Hepatitis ''A'' Outbreak in Rania, Taif region, 2009.

On 15/1/1430H, the General Health Directorate of Taif region reported an unusually large number of hepatitis A cases from different villages of Rania, an area located in Makkah Al Mokarramah region, south west Saudi Arabia (total population 13500). A team from the Field Epidemiology training program (FETP) investigated this outbreak.

A case control study was conducted to identify risk factors associated with the occurrence of the disease. The objectives of this study were to describe the outbreak, identify possible risk factors, and provide recommendations for control and prevention.

All villages of Rania area were included. A case was defined as any person living in the catchments areas of Rania, who had presented to the PHCC with jaundice, and/or had been diagnosed as suffering from hepatitis A clinically, and/or confirmed by laboratory tests, during the period from 14/01/1430 to 15/02/1430 H (10 January to 10 February 2009). A control was defined as any person who lived in the same area who had not complained of jaundice symptoms before 15/02/1430H (10 February 2009). Three controls were selected for each case, either from the same household or nearest neighbor. Data was collected by face to face interviews and documented on a structured data collection instrument.

The epidemic curve showed three peaks (once every 1-2 weeks) which most likely represents person to person transmission and may be some sort of extended common source (Figure-1).

The cases were scattered over 8 villages. We were able to identify and interview 25 cases that fulfilled the case definition criteria. Their ages ranged from 7-15 years (mean ±Standard Deviation (SD) of 11.2 ±2.2 years). There were 17 males (68%), and 8 females (32%). Twenty three cases were students at different levels, 23 (92%) were Saudis and 2 (8%) were Yemenis.

Symptoms reported were vomiting (72%), fever (68%), dark urine (64%), jaundice (48%), nausea (48%), anorexia (48%), abdominal pain (40%), diarrhea (27.6%), headache (24%), itching (24%), muscles and joints pain (20%), and general weakness (12%).

We were able to identify and interview 75 controls. Their ages ranged between 4 – 17 years (mean ± SD of 11.2 ± 3.13 years); 46 males (61.3%), and 29 females (38.7%); 71 were students; 69 (92%) were Saudis and 6 (8%) were Yemeni.

Among the 25 cases, 18 (72%) reported contact with a known case of jaundice, compared to 33 (44%) of the 75 controls (OR= 3.27, 95% CI=1.22 – 9.21) and this association was statistically significant. The risk was much higher when the jaundiced cases were school peers (OR=16, 95% CI= 2.82 – 103), which was statistically significant. However, contact with a jaundiced person who lived in the same household (OR=2.12, 95% CI=0.53 – 8.48), or was a relative (OR =1.33, 95% CI= 0.16 – 9.11), or neighbor (OR=3, 95% CI=0.31 – 26.0), was not statistically significant. Those who attended school were less likely to acquire hepatitis A in comparison to those who did not (OR = 0.65, 95% CI= 0.09 – 5.49), but this was not statistically significant.

The study showed that 76% of cases washed their hands before eating, compared to 96% of controls (OR= 0.13, 95% CI= 0.02 – 0.67).Washing hands with water and soap before eating was reported by 28% of cases compared to 72% of controls (OR= 0.06, 95% CI= 0.01 – 0.39). Washing hands after eating was reported by 96% of cases, compared to 97.3% of controls (OR= 0.66, 95% CI= 0.04 – 19.22). On the other hand, 72% of cases washed hands after going to toilet compared to 96% of controls (OR= 0.11, 95% CI= 0.02 – 0.53). Washing hands with water and soap after going to toilet was reported by 8% of cases, compared to 13.3% of controls (OR= 0.09, 95% CI= 0.01 - 0.89).

Vaccination of the population at risk with immunoglobulin was carried out by the preventive department of Al Taif health directorate as part of the control measures; 52% of controls had received the vaccine, and 36% of the cases had also been vaccinated. Those who had received the vaccine among controls were protected against infection (OR= 0.52, 95% CI = 0.18 – 1.45).

There were 2 different water sources from scattered wells around the area. The water was brought to the households by the tank vehicles (Wayet) in all the villages where cases were reported. Schools in these areas used the same water source as houses.

There was no general sewage system in these villages; each house either had its own sewage system (sewage tank or bayara), or had artesian-well-holes for sewage disposal done by digging a deep hole down to 40 meter below ground. We found that 92% of cases and 96% of controls used these sewage tanks, and 8% of cases and 4% of the controls used artesian well-hole (OR= 0.48, 95% CI = 0.06 – 4.41), indicating that type of sewage disposal was not a risk factor for acquiring infection.

All the cases and controls used the same source of water for drinking, cooking and washing, brought by the tank vehicles (Wayet) and did not knowthe exact source, except either (Alhojra) which is the collection of many wells, or AlHasawi which is superficial pools of water inside the valley. We were not able to distinguish if a specific well caused the outbreak.

The majority of both cases (80%) and controls (68%) drank from the pipes at their houses (OR=1.88, 95% CI = 0.57 – 6.54); 95.7% of cases drank water from coolers at schools compared to 84.5% of controls. Eating food bought from outside was not associated with acquiring infection (OR=1.06, 95% CI = 0.38 – 3.02).