THE DANGER OF MOSQUITO AND REASONS WHY WE MUST NOT ERADICATE THEM COMPLETLY.
I usually talk about a general overview of malaria in all most of my talks but this is different. Today, I won’t just talk about malaria, I’d elaborate on the deeper part of the whole situation, the submerged part of the ice-berg if you will. Malaria is a giant public health concern both nationally and internationally and its effects are felt largely around us today. But there are bigger threats and although malaria takes the top spot, it is just one of the actors on the drama stage of disease. We know that malaria is caused by a protozoan virus and that it is transmitted by the mosquito bite. These are the fundamental things that we have learnt over the years. However I am very worried about the ‘hidden threats’ that still lurk round us. At the end of my discussion, you should have an open mind about the dangers and threats alike that face us every day.
INTRODUCING THE MOSQUITO. Lets get down to business. Everyone I believe that everyone has a little understanding of biology. We all know that we are living things. And honestly we are a very successful species, But we are not the most successful. Another contender for one of the most successful species is well an insects.
Ladies and gentlemen, I introduce to you, the mosquito. The mosquito has unknowingly declared war on us. Yes, I know… I said unknowingly. After the entire mosquito is just trying to ensure its own survival just the same way you are trying to survive. There are over 3500 classified species of the mosquito and yet only a few of that number carry diseases that affect humans directly. Today i’ll expose you to four of these mosquitoes. We have Anopheles gambiae, Aedes aegypti, Aedes abulpictus and Culex pipiens. These four mosquitoes transmit about six diseases that calls for great concern. They are Malaria, Dengue, West Nile virus, Zika virus, Usutu, Yellow Fever and the Chikungunya. What is most worrisome is that most if not all of aforementioned diseases likely originated in Africa. Now I want you to cast your mind back to December 2015. The Zika virus had just being discovered in Brazil for the first time. The carrier? The mosquito known as Aedes aegypti. Consequently, the Zika virus spread extremely fast and by the latest data, we know that the virus is being transmitted in about 84 countries. The virus doesn’t seem to have any effect on adult humans. In fact it is so silent that 4 in 5 infected people will never know that they have the virus. The only visible marker of the zika virus is micro-cephaly, a condition where babies are born with smaller heads and consequently smaller brains than usual. In fact 2653 newborns where born with micro-cephaly in 2015. The problem now is the rate at which the vector of the disease in this case, Aedes aegypti, is spreading. Another reason for concern is that this particular mosquito carries three other diseases; Dengue, Yellow fever and Chikungunya.
Dengue is also known as break-bone fever because of the sensation breaking bones a person gets when they experience the disease. This disease is also viral and much likes malaria, it is transmitted in tropical and sub-tropical regions of the world. It is also carried by the Aedes aegypti mosquito. Symptoms appear 3- 14 days after infection and may include a high fever, headache, vomiting, muscle and joint pains accompanied by a characteristic skin rash. This could develop into dengue hemorrhagic fever, resulting in bleeding and blood plasma leakage. Another deadly variation of this disease is dengue shock syndrome, where blood pressure dips dangerously below normal. As the range of the Aedes aegypti increase, so does the range of the disease. Consequently, Dengue has been reported to be the fastest growing mosquito borne disease in the world, apparently beating malaria at its own game.
Now let me take you into the mind of a mosquito. Most mosquitoes have a life span of roughly two weeks. An adult mosquito that emerges from its pupa shell, has two objectives, the first is to feed and the second one is to mate. Once it achieves the second objective, in the case of the female, it needs to feed more in order to provide protein for its developing eggs. This is where we come in. They locate their food source which we are and feed. And because mosquitoes respond to body heat and compounds from the skin, there is no hiding from them. The moment a mosquito lands on the skin, it inserts its proboscis into the skin and sucks blood through a punctured blood vessel. In the process it injects its saliva which contains anti-coagulants to stop blood from clotting. An uninfected mosquito will naturally pick up pathogens from the body of its blood meal. Consequently, it repeats the process over again except that this time when it injects its spit into the blood stream of another person, it acts as a delivery system for a cocktail of biological hazards. Then it spreads disease. The problem is that since many of these diseases originated in Africa, they have since been exported to other parts of the world. Now I have mentioned that diseases have been exported to other parts of the world, but what is alarming is how humans have contributed to their spread. It took over 300 hundred years for malaria, dengue and yellow fever to spread from Africa to the Europe and the Americas. However it took an exceptionally quick 16 years for Zika, WNV, and chikungunya to spread. Why?
The simple answer is the human factor. Human beings are now in the age of technology and population explosion. It doesn’t take much for a person to travel anywhere in the world any more. You can get anywhere you want to in the world in a matter of hours along with any disease you may carry with you and so a non-native disease quickly becomes a giant endemic problem in another region of the world. Also remarkable is how we have been able to facilitate the spread of mosquitoes around the world. Mosquito eggs have been spread round the world through commerce and trade between countries. Another factor is the man-made environment that has created perfect breeding grounds for these insects. In the wild, you’d have maybe 2 ponds in certain location where mosquitoes breed. But in our cities, everywhere has become breeding a ground, from the garbage dump, to the underwater sewer network and the aloe vera plant in your backyard. As a result mosquitoes shorten their lifespan and breed faster therefore increasing their populations.
Climate change and global warming is also facilitating the growth of their species. As temperatures get warmer, the survivability of the insects and parasites increase. And by increase I don’t mean a proportional climb but rather a dramatic climb in survivability. So as we change the planet, we are changing the way other species evolve.
So, should we completely wipe out mosquitoes from the face of the earth?
My answer is Capital NO. I know it’s surprising but there are reasons behind my conclusion. Mosquitoes are part of the ecosystem and although we tend to see them as predators, they are in a lot of respect prey to other species. Think of a classical food chain, with grass, grass cutters, snakes and eagles. What do you think will happen if grass cutters are suddenly wiped out? Note that male mosquitoes are important pollinators of our food crops so removing them from the equation will cause a disastrous plummet in human food supplies. The measures we have taken so far to control mosquitoes have not been very successful. Each time you spray an insecticide; there is a tendency that you kill off other insects other than the mosquito whose economic importance benefits man. When the government of a country decides to embark on a mass vector control program, it might kill off other species in the process which might directly or indirectly affect us.
At the end of the day, it is important to understand that humans are the driving force behind the spread of these diseases. although malaria is dangerous, it should not be the only disease we are worried about. For the fact that other MBD’s {mosquito borne-diseases} are not endemic here, we must know that they have the potential to quickly become a health concern. So much education and awareness is needed now.
NB: Mosquitoes are resisting chemical warfare, evolving to get stronger with each passing day. We have reached a stage where many insecticides and ITN’s can’t control them anymore yet causing more damage to the delicate fabric of our planet. We are on the battle field and we have been helping the enemy all along. We must rise up to the threat and urgently review our policies concerning a lot of things.
The bottom line; save the planet, save lives.