Key Message: There was an outbreak of gastrointestinal infection in a health rehabilitation center in Riyadh, affecting residents with intellectual disability conditions and other associated health conditions. This outbreak brought to light a compelling need for improved hygiene and infection control practices. The likely cause of the outbreak was poor hand hygiene practice and inadequate personal hygiene rather than foodborne transmission. This clearly points out the need for improved practices of infection control in order to prevent recurrence of such outbreaks in the future.
Objectives: The present investigation was undertaken with objectives to find out the cause of the gastrointestinal outbreak occurring in the health rehabilitation center and to implement effective control measures to prevent further cases. This outbreak investigation was done to completely describe the outbreak and investigate the potential risk factors and also evaluate the efficacy of the hygiene practices currently followed in the institution in order to implement better measures to protect these institutionalized residents from further outbreaks in the future since the population at risk was very vulnerable.
Methods: A case-control study design was used involving 20 cases and 40 controls. All case-patients were females and consisted of residents from the rehabilitation center. The definition of the cases used in this investigation was residents who had developed symptoms of gastroenteritis— vomiting, diarrhea, fever, beginning August 16, 2023. Controls were asymptomatic residents who had similar opportunities for exposure to a common source within the center. Data were collected through structured questionnaires, medical records review, and appropriate laboratory testing of stool and environmental samples. Questionnaires obtained demographic information, symptom history, exposure history, food history and contact with ill people. Food samples were tested for microbial contamination to identify a possible agent of the outbreak.
Results: Among the 20 cases under investigation, most of them reported moderate-intensity symptoms. The most commonly reported symptoms were vomiting in 16 cases, diarrhea in 13, and fever in 7. The first case was reported on August 16, 2023, but the outbreak itself was not reported officially until September 3, 2023. Extensive laboratory testing did not identify any pathogens in stool samples, and all food samples tested were safe; thus, the investigation ruled out foodborne transmission as an explanation for the outbreak. Statistical analysis did not show significant association of any particular food items with the outbreak. This perhaps would suggest poor personal hygiene, especially hand hygiene, at its root. The temporal distribution of cases showed evident clustering of symptoms, pointing toward a common source or multiple brief exposures to a contaminating agent. It was further investigated that person-to-person transmission or environmental contamination would be more probable in terms of mode of transmission. Poor hygiene practices were therefore considered to be the chief contributing factors to the outbreak, which was supported by the temporary clustering of cases and the absence of a clear food or waterborne pathogen.
Conclusion: This gastrointestinal outbreak in the health rehabilitation center was not linked to foodborne pathogens, as it was driven by poor hygiene practice. This outbreak therefore puts a premium on the establishment of broad hygiene programs, improvement in environmental sanitation, and development of a robust system for tracing caregiver-patient interactions in this facility. Such measures are therefore instituted to ensure the protection of residents' health and the effective control and prevention of outbreaks in comparable settings. Improved hygiene practice, especially frequent and appropriate hand washing, is the mainstay of preventing infection spread in a setup like a rehabilitation center where residents stay together and share facilities. Environmental cleaning should take place regularly and more often in shared facilities such as bathrooms, dining halls, and recreation areas.
Figure 1: Sequences of the cases by days
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