Healthcare worker exposure to Middle East respiratory syndrome coronavirus (MERS-CoV): Revision of screening strategies urgently needed

Travel Medicine and Infectious Disease

Gautret

2019

101

Background: The Middle East Respiratory Syndrome Coronavirus (MERS-CoV) emerged in 2012 and attracted an international attention as the virus caused multiple healthcare associated outbreaks. There are reports of the role of asymptomatic individuals in the transmission of MERS-CoV, however, the exact role is not known. Method: The MEDLINE/PubMed and Scopus databases were searched for relevant papers published till August 2018 describing asymptomatic MERS-CoV infection.Results: A total of 10 papers were retrieved and included in the final analysis and review. The extent of asymptomatic MERS infection had increased with change in the policy of testing asymptomatic contacts. In early cases in April 2012-October 2013, 12.5% were asymptomatic among 144 PCR laboratory-confirmed MERS-CoV cases while in 2014 the proportion rose to 25.1% among 255 confirmed cases. The proportion of asymptomatic cases reported among pediatric confirmed MERS-CoV cases were higher (41.9%-81.8%). Overall, the detection rate of MERS infection among asymptomatic contacts was 1-3.9% in studies included in this review. Asymptomatic individuals were less likely to have underlying condition compared to fatal cases. Of particular interest is that most of the identified pediatric cases were asymptomatic with no clear explanation.Conclusions: The proportion of asymptomatic MERS cases were detected with increasing frequency as the disease progressed overtime. Those patients were less likely to have comorbid disease and may contribute to the transmission of the virus. * Corresponding author.

Section: Resultsmentioning

confidence: 99%

“…In South Korea, 3 (0.5%) of 591 asymptomatic HCWs were detected positive via PCR screening [34]. In a recent study from Saudi Arabia, 17 out of 879 HCWs tested positive for MERS-CoV and 53% of them were asymptomatic by PCR [41].…”

Section: Extent Of Asymptomatic Mers In Humansmentioning

confidence: 99%

Asymptomatic Middle East Respiratory Syndrome Coronavirus (MERS-CoV) infection: Extent and implications for infection control: A systematic review

Travel Medicine and Infectious Disease

Gautret

2019

101

“…Our results demonstrate the need for a minimum of 2 samples to confirm MERS-CoV, and that a third sample will increase the yield by only 1% (from 96.5% to 97.6%). Concerns about the infectivity of RT-PCR−positive patients 16,17 have been confirmed by a recent report of a positive MERS-CoV culture from the upper respiratory tract of an asymptomatic positive case from KSA obtained at 15 days after illness onset. 18 There is an urgent need to verify how many negative results are needed to confirm negativity.…”

Section: Discussionmentioning

confidence: 91%

Middle East respiratory syndrome coronavirus intermittent positive cases: Implications for infection control

Alfaraj

American Journal of Infection Control

Memish

2019

Self Cite

Background: Middle East respiratory syndrome coronavirus (MERS-CoV) continues to be reported from the Kingdom of Saudi Arabia. Data on the phenomenon of intermittent positive results for MERS-CoV on reverse-transcription polymerase chain reaction (RT-PCR) with negative results in between are lacking. Here we describe cases with intermittent positive MERS-CoV test results and highlight the required number of tests to rule out or rule in MERS-CoV infection based on a large retrospective cohort of patients with confirmed MERS-CoV. Methods: This analysis included cases admitted between January 2014 and December 2017. The included patients had a minimum of 3 nasopharyngeal MERS-CoV RT-PCR tests for confirmation and needed 2 negative samples for MERS-CoV evaluated 48 hours apart with clinical improvement or stabilization apart to ensure clearance. Results: A total of 408 patients with positive MERS-CoV test results were treated at the referring hospital. We excluded 72 patients who had only 1 swab result available in the system and were treated in the initial years of the disease. Of the remaining 336 patients, 300 (89%) had a positive result after 1 swab, 324 (96.5%) had a positive result after 2 consecutive swabs, and 328 (97.6%) had a positive result after 3 consecutive swabs. Of the total cases, 46 (13.7%) had a positive MERS-CoV test then a negative test, followed by positive test results. Conclusions: Our data indicate that 2 to 3 nasopharyngeal samples are needed to produce the highest yield of positive results for MERS-CoV. In addition, 2 negative results 48 hours apart with clinical improvement or stabilization are needed to clear patients from MERS-CoV. Evaluation of the yield of sputum samples is needed to assess the effectiveness against nasopharyngeal swabs.

“…During the study period 2017-2018, there was a large outbreak in Saudi Arabia in June 2017 involving 3 health care settings. [15][16][17] The most common route of transmission of MERS-CoV to HCWs is health care−acquired infections from patients to HCWs. 5,[18][19][20][21][22][23][24][25] There are multiple factors contributing to the transmission within health care facilities and these factors were recently reviewed 12 and are clearly reported, 5,18,19,21 as summarized in a previous study.…”

Section: Discussionmentioning

confidence: 99%

Middle East respiratory syndrome coronavirus in the last two years: Health care workers still at risk

American Journal of Infection Control

Memish

2019

Self Cite

Background: An important emerging respiratory virus is the Middle East respiratory syndrome coronavirus (MERS-CoV). MERS-CoV had been associated with a high case fatality rate especially among severe cases. Methods: This is a retrospective analysis of reported MERS-CoV cases between December 2016 and January 2019, as retrieved from the World Health Organization. The aim of this study is to examine the epidemiology of reported cases and quantify the percentage of health care workers (HCWs) among reported cases. Results: There were 403 reported cases with a majority being men (n = 300; 74.4%). These cases were reported from Lebanon, Malaysia, Oman, Qatar, Saudi Arabia, and United Arab Emirates. HCWs represented 26% and comorbidities were reported among 71% of non-HCWs and 1.9% among HCWs (P < .0001). Camel exposure and camel milk ingestion were reported in 64% each, and the majority (97.8%) of those with camel exposures had camel milk ingestion. There were 58% primary cases and 42% were secondary cases. The case fatality rate was 16% among HCWs compared with 34% among other patients (P = .001). The mean age § SD was 47.65 § 16.28 for HCWs versus 54.23 § 17.34 for non-HCWs (P = .001). Conclusions: MERS-CoV infection continues to have a high case fatality rate and a large proportion of patients were HCWs. Further understanding of the disease transmission and prevention mainly in health care settings are needed.