Surveillance of adverse events following immunization: 10 years' experience in Oman.

A descriptive record-based review of adverse events following immunization (AEFI) was carried out in Oman using the national database for the period 1996-2005. A total of 790 adverse event reports were received with an annual rate during the review period of 33.7 per 100 000 population or 10.8 per 100 000 doses administered. There were no reported deaths. The most frequently reported AEFI were BCG adenitis (69.7 per 100 000 doses) and local reactions (3.6 per 100 000 doses respectively). The statistically significant higher rates among males, in children aged > 2 years and in some sparsely populated regions of Oman need further research. AEFI rates in Oman were similar or below the international averages

Absence of lymphatic filariasis infection among secondary-school children in Oman.

The endemicity status of lymphatic filariasis in Oman is uncertain, with only sporadic cases reported, mostly imported. Immunochromatographic card test surveys were carried out to assess the presence of circulating Wuchereria bancrofti antigenaemia as a marker for active infection in children from suspected high-risk areas of Oman (South Batinah and Dhofar). Lot quality assurance sampling surveys were carried out on a minimum of 250 secondary-school children aged 17-18 years in each of 8 districts from February 2004 to March 2004. All tested students were negative for circulating W. bancrofti antigen. Based on these findings as well as previous data, Oman may possibly be classified as a nonendemic country, with no evidence of indigenous lymphatic filariasis transmission.

Considerations for introduction of a rotavirus vaccine in Oman: rotavirus disease and economic burden.

Rotavirus is the most common cause of fatal childhood diarrhea worldwide. We provide the first estimates of the health care and economic burden of severe rotavirus disease in Oman. We conducted active, hospital-based surveillance of rotavirus disease at 11 regional public hospitals in Oman, using the guidelines suggested by the generic World Health Organization protocol. From July 2006 through June 2008, all children aged <5 years who were hospitalized for acute gastroenteritis were enrolled in the surveillance program, and their stool samples were tested for rotavirus using a commercially available enzyme immunoassay (ID EIA Rotavirus Test; Dako Diagnostics). Rotavirus was detected in samples from 1712 (49%) of 3470 children. These children were hospitalized for a median of 3 days for severe diarrhea. A marked seasonal peak was evident with a majority of the cases occurring from December through May. Of the rotavirus cases, 69% occurred in children aged 6-17 months. We identified a diverse strain pattern in Oman, with G2 (37%), G1 (38%), and G9 (11%) accounting for most of typeable strains. By our burden estimates, the Omani government spends an estimated US$791,817 and US$1.8 million annually to treat rotavirus-associated diarrhea in the outpatient and hospital settings, respectively. A rotavirus vaccination program might substantially reduce the burden of severe diarrhea among children in Oman.

Epidemiology of meningitis in Oman, 2000-2005.

We reviewed the epidemiologic features and trends for 771 cases of meningitis in Oman from January 2000 to December 2005. We found 69% were bacterial in origin and 13% were viral. Leading bacterial pathogens included Haemophilus influenzae (15%), Streptococcus pneumoniae (14%) and Nesseria meningitidis (12%). For 56% of patients with suspected pyogenic meningitis, no specific bacterial pathogen could be identified. Peak occurrence was in children under 2 years old. The incidence of H. influenzae type b decreased by almost 100% after implementation of the national immunization programme in 2001, while the incidence of cases caused by S. pneumoniae and N. meningitidis remained steady.

Measles epidemiology and its implications for a vaccination programme in Oman.

To describe the epidemiology of measles in Oman and the implications for a vaccination programme, we conducted a retrospective record-based study from 1 January 2000 to 31 December 2003 using data from the national epidemiological surveillance system. All cases notified as suspected measles during the study period were included. Of the 185 notified cases, 19.4% were confirmed measles positive. Blood samples for measles IgM were collected in 97.3% of cases. The mean age of measles cases was 8.0 (SD 10.7) years. The estimated overall incidence rate of measles for the study period was 0.53 per 100,000 person-years. Regression analysis indicated measles was significantly commoner among non-Omanis and children who had not been vaccinated.

Safe injection practices in a primary health care setting in Oman.

