9-15 December 2016 #836

Counter-attack of the microbes

Nepal has issues of overuse of antibiotics in both humans and animals, uncontrolled prescription, or hospital-based infections
Sameer M Dixit, Buddha Basnyat and Paras Pokhrel

Pic: Gopen Rai
Health Minister Gagan Thapa takes part in a cycle rally on the occasion of World Antibiotics Awareness Week 2016 at Basantapur Darbar Square.

Ever since the discovery of Penicillin in 1928, antibiotics have been used to treat major human infections caused by bacteria. Since then, more than 100 varieties of antibiotics are in commercial production worldwide. 

However, there is now a new threat to global health posed by Antimicrobial Resistance (AMR) because of which antimicrobials including antibiotics, antivirals and antifungal medication can no longer be used to treat infections. Of particular interest is antibiotic resistance, which makes up the majority of the AMR threat. 

Bacteria are interesting organisms -- they can be our friends or foes. They are found all over the human and animal body and have a role to play in our bodily functions, including digestion. However, there are some that do not necessarily live within our bodies which can cause major diseases in humans. Sexually transmitted infections, food poisoning, tuberculosis are some examples.

These tiny organisms reproduce very fast and can change their genetic makeup through mutation. When their growth environment is suitable, they reproduce in a stable manner and co-exist with other inhabitants in the human body. However, when under stress due to various limitations within their habitat, they can go rogue. 

When bacteria identify antibiotic families as threats to their survival they develop resistance. Bugs that survive the first rounds of antibiotic attack undergo mutation that allow them to either counter or bypass antibiotic molecules they are exposed to. This leads to development of progeny bacteria that are resistant to the given class of antibiotic(s).

These bacteria develop Anti-microbial Resistance within the human host. AMR bacteria can pass genetic information not only to their progeny, but also to bystander bacteria. They, in turn, pass it on to their progeny and other bystanders and so forth. Human to human transmission of bacteria is also possible, leading to the spread of AMR bacteria in a population, and globally. 

To add to this dilemma, food animals such as poultry, dairy, livestock and fish are being given antibiotics in their feed as growth promoters. The idea is to prevent bacterial infection in these animals, but this has lead to more AMR bacteria, which can again be transmitted to humans in meat and dairy products. AMR is therefore a ‘One Health’ problem -- human health is affected by both non-humans and the environment and there is only one approach required to tackle it.

Nepal is not immune  to the global threat of AMR. We have issues of overuse of antibiotics in both humans and animals, uncontrolled prescription, or hospital-based infections. AMR is already present within Nepal, and each of us is susceptible to the threat. Kathmandu and other cities are at heightened risk because of the combination of AMR and dust pollution. 

Everyone on the streets of Kathmandu breathes in copious amounts of polluted and dust-ridden air. While there are various health risks (respiratory, visual) associated with this, some dust particles which are too small for the naked eye to see can also be bacterial and viral organisms in the air. Bacteria and viruses are very small, and in fact, a single dust particle can carry numerous such pathogens. If one is to imagine breathing in such particles while walking, cycling, or jogging, there is a very high chance that they would be breathing in not only the particles but also infectious pathogens along with them. 

These particles can make their way into the lungs, our digestive system, as well as the blood stream. Not only do they cause physiological damage to the linings of our organs, but the particles allow the pathogens to colonise various parts of our body. 

A healthy human body has its own defence mechanism and can fight off a majority of the infecting pathogens. However, the very young, the very old and immunologically compromised individuals may not be able to fight these on their own and have to rely on antibiotics. Even healthy people can only fight off so much of the infection, and may need antibiotics. 

The whole cycle then repeats itself: patients get treated for infection, they may recover if the pathogens in their body are not AMR bacteria, but if the treatment may be difficult or in some cases, useless. If patients do recover, they may become hosts to AMR bacteria which they can then pass on to others over their lifetime. The irony of this is that the very activities that should be making a person healthy is doing quite the opposite.

The next time you venture out on to the streets of Kathmandu, do enjoy the fresh air, but also keep in mind that the dirtier the air, the higher the chance of getting not only sick but also contributing to the spread of AMR.

Sameer M Dixit, PhD, is Director of Research at Centre for Molecular dynamics Nepal (CMDN)*

*Buddha Basnyat, MD is a consultant at Patan Hospital

Paras Pokhrel, MD is head of Community Medicine, BPKIHS Dharan

All three are also associated with the Global Antibiotic Resistance Partnership (GARP) run under the Nepal Public Health Foundation (NPHF).

Read also:

The return of the microbes, Sunir Pandey

“Patients are impatient”, Sonia Awale

Antibiotic resistance, Buddha Basnyat and Hellen Gelband

Multiple resistance, Juanita Malagon