Contact tracing: what is it and how will it help?

Contact tracing is a type of epidemiological investigation which is conducted whenever a new disease or infection, or an old disease, breaks out. Epidemiologists start with the index patient or patient zero with whom the infection in a location originated. Interviews, tests and screenings are conducted to understand the patient’s symptoms as well as to figure out who he or she has been in contact with after getting infected. 

On the basis of these answers, epidemiologists then contact airlines, restaurants, people, etc the index patient has come in contact with to understand if similar symptoms are showing up with different types of contacts. This list of people and places can be quite extensive, especially if the patient zero has a travel history. Once all the people exposed to the index patient are accounted for, epidemiologists can tell if the disease has spread rapidly or slowly, what its incubation time is, who has minor symptoms and who has more severe ones, etc 

If the disease spreads too rapidly, contact tracing becomes even more wider in scope since all the primary contacts of the index patient would have further spread it to their contacts too. Contact tracing is therefore a painstaking, laborious process which takes a lot of patience. However, its significance is huge in calculating the current and future spread of an infectious disease.

COVID-19 is a highly contagious infection which is transmitted through human contact or after coming into contact with a contaminated surface. The disease originated in Wuhan, China, and spread to 177 other countries over a period of just three months (as of March 2020). Currently, there are over eight lakh confirmed COVID-19 cases all over the world, and the death toll is also globally on the rise. 

Contact tracing is the method used to identify patients and carriers of the disease in the initial stages of transmission. Once the transmission transcends the local stage and moves into the community stage, contact tracing can no longer be used. For example, in countries like Italy and the USA, contact tracing can no longer be effectively used.

However, in countries like India and New Zealand, where transmission is still at the local level, contact tracing is the best means of limiting the spread of COVID-19. Once the index patient and all his or her contacts are identified and quarantined, the spread of a disease like COVID-19 can be contained. Of course, awareness about the disease and government support in executing preventive measures also plays a huge role in containment of a contagious disease, but without the details provided by contact tracing, these data would be unavailable.

While contact tracing from the index patient, epidemiologists have a way of demarcating the different levels of contact to understand what advice to give to suspected patients and the general public. The following are the two types of contacts epidemiologists take into account immediately after a new disease or infection is discovered and the index patient identified.

Whether you came to know about the existence of a disease outbreak on the news or after epidemiologists contacted you, thinking that you’re a contact - close or casual - of a confirmed patient can lead to panic and fear. While these feelings are quite natural, especially if the disease is new and neither a cure nor vaccine is available for it, it’s important to pay attention to your health.

You should call emergency health services or your doctor and share your suspicion immediately, and not wait for symptoms to arise. Acting on the recommendation of healthcare professionals is the best way to go during a disease outbreak, especially a pandemic like COVID-19. If you’re asked to visit a hospital, quarantine yourself, or watch your health closely, do it. 

No matter how new or old a disease, early detection is always the best way to get diagnosed, access healthcare and recover faster. If you believe you’re a contact, it’s also your civic and moral duty to self-isolate and contact healthcare providers instead of going ahead with your normal life and risking the lives of others.