An investigation of a suspected institutional tuberculosis outbreak in a long-term psychiatric hospital, South Africa, December 2018

Background: Despite the availability of vaccine, prophylaxis and treatment, tuberculosis(TB) remains a major public health challenge.Institutional transmission of TB presents a major health problem especially to healthcare workers who are at increased risk of infection at the workplace.Following reports of a suspected TB outbreak in a long-term psychiatric hospital in eThekwini District,KwaZulu-Natal Province,an outbreak investigation was conducted to investigate a possible institutional spread of TB and make recommendations to reduce TB transmission risks. Methods and materials: Staff members were screened for TB symptoms using the World Health Organization(WHO) standardized TB screening questionnaire.A TB suspected case was defined as any staff member who presented with any of the TB symptoms; coughing for more than two weeks,weight loss, night sweats or fever.Sputum was collected on suspected cases and tested for TB using GeneXpert and culture.Chest radiograph(CXR) was done on suspected cases in whom sputum was not obtained. Results: A total of 298 staff members was screened, median age of 42 y (IQR 34–51 years). The majority were females 70% (208/298). Of the 298 screened, 17% (50/298) screened positive and were suspected of having active TB disease. Of these, the highest proportion were the nursing professionals, 50% (25/50). Sputum was obtained in 34% (17/50) of suspected TB cases. TB was laboratory-confirmed in seven case-patients’ sputa, 41% (7/17) by culture and GeneXpert. All seven were nursing professionals. Of the remaining 33-suspected cases in whom sputum was not obtained, chest x-ray was done in one, and this was suggestive of active TB infection. A high number of nursing professionals were diagnosed with TB. TB diagnosis may have been missed in a number of suspected cases who could not provide sputum, and in whom chest x-ray was not done. Conclusion: We recommend ongoing infection prevention and control practices in the hospital, and routine TB screening of staff members with follow-up sputum tests or chest x-ray for suspected cases. Molecular typing is advised to identify TB strain relatedness among staff and patients in the psychiatric hospital.