acid-phosphatase and Onchocerciasis

Topics: Acid Phosphatase; Animals; Central America; Humans; Onchocerca; Onchocerciasis; Rain; South America; Tropical Climate

Onchocerca gutturosa and O. lienalis infections in British cattle were studied by examination of cattle post-mortem originating from North Wales and Cheshire (north west England). In 463 adult animals, the microfilarial (mf) prevalence was 28.5%. In 95.3% of the mf infected animals, gravid worms could not be found at either the ligamentum nuchae or the gastro-splenic omentum. Dermal mf at the head were identified as O. gutturosa on the basis of their highly significant association with the presence of gravid O. gutturosa at the ligamentum nuchae, which were found in only 3.2% of cattle. Mfs were isolated from different skin sites and from adult worms and a minimum of 10 mfs from each isolate were examined for width and acid phosphatase (AP) staining pattern. The width of O. gutturosa dermal mf was less than 4 micron (4 isolations), narrower than that of putative O. lienalis mf isolated from umbilical skin of cattle without evidence of O. gutturosa, which were in 20/22 isolations greater than 4 micron wide. The dermal mf were also distinguished on the basis of different AP staining patterns which, for each species, correlated closely with that of hatched intrauterine mf from their respective adult female worms. Based on the criteria of morphology and AP staining patterns the mf species prevalences in the survey population were estimated as O. lienalis 24.1% and O. gutturosa 2.2%, with a further 2.2% of cattle infected with both species. The results indicate that the predilection site of adult O. lienalis is not the gastro-splenic omentum. In North Wales, the distribution of the two species was different; O. lienalis was widely distributed in all cattle rearing areas both lowland and upland, whereas O. gutturosa was largely restricted to valleys close to major rivers.

Topics: Acid Phosphatase; Animals; Cattle; Cattle Diseases; England; Female; Male; Microfilariae; Omentum; Onchocerca; Onchocerciasis; Staining and Labeling; Wales

The patterns of acid phosphatase in strains of Onchocerca volvulus s.l. which parasitize an Amerindian population (Yanomami) in Venezuela's Upper Orinoco Basin were examined by using the naphthol AS-TR phosphate method. The study sample consisted of 40 Yanomami inhabiting a savannah area at 950 m above sea level and 21 Yanomami residents of a tropical rainforest area at an altitude of 250 m. Stained intrauterine microfilariae, still within the egg case, exhibited a diffuse distribution of the enzyme in the early stages of embryonic development and a negative reaction at a more developed stage. Four of the five enzyme staining patterns described by Omar (1978) were found in the 3157 microfilariae examined from skin snips. Their distribution was: Type I--17.2%, Type III--0.5%, Type IV--75.6% and Type V--6.6%. No examples of Type II were observed. The results indicate that acid phosphatase patterns of the Upper Orinoco Onchocerca strain most resemble those of strains from Guatemala and Yemen, and are different from the African strains found in Upper Volta and Liberia. The relative frequency of acid phosphatase patterns was modified by cryopreservation of microfilariae.

Topics: Acid Phosphatase; Adolescent; Adult; Animals; Child; Female; Freezing; Humans; Indians, South American; Microfilariae; Onchocerca; Onchocerciasis; Ovum; Skin; Venezuela

Histochemical differentiation of Onchocerca volvulus microfilariae from 164 patients in West African rain-forest (Liberia), Sudan-savanna (Upper Volta), Guatemala and the Yemen has been carried out using a staining method for the demonstration of acid phosphatase. Intrauterine microfilariae showed considerable changes in their enzyme activity during embryonic development which are probably associated with the maturation of the parasite before migration to the tissues. Five distinct types of staining patterns could be distinguished among microfilariae from the skin according to the localization of the enzyme in specific structures of the microfilaria. Two or more types of staining patterns were found in most persons in the different geographic regions. There were significant differences in the overall distribution of the various staining patterns in persons from the different areas. At the present state of our knowledge, little is known about the nature and significance of these differences in the staining patterns of microfilariae. The question of whether they can be ascribed to an ageing process, strain differences or other factors is discussed.

Topics: Acid Phosphatase; Burkina Faso; Guatemala; Humans; Liberia; Onchocerca; Onchocerciasis; Staining and Labeling; Sudan; Yemen