Sero-prevalence of Rift Valley fever in south-western Saudi Arabia and study of risk factors

Abstract number: P921

Alazraqi T., Mahfouz A., Mekki A.

Seroepidemiological studies are valuable tools to identify the state of immunity among the general population to Rift Valley Fever (RVF) in the affected zones.

The objectives of the present research were to study the seroepidemiology of RVF infection in Jizan, Aseer and Al Qunfuda regions (Southwest Of Saudi Arabia), potential risk factors leading to the infection and to elucidate the predisposing factors of developing severe RFV disease requiring hospitalisation.

Through a series of field trips, (during the period September 2007–June 2008) to the centres selected for the present study (Jizan, Abu-Areesh, Al-Arda, Samtah, Beesh, Al-Birk, Al Gahma, Muhayeel, Al-Majardah and Al-Qunfuda) a random sample of individuals attending the outpatients' clinics for any reasons were included. All abattoir workers in those regions were also enrolled.

Through questionnaire interviews, data were collected.

Blood samples were taken and tested for RVF-specific IgG and IgM utilising commercially available enzyme-linked immunosorbent assays (ELISAs).

Out of 2,322 persons included in the study, only 137 were positive for RVF-specific IgG thus giving an overall prevalence of 6.0%. On the other hand, none of the study samples were found to be sero-positive to RVF-specific IgM. The highest prevalence of sero positive RVF IgG was observed in Al Birk of Aseer region (13.3%) followed by Al-Arda of Jizan Region (11.8%), where the first animal deaths were reported during 2000–2001 outbreak. The study revealed zero prevalence of specific IgM and IgG among pre-school children born after the 2000–2001 outbreak. Using multivariate binary logistic regression analysis to identify potential risk factors associated with seropositive RVF IgG, the following significant risk factors were identified; lacking electricity, having animals in the house, history of slaughtering animals, contact with or transporting aborted animals.

The study included a retrospective cohort of 61 cases with severe RVF infection hospitalised in Aseer Central Hospital during the outbreak of 2000–2001. Results revealed that prior hepatic (HBV, HCV) and renal involvement on admission were strong predictors of poor outcome.

In conclusion, the study documented a seroprevalence of 6% of RVF-specific IgG among the general population and the lack of recent RVF activity among humans in th study areas, the major risk factors were contact with animals especially aborted animals.

Session Details

Date: 16/05/2009
Time: 00:00-00:00
Session name: 19th European Congress of Clinical Microbiology and Infectious Diseases
Location: Helsinki, Finland, 16 - 19 May 2009
Presentation type:
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