How public health officials attempt to control and contain outbreaks? Dr David Muscatello outlines the key measures used by public health clinicians.
In this article, you will learn about how public health officials attempt to control and contain outbreaks – the kinds of interventions and policy measures that can be introduced to limit the spread of a disease. There are two main aspects to outbreak control – limiting the impact of an active outbreak and preventing future outbreaks.
Regardless of whether an outbreak was caused naturally, through a laboratory accident, or through intentional dissemination of an infectious agent, the public health response would initially attempt to contain the outbreak and prevent further spread. There would need to be strong involvement of medical and other health services to treat the people who are infected, and sometimes to administer preventive measures to people who may have had contact with a case, such as vaccination. Public health authorities play an important role in these health service activities because hospitals and clinics need to understand appropriate measures for preventing infection of their own personnel and of other patients. Competent and well managed microbiology laboratory capabilities to diagnose and understand the microbiology of infectious diseases are important. Biocontainment laboratory facilities may be needed in the case of bioterrorism.
Active public health surveillance may need to be introduced to facilitate rapid identification of cases and quick delivery of treatment to minimise morbidity and mortality. Information would need to be provided to doctors and health services so that they understand how to identify the disease and what to do if they suspect a case of the disease. Once cases are identified, public health personnel may need to step in and identify contacts of cases so they can be followed up in case they also have the disease, or so that preventive measures can be administered.
An important step is to prevent exposure to the infectious agent
. For diseases that are transmitted from person to person, this could be done through isolating patients with the disease at home or in a hospital or clinic. Separating infected patients from patients in health facilities for other reasons (cohorting) is another strategy. People who have been exposed to the disease, but that do not have symptoms, can be quarantined to prevent further spread in case they do become unwell
. Remember, some diseases are infectious before the patient has symptoms, so this needs to be considered in planning the response. Quarantine can be at home (usually) or in an institution.
The design of health facilities is also important in preventing further spread. Hospitals can have negative pressure rooms that prevent contaminated air from escaping and being circulated to adjacent areas. Isolation wards can ensure infected patients are kept separate from other vulnerable people. Isolating people who may be infected is an important first step when they enter a health facility, even before the infection is confirmed. However, it is also important to prevent these people from being exposed to people with confirmed infections in case they do not have the disease.
Communicating with and educating the population at risk of infection about personal preventive measures and personal hygiene is important, depending on the disease. Hand washing is a simple and effective measure to reduce the risk of infection by many contagious diseases. Access to clean water, well maintained and hygienic toilets, bathing facilities and hand washing facilities are essential to prevent outbreaks and to prevent outbreaks spreading, particularly for waterborne or foodborne diseases like cholera. Water, sanitation and hygiene is often abbreviated as WASH
to make it easy to remember what is required when confronting or preventing an outbreak emergency. WASH is important in other types of emergencies, because disasters of any kind can create an environment for infectious diseases to take hold.
For vector borne diseases such as yellow fever, Zika, and dengue fever, controlling the vector or animal reservoir may be an important measure. During the Zika outbreak in South America that started in 2015, spraying to control mosquitoes was introduced.
If time allows and a safe and suitable vaccine is available and affordable, vaccination against the disease is an important option. The outbreak of yellow fever in 2016 in Angola and the Democratic Republic of the Congo in Africa has so far been successfully controlled through mass vaccination campaigns. Prophylactic pharmaceutical measures may be another option, either before or after exposure.
If the outbreak is intentional, some aspects of the control measures may be very different. Police or military services will also need to be involved. They may need to undertake a criminal response to identify the perpetrator or perpetrators of the event and bring them to justice. They cannot work in isolation though – they will need to coordinate their activities with health and medical authorities to ensure the safety of their own personnel and that of people in the community.
Other things to consider are border control measures, using vaccines or pharmaceuticals that have been stockpiled in case of an outbreak, and notifying the situation to the World Health Organization under the International Health Regulation.
In the longer term, it is important to study an outbreak and learn lessons from it to prevent future outbreaks. This might lead to new disease prevention policies, maintenance or improvement of surveillance systems, maintenance of stockpiles, development of new drugs or vaccines, and improved microbiology facilities.
After watching this video, in the comments section below discuss your answer to the following question:
Can you think of some ways that controlling bioterrorism outbreaks might differ from controlling naturally occurring or unintentional outbreaks?