, Society Islands. Marquesas. Midway Islands, 

 Hawaiian Islands. 



Biology and Pathogenesis. — The housefly breeds in decaying and 

 fermenting organic matter of sufficient moistness, and in human and 

 animal excrement. It is oviparous. A single female may produce 

 120 to 150 eggs at a batch and may deposit from 5 or 6 to 20 or more 



Figure 83. — Musca domestica, mature larva, side view. 



batches during her lifetime. Development is rapid : under favorable 

 conditions, a generation may be completed in 3 weeks. In warmer 

 climates breeding may be continuous throughout the year ; the ques- 

 tion as to how the flies hibernate in temperate climates has not been 

 completely answered. 



In spite of the experiments of Komarek (76), it is hard to discredit 

 statements by various workers that larvae of M. domestica have been 

 recovered from stools and vomits under conditions that vrould pre- 

 clude subsequent infection. Apparently authentic cases have been 

 reported from Illinois, Scotland, South Africa, and other parts of the 

 world. Seemingly authentic cases of urinary myiasis, similar to those 

 produced by Fannia, have been reported. In a case reported by Leon 

 (81) in Rumania, the actual emergence of the larvae from the urinary 

 tract of a young man was observed. Some detailed observations on 

 breeding habits are given by Mellor (88). 



Several cases of wound and cuticular myiasis in man and animals 

 are on record; in most of these, however, the larvae attack only the 

 diseased tissue. In India larvae have been known to attack the 

 diseased nasal cavities and wounds on the bodies of lepers. A severe 

 auricular myiasis in the suppurating ear of a boy and an extensive 

 dermal nryiasis in the leg of an elderly man with varicose veins have 

 also been reported. In the man the larvae probably hatched from 

 eggs deposited on or near an ulcerous cavity : though some had reached 

 the third stage, they were undersized and gave evidence of attempting 



