Every 20th day of August annually the world celebrates Day of the mosquito to draw attention to the vector carrying multiple diseases. In this piece SADE OGUNTOLA and NEWTON RAY UKWOUOMA writes on attempt so far to conquer this killer.
It is very tiny, yet the whole world celebrates it every year with the World Mosquito Day. Its size belies its lethal power. There is even a folktale about the resilience of the mosquito.
Sometimes, long, long, time ago, the mosquito fell in love with the ear. The ear was embarrassed by this show of love and burst out laughing. “How could you such a tiny thing looking like someone who would kick the bucket anytime soon come to talk to me about love,” the ear said.
However, the mosquito made it a point of duty whenever the occasion permits to whisper into the ear that it is still alive, after all these years. That is why when one is sleeping the mosquito buzzes in the ear making such terrible sound.
The World Mosquito Day is observed annually on 20 August in commemoration of British doctor, Sir Donald Ross’s discovery in 1897 that female mosquitoes transmit malaria between humans.
Although a few species are harmless or even useful to humanity, most mosquitoes are a nuisance because they consume blood from living vertebrates, including humans. Mosquito is said to be one of the most dangerous insects in the world killing at least two million people annually.
Professor Catherine Falade, Director, Institute of Medical Research and Training, University of Ibadan, said that a lot of work and money has gone into research into malaria vaccine; but getting a vaccine that is 100 per cent effective against the disease is still quite a problem.
According to her, “this is an issue that has resulted from the fact that the immunity to malaria is very complex. It is both specie specific and stage specific.”
Falade, a malaria expert, added: “the parasite mutates very frequently. You can imagine that billion of dollars have gone into the vaccine production and just when you think we are getting there you discover that we are not.
“The best vaccine that has been prepared so far has been the RTSS. It has gone to a phase three trial but the results are very modest and we clinicians do not think that it is practicable because the protection given is just like reducing the chances of the child having malaria by 25 -35 per cent and you need to give four doses to get maximum benefits.
“In addition, the protection wanes over time. So a healthy child will have to be brought to the hospital four times in a year to get malaria vaccine that does not give 95 per cent protection
“But the greater danger is that we may compromise the acceptability of existing vaccines. Even though these other vaccines remain effective, mothers would be tuned off. They will say that no vaccine is functional.
“WHO in its wisdom said that if it cannot be demonstrated that programmatic 80 per cent of children can receive four doses, it will not happen. And so to all intents and purposes, there is no malaria vaccine at this point in time that is ready for redeployment.”
Can sanitary inspectors help in curtailing mosquitoes from breeding? Professor Falade said “environmental sanitation is very important, however, I do not subscribe to the efficacy of the sanitary inspector. Each and every one of us must take responsibility for out environment.”
In addition, observance of designated environmental sanitation days to clear open drainage and makes sure that there is no stagnant water as well as clearing of bushes around the home is important.
All these measures, she assured would also protect against bites of Aedes egypti, the mosquito that transmits Zika virus.
According to her, “Mosquitoes seem so small, but they carry a whole lot of disease causing germs like Zika, Dengue and yellow fever and so maintaining our environment is a big deal. “
However, according to her, incidence of malaria has reduced, adding that it was wrong to assume that all fevers are malaria.
‘‘We should stop assuming that every fever is malaria because the proportion of febrile children and much more so adults who have malaria are going down every day because we are successfully curing those who been infected if they take Arthremisine Combination Therapy (ACT) in the adequate doses and for long enough duration.’’
An entomologist and lecturer at the Department of Zoology, University of Ibadan, Dr Okorie Anyaele said marking World Mosquito Day was significant.
According to him,”Marking it is to create awareness on diseases like malaria, filariasis and even the Zika virus in Brazil. There cannot be such diseases if there are no mosquitoes.”
However, Dr Anyaele assured that Zika virus can only be transmitted in Nigeria, peradventure the virus is brought into the country from places like Brazil.
“The mosquitoes that can transmit it are available, per chance somebody brings it from, say Brazil, the parasite would start to circulate around,” he said.
But the expert declared that prevention of bites from the mosquitoes that transmits Zika virus may not be possible by sleeping under insecticide treated nets because the mosquitoes bite during the day time.
“During the day time, they can enter your office where you are working and bite. So, they bite at any time of the day,’’ he added.
In order that Nigerians may be protected from ZIka virus, he stated the need for people coming into the country to also be screened of the virus.
Also, the new chairman of Nigerian Medical Association (NMA), Lagos Chapter, Dr Omojuowolo Olubunmi, also described the prevalence of malaria as endemic to Nigeria. He attributed environmental factors such as poor hygiene, presence of stagnant water, poor drainage system as agents perpetuating the “age long affliction” in Nigeria.
According to him, mosquitoes, which are the agents that carry not only malaria, but also yellow fever and Zika, “have less chances of breeding in clean environments.”
Speaking about severe and uncomplicated malaria as two major aspects of the disease, Dr Omojuowolo said fetuses, new borns and visitors to an endemic countries record high fatal casualties as they lack sufficient immunity to fight the parasite, adding that pregnant women with malaria should be “treated aggressively,” while visitors to endemic countries should be on chemoprophylaxis.
Omojuolwo, who also addressed the issue of Zika and Nigeria said, “We have to be very vigilant. I am very sure the people at the Lagos State Ministry of Health are alert. The Olympic Games is happening in Brazil, where Zika virus started. We need to make sure we have preventive measures, one of which is to make sure that people that travel to and from the country are properly screened. The airport is one of the major places the health authorities need to concentrate on. People who have visited the places where there is Zika need to be monitored closely.”