I've always admired CIDRAP's Lisa Schnirring as a superb medical writer, but today she's outdone herself: As Korean MERS cases grow, experts analyze patterns. Excerpt from a long, detailed and informative report:
South Korea announced 5 more MERS-CoV cases today, raising the number of cases to 30 and leading experts to question if the rapidly evolving hospital cluster is following a pattern seen in Saudi Arabia or if other factors are helping fuel the outbreak.
South Korea is on a list of 16 countries—including the United States—that have reported travel-linked cases. Its outbreak began on May 20 with the detection of MERS-CoV (Middle East respiratory syndrome coronavirus) in a man who had returned from the Middle East.
A flurry of hospital-linked illnesses linked to the man, though, has quickly vaulted the country into the third-most-affected country, behind Saudi Arabia and the United Arab Emirates.
Five new cases, four tied to index case
In a statement today translated and posted by the infectious disease news blog Avian Flu Diary, South Korea's health ministry said the five new MERS cases include four patients who are direct contacts of the index patient and one who was exposed by a secondary case.
That raises the number of tertiary cases (involving three generations of transmission) in the cluster to three.
The translation suggests that the likely tertiary case-patient had been exposed to a 40-year-old man who got sick after being on the same hospital ward as the index patient.
WHO warns of further cases
The World Health Organization (WHO) said in a statement today that it is in close contact with South Korea and that the quality of reporting has allowed a nearly real-time insight into outbreak dynamics. It added that aggressive contact tracing and testing may help explain the cluster's rapid expansion.
Though human-to-human transmission has been documented, there is no evidence that it is sustained, the WHO said in discussing the first 25 outbreak patients.
Patients sickened in the outbreak so far had a range of exposures. Some were in the same room as the index patient and others were on the same ward. Preliminary data suggest exposure times may have been as short as 5 minutes to a few hours, the WHO said.
It warned that because a number of clinics and hospitals cared for the index patient, more cases are expected.
