Centers for Disease Control/Division of Parasitic Diseases and Malaria
EOL staff
Life cycle of the Human Pinworm (Enterobius vermicularis and V. gregorii)Human pinworm eggs are deposited on the human host's perianal folds (1). Self-infection occurs by transferring infective eggs to the mouth with hands that have scratched the perianal area (2). Person-to-person transmission can also occur through handling of contaminated clothes or bed linens. Enterobiasis (pinworm infection) may also be acquired from surfaces in the environment that are contaminated with pinworm eggs (e.g., curtains, carpeting). A small number of eggs may become airborne and inhaled. These would be swallowed and follow the same development as ingested eggs. Following ingestion of infective eggs, the larvae hatch in the small intestine (3) and the adults establish themselves in the colon (4). The time interval from ingestion of infective eggs to oviposition by the adult females is about one month. The life span of the adults is about two months. Gravid females migrate nocturnally outside the anus and oviposit while crawling on the skin of the perianal area (5). The larvae contained inside the eggs develop (and the eggs become infective) in 4 to 6 hours under optimal conditions (1). Retroinfection, or the migration of newly hatched larvae from the anal skin back into the rectum, may occur but the frequency with which this happens is unknown.From Centers for Disease Control Parasites and Health website.
Saša Širca, Gregor Urek, Stela Lazarova, Milka Elshishka, Vlada Peneva
Zookeys
Figure 1.Longidorus carniolensis sp. n. Female: A Neck region F Habitus H Pharyngeal bulb Male: G Habitus I Pharyngeal bulb; Juveniles: B–E Habitus of first, second, third and forth juvenile stages J–M Pharyngeal bulb of first, second, third and forth juvenile stages. Scale bars: B–G 1 mm; A, H–M 100 μm.
Figure 1.Crassolabium persicum sp. n. (all images are in lateral view) A Anterior region B Lip region and amphid fovea in surface C Pharyngeal expansion D Vagina E Spicules and lateral guiding piece F Female, posterior body region G Female, anterior genital branch H Male, posterior body region I Male, entire J Female, entire.
Vlada K. Peneva, Stela S. Lazarova, Francesca De Luca, Derek J. F. Brown
Zookeys
Figure 1.Longidorus cholevae sp. n. Female: A Anterior end F Habitus I Pharyngeal bulb J Anterior genital branch Male: G Habitus H Pharyngeal bulb Juveniles: B–E Habitus of first-, second-, third- and fourth-stage juveniles. Scale-bars: A, H, I, J 50 μm; B–G 1 mm.
Sevdan Nedelchev, Milka Elshishka, Stela Lazarova, Georgi Radoslavov, Peter Hristov, Vlada Peneva
Zookeys
Figure 2.Calcaridorylaimus castaneae sp. n. Female: A Pharyngeal gland nuclei B Anterior region C Pharyngeal region D Genital system E Vulval region F Sperm cells in uterus. Scale bars: A, B, E, F – 30 μm; C, D – 50 μm.
Figure 2.Longior longior Morffe & García sp. n. (female). A Esophageal region B Cephalic end C Tail, ventral view D Vulva E Egg F Genital tract G Entire nematode, lateral view.
Genus Monhystera body is mostly tapering considerably posteriorly. Caudal sucker small, somewhat pointed. Setae very few. Pharyngeal cavity none. Oesophagus uniform. Spicules long and narrow. Ocellus single, often absent.
