Risk of contamination of human and agricultural environment with parasites through reuse of treated municipal wastewater in Riyadh, Saudi Arabia.

Two selected sites in the Riyadh metropolitan area were surveyed for the presence of human pathogenic parasites in treated municipal wastewater (TMWW). A total of 100 samples were collected from both sites at two different seasons, the winter and summer reason. The most common parasites seen were the larvae and adult of Strongyloides sp. There were few Ascaris lumbricoides ova, some of which were embryonated and possibly infective, while the highest frequency of Ascaris ova (100 +/litre) was found at site 2 h, the highest frequency of Strongyloides sp. larvae (36-72/litre) and Strongyloides sp. adult (100 +/litre) were found at sites 2 W and 1 W respectively. The variation between sites and seasonal fluctuations showed a significant difference in parasite per litre. High atmospheric temperatures in the Riyadh area seem to be lethal to most intestinal pathogens similarly the absence of protozoal cysts in the TMWW could be attributed to certain treatment processes and other environmental factors. Data obtained from this study will be valuable in planning for the control of parasitic diseases in particular and public health pathogens in general.

Cryptosporidiosis in young children suffering from diarrhoea in Riyadh, Saudi Arabia.

A one-year study of patients (0-120 months of age) with diarrhoea at King Abdel-Aziz University Hospital (KAUH) in Riyadh, Saudi Arabia, detected two cases of cryptosporidiosis. Stool specimens from 174 children with diarrhoea and negative for other parasitic infection were examined using a safranin-methylene blue stain (S-MB). Two children (L.1%) were showing Cryptosporidium oocysts. None of 50 control children who did not have diarrhoea and was free of Giardia lamblia was Cryptosporidium positive.

Bertiella sp. infection in man in Saudi Arabia.

Tapeworm proglottids and eggs of Bertiella sp. were reported from the stools of a 28-year-old Yemeni male worker in Saudi Arabia, who complained mainly of non-specific gastro-enteritis. This appears to be the first report of an Anoplocephaline infection in man in Saudi Arabia. Niclosamide was effective in removing the parasites.

Serodiagnosis of human hydatid disease in Riyadh, Saudi Arabia.

The Indirect Haemagglutination (IHA) test was used routinely for the diagnosis of hydatid disease in patients at the King Abdul Aziz and King Khalid University Hospitals, Riyadh, Saudi Arabia. Among 52 patients with suspected human hydatid disease, 30 positive cases were detected by means of serodiagnosis. As a control group, the level of hydatid IHA antibodies were determined in blood donors and in patients with no history of human hydatid disease. The serological results obtained in this control group showed that 70% had no hydatid IHA antibodies whereas 25% had antibody titres of 1:4 to 1:8, which are of no clinical significance.

Some aspects of the epidemiology of cutaneous leishmaniasis in the Al-Kharaj area of Saudi Arabia.

Four hundred and thirteen patients with skin ulcers were clinically diagnosed as suffering from cutaneous leishmaniasis; 82 (approximately 20%) of these cases were confirmed microscopically. Ulceration occurred mainly on the exposed parts of the body. Of the total cases 69% were Egyptian labourers, 14% Saudis and the remaining 17% Syrian, Pakistani, Yemeni or Filippino. Most of the Saudi patients were children aged up to ten years. Two Rattus rattus collected during the study had skin ulcerations on the face, indicating possible infection with leishmaniasis. Poor living conditions on the farms seem partly responsible for the high rate of incidence of cutaneous leishmaniasis among the labourers.

Prevalence of intestinal parasitic infections in Riyadh district, Saudi Arabia.

A total of 23,516 stool specimens collected from patients attending three medical centres in Riyadh, Saudi Arabia, were examined for intestinal parasites. Of these 5737 (24.4%) were positive. Entamoeba histolytica (8.8%) and Giardia lamblia (6.3%) were the commonest parasites found, and in the age group of one to 15 years. Giardia was found in 14.8% of males and 11.9% of females. Other intestinal parasites present included Ascaris lumbricoides, Trichuris trichiura, Schistosoma mansoni, Hymeolepis nana. Ancylostoma duodenale, Enterobius vermicularis. Taenia saginata and Schistosoma hematotium.

A serological survey of the prevalence of Toxoplasma gondii antibodies in dogs and cats in Saudi Arabia.

The prevalence of Antibodies to Toxoplasma gondii in dogs and cats were determined by an indirect haemagglutination (IHA) test. 3% of the dogs' sera and 15.2% of that of the cats showed titres diagnostically significant of toxoplasmosis in humans; their possible role in transmission of toxoplasmosis to humans in Saudi Arabia is discussed.

Pattern of intestinal parasitic infection in preschool children in Riyadh, Saudi Arabia.

A total of 1,167 stool specimens collected from 0.6-6 years old patients attending King Abdel Aziz University Hospital (KAUH) in Riyadh, were examined for intestinal parasites. Of these 243 (20.8%) were positive. Giardia lamblia (13.5) and Enterobius vermicularis (4.2%), were the commonest parasites found. Other parasites present include Ascaris lumbricoides, Entamoeba histolytica and Hymenolepis nana. Abdominal pain (38.6%) and diarrhoea (27.6%) were the most common causes of referral presented among both males and females examined groups. Out of 211 patients positive for different parasites and showing different causes of referral, 45.5% were accompanied with abdominal pain and 22.3% having pruritus ani, while the percentage of patients having diarrhoea and positive for different parasites (9.5%) are less. It has been concluded that diarrhoea is not a major sign of parasitic infestation in 0.6-6 years old age group. Other causes of referral include, loss of appetite, underweight and failure to thrive which are mainly associated with Giardia lamblia infection.

Indirect haemagglutination (IHA) test in the serodiagnosis of amoebiasis.

Among 72 patients clinically suspected of Entamoeba histolytica (E. histolytica) infections, 39 positive cases (54%) were detected serologically by the indirect hemagglutination (IHA) test. Parasitologically, microscopic examination of three consecutive stool specimens from all these patients indicated positivity for E. histolytica cysts and or trophozoites in 10 of the patients with IHA antibody titers greater than or equal to 1:128, which is of clinical significance. Another 2 patients were parasitologically positive but showed low IHA antibody titres (1:32-1:64); follow up indicated response to treatment with metronidazole. The highest serological positivity (100%) were detected in patients with liver abscess, all were clinically proven cases of extra-intestinal amoebiasis. IHA antibody levels of clinical significance were seen in all four patients with chronic dysentery with parasitological evidence of E. histolytica in their stools. In a group of patients with abdominal pain nine positives were detected serologically, four of which were positively diagnosed concurrently by parasitology; the remaining five patient's sera showed high IHA antibody titres with absence of cysts or trophozoites in stools, indicative possibly of persistence of antibodies from past infection. The serologic determination of E. histolytica IHA antibodies in a control group consisting of normal healthy school children and adults of both sexes without any clinical evidence of amoebiasis showed the absence of any positive titres of clinical significance; low titres (1:32-1:64) were detected in 5.2% of 232 sera tested. Parasitological examination of three consecutive stool specimens from all individuals in the control group showed the presence of cysts of E. histolytica in just two among 232 tested (0.9%).