key: cord-0955272-zmvs4v20
authors: Mishra, Baijayantimala
title: Combating the spread of Middle East respiratory syndrome coronavirus: Indian perspective
date: 2016-04-30
journal: Indian Journal of Medical Microbiology
DOI: 10.4103/0255-0857.176851
sha: db1df6e9c89d3758e06d7ed3c9f5369164dd8562
doc_id: 955272
cord_uid: zmvs4v20

nan

is, however, the absence of obvious direct exposure to the camel in majority of the cases. The transmission of virus in such cases has been attributed to consumption of unpasteurised camel milk or possibility of another intermediate host. Though CoV similar to MERS-CoV has been isolated from European hedgehog, its role as intermediate host has not been proved. [4] The present spread of virus in South Korea was not unexpected in itself as the virus has already spread to so many other countries outside the Middle East and this time it would have just been like before. However, here it turned out to be the largest cluster of human cases outside the Middle East where even the secondary and tertiary cases were many and possibly some quaternary human cases. [7] The event started from a 68 years old index case, who had a recent history of visit to the Middle East from 18 th April to 3 rd May 2015 and developed symptoms on his return to South Korea and reported positive for MERS-CoV on 20 th May 2015. [8] This individual case could have gone unnoticed, but only by 3 rd June 2015, 30 positive cases with two deaths were reported and in next few weeks the number of MERS-CoV positive cases went up to 174 including 27 deaths. [9] This rapid spread of MERS-CoV within a short span of time has raised the possibility of the emergence of a mutant form with more virulence and better efficient human to human transmissibility. However, the result showing Korean MERS virus as non-mutant brought a sigh of relief, nevertheless, the threat of getting evolved remains and so does its chance of global spread. [10] The absence of any obvious exposure either to camel or health care settings in South Korean index case is another cause of concern. Majority of the MERS virus infected patients usually presents with severe respiratory illness leading to pneumonia, acute respiratory distress syndrome After influenza and Ebola, another virus the Middle East respiratory syndrome coronavirus (MERS-CoV) a deadly respiratory virus has sparked international concern. The rapid spread of MERS-CoV caused havoc in the capital city of South Korea amounting to 174 cases, 27 deaths and over 5000 quarantine (as of 23 rd June 2015) within a short span of time has raised an alarm to the global health security. [1] After the first identification of the virus as a cause of severe respiratory illness, in June 2012, cases were reported from more than 25 countries including several from Europe and US and as of 11 th September 2015, World Health Organisation (WHO) has reported a total of 1569 laboratory-confirmed cases including 554 deaths.

[1] The unprecedented high number of MERS-CoV cases in South Korea has posed the threat of global spread including India, which has now been urged by the Director, WHO South-East Asia Region to remain vigilant for the MERS virus attack.

The virus was first detected in September 2012 in a 60-year-old patient, who died of severe respiratory illness and renal failure in Jeddah, Saudi Arabia in June 2012 and was provisionally named as human CoV Erasmus Medical Center and later named as MERS-CoV with the recommendation of Coronavirus Study Group of the International Committee on Taxonomy of Viruses. [2] This novel human CoV belongs to the lineage C of genus beta-CoV and thus related to the severe acute respiratory syndrome-CoV (SARS-CoV), a member of lineage B of the same genus, which was responsible for causing an outbreak of SARS during 2002-2003. [3] Majority of MERS virus cases so far have been reported from Saudi Arabia (1026 as of 30 th May 2015), and cases reported outside the Middle East either had a recent history of visit to Saudi Arabia or exposure to a patient thought to have acquired the infection there. [4] During the initial hunt for the possible zoonotic source of infection in Arabian Peninsula, 100% seropositivity was reported in dromedary camels and later the virus was isolated from camels, confirming the zoonotic transmission. [5, 6] Considering the evidence so far, camel to human and human to human are considered to be the major modes of transmission. The missing link in the transmission from camel to human and death with an average mortality rate of 36% and the risk of severity is more among persons with a chronic underlying disease. Whereas some people suffer only from mild cold-like symptoms, and some may remain even asymptomatic. [11] The proportion of asymptomatic persons and mildly symptomatic patients and their contribution in disease transmission is not clear till date.

The entry of MERS virus to another country may be possible either through infected camel or infected patients. However, the second one certainly appears to be more feasible in the Indian context. After experiencing SARS, pandemic influenza and recently Ebola, most parts of the globe including India is now much more experienced and matured in handling new or emerging viruses in terms of preventing the spread of the virus, diagnosis and management. Detection of MERS-CoV nucleic acid by reverse transcriptase real-time polymerase chain reaction from nasal/throat swabs along with lower respiratory tract samples (wherever possible) or antibody detection in paired serum samples by ELISA and immunofluorescent antibody are recommended for confirmation of diagnosis by CDC. [12] The facility for MERS virus diagnosis in India is available in NIV, Pune and NCDC, Delhi. [13] During the Influenza A H1N1 pandemic, country wide laboratory network was made available for H1N1 testing and for the first time across the country the system was channelised effectively for patient screening, sample transport, diagnosis and patient management. Thus, India should be able to handle the situation with equal efficacy in case MERS virus enters the country. However, the overall scenario of MERS virus is different from pandemic influenza A in many aspects. First, it must be remembered that the epidemiology of MERS virus is still poorly understood. The role of patients with mild upper respiratory illness, asymptomatic persons and intermediate host in disease transmission is still not clear. The finding of similar sequence as MERS virus in bats has added a possible query regarding the role of bat in MERS virus epidemiology. Second, considering the experience of SARS and influenza A pandemic H1N1, availability of an effective vaccine does not seem to be practicable in the present context. Third, it is also important to note that to tackle the influenza pandemic at least some effective antivirals were there which is not the case with MERS virus, and the world may have to pay heavily for the absence of antiviral for this deadly respiratory virus if the situation worsens. This again has resurfaced the fact of neglected and ignored field of antiviral research which demands its due attention. Fourth, the occurrence of MERS cases mostly in clusters in the family or in hospital settings rather than sporadic community spread indicates the transmission amongst close contacts emphasizing the implementation of strict and appropriate transmission-based precaution in the presence of suspected MERS virus infected patients. Finally, the time has ripened enough for the development of an integrated human and veterinary health system. Lastly, unlike SARS-CoV which almost disappeared after one year of its emergence infecting around 8000 cases with nearly 800 deaths across the globe, [14] this novel 3 years old MERS-CoV with its gradual, steady spread in the Middle East as well as countries across several continents has already made a strong foothold and is possibly going to stay with mankind.

Middle East respiratory syndrome coronavirus (MERS-CoV): Announcement of the Coronavirus Study Group

Genomic characterization of a newly discovered coronavirus associated with acute respiratory distress syndrome in humans

Middle East respiratory syndrome

Middle East respiratory syndrome coronavirus neutralising serum antibodies in dromedary camels: A comparative serological study

Isolation of a novel coronavirus from a man with pneumonia in Saudi Arabia

Middle East Respiratory Syndrome -Advancing the public health and research agenda on MERS -Lessons from the South Korea outbreak

MERS in South Korea and China: A potential outbreak threat?

Spread of MERS to South Korea and China

Korean MERS virus is not a mutation, say experts

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Advisory to Keep a Vigil for Middle East Respiratory Syndrome Corona Virus (MERS-CoV)

Summary of Probable SARS Cases with Onset of Illness from