Malaria cannot be confined by boundaries, having been found to affect people in all the continents of the world. Without much saying, it is very glaring that malaria as a disease has been a scourge to mankind.
It is on records that the first officially known treatment of malaria came by the way of using quinine extracted from the bark of the “Cinchona” tree also known as the “Jesuits bark” in Viceregal Palace in Lima, Peru, in 1938.
Quinine went on to become the only compelling treatment for malaria until the 1920’s. Scientists went into the laboratories all over the world trying to find a way of synthetically producing this “wonder” drug and in 1944, they were able to discover the structure of the alkaloid molecule C20H24N2O2.
Variants of quinine have been produced since then, with some having serious side effects to the extent that their usages have been discouraged but the astounding thing is that the ravages of this disease have by no means abated to an appreciable degree.
The World Health Organization (WHO), reported that nearly half of the world’s population is at a risk of malaria and that in 2015, there were roughly 212 million malaria cases and an estimated 429,000 malaria deaths. The fact that most developing countries do not have accurate statistics will definitely underscore this data.
The causative agent of malaria is the obligate intracellular protozoan parasites of the genus Plasmodium. The protozoan has been found to be transmitted by the female Anopheles mosquito.
This fact and the number of people killed annually by the disease has led a lot of people to recognize mosquito notwithstanding the small size, as the world’s most dangerous animal. Certain schools of thought view mosquitoes as the world’s deadliest animals on earth.
The female Anopheles mosquito transmits the parasites during the process of blood-meal feeding on humans for the purpose of breeding its offsprings. The mosquito goes through a life cycle of laying eggs which are hatched into larvae that develop into pupae and then mature to adults.
The breeding process is carried out in bodies of water which may be stagnant or free running.
The malariae species that infect humans are Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae, and Plasmodium ovale. Among these species, P. vivax and P. ovale
have been found to develop dormant liver stages that can reactivate after symptomless intervals of up to 2 ( P. vivax) to 4 years ( P. ovale).
The parasites have two stages of living. One stage is the mosquito, while the second stage is in humans. The sporozoites are the infective form in humans and after being transmitted, they invade and reside within hepatocytes, where they intend to increase.
Right there in the liver, the parasites are known to multiply exceedingly by undergoing asexual reproduction after which they leave the liver and invade the red blood cells all the time increasing in number by further reproducing asexually.
The red blood cells then break open releasing Plasmodium which in turn infects other red blood cells and the cycle continues. Some of these parasites turn into the sexual form which eventually forms the male and female gametes that circulate in the blood and are then picked up by mosquitoes during the course of their blood meal.
Within 9 to 16 days of infection, the human body experiences a fever as a result of cell debris produced by the Plasmodium. Other symptoms that can be experienced by the host include chills, headache, body pains, nausea, vomiting, and anemia.
Governments, the WHO, and other related agencies all over the world have sunk in huge sums of money in an effort to eradicate this scourge apart from the human resources it has destroyed, all to no avail. All the efforts being put in place seem not to be yielding the desired result.
Should the world then resign to fate and the feeling that the scourge can’t be tackled?
That can’t and should never be the case. The truth is that despite the fact that a lot of research work has been done in the area of eradicating this disease, the problem is that we are not in concert on how to actually tackle the problem.
Since everything about the parasite and the mosquito-host are known it shouldn’t pose too much of a difficulty in faceting a complete eradication. The war on malaria should be waged on two fronts simultaneously. One is to fight the vector doggedly and the other is to completely tackle the parasite.
In fighting the vector, the following steps should be taken.
- Fumigation with insecticides
This may be a very costly venture but taking into consideration the number of people that die yearly from malaria, I don’t believe any measure should be seen as being too expensive. The whole idea is to first rid the world of all adult mosquitoes.
This process may have its own environmental consequences but that can be worked upon after the scourge of mosquitoes have been taken care of. It is reported that the increase in the rate of malaria is as a result of the cessation of use of DDT in some countries.
In a situation where DDT is found to be inducing breast, liver, and pancreatic cancer as has been propounded, an intensified research work can be embarked upon to fashion out another form of insecticide that will be environmentally friendly.
If the world could be talking about autonomous vehicles, artificial intelligence, 3D printing, and electric cars effectively, there shouldn’t be any reason why we can’t work out something at this angle. It only requires more doggedness from our scientists.
- Biological control
The egg, larval, and pupal stages of the mosquito’s life cycle are all water-based. This is an opportunity to attack them from that angle. The fact is that once we are able to completely do away with one of these stages, mosquitoes will go into extinction and without mosquitoes, we have rolled malaria back finally.
The biological control of malaria can be achieved through the use of entomopathogenic fungi, bacterial larvicides, larvivorous fish, parasites, viruses, and nematodes.
Many studies point to a role of fungi in disrupting the mosquito nutritional balance.
From the angle of bacterial larvicides, Bacillus thuringiensis (Bti) and Bacillus sphaericus have been found to be effective in the vector-parasite control and may even have to replace the use of synthetic chemical insecticide.
