Pollution exacerbates influenza

Written by
Dr Ayub Macharia

A few days ago, the Kenyan media reported an outbreak of influenza in Nakuru county that led to deaths of over 40 children. This is a major epidemic and there were fears that the menace could spread to other parts of the country. There were reports that the government planned a major vaccination exercise to prevent further spread of the disease.
Many Kenyans are not familiar with Influenza flu and if you check the google trends, the terminology has attracted a lot of attention. What exactly is influenza flu? How is the disease spread? Does pollution play a role in spread of the disease? Considering polluted and less polluted environments, where are we likely to get more disease prevalence? These are some of the questions that beg answers to assure Kenyan people that they are safe from this epidemic.
Influenza is a contagious flu or respiratory illness caused by influenza viruses that infect the nose, throat and the lungs. The disease can be mild, severe and at times may cause death. Some of its symptoms include fever, chills, cough, sore throat, running nose, muscle or body aches, headache, fatigue, and sometimes vomiting and diarrhea especially in children.
Studies show that influenza spreads through droplets released when people cough, sneeze or talk. Any contact with these droplets through inhaling them, touching them and then touching the mouth and nose spreads the disease.
Studies have also shown that air pollution by particulate matter suspended in the air such as smoke and dust exercerbates the problem by serving as carriers of the influenza virus. When one sneezes in a dusty environment without covering the mouth and nose, millions of viruses are released and attach on the surface of the suspended air particulate matter. The particulate matter act as ‘condensation nuclei’ to which the virus droplets attach. These virus laden particles can remain airborne for a long time and can get dispersed by wind over a wide area. Hence disease spread could be exacerbated by presence of air pollutants as compared to just sneezing within non-polluted areas.
Hence if one is to compare possibility of disease prevalence in an urban area and a rural set up, it is evident that urban areas could be adversely affected. Urban areas have a lot of particulate matter arising from diesel exhaust and normal dust disturbed all the time by the mobile vehicles. Indeed studies have shown a relationship between hospital admissions to influenza with increase in levels of particulate matter.
Another challenge with pollution is that when they attach to sensitive body surfaces such as nasal cavity, they cause irritation and inflammation. This is normally dismissed as allergy. The human body cells when in contact with pollutants and viruses produce chemicals called cytokines. Cytokines are proteins released by the body’s immune system causing inflammation and release of fluids. That is why people when exposed to air pollution normally sneeze and produces mucus from their noses causing them to blow their noses regularly. Hence a person suffering from influenza and living in a place experiencing air pollution suffers double tragedy whereby his/her body cells get enhanced irritation and inflammation.
In Kenya, most areas experience some level of air pollution be it in form of dust or smoke. Since a mild influenza epidemic has been reported in Nakuru, one cannot be certain that you will not contract the virus through suspended particles in the air. Hence its crucial to understand that likelihood of getting the virus is substantial even though you have not been in contact with an infected patient.
So, what can we do to remain safe from influenza virus? We are fortunate that our scientists have successfully developed an Influenza vaccine. It’s advisable that everybody gets an annual jab of this vaccine. Right now it’s advisable that we support the government vaccination initiative regarding influenza.
Additionally it is also advisable to take preventive action to stop the spread of germs. This could be done by making sure that we do not cough and sneeze carelessly without covering our nose and mouth. This would prevent releasing jets of viruses into the atmosphere to attach to the particulate matter and get dispersed other people. Minimize the infection to yourself. We could also go a step further, though cumbersome, and use nose masks to filter the particulate matter getting into our noses.
All of us have a role to play to ensure that further spread of influenza is curbed. Make sure you do not contribute to infection of your neighbor by sneezing responsibly. Lets also contribute as government or individuals to ensure that pollution levels are reduced. Make sure our roads are not dusty. Vehicles should ensure that their pollution levels are as prescribed in the Environmental Management and Coordination Act -Air Quality regulations 2014.

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