Researchers predict spread of acute respiratory syndrome that originated in the Middle East by studying population movements; Mumbai, Kozhikode among top 12 high risk cities
India faces serious threat of spread of a disease called Middle East respiratory syndrome (MERS) in post-Haj period, a study by a Canadian hospital has suggested. Mumbai and Kozhikode in Kerala are among the top 12 high risk cities worldwide. MERS is a severe acute respiratory syndrome, similar to the infectious severe acute respiratory syndrome (SARS) which killed 800 people worldwide a decade ago. Both the diseases are caused by unknown coronavirus, but unlike SARS which spread to high-income countries, MERS is more likely to spread in lower income countries.
According to an editorial in the journal The Lancet Infectious Diseases, MERS coronavirus appeared in West Asia in June 2012. It was isolated from the sputum of a patient in Saudi Arabia who died from acute pneumonia and kidney failure three days later. Since April 2012, 90 cases of MERS infection have been reported, 45 of which were fatal (see table). The disease has already spread to several countries in Western Europe and North Africa where the transmission of infection has been at the local level. The disease has influenza-like symptoms that can manifest as pneumonia or severe respiratory illness with cough, shortness of breath, and breathing difficulties.
Results of the study were published in the online journal PLoS Currents: Outbreaks, titled "Potential for the International Spread of Middle East Respiratory Syndrome in Association with Mass Gatherings in Saudi Arabia".
|MERS cases and deaths, April 2012 - present
Current as of July 24, 2013
|Saudi Arabia||70 (38)|
|United Kingdom (UK)||3 (2)|
|United Arab Emirates (UAE)||6 (1)|
|Source: US Centers for Disease Control and Prevention|
Learning from the experience of SARS, which spread through air travellers, researchers at St Michael’s Hospital in Toronto city in Canada have evolved a model to anticipate the spread of MERS, rather than waiting to react in a post-event situation. The researchers, led by Kamran Khan, analysed 2012 worldwide airline traffic and historic Haj data to predict population movements in and out of Saudi Arabia and the broader Middle East.
Pilgrimage hastens virus spread
Khan said there is potential for the virus to spread faster and wider during two annual events that draw millions of domestic and foreign Muslims to Saudi Arabia. The first is Umrah, a pilgrimage that can be performed at any time of the year but is considered particularly auspicious during the month of Ramadan. Ramadan this year began on July 9 and will end on August 7. The second is the Haj, a five-day pilgrimage required of all physically and financially able Muslims at least once in their lifetime. It will take place Oct 13-18 this year and is expected to draw more than three million people.
Khan's team found that 16.8 million travellers flew on commercial flights out of Saudi Arabia, Jordan, Qatar and the United Arab Emirates between June and November 2012 (the period starting one month before Ramadan and ending one month after the Haj). Among them, 51.6 per cent were bound for destinations in just eight countries with India having the highest proportion at 16.3 per cent. The other top countries were Egypt (10.4 per cent), Pakistan (7.8 per cent), Britain (4.3 per cent), Kuwait (3.6 per cent), Bangladesh (3.1 per cent), Iran (3.1 per cent) and Bahrain (2.9 per cent).
Twelve cities—Mumbai, Kozhikode, Cairo, Kuwait City, London, Bahrain, Beirut, Dhaka, Karachi, Manila, Istanbul and Jakarta—each received more than 350,000 commercial air travellers between June and November 2012 from the four countries where MERS cases have been traced.
The study says that of particular note is the degree of connectivity between the Middle East and South Asia. Collectively, India, Pakistan, Bangladesh, Afghanistan and Nepal represent the final destinations of almost one-third of all international air travellers departing Saudi Arabia, Jordan, Qatar and the UAE, and the origins of roughly one in four foreign Haj pilgrims worldwide.
“Given that these countries have limited resources, they may have difficulty quickly identifying imported MERS cases, implementing rigorous infection control precautions and responding effectively to newly introduced cases,” Khan said.
India yet to wake up to threat
"We have not received any advisory or notice from Union Health Ministry. We will work out measures once that happens. In any case travel for Haj begins in September, so there is enough time to act," said Shakir Hussain, chief executive officer of Haj Committee of India, the nodal agency for Haj operations in India.
The region-wise number of registries received so far by the committee shows that Gujarat and Kerala have the highest number of travellers for Haj at 44,000 each, followed by Maharashtra (41,000) and Uttar Pradesh (35,000).
The researchers at St Michael's used BioDiaspora, a web-based technology that uses global air traffic patterns to predict the international spread of infectious disease. The BioDiaspora platform has been used by numerous international agencies, including the US Centers for Disease Control and Prevention, the European Centre for Disease Prevention and Control and the World Health Organisation to evaluate emerging infectious disease threats.