Q Fever in human and livestock populations in Oman.

In 2000, Q fever was documented for the first time in the Sultanate of Oman in two patients, one with chronic pericarditis and the other with acute pneumonia. In 2001, a study of a randomly selected group of 102 adult patients from different provinces in northern Oman, presenting to the University Hospital in Muscat with unrelated conditions (e.g., diabetes mellitus, ischemic heart disease), revealed that 10 (9.8%) were seropositive for previous Coxiella burnetii infection. Examination of sera from a randomly selected group of 54 healthy goats from eight different herds from three different provinces of Oman, obtained by the Veterinary Research Center in Muscat, revealed that 28 (52%) had been infected, and 5 sheep, each from one of four herds, were seropositive for C. burnetii. We suspect that Q fever is widely prevalent in human populations in Oman, and that infection is widespread in goat, and probably sheep and other livestock populations, throughout the country.

Poliomyelitis in Oman. I. The last outbreak?

Since 1988, the Sultanate of Oman has experienced three outbreaks of paralytic poliomyelitis. The last outbreak occurred in December 1993 and involved two children aged 10 months and 4 1/2 years. The children had received five and four doses, respectively, of trivalent oral polio vaccine (OPV) and lived in the same village. Serum neutralizing antibody tests suggested that paralytic polio in these children was due to poor antibody response to OPV. Wild poliovirus type 1 was isolated from both patients, as well as from seven of ten close contacts of the older child, and one of eight contacts of the younger child. All contacts had received three to six doses of OPV. Genomic sequence studies indicated that the virus isolates belonged to a genotypic group prevalent in southern and western Asia, but differed markedly from virus isolated during the 1988/89 outbreak, suggesting another importation of poliovirus. In response to the outbreak, supplementary immunization with OPV was given to children <6 years of age, initially in the affected district, and subsequently to children in the whole country. This study demonstrates that immunization with three to six doses of OPV did not prevent infection with wild poliovirus. In those children with sub-optimal response to OPV, infection resulted in paralytic poliomyelitis. The outbreak remained localized in one village, indicating that the outbreak control measures were effective.

Poliomyelitis in Oman. II. Toward eradication.

In the past decade, the Sultanate of Oman has experienced three outbreaks of paralytic poliomyelitis--a widespread polio type 1 epidemic in 1988/1989, four cases of polio type 3 in three different regions in 1991, and a localized type 1 outbreak in 1993. The lessons learnt from each of these epidemics have guided us to modify and improve our polio eradication activities. Currently, these activities include administration of five primary and three booster doses of trivalent oral polio vaccine, yearly national immunization campaigns (NIDs) since 1995 with coverage of >90%, localized immunization campaigns, acute flaccid paralysis (AFP) surveillance which involves reporting of all cases by facsimile to the Department of Surveillance within 24 h of detecting a case and weekly zero reporting from 22 sentinel sites, and virological testing of stool specimens of all AFP cases and their close contacts at the national, World Health Organization accredited laboratory. The cumulative success of these activities has resulted in Oman being free from polio for the past 6 years. However, the possibility of importation of wild poliovirus, particularly from southern and western Asia still exists.

Schistosomiasis in patients in the Sultanate of Oman.

BACKGROUND: Following an intensive public health eradication program, the focus of schistosomiasis mansoni at Salalah in Southern Oman (the only focus of schistosomiasis in Oman), appeared to have been eradicated in 1994. Since the vector snails for Schistosoma mansoni (and also for S. haematobium) were widely endemic in freshwater springs at Salalah, and reintroduction of infection (or introduction in the case of S. haematobium) was possible, we undertook a prospective study in 1995 for schistosomiasis in patients at the Sultan Qaboos University Hospital (SQUH), and to obtain evidence of visits by these patients to Salalah. PATIENTS AND METHODS: From May 1995 to May 2000, Omani and expatriate patients presenting at SQUH were evaluated for possible schistosomiasis (residence in an endemic region, suggestive clinical features) by a search for ova in stool, urine, or in tissue biopsies, or when ova were absent, by serodiagnosis. A retrospective survey of schistosomiasis patients diagnosed in SQUH from 1990 to April 1995 was also performed. Ministry of Health (MOH) data on reports of schistosomiasis (a notifiable disease) in Oman from 1991 to 2000, were obtained. RESULTS: Thirty patients with schistosomiasis were identified, 10 retrospectively and 20 in the prospective study. Patients were aged 9 to 60 years, and 25 of them (10 Omanis, 14 Egyptians, 1 Sudanese) contracted the infection in Africa, while 5 Omanis became infected in Salalah (3 in 1999). Twelve patients had schistosomiasis mansoni, 6 had schistosomiasis haematobia, and in the rest, infection by both parasites was confirmed or possible. The most common presentation (23%) was hepatosplenic schistosomiasis with portal hypertension. No patient admitted to contaminating freshwater with excreta in Salalah. MOH data revealed 3 to 14 cases of schistosomiasis were reported annually between 1991 and 2000, and that all schistosomiasis cases reported from 1994 to 1998 originated from Africa. CONCLUSION: Schistosomiasis remains an important health problem in Oman. Many doctors are unfamiliar with the clinical features and methods of diagnosis, thereby frequently causing delays in diagnosis. Because vector snails are endemic in Salalah, schistosomiasis patients must be detected and treated early. At infested freshwater sites at Salalah, mollusciciding should continue indefinitely, and notices should warn visitors not to contaminate the spring water.

