While Not an International Public Health Emergency – Proactive Measures Can Still be Taken Against Spread of MERs
July 22nd, 2013 by CHHS RAs
By Victoria Plotkin, CHHS Extern
CHHS Public Health Program Manager Earl Stoddard III also contributed to this blog
An infectious disease that appears to have originated in the Middle East is causing great concern within the medical community. There have been 84 confirmed cases of Middle East Respiratory Syndrome coronavirus (MERS-CoV), and 45 of those patients have died. The methods of transmission, the incubation period of the virus, the factors that increase susceptibility to infection and the treatment regimen are all currently unknown. The World Health Organization (WHO) Director-General, Dr. Margaret Chan, has gone so far as to describe this virus as “a threat to the entire world.” More recently, a WHO emergency committee assessed the spread of the virus to additional countries and determined that, while MERS-CoV poses a serious threat, it “does not constitute a public health emergency of international concern at this time.” WHO continues to work with the international medical community to disseminate information and to better understand this virus, but the actions taken must be assessed to determine if more can and should be done to better protect the public.
MERS was first identified in a 60-year old man in Saudi Arabia who presented himself to the hospital on June 13, 2012. The patient died from respiratory and renal failure after 11 days of hospitalization. The patient exhibited symptoms similar to severe cases of influenza or the Severe Acute Respiratory Syndrome coronavirus (SARS-CoV), which caused upper and lower respiratory tract infections. The manner of infection for this patient was not identified, and the studies later completed on the pathogen revealed a coronavirus that was distinct from those previously known. Subsequent cases made the factors of susceptibility more difficult to ascertain. Four male members of a family in Saudi Arabia became infected with MERS-CoV in October and November of 2012, and two of these four patients died following hospitalization. Although the family lived in an extended household comprised of 28 people and multiple members of the household helped to care for the infected individuals, no other family members became ill. The mortality rate for MERS-CoV has been estimated to exceed 50%, but any estimation cannot be confirmed because the number of asymptomatic patients is currently unknown.
While research is underway to identify a treatment regimen for MERS-CoV, organizations such as the WHO and the Centers for Disease Control and Prevention (CDC) have provided information for healthcare practitioners and the public. The WHO has identified symptoms to aid in MERS-CoV diagnosis and warned the public of behavior that increases the likelihood of MERS-CoV exposure. The CDC continually updates the information it has made available regarding the spread of MERS-CoV, the questions that are typically posed and the pertinent guidelines for individuals within the medical community and members of the public with a higher likelihood to be exposed to the virus.
Initially, cases of infection were limited to Saudi Arabia, Qatar and Jordan. Virus transmission appeared to be geographically-related, but cases in Jordan and the United Kingdom demonstrated that the virus is capable of being transmitted amongst humans. Although MERS-CoV exhibits similar symptoms as SARS-CoV, recent studies indicate that the method of transmission differs. The transmission of SARS-CoV may have been limited due to the enzyme that the pathogen relied upon for transmission. The transmission of MERS-CoV, on the other hand, appears to rely upon a protein, which has been found on the surface of airways and kidneys of infected patients. It remains unclear if the pathogen’s potential reliance on this protein will augment or impede the spread of this virus or if the medical community will be able to utilize this information to develop a treatment regimen. Research recently published in the Lancet medical journal found that this difference in transmission significantly reduces the likelihood of MERS-CoV developing into a worldwide epidemic comparable to SARS-CoV. Health officials in Saudi Arabia remain concerned regarding the spread of MERS-CoV and recently warned pilgrims against completing the Hajj this year. Additional research regarding the transmission and likelihood of a pandemic continues.
While research on MERS-CoV continues, laboratories within the United States have accepted samples of the virus for testing. Agents and toxins that may pose a severe threat to the public within the United States (U.S.) must be listed and prioritized on the Select Agents and Toxins List. Once a pathogen is listed, laboratories handling the pathogens must register with the U.S. Department of Health and Human Services and meet requirements addressing security, personnel screening and personnel training. MERS-CoV is not currently included on this list. It is common for there to be a delay of a number of years from the initial confirmation of a pathogen to its inclusion on the list. For example, although SARS was initially confirmed in 2002, the CDC didn’t propose its listing until 2009. In the past, members of the medical research community have resisted the inclusion of pathogens on the Select Agents and Toxins List, citing concerns of unnecessary hindrances to ongoing research efforts.
It is important for the medical community to refrain from asserting conclusions before more information on MERS-CoV is known. The dissemination of assumptions based upon limited data can result in an ineffective response and mitigation plan. Preliminary analysis of the H1N1 pandemic, for example, suggested that the elderly were more vulnerable to the virus. Additional studies revealed however that many individuals over 60 actually already had antibodies that protected them from the virus. When a treatment regimen for MERS-CoV is developed, it will be vital that it be provided to the individuals most susceptible to the virus. When enough data becomes available for the medical community to confirm the manner in which MERS-CoV is transmitted, procedural delays for the addition of this virus to the Select Agents and Toxins List must be addressed. The latitude granted to researchers laboring to prevent a pandemic must be subject to limitations that protect the public from a pathogen with the lethality of MERS-CoV.