What are Coronaviruses (CoV) and the 2019-nCoV?
Coronaviruses are a large family of viruses that are common around the world and often cause respiratory illnesses of humans and other animals. Among recent global occurrences, the Severe Acute Respiratory Syndrome (SARS) coronavirus and Middle East Respiratory Syndrome (MERS) coronavirus (also known as MERS-CoV) have caused several illnesses and deaths among humans. The 2019-nCoV was first detected in Wuhan City, Hubei Province, China in December 2019 and continues to expand to other provinces and countries. As of January 26, 2020, there are more than 2,700 confirmed cases and 80 deaths linked to the 2019-nCoV virus. A total of 14 countries have reported cases. In the United States, thus far five confirmed cases in four states, including Washington, Illinois, California and Arizona (as of Sunday Jan. 26, 2020).
How are Coronavirus infections transmitted to humans?
Like most other respiratory viral infections, Coronaviruses are transmitted airborne with inhalation of droplets. In addition, direct contact with infected animals, humans, surfaces and fomites can result in infection. The complete clinical picture with regard to 2019-nCoV is still unclear. Both MERS and SARS have been known to cause severe illness and deaths in people. Of key significance for the current 2019-nCoV infections is that infected people may be contagious and transmit the infection to other people before showing signs and symptoms themselves. Therefore, quarantining sick persons alone may not be sufficient to control the spread of the virus. Furthermore superspreaders (persons who can infect a multitude of others) and infection of healthcare workers played major roles in the SARS pandemic, but their role in the spread of 2019-nCoV infections remains unknown.
What are the clinical signs, symptoms and epidemiological risk factors of Coronavirus infections?
Coronaviruses cause lower respiratory illness in people with symptoms of fever, cough and shortness of breath. Severe infections can cause pneumonia, severe acute respiratory syndrome, kidney failure and death. Symptoms may appear 2 to 14 days after exposure. Increased epidemiological risk of the 2019-nCoV infection in those with travel to Wuhan City, China or close contact with a person suspected or confirmed 2019-nCoV infection in the last 14 days. CDC has developed a test to diagnose 2019-nCoV from respiratory and blood specimen. Currently there is no specific antiviral treatment recommended for 2019-nCoV infection and no vaccine is available. Supportive care is given to those infected with 2019-nCoV to help relieve symptoms.
How did the current outbreak of 2019-nCoV occur?
Similar to other coronaviruses, the 2019-nCoV appears to have a broad host range and has been implicated as a zoonotic (animal-to-human) transmission with a wild animal origin. Early on, many of the patients in the 2019-nCoV outbreak in Wuhan, China reportedly had some link to a large seafood and animal market in Wuhan, suggesting an animal origin for the initial spread to humans. Comparison of the genetic sequence of the new virus and comparison with the genetic sequences of more than 200 other coronaviruses from around the world indicated that it is closely similar to strains that originate from wild animals. According to a CDC report, the available sequences suggest a likely single, recent emergence from a virus related to bat coronaviruses and the 2003 SARS coronavirus.
What is the significance of animal-to-human transmission?
Zoonotic (animal-to-human) transmission is reported to contribute to up to 75% of new or emerging infectious diseases. Like other coronaviruses, the 2019-nCoV has zoonotic significance and is thought to have resulted from a spillover from either a wild or domestic animal to humans in close contact. While the index case of the 2019-nCoV likely originated this way, direct human-to-human transmission is known to be occurring. At this time, animals or pets outside China are not believed to be a source of infection of the 2019-nCoV. Because some bats harbor SARS-related CoVs that are genetically closely related to 2019-nCoVs, they could have been the source of the 2019 nCoV human infection in the markets. However there may be other animals, especially wild animals, in the Chinese animal markets that may have SARS-related CoVs and could serve as intermediate hosts, facilitating in virus transmission to humans, but this remains to be discovered.
What do people and nations, globally, need to do to prevent and control the 2019-nCoV?
The World Health Organization recommends hand and respiratory hygiene, and safe food practices in areas where the 2019-nCoV has been detected. Specific hygiene and preventive measures to take in outbreak areas include frequently cleaning hands with soap and water for at least 20 seconds or use an alcohol-based hand sanitizer, covering mouth and nose with a tissue or your sleeve (not your hands) when coughing and sneezing, avoiding close contact with persons experiencing fever and cough, avoiding direct, unprotected contact with animals live and dead, and avoiding consumption of raw or undercooked animal products. In the absence of vaccines and antivirals for 2019-nCoV, rapid diagnosis, quarantine and basic public health strategies as implemented for the successful control of the SARS outbreak will be essential to stem this outbreak. Further expansion of the outbreak globally is likely beyond Asia, Australia, Europe, and United States, including developing regions Latin American and sub-Saharan Africa where significant number of people between China and Africa travel occurs. The Global One Health initiative (GOHi) advises nations and regional bodies to strengthen diagnostic, control laboratory infrastructure and skilled manpower capacity through the African Centers for Disease Control and Prevention (AU-CDC) and similar entities in order to prepare, detect and control current and future outbreaks using the One Health integrated approach.
Useful references
cdc.gov/media/dpk/diseases-and-conditions/coronavirus/coronavirus-2020
who.int/emergencies/diseases/novel-coronavirus-2019/situation-reports
Ohio State University Coronavirus Experts
cfaes.osu.edu/news/articles/ohio-state-experts-available-for-comment-new-coronavirus
About the Ohio State Global One Health initiative (GOHi)
The mission of GOHi is to expand capacity for a One Health approach via applied education, training, research and outreach to more efficiently and effectively address causes and effects of diseases at the interface of humans, animals, plants and the environment. GOHi envisions building capable professionals and institutional systems that support and advance a healthy, enduring global community. More information can be found at globalonehealth.osu.edu.
About Ohio State Infectious Diseases Institute (IDI)
The mission of IDI is to generate solutions to the detrimental effects of microbes on the health of humans, animals, plants, and the environment for the benefit of society. IDI envisions a world free from the threat of infectious diseases. More information can be found at idi.osu.edu