Thursday, June 25, 2015

Eurosurveillance: Three MERS Rapid Communications From Korea

Coronavirus PHIL


# 10,261

We’ve a trio of rapid communications published today in the journal Eurosurveillance that deal with the ongoing MERS outbreak in Korea.   Although I’ve not had time to properly read each of them, I wanted to get links (and short abstracts) up so that others can get started reading them.

Although there is a lot here to absorb, one of the very interesting findings in the first report is that the incubation period (time of last exposure to onset of symptoms) averaged 2 days longer in tertiary cases than in secondary cases, but the time from symptom onset to laboratory confirmation was much shorter.

The authors note:

The shortened duration of symptom-to-laboratory confirmation in tertiary cases may reflect the disease recognition and consecutive earlier testing. However, explanations for a longer incubation period in tertiary infections, compared with secondary infections, require further investigations.

This is the sort of teasing out of epidemiological details we should have been getting from the Saudis all along, but have not.   Eurosurveillance's hat trick of MERS papers is a promising sign that we are apt to learn more about how the MERS virus works from this one outbreak than we have from three years of viral activity in the Middle East.  



Rapid communications

Epidemiological investigation of MERS-CoV spread in a single hospital in South Korea, May to June 2015

by HY Park, EJ Lee, YW Ryu, Y Kim, H Kim, H Lee, SJ Yi

Date of submission: 10 June 2015

In this report, we describe 37 MERS-CoV infection cases (1 primary, 25 secondary, 11 tertiary cases) in a single hospital in South Korea. The median incubation period was six days (95% CI: 4–7 days) and the duration between suspected symptom onset and laboratory confirmation was 6.5 days (95% CI: 4–9). While incubation period was two days longer, the duration from suspected symptom onset to confirmation was shorter in tertiary compared with secondary infections.




Preliminary epidemiological assessment of MERS-CoV outbreak in South Korea, May to June 2015

by BJ Cowling, M Park, VJ Fang, P Wu, GM Leung, JT Wu

Date of submission: 15 June 2015

South Korea is experiencing the largest outbreak of Middle East respiratory syndrome coronavirus infections outside the Arabian Peninsula, with 166 laboratory-confirmed cases, including 24 deaths up to 19 June 2015. We estimated that the mean incubation period was 6.7 days and the mean serial interval 12.6 days. We found it unlikely that infectiousness precedes symptom onset. Based on currently available data, we predict an overall case fatality risk of 21% (95% credible interval: 14–31).



The role of superspreading in Middle East respiratory syndrome coronavirus (MERS-CoV) transmission

by AJ Kucharski, CL Althaus

Date of submission: 15 June 2015

As at 15 June 2015, a large transmission cluster of Middle East respiratory syndrome coronavirus (MERS-CoV) was ongoing in South Korea. To examine the potential for such events, we estimated the level of heterogeneity in MERS-CoV transmission by analysing data on cluster size distributions. We found substantial potential for superspreading; even though it is likely that R0 < 1 overall, our analysis indicates that cluster sizes of over 150 cases are not unexpected for MERS-CoV infection.

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