Syngamosis

SYNGAMOSIS, a helminthiasis caused by nematodes of the genus Syngamus v. Siebold, 1836 (of the order Strongylata), which parasitize the upper respiratory tracts of birds and mammals. Characteristics of the genus Syngamus: there are usually 6 small triangular teeth; the anterior end is provided with 2 lateral and 4 submedian papillae. The males are significantly smaller than the females, with which they are permanently connected (fig. 1). The male bursa is short, the spicules are equal, rather thick and short. There is no gubernaculum. The vulva in the female is in the anterior part of the body. The parasites are egg-laying. The eggs are slightly flattened on one side. In the external environment, larvae hatch from the eggs, which become invasive several days after the eggs are laid by the female. Infection occurs per os. Sexual maturity occurs approximately two weeks after infection. By firmly attaching to the mucous membrane, the parasites can cause sharp violations of its integrity (fig. 2). The most widespread is S. trachea Montagu, 1811, which, parasitizing in the tracheae of chickens and pheasants (less often waterfowl), causes large mortality rates in young birds. Syngamosis is less common in mammals (S. laryngeus; male length 2.6-5 mm, female 7-20 mm). In humans, 4 cases of Syngamosis have been registered in world literature. In the USSR, Syngamosis in humans has not been confirmed.

Figure 1.

Figure 2.

Figure 1. Syngamus trachea: 1-male; 2-female; 3- horny capsule. (After Railliet.) Figure 2. Fixation of the nematode Syngamus trachea to the mucous membrane of the rook's trachea. (After Pavlovsky.)