The worst pandemic in recent history was the 50-100 million deaths caused by the Spanish flu in 1918-1920. Bhutan was not spared from this pandemic where FM Bailey, the resident Political Officer in Gangtok wrote in his annual report that influenza had spread throughout Bhutan and that there were many fatal cases.
In the 1967 global outbreak of smallpox where 15 million people contracted the infection and 2 million died, there were 14 reported cases in Bhutan and the source was linked to the outbreak in neighbouring Assam. These events show that diseases know no boundaries and emerging diseases pose real challenges.
There are 1,400 human pathogens and about 30 new infectious agents that were previously not experienced by humankind have been identified in the last three decades. These, called as emerging infectious diseases pose public health challenges by presenting as new diseases, appearing in new geographical locations or with new clinical features, and occurring in epidemic or pandemic scales.
Why are diseases emerging?
The emergence of new diseases depends on the factors that make up the epidemiologic triad: the host (human or animal), agent (pathogen), vector (that transmits the agent to the host) and the environment.
SARS epidemic in 2002-2003, MERS outbreak in 2012 and the present Wuhan outbreak of 2019-2020 were caused by the evolution of new infectious agents. Development of resistance of agents to drugs or pesticides such as drug-resistant tuberculosis, HIV and malaria, and pesticide resistant malaria are some examples.
Ecological changes and human invasion of forested areas have been linked to diseases such as the Nipah virus (nearest reported outbreak near Bhutanese border was in Siliguri, 2001), scrub typhus and Japanese Encephalitis. International trade and travel are linked to the rapid spread of infectious agents. For example, travel from Hong Kong to Toronto by one person with SARS-CoV resulted in 128 SARS cases in a local hospital. Similarly, a single patient with MERS-CoV from Saudi Arabia who came to South Korea resulted in 186 MERS cases. Human behaviour involving close contact with civet cats were linked to the emergence of SARS and bushmeats (smoked animal meat) involving bats were associated with the emergence and spread of Ebola.
Combating emerging infectious diseases
Emerging and re-emerging infectious diseases will continue to challenge modern health systems. Outbreaks such as Ebola and the novel coronavirus in the affected countries have led to prolonged disruption of social and economic activities. Case recognition, case management, and active contact tracing are essential in controlling the initial outbreak of infectious diseases. This requires active public health intervention along with strong surveillance and laboratory networks, research and development, and sharing of information and partnership with centres with expertise. With increasing cross border travel, global cooperation is crucial to contain emerging infectious threats. The World Health Organization proposed the International Health Regulation 2005 to regulate global efforts in combatting common threats.
International Health Regulation 2005
The International Health Regulation 2005 is a set of international laws that govern identification, surveillance and reporting of diseases that may be a Public Health Emergency of International Concern (PHEIC). Bhutan is a signatory to the IHR and has dedicated national framework for surveillance and reporting of internationally notifiable diseases (SARS, Smallpox, New influenza viruses, Wild-type polio) and other notifiable diseases that may be a Public Health Emergency of International Concern. The present 2019 novel coronavirus outbreak, now declared a PHEIC, is a case example of the threats of global emerging infectious disease to the social and economic security of our country.
The 2019-novel Corona Virus
In December 2019, there appeared a cluster of pneumonias of unknown cause in Wuhan, China. By January 2020, it was identified that the disease was caused by a new type of virus, named by the World Health Organization, as the 2019-nCoV. This new virus has spread to 20 countries outside China with known human-to-human transmission. There are more than 9,000 confirmed cases and more than 200 fatalities with the number increasing by each hour.
The 2019-nCoV infection causes symptoms ranging from fever, cough and flu-like illnesses to more severe forms such as pneumonia and respiratory distress requiring intensive care support. While its fatality rate is lesser than other coronaviruses, it will pose significant clinical challenge as this virus has sustained human-to-human transmission.
The outbreak in China happened around the time when many Bhutanese travel to Thailand, India and Nepal. Pilgrimage sites in India and Nepal experience heavy traffic of visitors from many Asian countries, mostly from China. Back at home, the tourism industry is being sensitized on the preventive measures on the travel-related spread of the infection.
How do new corona viruses emerge?
Corona viruses have been long considered inconsequential pathogens. They (Human Corona Viruses named HCoV 229E, NL63, OC43, and HKU1) cause 10-30% of the upper respiratory tract infections (common cold) that are self-limiting in adults in the USA. However, two highly pathogenic types of corona viruses emerged: Severe Acute Respiratory Syndrome Corona Virus (SARS-CoV) in Hong Kong in 2002-2003 and the Middle Eastern Respiratory Syndrome Corona Virus (MERS-CoV) in Saudi Arabia in 2012. SARS spread to 30 countries in Asia, Americas, Europe with 8,439 cases and 812 deaths within 7 to 8 months with an economic loss estimated USD 10-30 billion. The MERS-CoV infection has been reported from 27 countries with at least 722 deaths. Both these viruses have originated from animals and spill over to humans have caused human infections.
The origin of the 2019-nCoV has not yet been confirmed but like the SARS and MERS CoV, it is likely a spillover from zoonotic sources. However, with sustained human-to-human transmissions reported with MERS and 2019-nCoV, the virus can spread virtually to any place on earth due to human travel. The 2019-nCoV has predominantly lower respiratory symptoms and is spread through cough and close contact with infected individuals.
The medical and scientific community are still trying to understand the 2019-nCoV and the novel coronavirus infected pneumonia as more clinical and medical information are published in medical journals.
Bhutan’s response to prevent 2019-nCoV entry
The Ministry of Health has led the multisectoral response in the prevention of the entry of the novel coronavirus into the country. This involves screening persons with symptoms of influenza such as fever, cough and malaise. The health workers are sensitized on the detection of cases. The Royal Centre of Disease Control, Thimphu has issued guidelines on the collection of samples from suspected cases and the hospitals are altered on the contingency plan to isolate and provide care of cases if detected. The government has issued travel advisory to avoid travel to countries.
Both the mainstream and social media are playing important roles in the sharing of information on the symptoms of the novel coronavirus infection and individual-level preventive measures such as washing hands and use of face masks. Rumours and misguided information play a very destructive role in such outbreaks and hamper public health intervention measures.
Care of infectious diseases requires trained professionals and specialized centres such as infectious diseases hospital. For the time being, the Ministry of Health has identified specific centres and emergency teams for the isolation and treatment of novel coronavirus infected cases if detected.
While there are multiple versions of epidemiologic projections on how and when the present coronavirus infection will end, it has also tested the response of the present development of our health system to countering emerging and re-emerging infectious diseases. Emerging diseases will continue to challenge in modern health systems in different forms and times.
Contributed by Dr Thinley Dorji
Postgraduate student in MD Internal Medicine at Armed Forces Medical College, Maharashtra University of Health Sciences, Pune, India. Email: firstname.lastname@example.org