The Saudi MOH is reporting their 8th MERS infection of November, this time a primary (community acquired) case involving a 51 y.o. female from Afeef who is listed in stable condition.
While centered in the heart of Saudi Arabia, the distribution of cases this month (see map below) runs from Tobuk in the far northwest to Najran near the Syrian border.
Three of the 8 cases (37.5%) this month are listed as having camel contact, while the 5 remaining cases are listed as `primary', with no known risk exposures.
We've not seen any nosocomial infections this month, and overall, the number of healthcare related infections is down this year. A sign, perhaps, that the MOH's efforts to improve infection control protocols in local hospitals is showing some progress.
An encouraging sign, but last September's EID Journal: Estimation of Severe MERS Cases in the Middle East, 2012–2016, suggested 60% of symptomatic cases likely go undiagnosed.
Like most viral infections, MERS-CoV can produce a wide range of illness, and so it is likely that many mild or asymptomatic cases go undetected.A year ago, a study in the EID Journal: Risk Factors For Primary MERS-CoV Infection, Saudi Arabia found camel exposure a significant factor for infection, but that many community cases had no obvious exposure risk. They 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.So, for a large proportion of community acquired cases, the source of infection still remains unknown. The role of mild or asymptomatic cases in spreading the virus remains suspected, but largely unproven.