Credit WHO report
# 8600
The World Health Organization has released their 15th MERS-CoV summary and Literature update (see list) in advance of Tuesday’s meeting of the IHR Emergency Committee on MERS. This is the first major review since the Jeddah/Riyadh & UAE clusters began in earnest in late March.
The 8-page document contains new graphics, a summary of the WHO’s findings during their visit to Saudi Arabia, a country-by-country synopsis of recent cases, and a list of recent studies pertaining to the MERS coronavirus.
While there remain many unanswered questions, the WHO’s primary finding from their recent investigation boils down to: `there is currently no evidence of sustained human‐to‐human transmission in the community’
The entire document (pdf file) is of interest, but I’ve excerpted the summary and Risk Assessment below:
(EXCERPT)
Summary and Risk Assessment
WHO is currently working with the Ministries of Health in Saudi Arabia and other affected countries and international partners to better understand the reasons for the increase in cases reported since March 2014. From preliminary investigations in KSA, it is clear that cases continue to be reported in a number of locations across the country. Importantly, health care workers have been infected across the country, including in Jeddah, Riyadh, Tabuk, Asir and Medina in recent weeks.
The large number of the recently reported cases from KSA reflects infection acquired through transmission in health care settings. The large outbreaks in Jeddah and Riyadh, and the reports of smaller hospital‐associated cases in other parts of the country, emphasise the importance of infection control strategies and practices, not only when caring for suspected MERS‐CoV patients but also – and most importantly ‐ when caring for patients in all circumstances. It is therefore important to emphasize the implementation of standard precautions at all levels and also to apply additional precautions according to the risk assessment.
The WHO mission found that the upsurge in cases in Jeddah is explained by an increase in the number of primary cases, amplified by several hospital‐acquired outbreaks that resulted from a lack of systematic implementation of infection prevention and control measures. The apparent seasonal increase in primary cases occurring for unknown reasons may be related to the weaning of young camels from their mothers in the spring of each year. Recent phylogenetic analysis using three human sequences from Jeddah suggests that the virus has not changed from previously recovered strains.Based on available information from recent cases in KSA, in particular, from Jeddah, and from all recently affected countries, there is currently no evidence of sustained human‐to‐human transmission in the community. The overall transmission patterns previously observed remain unchanged. WHO bases this assessment on the evidence that:
- The clinical picture appears to be similar to what was observed previously; secondary cases tend to present with a milder disease than primary cases, and many of the recently reported secondary cases have been mild, or were people whose tests were positive for MERS CoV but were asymptomatic;
- The recently exported cases to Greece, Malaysia, the Philippines and the USA have not resulted in onward transmission to persons in close contact with these cases on airplanes or in the respective countries outside the Middle East (contact tracing is still ongoing);
- Intensive screening of MERS‐CoV contacts revealed very few instances of household transmission; and
- There has been no increase in the size or number of observed household clusters. The increase in the community cases might reflect a seasonal increase in zoonotic infections from an animal population such as dromedary camels. Alternatively, as many of the community cases had no reported animal exposures, it is also possible that such cases reflected either person‐to‐person transmission or exposure to another source. Further epidemiological investigations are urgently needed to confirm or refute these hypotheses.
WHO expects that additional cases of MERS‐CoV infection will be reported from the Middle East, and that it is likely that cases will continue to be exported to other countries by tourists, travellers, guest workers or pilgrims who might acquire infection following exposure to an animal (for example, while visiting farms or markets) or human source (possibly in a health care setting). Until more is understood about the exposures to non‐human sources in the community, or human or environmental exposures in health care settings and implementation of preventive measures, cases will continue to be reported.
Urgent investigations are required to better understand the transmission patterns of this virus. The most urgent needs include detailed outbreak investigations, understanding how humans become infected from animal or environmental source(s) through case‐control studies, identifying risk factors for infection in health care settings, and enhancing community studies and surveillance for community‐acquired pneumonia. Collaboration between human and animal health sectors is essential to understand the risk of transmission between animals and humans.
