FIGURE 1. Number of confirmed cases of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) (N = 55) reported as of June 7, 2013, to the World Health Organization, by month of illness onset — worldwide, 2012–2013 – CDC MMWR
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The CDC has been busy this week, yesterday issuing three new guidance documents (see CDC: Updated H7N9 Guidance Docs) and a HAN Health Update (Human Infections with Avian Influenza A (H7N9) Viruses) on the emerging avian flu virus.
Late yesterday, the CDC also released an updated HAN Health Update on the novel coronavirus (MERS-CoV), along with an early release MMWR. We’ll start with the MMWR, and I’ll highlight the HAN in my next post.
Some of the ambiguity in this MMWR report (source of virus, incubation time, genetic analysis of samples, mode of transmission, spectrum of illness, etc.) can no doubt be traced to the Saudi’s reluctance to share information and virus samples with the rest of the world.
Helen Branswell’s absolutely terrific reporting yesterday in her SciAm article Saudi Silence on Deadly MERS Virus Outbreak Frustrates World Health Experts and Canadian Press report Saudi paperwork demands delay work to research to find MERS source: CDC are `must reads’, and help to explain why this virus has elicited such alarm in public health circles.
As the graphic at the top of the page shows, while the numbers of lab-confirmed cases of MERS-CoV remain small, the trend over the past couple of months is less than reassuring.
A few highlights from the MMWR (bolding mine) include:
- As of June 7, 2013, a total of 55 laboratory-confirmed cases have been reported to WHO
- Illness onsets have occurred during April 2012 through May 29, 2013 (Figure 1)
- All reported cases were directly or indirectly linked to one of four countries: Saudi Arabia, Qatar, Jordan, and the United Arab Emirates (Figure 2)
- To date, no cases have been reported in the United States.
- The median age of patients is 56 years (range: 2–94 years), with a male-to-female ratio of 2.6 to 1.0.
- All patients had respiratory symptoms during their illness, with the majority experiencing severe acute respiratory disease requiring hospitalization
- Thirty-one of the 55 patients are reported to have died (case-fatality rate: 56%)
- Patients with comorbidities or immunosuppression might be at increased risk for infection, severe disease, or both.
- Eight clusters (42 cases) have been reported by six countries (France, Italy, Jordan, Saudi Arabia, Tunisia, and the UK) (5) among close contacts or in health-care settings and provide clear evidence of human-to-human transmission of MERS-CoV.
- Importantly, the incubation period might be longer than previously estimated.
Here then is the link to last night’s MMWR and the opening passages. By all means, read it in its entirety.
Update: Severe Respiratory Illness Associated with Middle East Respiratory Syndrome Coronavirus (MERS-CoV) — Worldwide, 2012–2013
Early Release
June 7, 2013 / 62(Early Release);1-4CDC continues to work in consultation with the World Health Organization (WHO) and other partners to better understand the public health risk posed by the Middle East Respiratory Syndrome Coronavirus (MERS-CoV), formerly known as novel coronavirus, which was first reported to cause human infection in September 2012 (1–4).
The continued reporting of new cases indicates that there is an ongoing risk for transmission to humans in the area of the Arabian Peninsula. New reports of cases outside the region raise concerns about importation to other geographic areas. Nosocomial outbreaks with transmission to health-care personnel highlight the importance of infection control procedures. Recent data suggest that mild respiratory illness might be part of the clinical spectrum of MERS-CoV infection, and presentations might not initially include respiratory symptoms. In addition, patients with comorbidities or immunosuppression might be at increased risk for infection, severe disease, or both.
Importantly, the incubation period might be longer than previously estimated. Finally, lower respiratory tract specimens (e.g., sputum, bronchoalveolar lavage, bronchial wash, or tracheal aspirate) should be collected in addition to nasopharyngeal sampling for evaluation of patients under investigation. An Emergency Use Authorization (EUA) was recently issued by the Food and Drug Administration (FDA) to allow for expanded availability of diagnostic testing in the United States.
