Introduction
In August 2000, the first confirmed occurrence of Rift Valley Fever (RVF) outside the African continent was described in the Arabian Peninsula. Till that time, the true risk to health-care workers (HCWs) for acquiring RVF in the hospital setting had remained unstudied. The objective of this study is to estimate the risk to HCWs for the nosocomial acquisition of RVF in Jazan.
Methodology
A retrospective cohort study was conducted at four hospitals in Jazan. Two groups, high and low risk, were identified according to their exposure to potential nosocomial risk factors. These risk factors included contact with 10 or more RVF patients, body fluids, potentially infectious material, or performing invasive procedures. A questionnaire inquiring about demographic characteristics, jobs and places of assignment, level and type of hospital exposures, precautionary measures, and possible environmental exposures was completed by HCWs in both groups. A blood sample was taken from each participant to be tested for IgM and IgG antibody to RVF virus. Evidence of infection during the epidemic was defined as any individual in the cohort with detectable IgM and IgG antibody to RVF virus.
Results
A total of 703 HCWs participated in this study. Their mean age was 33 years (SD ± 9) and males represented 49.2%. The most common nationalities included were Indians (37%), Saudi Arabians (26%) and Filipinos (12.5%). By occupation, nurses ranked first 312 (44.4%), followed by cleaners 115 (16.4%) and physicians 80 (11.4%). A total of 336 (47.8%) of the HCWs were enrolled in the high-risk group. Among them, the most common potential risk factors were close contact with 10 or more RVF patients (64.3%), inserting peripheral line (29.2%), and drawing arterial blood gas (23.8%). With respect to community exposure, 74 (10.7%) of HCWs reported direct contact with animals, 347(49%) were living in areas with heavy mosquito infestations, but only 242 (35%) participants reported having had mosquito bites. With respect to hospital protective measures employed by hospital staff, 73.3% wore gloves, 65% used face masks, and 57.5% reported always wearing gowns when dealing with suspected or confirmed RVF patients, body fluids, or potentially infectious material. Four (0.6%) of 703 participant HCWs had evidence of recent RVF virus infection. All of them were in the "low risk group" and reported exposure to known RVF risk factors at their community level.
Conclusion
The four RVF antibody positive HCWs probably acquired the infection as a result of environmental exposure rather than nosocomial acquisition. Nosocomial transmission, if it occurs, seems to be very rare in the context of at least rudimentary standard precautions. Implementation of standard precautions alone is sufficient when dealing with known or suspected RVF patients.