Breaking the chain of infection

Breaking the chains of the infection

 These small measures can the “Sanjeevani” to  remain safe even if we cannot avoid coming into contact with the pathogen.

By Hasitha Durgavajjhala



The COVID-19 pandemic has forced all of us to step back and evaluate ourselves on our approach to diseases at large. For many, it has served as a wake-up call on the importance of day to day hygiene and public health. Where many infections were previously overlooked as inevitable for a season – some such diseases being  common cold and dengue – it’s now shown to be easily prevented, or at least reduced, by taking some basic precautions.

Infections are caused by the entry of pathogenic organisms into a healthy body. These organisms could be any: bacteria, viruses, fungi, protozoans, or parasites. Once they enter the body, they produce antigens, which produce the “effects” or the symptoms of the disease, and activate our immune response.  Our  immune system tries to destroy these antigens and expel them from the body in a variety of ways. This is often the reason for transmission of communicable diseases in a society – the infected person is often releasing these antigens through breaths, sneezes, phlegm, etc.. People in contact with an infected person are therefore, automatically at risk.

However, it is important to remember that each body is different. Depending on genes(family history), the environment and a plethora of other reasons, people’s bodies react differently to the same infection. Some may show multiple symptoms, whereas others may present none. The latter, called carriers, are very dangerous in terms of public health. The lack of observable symptoms means they may never know of the infection, and yet continue to transmit it.

A notable example of this is Mary Mallon, known colloquially as Typhoid Mary.  She was an asymptomatic carrier of typhoid. In her career as a personal chef to various affluent families, she unknowingly transmitted the disease to an estimated 53 people over her fifteen year career span, and was forcibly quarantined for the rest of her life once she was discovered as a carrier of the disease.

Therefore, it’s important for us to understand the various routes of  transmission of infection. They are as follows:

Direct Contact: This is when an infected person’s tissues or bodily fluids come into direct contact with an uninfected person, giving the pathogens the opportunity to enter the uninfected person’s body. This includes bites, scratches, sexual contact, and needle sharing.

Air: This is a form of indirect contact, where pathogens suspended in the air are breathed in by uninfected persons. Pathogens can enter the air through sneeze droplets, breathing and even speaking from infected persons, and during medical procedures. These tend to be very small particles so they can travel quite quickly through air currents. However, most pathogens cannot survive very long in the air.

Vectors: Vectors are living beings, usually insects or rodents, which can carry pathogens and spreading them to uninfected persons. A good example of this phenomenon is mosquitoes transmitting malaria. They obtain the pathogen through sucking the blood of an infected person and can transmit the pathogens to an uninfected person by biting them.

Ingestion: Food and drinks can get contaminated by feces, urine, saliva, or contaminated cooking equipment. Ingestion of contaminated food introduces the pathogen to the body and leads to infection.

Fomite Transmission: This is when inanimate objects get contaminated, and those coming in contact with these objects get infected. These objects can include surfaces, clothes, medical equipment, cutlery, and vehicles.

Direct transmission and air-based transmission are the major routes of spread of infection. Diseases like COVID-19 and seasonal epidemics like the common colds  have been known to spread very fast and very far by this phenomenon. An easy way to combat this spread is to hinder direct contact, by simply maintaining distance between oneself and people whose infection status is unknown. This is known as social distancing. A major transmission route for many diseases is inhalation of respiratory particles suspended in air. However, as discussed previously, pathogens cannot survive very long in air. Therefore, a combination of social distancing and protecting inhaled air using masks or face coverings can go a long way in protecting people from this pandemic. 

However, pathogens do not just exist in the air – they also settle on surfaces, inanimate objects, and may be transmitted by vectors or through food. However these issues could be resolved by applying very simple solutions, i.e., cleaning and disinfecting objects and surfaces, timely and thorough washing and sanitizing of our hands after touching something that may be contaminated. These are all small measures that should already be a part of our hygiene routine. However, in times of pandemic,  these small measures can the “Sanjeevani” to  remain safe even if we cannot avoid coming into contact with the pathogen. As for food, it is always best to know where your food is coming from, to eat healthy, and to make sure that kitchens and chefs are properly upholding food safety standards. In times of vector-spread epidemics, making use of repellents, and staying up to date on vaccinations for preventable diseases is the key to an individual’s health. 

In East Asia, such responses are common even for seasonal epidemics like the common cold. Wearing a mask to prevent further infection when one has an infectious disease is considered basic courtesy in Japan, China, and South Korea. Coupled with the lower obesity and pollution rates, this has been linked to better public health and reduced spread of such infectious diseases in these countries.

It may seem simplistic to say that these small measures can actually make a difference. However, the pandemic has shown us the true power of social distancing. In New Zealand, the first COVID-19 case was reported on the 11th of March 2020. The country adopted a policy of “go hard, go early” and announced an immediate lockdown and social distancing requirements. After less than a month, on the 9th of June, the country reported a streak of no new cases, and the lockdown was lifted. The virus, once eliminated, has yet to be reported again.

The true solution to this pandemic, of course, is in finding effective medication, vaccines and in governmental regulations to allow these to be availed by the entire population. However, public health is not just the responsibilities of the authorities, but also a personal duty. The public is, after all, just a collection of individuals. Herd immunity is only effective to a point. After this, it is up to each person to take care of their own hygiene, and for those infected to step up and minimize the spread of the disease from themselves.

Imagine a series of dominoes: once they start, it may seem impossible to stop them from all falling, as they move so fast. However, removing a single domino piece can make it impossible for the previous piece to reach the next one, and stop the collapse of the entire line. The fallen pieces may have fallen already, but the ones ahead of the removed dominoes remain standing. This is exactly how public health works.

Our duty now is to wear a mask, maintain social distance and wash our hands often. We cannot single-handedly end the pandemic – but we can make sure our loved ones and those around us remain safe.

Hashita is student in the final year of a master’s degree in biotechnology. Based in India. Passionate about mental health, sunsets and her cat.