Threat of the tiny tormentors

As long as one has blood to offer, king or common man; rich or poor; Brahmin or Dalit; Hindu, Muslim or any other; everyone is the same for the hardy mosquito of over 225 million years standing. Playing host to tinier micro-organisms, it has been preying on the later-evolved birds, animals and humans and has mostly been emerging as the victor. While others are left only to die, humans are left with physical strain, financial drain and sometimes death; always with contempt.

It is because of this contempt that we enjoy watching even century-old animation films like, 'How a Mosquito Operates' of Winsor McCay, depicting a giant mosquito tormenting a sleeping man. Also, contemptuously, we compare this petty creature with an elephant and derive immense satisfaction when we wield a swatter or even with bare hands, smash this whining tiny fly that tries to interrupt our peace.

More than invoking contempt through their irritating buzz and bites, they terrify us with their numbers and diseases. We should indeed be grateful to predators like lizards, spiders, birds, etc. If not for them, mosquito numbers would have been multiples of what we encounter every day. A single female mosquito lays hundreds of eggs each time and generates its progeny in thousands in a matter of a few days. Come the rainy season, they have a field day.

With continuous rains battering, people of Vizag were scared. Aedes and Anopheles mosquitoes that cause dengue and malaria respectively became buzz-words. Patients with viral fevers were spilling over from beds to floors of hospitals. Around 90 dengue cases were reported in just one single week of September with numbers being added every day with unmistakable symptoms. Without exception, they would show high fever, muscle pain and general fatigue; their BP reading an alarming difference of 20 in systolic and diastolic levels as against the normal 40. At the same time, there was another cause for alarm — 35 out of the 60 cases of malaria in the state, with symptoms of high fever and chill. For the health officials of this district, it was a nightmare. The situation required them to visit houses in order to perform reconnaissance for such cases, spraying and fumigating alongside educating people on cleaning out possible breeding places like stagnant water containers. They instructed them to use repellents, mosquito nets, etc., and also replenish the fast dwindling stocks of Doxycycline which was the crucial drug to prevent fatalities. The situation was taking its toll.

Yet, one relief is that Chikungunya and Japanese Encephalitis are not much heard of this year. Otherwise, Aedes that causes the former and Culex mosquito that infects us with the latter, love the blood of Andhra people. The Andes went on a rampage with an outbreak of Chikungunya in 2005-2006, with over 80,000 known cases. Then it was reported that a change in the CHIKV genotype which enhanced the efficiency of mosquitoes to transmit the virus has been observed. Coupled with an immunologically naive population, global warming and lack of an efficient public health system, the resulted was an explosive re-emergence of this virus in the monsoon season of 2013. 1000 cases were reported from Guntur alone. Although the fever subsided, joint pains and other deleterious effects last for months. And even though it was not as fatal as dengue, doctors were helpless with no anti-viral treatment and were limited to giving supportive care for the symptoms. The only solace is that one does not get Chikungunya the second time.

Japanese Encephalitis also created panic in the past. Beginning with fever and headache, the symptoms rapidly worsened, often along with fits, confusion, drowsiness and loss of consciousness or even coma at times. It is all because the body attempts to fight off the virus and in the process, the brain gets inflamed. However, unlike rabies, that is invariably fatal, encephalitis is kind enough not to take lives as a routine.

It is only in such difficult times that we feel concerned that such vector-borne diseases account for more than 17 per cent of all infectious diseases world over, causing more than 700,000 deaths annually, with 96 million dengue cases and 4 lakh malaria deaths. And, there are always more like Zika and Chagas that routinely plague humanity. But, this concern is only a passing phase. While people fall back to their old ways, these smart and well-equipped marauders stay busy, choosing their targets at their will.

Using their chemical, visual and heat sensors, at least 27 out of the 72 odour receptors on the antennae, they primarily choose heavy breathers of type 'O' blood, with chemicals like carbon dioxide, octenoi, etc., in their perspiration and breath who have abundant skin bacteria alongside high body heat. They mostly prod around such people. Smartly dodging their responses, they attack.

