At present, the new coronavirus has caused infections in more than 60,000 people, 8,000+ severe cases, and 1,000+ deaths. Mortality is similar to SARS, about 2%. The World Health Organization has named it SARS-CoV-2, and COVID-19 (Coronavirus disease 2019), together with SARS is classified as a Class B infectious disease.
Figure: scanning and transmission electron microscope images of the coronavirus by NIAID
With those numbers, New coronavirus is classified as class B! What are the Class A?
There are three types of Class A infectious diseases: plague, cholera, and smallpox.
Yersinia pestis was first carried by mice, and then transmitted by mice-fleas-people, and then from person to person, from person to mouse. According to the degree of infection, they can be divided into bubonic plague, pneumonic plague, and septicemic plague, which are aggravated in order. The infection mortality is 55% of plague, 95% of plague, and 100% of septicemia.
The plague in 1346 began with the spread of merchant ships in Genoa and Venice, and then entered the European hub-Constantinople. From then on, it was out of control! It lasted for more than 300 years, and it was not announced until the plague suddenly disappeared in the early 18th century. This pandemic caused at least 60 million deaths in the three continents of Europe, Asia and Africa. More than half of the population in Europe died of the epidemic. The name “Black Death” also came from this pandemic.
The latest plague was in Northeast China in 1911. The plague has not been eliminated by humans, but has been in the historical cycle of latency-outbreak- latency.
Cholera is an acute diarrheal infectious disease caused by food or water contaminated with Vibrio cholerae. Each year, there are an estimated 3 to 5 million cases of cholera, and another 100,000 to 120,000 deaths. The peak of the disease is in summer, which can cause diarrhea, dehydration and even death within hours.
Cholera is mainly transmitted by water. In pre-industrial Europe where sanitary conditions are backward, large-scale cholera epidemics have occurred in modern China, contemporary Africa and India. Hundreds of millions of people were infected during 160 years, with a mortality rate of 7.5%!
Smallpox (Variola Virus) is one of the oldest and most deadly infectious diseases. It is highly contagious and severely ill. People who have not had smallpox or have not been vaccinated against smallpox can be infected, mainly as severe viremia. After infection, The mortality rate is high. The most basic and effective method of prevention is vaccination. The clinical manifestations of smallpox are severe and mild. The mortality of severe smallpox is about 25.5%, fusion rash occurs in 45% of cases, and bleeding occurs in 79%. The mortality of smallpox is 0.1% to 1.0% in mild. Smallpox virus is a type of poxvirus. After a person is infected, there is no specific cure for it.
The smallpox virus will make the infected person unrecognizable and unbearable. It will cause severe damage of the infected person’s appearance. Variola virus is currently the only Class A infectious disease confirmed to be eliminated!