Hospital outbreak of COVID-19 in South Africa
Hospital outbreak of COVID-19 in South Africa.
Jefferson T, Heneghan C.
Published on June 1, 2020 | Last modified on June 4, 2020
Transmission Dynamics of COVID-19
||Lessells R, Moosa Y, de Oliveira T. Report into a nosocomial outbreak of coronavirus disease 2019 (COVID‐19) at Netcare St. Augustine’s Hospital. KwaZulu‐Natal Research Innovation and Sequencing Platform (KRISP). https://www.krisp.org.za/news.php?id=421(pdf) 2020
||Fomites, Person to Person
||Frequent movement of patients
Separate access and segregation of potentially infected patients are required to prevent or control nosocomial outbreaks of COVID-19.
This was a report of the independent investigation into an outbreak at St. Augustine’s Hospital, Durban, South Africa. The outbreak took place between 9 March and 30 April 2020 with 119 confirmed cases identified (39 patients and 80 staff). There were 15 deaths among elderly patients with multiple pathologies. The investigation was carried out by inspection, medical record review and interviews
Lack of separation of potentially COVID-19- infected patients from other patients, probably beginning at the Emergency Room led to a nosocomial outbreak claiming the lives of 15 patients who were mostly elderly with pre-existing multiple pathologies.
A lack of suspicion and awareness of the threat together with frequent movement of patients inside the hospital contributed to the swift spread. The mode of transmission appears mainly to be indirect, through fomites and health care workers contact. Emergency Room (ER) with bays opening on a single corridor probably facilitated initial transmission.
What did they do?
The authors carried out the investigation by inspection, medical record review and interviews. In addition samples of SARs-CoV-2 were tested for phylogenetic analysis and found to be related to European Phila.
The patients included three outpatients seen only in the emergency department, the first two had a history of travel from Europe but not the third. The epidemic curve shows clearly how the first three cases infected health care workers at the hospital who in turn infected mostly other health care workers and inpatients.
The first inpatient case as admitted and discharged on the 9th of March with a transient ischaemic attack discharged to a home and then readmitted in severe respiratory distress. The authors map out in Figure 4 of the report the entry into the hospital of COVID-19 – probably through one of the people seen at the ER and then its rapid spread throughout the structure.
The index patient had been in close proximity in the ER to the first inpatient case and had the same medical attendant. The entry and exit structures of the bays in ER involved crossing the main corridor with closeness to other patients and staff (see map in Figure 4).
The chain of transmission chapter with maps deserves reading as clear examples of an accurate investigation, the level of closeness between patients and staff, missed symptoms such as fever and faulty hospital design. The outbreak seeded several other cases in nearby institutions, including discharge homes.
The spatial distribution of cases and exposed individuals who became infected on the wards suggests that indirect contact via health care workers or fomite transmission were the predominant modes of transmission between patients in this outbreak although there may have some cases caused by droplet transmission.
The authors believe that frequent movement of patients throughout the hospital was a factor accelerating transmission and low index of suspicion in the first cases delayed appropriate action. The authors remark on the speed of transmission inside the hospital.
The authors report they present basic information on the infections in health care workers and other staff. Detailed information was obtained on some of the first staff cases but they were unable to interrogate all the health care worker data fully to understand where precisely people worked on specific wards. They also cannot say to what extent direct health care worker to patient transmission contributed to the outbreak and to what extent redeployment of health care workers to different wards might have facilitated the spread through the hospital.
Eight agency nurses also tested positive, but they did not have full details of these cases and whether there has been a risk of spreading the infection to other health facilities. The authors also did not interrogate the cleaning and disinfection records to understand gaps and weaknesses in environmental cleaning that may have contributed to transmission.
|Clearly defined setting
||Demographic characteristics described
||Follow-up length was sufficient
||Transmission outcomes assessed
||Main biases are taken into consideration
What else should I consider?
The evidence from this investigation needs replicating, updating and incorporating into a systematic review with a predefined protocol and a clear search and inclusion strategy. We recommend that this study is replicated at multiple hospital sites where feasible to further understand transmission the hospital settings which will vary substantially in their design and structure.
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About the authors
Carl is Professor of EBM & Director of CEBM at the University of Oxford. He is also a GP and tweets @carlheneghan. He has an active interest in discovering the truth behind health research findings
Tom Jefferson, epidemiologist.