It seems the pathogen viruses that take piggy-rides with them, are even smarter. They enter the mosquito when it takes a blood meal from an infected host and house themselves in their salivary glands with a premonition that they can find their way into the future host's blood via the saliva. Till such time, they enjoy their long rides. Their carrier-aircrafts can fly up to four hours continuously and cover about 12 kilometres in a single night. But nature comes in the way of their happiness and anticipation. Even before they develop well, most of them perish since over 90 per cent of the mosquitoes die for several reasons. Only those lucky ones living in the trillions and trillions of the surviving carriers can reach the next host.

When the female mosquito lands on its chosen-host, it touches the tip of the labium in its probing instrument – the proboscis – to the skin and carefully inserts the hypopharynx into it, releasing the saliva. The saliva is replete with anti-coagulating, anaesthetising agents and naturally, the virus. While pathogens wade their way into the bloodstream, it fills its stomach. Interestingly, expelling unwanted droplets of plasma, it creates room for more of solid nutrients like protein and iron needed to produce eggs and continues with the blood-sucking until it is satiated unless disturbed midway by the host. It is at this time that the host feels the bite – the itching, redness and swelling. This is caused by the response of the immune system of lgG and IgE antibodies by binding to the antigens in the saliva. He is disturbed; even disgusted that nothing is working.

We close windows and use mosquito nets. We use repellents, like the chemical DEET and electronic devices that produce ultrasounds. We inject medicines and vaccines into our body and fumigate breeding places. We employ parasites like fungi, predators like fish, lizards, etc. Yet, the relief is only short-lived. They develop resistance and re-emerge in greater numbers. Moreover, climate changes impact each of the seasonal factors, like humidity, temperature and precipitation, to help in their dispersal. They also make the transmission season longer and more intense. Further, global warming increases natural calamities and heighten the risk of these vectors.

No one is safe. One gets exposed to their lethally efficient attacks some time or the other; in the house or at a public place – a park, school, market, office, or any other. They are omnipresent.

Thus, in spite of all that we do, come the rainy season, worriedly, we find these indomitable creatures emerging from stagnant waters in every place. The males which survive only on nectar move in swarms, mating and dying in a week. Yet, the female survives for about a month. It mates, sucks blood, lays eggs and then repeats the process several times. All this provided it escapes from predators, humans, and nature. Nature has endowed them with so much intelligence and equipment that we tend to squarely blame it for our woes.

But, we are also to blame. Urban slums, inadequate solid waste management, etc., are all our creations. WHO says, "There should be targeted Sustainable Development Goals". But, when we still don't have the state action plans ready and even our infrastructure is not strong enough and when we stood at a shameful 177 out of 180 countries in the Global Environment Performance Index, it is not surprising that Paris Agreement targets and Sustainable Development Goals are a far cry. We have a tendency to wake up only when there is a crisis.

The crises of vector-borne diseases are mostly preventable, being even more so when we keep our immunity system in its prime of health. Yet, we do not care as we are so pre-occupied with life-activities. In bargain, we even invite several lifestyle diseases like obesity, diabetes, high BP, heart problems and cancer. All because of the stress of life, lack of physical exercise, dependence on unhealthy and junk foods, excessive smoking and consumption of alcohol. Our diabetics and heart patients outnumber those of any country. Apart from genetic factors and environmental pollution, our lifestyle causes cancer that takes thousands of lives. In all, it would appear that we are achieving the dubious distinction of becoming the patrons of the medical field that is already beset with several unethical practices.

"There is a corruption of medicine," says Fiona Godlee, a crusader of medical ethics and editor of the British Medical Journal, while condemning prescribing of expensive insulin as a medical scam. She describes this as a collusion of the pharma companies with others since the mean of 250 of PP and fasting sugar levels is absolutely normal. She rightly advocates that it is not medicine but the correction of our lifestyles that is needed to avoid these diseases.

Likewise, it is our constant commitment to improve our immune systems and work against the causes required to keep us away from the tiny tormentors. Our health is mostly in our hands.

Dr N Dilip Kumar is a retired IPS officer and a former Member of Public Grievances Commission, Delhi. Views expressed are strictly personal