First report of Q fever in Oman.

Although serologic evidence suggests the presence of Q fever in humans and animals in Saudi Arabia and the United Arab Emirates, acute Q fever has not been reported on the Arabian Peninsula. We report the first two cases of acute Q fever in Oman.

Epidemiological and clinical features of rotavirus gastroenteritis in Oman.

Two-hundred-and-seventeen children admitted with diarrhoea and 204 unmatched controls hospitalized during the 2-year period from November 1990 to October 1992 were included in this prospective study. Their stool samples were subjected to microscopy, cultures, ELISA for rotavirus and electron microscopy. Human rotavirus (HRV) was detected in 68 (31 per cent) of the stool samples in the study group and 12 (6 per cent) in the control group. There was an increased incidence in the cooler months of the year; typically, most of the affected infants and children presented with vomiting and respiratory symptoms, and had mild to moderate dehydration. Biochemical profile showed normal or hyponatraemia and normokalaemia. A more detailed community-based study of diarrhoeal diseases in Oman is to follow this pilot study.

Poliomyelitis in Oman: acute flaccid paralysis surveillance leading to early detection and rapid response to a type 3 outbreak.

Countries are increasingly requesting guidance on carrying out acute flaccid paralysis (AFP) surveillance, aimed at detecting and confirming all cases of acute paralytic poliomyelitis. The experience of Oman provides many lessons in this respect. AFP surveillance in Oman was established systematically. First, an epidemiologist was assigned to coordinate surveillance, and a laboratory for performing polio-virus isolation was identified. Next, operational guidelines for AFP surveillance were developed and widely promoted among health staff. The quality of the system has been monitored for more than 3 years with selected performance indicators. From January 1990 to April 1993, 49 AFP cases were reported, corresponding to an average annual rate of 2.1 AFP cases per 100,000 children aged less than 15 years. A total of 98% of the AFP cases were investigated within 48 hours of being reported; two stool samples were obtained from 94% of the cases. Following complete investigation, nearly a third of the reported AFP cases were classified as being clinically compatible with Guillain-Barré syndrome. Four AFP cases, all reported in 1991, were confirmed to be due to wild type 3 poliovirus. Because AFP surveillance detected these cases rapidly, Oman was able to carry out outbreak control measures promptly and more than 350,000 extra doses of oral poliovirus vaccine were delivered to children under 6 years of age.

Prevalence of antibodies to hepatitis C virus among Omani patients with renal disease.

The prevalence of hepatitis C virus (HCV) infection in Omani patients with renal disease was determined using a second-generation enzyme immunoassay which detects antibodies to three HCV antigens. Based on the results of this assay, 27 of 102 (26.5%) sera from patients on haemodialysis, 11 of 82 (13.4%) sera from kidney transplant patients, and 1 of 103 (1%) sera from non-dialysed, non-transplanted patients with various renal diseases had antibodies to HCV. Among healthy subjects, none of 134 medical students and 5 of 564 (0.9%) blood donors were anti-HCV positive. Thus, the prevalence of HCV infection in dialysis and renal transplant patients was significantly higher than that found in patients with renal disease who had been neither dialysed nor transplanted (p < 0.05). In the latter group of patients, the frequency of anti-HCV was low, and comparable to that of healthy Omani subjects.

Prevalence of hepatitis B, hepatitis delta, and human immunodeficiency virus infections in Omani patients with renal diseases.

PIP: Patients treated at the Royal Hospital in Oman during January-June 1991 were divided in 3 groups. The 1st group included 103 patients (49 males, 54 females, with a mean of 39 years) who attended the Nephrology Clinic and none of whom were on dialysis. In the 2nd group there were 102 patients (46 males, 56 females, with a mean age of 42 years) on regular hemodialysis (with a mean duration of 35 months) because of end-stage renal failure. The 3rd group comprised 82 kidney transplant patients (44 males, 38 females, with a mean age of 33 years) with a mean duration of prior hemodialysis of 9 months in 80 patients. Blood serum samples from all patients as well as from 134 medical students and 564 blood donors were tested for hepatitis B surface antigen (HBsAg) and hepatitis B core antibody (anti-HBc) by enzyme-linked immunosorbent assay. HBsAg-positive samples were tested for antigen and antibody to hepatitis delta virus (HDV). The prevalence of HBsAg was significantly higher in hemodialysis and renal transplant patients than in nephrology clinic patients (P .05). Previous exposure to HBV was found in 48 of 103 (46.6%) nephrology clinic patients, in 53 of 102 (52%) hemodialysis patients, and in 43 of 82 (52.4%) renal transplant patients. Anti-HBc prevalence rates were significantly lower in medical students (23.1%) and blood donors (27%) than in the patient groups (P .001). In HBsAg-positive subjects HDV infection was found in 1 of 13 (7.7%) patients on dialysis and 2 of 9 (22.2%) kidney transplant recipients who had been transfused in the past. A double infection of HBV and HCV was found only in 4 hemodialysis and 2 transplant patients among 287 patients and 698 healthy subjects tested. Among 5 HIV-infected patients 3 transplant patients seroconverted between 3 and 7 months after kidney transplantation abroad; and 2 hemodialysis patients seroconverted after repeated dialysis and multiple blood transfusions used for kidney transplantation abroad.^ieng