ABSTRACT
Worm-free cats about 12 weeks old were infected with 100, 500, 1,000 and 2,000 third-stage larvae (L3) of Ancylostoma tubaeforme. The changes in packed cell volume (PCV) and haemoglobin content were monitored, and the worm populations developing in each infection recorded. Cats receiving infection doses of 1,000 L3 and above showed morbidity symptoms by the third week and a rapid decline especially in the PCV value. The low dose rates (500 L3 and below) produced an apparently symptomless condition without pronounced changes in the blood values. Adult hookworm populations were linearly related to the logarithm of the dose of infective larvae administered, but there was a lower female to male ratio (FMR) at high dose levels. No significant size differences were observed in the adult hookworm populations.
Subject(s)
Ancylostomiasis/veterinary , Cat Diseases/blood , Hemoglobins/analysis , Ancylostoma/physiology , Ancylostomiasis/blood , Ancylostomiasis/parasitology , Animals , Cat Diseases/parasitology , Cats , Female , Hematocrit , MaleABSTRACT
Detailed parasitological and climatological examination of two rural communities in a hookworm endemic area of Anambra State Nigeria, has shown that infection with the parasite follows a clearly defined pattern. The results suggested a break in the transmission cycle of the parasite during the dry season December--February when only a few larvae (< 500 L3S) could be recovered from contaminated soils for not more than 4 days. Transmission of the parasite and the manifestation of the disease in infected individuals appeared to be a rainy season phenomenon. The implications of these findings are discussed in relation to possible control of the disease.
Subject(s)
Hookworm Infections/epidemiology , Rain , Seasons , Weather , Feces/parasitology , Humans , Nigeria , SoilABSTRACT
Observations have been made over a 15-month period on the frequency distribution of human faecal deposits and infective larvae of Necator americanus in a hookworm endemic area. The agestructure of infective larvae in a field population and their vertical distribution in soils were determined. These studies were undertaken to examine the hypothesis that hookworm transmission in the tropics is discontinuous and limited mainly to the rainy season. The distribution of larvae was found to be overdispersed statistically and in general much greater numbers of L3s were recovered during the rainy season. The degree of overdispersion was also reduced during this season, and there was a tendency for larvae to be confined to the surface/topsoil. The implications of these findings have been discussed in relation to human hookworm parasitism in endemic areas of the tropics.
Subject(s)
Necator/growth & development , Soil , Animals , Feces/parasitology , Humans , Larva/growth & development , Nigeria , Rain , SeasonsABSTRACT
An investigation of the carbohydrate energy metabolism of Rhabdias bufonis, the lung-dwelling nematode parasite of the African toad, Bufo regularis, indicates that the nematode stores very little glycogen (0.137 +/- 0.003% on a fresh weight basis) but does utilize oxygen in vitro. The intracellular distribution and high levels of activity observed for the enzymes phosphoenolpyruvate carboxykinase, pyruvate kinase, lactate dehydrogenase, malate dehydrogenase, malic enzyme and fumarate reductase suggest two alternative pathways of carbohydrate energy metabolism.
