Abstract

The Middle Eastern respiratory syndrome coronavirus (MERS-CoV) is an emerging disease prevalent in the Eastern province of Middle East. The disease was first reported in September 2012 and it has a high mortality rate (CDC, 2013b). Infected individuals suffer from acute respiratory disorder, fever, gastrointestinal symptoms and heavy cough (CDC, 2013b). In some cases, the disease is asymptomatic; thus individual infected with this disease will not seek any medical intervention and can transmit the disease without knowing (CDC, 2013a). Gierer et al. (2013) study was designed to assess the seroprevalence and host cell entry mechanism via spike protein of MERS-CoV within two sample size population in the Eastern province of Saudi Arabia (Gierer., et al., 2013). The article advanced important information for possible prophylaxis methodology in detecting neutralizing antibodies and evaluated subsequent inhibition potency using infected and healthy serum from subject participants.

 Emerging Infectious Disease: MERS

Coronavirus family infects human and animal all over the world, but an emerging coronavirus called Middle East respiratory syndrome coronavirus (MERS-CoV) is prevalent in the Middle East. The MERS-CoV is a new strain of coronavirus discovered by scientists. This virus strain carries pathogen which causes respiratory syndrome. Based on phylogenetic sequence of the virus, the China putative bat coronaviruses BtCoV-HKU4 and BtCoV-HKU5, the Netherlands BtCoV/VM314/2008, and the recently discovered South Africa strain are the closest strains to MERS-CoV (Coleman, & Frieman, 2013). The primary reservoir of MERS-CoV is not yet conclusive. However, it is believed that the virus was transmitted into human through either dromedary camel or goat (Coleman, & Frieman, 2013). Thus for lack of conclusive scientific evidence it is safe to state that livestock (camels or goats) and humans are host to this virus with the possibility that livestock could be the reservoir for the virus.

The mode of transmission of MERS-CoV pathogen is still under investigation. Nevertheless, the disease can be transmitted via contact or airborne. Based on the limited knowledge and many unanswered question surrounding MERS-CoV infection mechanism and reservoir/host sources, the Centers for Disease Control and Prevention (CDC) is advising individuals within the high risk area to wash their hands frequently, use mask and wear protective gears around infected livestock (CDC, 2013a). In addition, individuals experiencing any sign of respiratory symptoms must be tested for the MERS-CoV sensitivity. Unfortunately, in some cases, patients are asymptomatic to the viral infection. Therefore, for the interest of public health effort in controlling and preventing MERS, seroprevalence analysis could be of clinical significance and critical tool in identifying both the symptomatic and asymptomatic prevalence of MERS-CoV within a population. Perhaps, this scientific niche is worth exploring.

In 2013, 108 confirmed cases were reported (Gierer, et al., 2013). For the cases that were reported 50 (46%) patients died and most of these cases were from Saudi Arabia (Gierer, et al., 2013). Based on the high mortality rate of MERS-CoV, public health concern among health professional around the world, the World Health Organization (WHO) and the CDC is on surveillance mode. There is a need for extensive study on this particular coronavirus to determine the seroprevalence and possible infection mode of action. Thus, Gierer et al. (2013) conducted a study with two sample size population involving 158 serum samples from children admitted in a Saudi Arabian Hospital in 2010 and 2011 for lower respiratory tract infection, 77 of the patients were female, and 81 were male patients. The patient’s age from this group ranges from 7.3 months to 9 years, with a median age of 11.6 months (Gierer, et al., 2013).

The second group in the study involved healthy individuals who donated their serum samples. This group included 110 male serum blood samples donated in 2012, ages ranging from 19-52 years, and the median age for this group was 28 years (Gierer, et al., 2013). Unfortunately, all the serum samples collected and tested for seroprevalence for the Middle East respiratory syndrome coronavirus’ spike protein (MERS-S) driven transduction of target cells had no neutralizing antibodies against MERS-S (Gierer, et al., 2013). The result was a set-back in research into seroprevalence model. However, the study assessment on inhibition of cellular entry mediated by the G-protein vesicular stomatitis virus (VSV-G), an animal virus not prevalent in Saudi Arabia, and the globally prevalent coronavirus spike protein of the human coronavirus NL63-S; showed no robust inhibition of VSV-G dependent entry, but most serum samples robustly inhibited entry driven by NL63-S, a promising result indicating the neutralizing potency of MERS-CoV positive serum sample’s sensitivity and specificity in inhibiting MERS-S (Gierer, et al., 2013).

Currently, the WHO is committed in improving the surveillance, laboratory capacity, contact tracing and serological investigation of the MERS research. In addition, infection prevention and control, clinical management, travel-related guidance, risk communications, epidemiological, clinical and animal research are some of the parameters implemented for the disease control and prevention (WHO, 2013). Furthermore, data collection, reports of all confirmed and potential MERS-CoV cases must be reported to the WHO on a timely manner in accordance with international health regulation (IHR) guidelines.

References

Centers for Disease Control and Prevention.  (2013a). Middle East respiratory syndrome (MERS). Retrieved from http://www.cdc.gov/coronavirus/MERS/hcp/home-care-patient.html

Centers for disease Control and Prevention. (2013b).  Updated information on the epidemiology of Middle East respiratory syndrome coronavirus (MERS-CoV) infection and guidance for the public, clinicians, and public health authorities, 2012–2013. Morbidity and Mortality Weekly Report, 62(38), 793-796. Retrieved from http://www.cdc .gov/mmwr/preview/mmwrhtml/mm6238a4.htm

Coleman, C., & Frieman, M. (2013). Emergence of the Middle East respiratory syndrome coronavirus. PLoS Pathogens, 9 (9). doi:10.1371/journal.ppat.1003595. Retrieved from http://www.plospathogens.org/article/info%3Adoi%2F 10.1371%2Fjournal.ppat.1003595

Gierer,S., Hofmann-Winkler, H., Albuali, W., Bertram, S., Al-Rubaish, A., Yousef, A.,… Pöhlmann, S. (2013). Lack of MERS Coronavirus neutralizing antibodies in Humans, eastern province, Saudi Arabia.  Morbidity and Mortality Weekly Report, 19(12). doi: 10.3201/eid1912.130701.  Retrieved from http://wwwnc.cdc.gov/eid/article/19/12/13-0701_article.htm.

World Health Organization. (2013). MERS-CoV not yet a public health emergency, advises emergency committee.  Retrieved from http://www.euro.who.int/en/health-topics/communicable-diseases/influenza/news/news/2013/07/mers-cov-not-yet-a-public-health-emergency,-advises-emergency-committee