We conducted a national survey of injection practices in 78 government health facilities in Oman in 2001. Data were obtained by interview and observation. The overall standards were good and the stock of disposable equipment was adequate. Recapping of needles was only observed in 1 facility but in 28%, waste disposal boxes contained recapped needles and 17.9% reported needle-stick injuries in the past year. In 9% of the institutions, sharps were observed around the facility, in 12.8% unsupervised disposal containers were seen and in 11.5% unsafe storage of full boxes was observed. While disposal of the used waste was done away from the health facility, only 33.3% disposed of it by correct incineration.

Pharyngeal carriage of serogroup W135 Neisseria meningitidis in Hajjees and their family contacts in Morocco, Oman and Sudan.

In 2000 the global outbreak that began in Saudi Arabia was caused by a W135:2a:P1.5,2 strain of Neisseria meningitidis belonging to the ET-37 complex and to ST-11. There was concern that introduction of this epidemic clone (EC) might lead to a wave of outbreaks in the African meningitis belt. The WHO therefore initiated studies of meningococcal carriage among pilgrims and their family contacts in Morocco, Oman and Sudan, 3 to 12 months after the Hajj 2000. In Morocco, 1186 persons were swabbed 3 times. Ninety-five meningococcal strains were isolated from 2.7% of the specimens. Pulsed-field gel electrophoresis showed that 32 (33.6%) were identical with the EC. In Sudan, 5 strains identical with the EC were obtained after sampling 285 persons. In Oman, among 18 meningococcal strains isolated from 399 subjects, 11 (61.1%) belonged to the EC. The important pharyngeal carriage of W135 (EC) and its role in the 2001-2002 outbreaks in Burkina Faso argues for the necessity of reinforcing surveillance, and adapting and planning responses in Africa and the Middle East using the most appropriate vaccine.

The WHO dose pole for the administration of praziquantel is also accurate in non-African populations.

In 2001, WHO developed a pole for the administration of praziquantel without the use of weighing scales, with encouraging results in African populations. In the present study, the pole was tested on height/weight data from 9354 individuals from 11 non-African countries. In more than 98% of the individuals (95% CI 97.8-98.4) the pole estimated an acceptable dosage (30-60 mg/kg), a performance statistically similar to that observed in African populations. Reproducing the present pole in the form of a strip of paper and including it in each container of praziquantel would greatly facilitate the administration of the drug in large-scale interventions.

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.

Drug-susceptibility pattern of mycobacterium tuberculosis among pulmonary tuberculosis patients in riyadh, saudi arabia.

OBJECTIVE: To identify the pattern of drug-susceptibility of newly diagnosed pulmonary tuberculosis patients in Riyadh, we conducted a study on all Mycobacterium tuberculosis positive-culture patients admitted to Sahari Chest Hospital from January 1994 to April 1995. METHODS: Demographic data, antituberculous therapy and drug-susceptibility testing results of each patient were reviewed from patients' hospital records. The samples were cultured on Lowenstein-Jensen media and drug susceptibility was tested by Bactec 12B (Middlebrook 7H12) media against selected antituberculous drugs RESULTS: Drug susceptibility was performed on 362 (91%) of the sputum positive-cultures. The overall initial resistance rate (1 or more drugs) was 12.4%. Initial. resistance was more common with a single drug (9.4%), followed by two drugs (2.3%) and then three drugs (0.3%). Resistance to isoniazid was most common (10.4%), followed by streptomycin (2.7%), rifampicin (1.9%) and ethambutol (0.6%). Single isoniazid resistance was 60%, followed by two drugs: streptomycin and isoniazid (13.3%). CONCLUSION AND RECOMMENDATIONS: Resistance to multiple drugs is not yet a significant problem in Riyadh. A continuous monitoring of drug resistance is important for planning and assessing the national TB control program. Timely and complete reporting is essential to identify the problem as and when it begins.

Crimean-congo haemorrhagic fever: a seroepidemiological and tick survey in the Sultanate of Oman.

