Intestinal polyparasitism in a rural Kenyan community.

BACKGROUND: Polyparasitism seems to be a common feature in human populations in sub-Saharan Africa. However, very little is known about its epidemiological significance, its long term impact on human health or the types of interactions that occur between the different parasite species involved. OBJECTIVES: To determine the prevalence and co-occurrence of intestinal parasites in a rural community in the Kibwezi, Makueni district, Kenya. DESIGN: A cross sectional study. SETTING: Kiteng'ei village, Kibwezi, Makueni district, between May and September 2006. SUBJECTS: One thousand and forty five who comprised of 263 adult males, 271 adult females > 15 years of age and 232 boys, and 279 girls <15 years of age. INTERVENTIONS: All infected members of the community were offered Praziquantel (at dosages of 40 mg/kg body weight) for Schistosomiasis and Albendazole (600 mg) for soil transmitted helminths. RESULTS: A total of ten intestinal parasite species (five protozoan and five helminth parasite species) were present in this community and polyparasitsm was common in individuals 5-24 years of age with no gendar related differences. Most of the infections were mild. The protozoan parasites of public health significance present were Entamoeba histolytica and Giardia lamblia with prevalence of 12.6% and 4.2%, respectively. The helminth parasites of public health significance in the locality were Schistosoma mansoni with a prevalence of 28%, and hookworms prevalence of 10%. About 53% of the study population harboured intestinal parasite infections, with 31% of the infected population carrying single parasite species infections, and 22% harbouring two or more intestinal parasite species per individual. Significant positive associations (p values <0.05) were observed between S. mansoni and hookworms, hookworms and Hymenolepis. nana and Entamoeba histolytica and Entamoeba coli. CONCLUSION: Intestinal polyparasitism was common in the Kiteng'ei community, particularly in individuals aged of 5-24 years old. An integrated control programme of approach would be recommended for the control of S. mansoni, hookworms and Entamoeba histolytica for this community.

A study of cystic echinococcosis in slaughter animals in three selected areas of northern Turkana, Kenya.

In an attempt to establish the prevalence of cystic echinococcosis, a study was conducted in slaughter animals in three divisions of northern Turkana, Kenya. A total of 5752 goats, 588 sheep, 381 cattle and 70 camels were examined at slaughter. Echinococcus granulosus metacestodes were found in 19.4% of the cattle, 3.6% of sheep, 4.5% of goats and 61.4% of camels. The prevalence of cystic echinococcosis in cattle, sheep and goats was higher in Lokichogio than in either Kakuma or Central divisions. On the other hand, the prevalence of the disease in camels was higher in Central (84.6%) than either Lokichogio (70.6%) or Kakuma (50%). The differences in prevalence rates in different study areas are attributed to differences in environmental conditions, livestock stocking intensity and cross-border migration of livestock.

Application of ultrasonography in prevalence studies of hydatid cysts in goats in north-western Turkana, Kenya and Toposaland, southern Sudan.

A study was done to determine the prevalence of hydatid cysts in goats using ultrasonography. A total of 1,390 goats were examined, 43,6 % (606/1,390) of them from north-western Turkana, Kenya, and 56,4% (784/1,390) from Toposaland, southern Sudan. Hydatid cysts were visualized in 1,82 % (11/ 606) of the goats from north-western Turkana and 4,34% (34/784) of those from Toposaland. Unlike abattoir surveys, the prevalence data obtained in this study were unbiased because entire flocks were examined. The lower prevalence rate of the disease in goats from Turkana was attributed to the hydatid disease control programme in that area, which is absent in Toposaland.

Hepatic cyst in a Turkana woman - case report.

An unusual case of hepatic hydatid cyst in a 27-year old female is reported. The patient had abdominal distention of 10-year duration, pain, pallor of mucous membranes, and was grossly wasted. Ultrasonography revealed a large hydatid cyst that covered most of the abdomen. A successful surgical intervention was performed and 24 litres of hydatid fluid drained.

Prevalence of intestinal parasites among children in southern Sudan.

A study was conducted in southern Sudan to determine the prevalence of intestinal parasites among school children. A total of 275 stool samples which were examined using formol-ether concentration techniques yielded 15 different species of parasites. Hook worm with a prevalence of 13.1% was the predominant nematode followed by Strongyloides stercoralis (3.3%), Trichostrongylus (2.5%), Schistosoma mansoni (2.2%) and Trichuris trichiura (1.8%). Ascaris lumbricoides and cestodes were not detected in this population. Intestinal protozoans were common. Entamoeba coli (37.8%), Entamoeba histolytica (28.4%) and Giardia lamblia (9.8%). Children in the age group 6-10 years old were the most affected followed by the 11-15 year-old age group. The infection rate was slightly higher in males than females.

