On what is arguably the most treacherous news blogging day of the year (April Fools Day), a relatively safe report from the Saudi Ministry of Health on that country's 17th MERS case of of March - a primary case from Dammam.
Unlike cases with recent camel exposure, and those exposed either to known cases or in a hospital environment, a significant number of MERS cases appear in the community without a known risk exposure.
We know that some people can be infected without showing signs of illness (see Saudi MOH: 2nd Asymptomatic HCW In Wadi Al Dawasir Cluster), which raises questions over whether mild or asymptomatic cases may be capable of spreading the virus.
A year ago, a study in the EID Journal: Risk Factors For Primary MERS-CoV Infection, Saudi Arabia, while finding camel exposure a major risk factor, wrote:
Other potential explanations of MERS-CoV illness in primary case-patients who did not have direct contact with dromedaries include unrecognized community exposure to patients with mild or subclinical MERS-CoV infection or exposure to other sources of primary MERS-CoV infection not ascertained in our study.
While it makes sense, for now the role of mild or asymptomatic cases in spreading the virus remains suspected, but largely unproven.