Coronavirus – Credit CDC PHIL
# 7431
The Lancet today has published two related MERS-CoV articles, one of which we examined several weeks ago when it was released early online (see Lancet: Clinical Findings On 2 French MERS-CoV Cases).
The new article - Middle East respiratory syndrome: new disease, old lessons by Charles D Gomersall & Gavin M Joynt – consolidates what has been learned from the imported case in France (and its nosocomial transmission), along with sparse details from cases in the Middle East, and discusses their findings.
Of the two French cases which provide a good deal of the clinical data used in their discussion, one died in late May (see France’s 1st MERS-CoV Patient Dies), while the other (the index case’s roommate) remains in critical condition a month later.
The original Lancet article (published online May 30th) provides a detailed review of the clinical findings on both patients, including lab results, radiographs and CT scans, and genetic analysis of specimens.
Benoit Guery, Julien Poissy, Loubna el Mansouf, Caroline Séjourné, Nicolas Ettahar, Xavier Lemaire, Fanny Vuotto, Anne Goffard, Sylvie Behillil, Vincent Enouf, Valérie Caro, Alexandra Mailles, Didier Che, Jean-Claude Manuguerra, Daniel Mathieu, Arnaud Fontanet, Sylvie van der Werf, and the MERS-CoV study group*
Interpretation
Patients with respiratory symptoms returning from the Middle East or exposed to a confirmed case should be isolated and investigated for MERS-CoV with lower respiratory tract sample analysis and an assumed incubation period of 12 days. Immunosuppression should also be taken into account as a risk factor.
This first report served to increase the supposed incubation period from 10 days to 12, and warned that lower respiratory samples are more likely to return a positive PCR result than samples retrieved from the upper respiratory system.
The second report, available online (free registration req.) can be accessed at the link below:
Middle East respiratory syndrome: new disease, old lessons
Charles D Gomersall, Gavin M Joynt
In 2003, severe acute respiratory syndrome coronavirus caused an epidemic of severe viral pneumonia. The emergence of Middle East respiratory syndrome coronavirus (MERS-CoV) has raised concerns of a similar epidemic. Although 55 laboratory-confirmed cases have been reported to WHO,1 published clinical details are sparse. In The Lancet, Benoit Guery and colleagues2 give a detailed description of two cases, occurring without co-infection.
This report is important not only because it provides information about the clinical features of the disease, but also because it confirms human-to-human transmission, shows the importance of travel and contact history-taking, draws attention to the need for analysis of lower respiratory tract specimens to exclude disease, and suggests that previous estimates of the incubation period might be too short.
While you’ll want to read the entire article, some of the points made include:
- Some patients with MERS-CoV infection might present with atypical, or mild symptoms.
- Patients with mild symptoms are less likely to be thoroughly investigated and current case counts might not reflect the true burden of the disease.
- Testing is difficult, and samples taken from the upper respiratory system may be unreliable.
- Repeated negative test results of of lower respiratory tract specimens are required to rule out infection.
- While many exposed HCWs have not fallen ill, it is prudent to take precautions against airborne transmission.
- Further investigations are needed into the presence or absence of MERS viral shedding via the stool.
- The authors stress the importance of travel and contact history-taking
The most recent MERS-CoV update (June 26th) from the World Health Organization puts the case count at:
Globally, from September 2012 to date, WHO has been informed of a total of 77 laboratory-confirmed cases of infection with MERS-CoV, including 40 deaths.
There are a number of other exposed individuals for whom serological testing is not completed, and so these numbers are subject to revision.