Oxfendazole treatment for cystic hydatid disease in naturally infected animals.

Few chemotherapeutic agents are available for the medical management of hydatid disease caused by the parasite Echinococcus granulosus. In order to test the potential of oxfendazole for the treatment of infection with this parasite, nine infected goats and four sheep were given oxfendazole twice weekly at a dose of 30 mg/kg of body weight for 4 weeks and monitored by ultrasound for an additional 4 weeks. Efficacy was finally evaluated by postmortem examination, including determination of protoscolex viability and cyst wall histology. In treated animals, protoscolices were dead or absent in 97% of cysts from oxfendazole-treated animals compared to 28% of cysts from untreated control animals. On postmortem examination, 53% of cysts from treated animals were found to be grossly degenerate. A sample of those cysts that appeared potentially viable all demonstrated evidence of severe damage to the cyst wall. By light microscopy, cysts showed severe disorganization of the adventitial layer with invasion of inflammatory cells and in some cases frank necrosis with no apparent adventitial layer. The follow-up period for assessment of the drug's ability to cause complete degeneration and resorption of cysts was relatively short. This study, however, indicates that oxfendazole is at least as effective as and is easier to administer than albendazole for the treatment of hydatid disease.

Ultrastructural changes in Ascaris suum after oxibendazole treatment.

The effect of oxibendazole treatment on adult Ascaris suum was assessed using scanning and transmission electron microscopy. The changes included collapse of the lip papillae, rupture of buccal cavity cuticle, prolapse of the pharynx, degeneration of epithelial cells and erosion of microvilli. Theses changes may lead to impaired digestion and absorption of nutrients and cause cellular autolysis, resulting in the death of the worm.

Hydatid disease in Toposaland, Southern Sudan.

A total of 1010 people in Toposa-land Southern Sudan were screened for hydatid disease using a portable ultrasound scanner. The prevalence of the disease was shown to be 3.5% with a majority of the cysts (60%) being located in the liver. Unlike the situation observed among the Turkana people, the level of hydatid infection within various age groups depict progressive linear increase. In addition, the level of the disease infection in both sexes show no significant difference whereas in Turkana the prevalence in women is twice that found in men. The occurrence of such differences within two culturally closely related communities is an enigma requiring further investigations. In the absence of guaranteed source of funding on a long term basis which is essential for a hydatid control programme, the control measures recommended include incorporation of hydatid education into the school and health curriculum.

Ultrastructural Changes in Ascaris Suum after Oxibendazole Treatment

The effect of oxibendazole treatment on adult Ascaris suum was assessed using scanning and transmission electron microscopy. The changes included collapse of the lip papillae; rupture of buccal cavity cuticle; prolapse of the pharynx; degeneration of epithelial cells and erosion of microvilli. Theses changes may lead to impaired digestion and absorption of nutrients and cause cellular autolysis; resulting in the death of the worm

Prevalence of Oncocerca volvulus in Southern Sudan.

Onchocerciasis is endemic in southern Sudan. The prevalence in human population may range from 10% to 40%. In the Eastern Equatorial Region of Southern Sudan, more cases are found in Nimule on the Sudan-Uganda border than in rural highlands of Labone and Chukudum basins. Onchocerciasis was highest in males (with a prevalence of 70.2% based on data from hospital records)) than in females, with prevalence of 19%. Overall, prevalence of onchocerciasis in children was 10.8%.Considering cost-effectiveness, public health priorities and the security situation in this area, we recommend active search on onchocerciasis cases in the community and treatment.

Prevalence of malaria in southern Sudan.

The prevalence of malaria in the human population of southern Sudan was studied during March to April, 1996. A total of 330 people including adults and children were screened for malaria by microscopic examination of Giemsa stained thick and thin blood smears prepared from a finger prick sample. Plasmodium falciparum was the only malaria parasite detected in blood smears in the present study, even though hospital records indicated presence of P. vivax. About 24.5% of those examined were infected. .

Prevalence of human hydatid disease in southern Sudan.

