Isolate
Persons suspected of having an infectious disease, must be isolated locally where they are found, and contact with uninfected individuals must be prevented. Isolation involves the transfer of patients to other designated treatment sites or directly into isolation.
Health care workers must consider whether necessary isolation precautions should be implemented when evaluating patients. At the same time, they must decide whether isolation, quarantine, or surveillance is most appropriate. Isolation refers to the separation of symptomatic infected persons (patients) from uninfected persons to prevent the spread of disease. Quarantine refers to the separation of individuals who are not infected, but who were or may have been exposed to an infectious disease or pathogen, from individuals who were not exposed or are more susceptible to infection (Brooks et al., 2020). Surveillance is a population-based measure used to observe people who are likely to have been exposed to a disease, but have no symptoms. Surveillance, which is similar to quarantine but may allow the individual to be isolated at home, was used during the assessment of MERS infections (Koenig, Shastry, & Burns, 2017). When observing patients during quarantine, the individual should be transferred into isolation when symptoms occur and infection is confirmed.
Diseases for which quarantine is suitable must pose a serious threat to public health, such as cholera, diphtheria, tuberculosis, plague, smallpox, yellow fever, viral hemorrhagic fever, and SARS (Koenig, 2012). Quarantine stations located at entry ports and national borders provide isolation as part of the national quarantine system to limit the introduction and spread of infectious diseases in a country. The duration of the quarantine is determined by the incubation period of the infection. At present, SARS-Cov-2 infected patients with symptoms of COVID-19 are the main sources of infection, but asymptomatic infected patients (no symptoms of COVID-19) may also be infectious (Xu et al., 2020). Therefore, the combination of quarantine and isolation is effective for the prevention and control of COVID-19, and this method has achieved good results in China (Figure 1).