What is the "super disseminator" in the outbreak?

February 2, 2020 news / BIOON / -- Wuhan coronavirus outbreak has become the focus of global public health The virus can spread from one region to another by human to human transmission, and then cause a global public health threat For patients who have been infected with the virus, some groups may not spread the virus further, while the other groups have strong transmission ability, the latter is generally called "super communicators" by epidemiologists Recently, Elizabeth McGraw, director of the center for infectious dynamics at Penn State University, explained what "super communicators" are and why they are crucial in the development of the epidemic What is a super communicator? Researchers now estimate that patients with Wuhan coronavirus can infect an average of 2.6 people A recent report in Wuhan also cited a case of infection with 14 medical and nursing staff Patients like this can be regarded as "super communicators", that is, those who can infect a large number of people around them For any new outbreak, epidemiologists often want to determine whether there are "super communicators" The existence of these groups can greatly speed up the spread of the virus, or greatly expand the geographical distribution of the disease In response to "super communicators", experts can recommend various ways to limit the impact of pathogens and slow down the spread of diseases according to the way they spread Different interventions are needed for air droplets, surface contact transmission, sexual transmission, needle transmission, food or drinking water transmission, etc For example, the coronavirus in this outbreak is mainly transmitted through droplets, so it should be recommended that the public wear masks, and for pathogens that can survive on the surface for a period of time, they need to wash their hands frequently and disinfect the surface What are the characteristics of "super communicators"? Whether a person is a super communicator depends on the pathogen, the physical characteristics of the patient, and specific time and environmental factors In a highly connected society, people who can quickly carry pathogens across a long distance often help to create a mature super communication environment Due to the working principle of the immune system, specific infected people may have stronger ability to transmit the virus For example, people who are resistant to the virus will not have obvious symptoms and will not feel uncomfortable, so they may continue their daily life, which will inadvertently infect more people In addition, for people with weak immune system, the virus in their bodies can replicate in large quantities, which also improves the replication efficiency of the virus People with frequent coughs, sneezes and poor hygiene habits are also potential "super communicators" Therefore, we should try to minimize contact with the above groups In addition, one's behavior, way of travel and contact with others may also contribute to the spread of the virus People who are engaged in the service industry or who usually have a large number of contacts with many people are more likely to spread the virus For example, store owners and international business people as well as health care workers and so on. When will super communicators have an impact in the epidemic? There are many examples of "super communicators" in history The most famous is "Typhoid Mary" It is said that in the early 20th century, the chef named "Mary" suffered from typhus She infected 51 people by cooking As Mary is an asymptomatic carrier, she does not feel unwell or change her health habits at the right time In the past two decades, there have been many outbreaks of "measles" in the United States, among which super communicators have played a very important role Many patients who are ill but not vaccinated appear in densely populated areas, such as schools, hospitals, airports and parks, which cause many people's infections Super communicators also play a key role in other coronavirus outbreaks, including SARS (severe acute respiratory syndrome) and mers (Middle East respiratory syndrome) For example, during the SARS epidemic, an infected person with SARS symptoms lived in a Hong Kong Hotel and infected many overseas guests, who then returned to their respective countries and introduced the virus to four other countries For SARS and mers, super transmission usually occurs in hospitals, and there are often dozens of people infected at one time In 2015, a Korean mers patient infected more than 80 other patients, medical staff and family members in the emergency room within three days Will "super transmission" occur in all infectious diseases? The answer is yes Some scientists estimate that during any outbreak, 20% of the infected people usually cause more than 80% of the total number of infections In common infectious diseases, such as tuberculosis caused by bacteria and measles caused by virus, mers and Ebola infection, the presence of super communicators has been found However, if we can develop and implement correct control measures (including hand washing, wearing masks, strict quarantine, vaccination, etc.) for the transmission mode of pathogens, we can effectively slow down the spread of the epidemic and eventually eliminate the epidemic Reference materials: 1 Release detectives identifying down more information about 'super spread' of Wuhan coronavirus 2 Coronavirus: how worded should I be about the shortage of face masks? 3 10 things you may not know about "typical Mary" 4 Factors associated with measures transmission in the United States during the postelimination Era 5
Hong Kong hotel is eliminating memories of SARS
6 Transmission characteristics of MERS and SARS in the healthcare setting: a comparative study 7 Patient proximity key in Korean MERS super-spreader event 8 Dimensions of superspreading