In 1995 and 1996, 4 persons from the Sultanate of Oman were confirmed with clinical Crimean-Congo haemorrhagic fever (CCHF). To assess the prevalence of CCHF virus infection in Oman, a convenience sample of imported and domestic animals from farms, abattoirs and livestock markets was examined by enzyme-linked immunosorbent assay (ELISA) for immunoglobulin G (IgG) antibodies to CCHF virus. Ticks were collected from selected animals, identified, pooled by species, host and location and tested for evidence of infection with CCHF virus by antigen-capture ELISA. Serum samples from individuals working in animal and nonanimal contact-related jobs were also tested for CCHF antibodies. Serological evidence of infection was noted in 108 (22%) of 489 animals. Most of the ticks collected (618 of 912) from all species of sampled livestock were Hyalomma anatolicum anatolicum, a competent vector and reservoir of CCHF virus. 243 tick pools were tested for CCHF antigen, and 19 pools were positive. Of the individuals working in animal contact-related jobs, 73 (30.3%) of 241 non-Omani citizens and only 1 (2.4%) of 41 Omani citizens were CCHF antibody-positive. Butchers were more likely to have CCHF antibody than persons in other job categories. The presence of clinical disease and the serological results for animals and humans and infected Hyalomma ticks provide ample evidence of the presence of CCHF virus in yet another country in the Arabian Peninsula.

Surveillance of adverse events following immunization: 10 years' experience in Oman

A descriptive record-based review of adverse events following immunization [AEFI] was carried out in Oman using the national database for the period 1996-2005. A total of 790 adverse event reports were received with an annual rate during the review period of 33.7 per 100000 population or 10.8 per 100000 doses administered. There were no reported deaths. The most frequently reported AEFI were BCG adenitis [69.7 per 100000 doses] and local reactions [3.6 per 100000 doses respectively]. The statistically significant higher rates among males, in children aged > 2 years and in some sparsely populated regions of Oman need further research. AEFI rates in Oman were similar or below the international averages

Absence of lymphatic filariasis infection among secondary-school children in Oman

The endemicity status of lymphatic filariasis in Oman is uncertain, with only sporadic cases reported, mostly imported. Immunochromatographic card test surveys were carried out to assess the presence of circulating Wuchereria bancrofti antigenaemia as a marker for active infection in children from suspected high-risk areas of Oman [South Batinah and Dhofar]. Lot quality assurance sampling surveys were carried out on a minimum of 250 secondary-school children aged 17-18 years in each of 8 districts from February 2004 to March 2004. All tested students were negative for circulating W. bancrofti antigen. Based on these findings as well as previous data, Oman may possibly be classified as a nonendemic country, with no evidence of indigenous lymphatic filariasis transmission

Epidemiology of meningitis in Oman, 2000-2005

We reviewed the epidemiologic features and trends for 771 cases of meningitis in Oman from January 2000 to December 2005. We found 69% were bacterial in origin and 13% were viral. Leading bacterial pathogens included Haemophilus influenzae [15%], Streptococcus pneumoniae [14%] and Nesseria meningitidis [12%]. For 56% of patients with suspected pyogenic meningitis, no specific bacterial pathogen could be identified. Peak occurrence was in children under 2 years old. The incidence of H. influenzae type b decreased by almost 100% after implementation of the national immunization programme in 2001, while the incidence of cases caused by S. pneumoniae and N. meningitidis remained steady

Measles epidemiology and its implications for a vaccination programme in Oman

To describe the epidemiology of measles in Oman and the implications for a vaccination programme, we conducted a retrospective record-based study from 1 January 2000 to 31 December 2003 using data from the national epidemiological surveillance system. All cases notified as suspected measles during the study period were included. Of the 185 notified cases, 19.4% were confirmed measles positive. Blood samples for measles IgM were collected in 97.3% of cases. The mean age of measles cases was 8.0 [SD 10.7] years. The estimated overall incidence rate of measles for the study period was 0.53 per 100 000 person-years. Regression analysis indicated measles was significantly commoner among non-Omanis and children who had not been vaccinated

Safe injection practices in a primary health care setting in Oman

We conducted a national survey of injection practices in 78 government health facilities in Oman in 2001. Data were obtained by interview and observation. The overall standards were good and the stock of disposable equipment was adequate. Recapping of needles was only observed in 1 facility but in 28%, waste disposal boxes contained recapped needles and 17.9% reported needle-stick injuries in the past year. In 9% of the institutions, sharps were observed around the facility, in 12.8% unsupervised disposal containers were seen and in 11.5% unsafe storage of full boxes was observed. While disposal of the used waste was done away from the health facility, only 33.3% disposed of it by correct incineration