The use of predatory fishes can also be revisited. Species like the Gambusia affinis and Cyprinodontidae were found to be very effective means of controlling the larval stage of the mosquito.
A point in case here is that the larvae are disadvantaged since they can’t easily evade measures put in place to eradicate them quite unlike the adults.
- Biogenetic engineering
It is a very bold step that researchers from NAID have successfully isolated the gene Pfs47 that makes some parasites invisible to the mosquito system.
The next step will be to work assiduously on this finding as a way of enhancing the destruction of the Plasmodium parasite right inside the body of the mosquito by the immune system, thereby ensuring that the parasite is not transmitted to humans.
4 Sterile insect technique (SIT)
The SIT method of control relies on sterilization of the male Anopheles mosquitoes before mass releasing them. This ensures a stiff competition during the process of mating.
SIT can be effected during the pupal or adult stage but males irradiated as pupae have been found to have a lower competitiveness edge as compared to males irradiated as adults.
- Draining breeding grounds
Since we now know that mosquitoes definitely need water to breed, we have to embark on making sure they don’t easily have access to such places.
Inasmuch as we can’t do much about our rivers, lakes, streams, and ponds we must ensure that we don’t leave stagnant water for them to breed in. Where we have marshes and swamps, such can be colonized for developmental purposes.
- Insecticide-soaked nets
Sleeping under nets is another way of fighting the malaria war. Where it is possible the nets should be soaked in insecticides. This is double-pronged.
First, the mosquito does not come in contact with the human and is devoid of a blood-meal. This enhances that no new offsprings will be formed. Secondly, the mosquito is destroyed by coming in contact with the treated net.
The process of securing nets will definitely be very expensive but the fact is that it can be done. If the report by UNICEF that 3,000 African children die every day is anything to go by and the fact that most of them are killed by malaria, then we don’t have any other course.
- Covering water with an oil film
Another strategy to eradicate the aquatic stages of the mosquito is to cover water surfaces with oil. The oil forms a film on the water surface thereby disabling them from taking in oxygen for respiration.
The good thing about this is that at warm temperatures especially in the tropics, the oil is heated up and evaporates eventually. Other aquatic lives may, however, be affected.
- Reinforcing entrances
Opening such as windows and doors should be fitted with flyscreens. This will ensure that the mosquito does not gain entrance into rooms where it wreaks havoc.
Having handled the angle of the vector, the next thing is to look at the parasite itself. Even if all the mosquitoes in the world today are eradicated, the fact still remains that a lot of people are loaded with one form of the parasite or another.
Under the treatment of malaria, we shall look at two different types.
- The use of drugs
Drugs have been variously used to fight malaria disease. The only major problem the world is facing in drug use as a form of treatment is the fact that the parasites have become resistant to most of the drugs in the market today.
This problem partially stemmed from the way people have generally abused malaria drugs, right from not taking the correct dosage of prescribed drugs to completely taking drugs without a prescription.
For this particular problem, the simple answer is to properly educate the people.
The other problem in the use of drugs is to properly identify which drug should be used for the different types of cases we have. The status of the person taking the drug is very important.
The important things to note before embarking on an effective treatment of malaria are whether the malaria is the complicated or uncomplicated type. We should also note if a woman is pregnant since the immunity is decreased by pregnancy.
Points like cerebral malaria and relapsing malaria should also be noted for proper drug efficacy.
Some of the drugs in the world today used as chemoprophylaxis or in actual treatment are fansidar, quinine, halofantrine chloroquine, primaquine, hydroxychloroquine, and proguanil.
Others like doxycycline and mefloquine can’t be used for pregnant women or lactating mothers, and those at risk of cardiac arrhythmia.
The most important thing is to ensure that the drugs are prescribed by competent medical practitioners who are armed with up to date information on drug use and side effects.
Quite unfortunately, no vaccine has been produced to fight malaria. This is a minus in our effort taking into consideration the number of people this malaria scourge kills on a daily basis.
A heartwarming development from CDC investigators is that “the malaria research community is in the process of developing vaccines effective against malaria parasites in order to provide new interventions that will help control and eliminate malaria.”
A pathway to this is to work on fine-tuning the acquired immunity people have been able to evolve based on the long proximity with mosquitoes and the malaria disease in particular.
Mothers have been observed to pass on antibodies crossing the placenta to babies in the womb, resulting in passive immunity. This angle can be expanded upon with the view of coming up with the much-needed vaccines.
The fact that the WHO is emphasizing on integrated vector management (IVM), is a welcome initiative. The approach that reinforces linkages between health and environment, optimizing benefits to both will work efficiently in the war against malaria.
The world will not be demanding too much if we ask for a multi-faceted approach to the fight against malaria and any other vector-borne disease. It is wholly warranted and even more than due.
The truth is that with this multi-faceted approach, we shall surely eradicate malaria.