A total of 3443 people were screened by ultrasound to determine the prevalence of hydatid disease in southern Sudan. Hydatid cysts were found in 16 (0.5%) of the people screened. Thirteen of the 16 hydatid cases were from among the Bouya people who showed an overall hydatid prevalence of 2% by ultrasound. All ultra-sound positive cases were further confirmed by dot-blot ELISA. At the time of the survey, Chukudum Hospital had five cases with histories and clinical manifestations consistent with hydatidosis. However, on scan examination only three of them were confirmed to be cases of hydatid disease. The proportion of hydatid infected women in south-western Sudan was almost twice that of men (M:F ratio of 1:1.7), with most of those infected being women in the child-bearing age bracket. Dogs are common in this area and they could be the main reservoirs of Echinococcus granulosus in the Sudan. Due to the low prevalence of hydatid in humans in the study area, and the dispersed nature of the population, it is recommended that hydatid control measures for south-western Sudan include an educational component coupled with treatment of the infected people.

Ascaris suum: ultrastructural effect of in vitro albendazole therapy.

The effect of albendazole therapy on adult Ascaris suum was examined using transmission electron microscopy. The drug induced prominent ultrastructural changes which included the presence of necrotic dense bodies, myelin whorls which appeared to represent various stages of lysosomal formation and autolysis, disruption and erosion of the microvilli. The effects were mainly confined to the central region of the intestinal epithelial cells.

Prevalence of Onchocerca Volvulus in Southern Sudan

Onchocerciasis is endemic in southern Sudan. The prevalence in human population may range from 10to 40. In the Eastern Equatorial Region of Southern Sudan; more cases are found in Nimule on the Sudan-Uganda border than in rural highlands of Labone and Chukudum basins. Onchocerciasis was highest in males (with a prevalence of 70.2based on data from hospital records)) than in females; with prevalence of 19. Overall; prevalence of onchocerciasis in children was 10.8.Considering cost-effectiveness; public health priorities and the security situation in this area; we recommend active search on onchocerciasis cases in the community and treatment

Prevalence of Malaria in Southern Sudan

The prevalence of malaria in the human population of southern Sudan was studied during March to April; 1996. A total of 330 people including adults and children were screened for malaria by microscopic examination of Giemsa stained thick and thin blood smears prepared from a finger prick sample. Plasmodium falciparum was the only malaria parasite detected in blood smears in the present study; even though hospital records indicated presence of P. vivax. About 24.5 of those examined were infected

Prevalence of Human Hydatid Disease in Southern Sudan

A total of 3443 people were screened by ultrasound to determine the prevalence of hydatid disease in southern Sudan. Hydatid cysts were found in 16 (0.5) of the people screened. Thirteen of the 16 hydatid cases were from among the Bouya people who showed an overall hydatid prevalence of 2by ultrasound. All ultra-sound positive cases were further confirmed by dot-blot ELISA. At the time of the survey; Chukudum Hospital had five cases with histories and clinical manifestations consistent with hydatidosis. However; on scan examination only three of them were confirmed to be cases of hydatid disease. The proportion of hydatid infected women in south-western Sudan was almost twice that of men (M:F ratio of 1:1.7); with most of those infected being women in the child-bearing age bracket. Dogs are common in this area and they could be the main reservoirs of Echinococcus granulosus in the Sudan. Due to the low prevalence of hydatid in humans in the study area; and the dispersed nature of the population; it is recommended that hydatid control measures for south-western Sudan include an educational component coupled with treatment of the infected people

Cellular immunity to Echinococcus granulosus cysts

A fundamental feature of Echinococcus granulosus infection is its chronicity. There are many reasons for this; including weak natural immunity and the ability of the larval stages to evade or resist elimination by the hosts' specific immune responses. To identify the types of hosts' cellular immune response; a series of ultrastructral studies of hydatid cysts surgically removed from Turkana patients was conducted based on transmission electron microscopy. Ultrastructurally; the ectocyst (adventitial layer) is organised into three layers; an inner layer containing mainly the infiltrating mononuclear leukocytes; a middle; loose connective tissue layer with inflammatory cells mainly plasma cells; fibroblasts; scant neutrophils; eosinophils and lymphocytes; and an outer loose connective tissue layer that blends with the surrounding host tissue. The mast cells and basophils were not observed. This study has showm that the adventitial layer of hydatid cysts infiltrated by leukocytes; principally by macrophages and plasma cells