Claim: According to a study undertaken in 30 locations by the Côte d’Ivoire Red Cross in December 2015, almost 78 per cent of people in the country know that malaria is transmitted by mosquitoes; however, around 12 per cent still think that hot sun can cause malaria. Thirty-six per cent know at least three symptoms of malaria, and only 14 per cent can mention at least three ways to avoid it.
Prolonged exposure to the sun cannot cause malaria, except a female mosquito carrying the disease.
Also, a Côte d’Ivoire radio presenter and Red Cross volunteer, Ulrich Kouame, noted that some communities in Côte d’Ivoire where malaria remains one of the most pressing public health issues also believe “that you will get malaria if you stay in the sun for a long time or if you eat a lot of mangoes.”
These beliefs are not only held by Ivorians, many other people also think exposure to the sun results in malaria.
Malaria is a common and life-threatening disease in many tropical and subtropical areas. It affects more than 500 million people worldwide and causes one to two million deaths every year. According to a report by the World Health Organisation (WHO), there are currently over 100 countries and territories where there is a risk of malaria transmission, and these are visited by more than 125 million international travellers every year.
A United States Center for Disease Control and Prevention, CDC, report notes that biologic characteristics and behavioral traits can influence an individual’s risk of developing malaria and, on a larger scale, the intensity of transmission in a population. Is long exposure to the sun one of these traits, as assumed by many people?
Another volunteer on the radio programme, Kone Amy, added that, “convincing communities to use mosquito nets does not really help unless we tackle the roots of their beliefs, understand why they are so rooted in their way of thinking, and discuss the true causes with them.”
But, are these beliefs and perceptions true? Is hot sun truly the major or one of the main causes of Malaria?
Scientifically, malaria is caused by infection with a parasite called plasmodium, a leading cause of death in Africa since remote times which is spread through the bite of female mosquitoes that carry it.
The natural history of malaria involves cyclical infection of humans and female anopheles mosquitoes. The parasite in an individual develops and increases first in the liver cells and then in the red cells of the blood. In the blood, successive broods of parasites develop in the red cells and ruin them, delivering female parasites (“merozoites”) that carry on the pattern by invading other red cells.
A public health expert at the University of Calabar Teaching Hospital, UCTH, Funmilola Shiyanbade, said a false assumption about hotness of the body and fever empowers the ligering belief.
She said, “thinking through the minds of the people carrying this myth, I’ll say that since many believe that malaria as a disease condition is synonymous with fever (hotness of the body), they assume that since the body becomes quite hot under the sun, and whoever develops malaria also manifests with high fever, then the sun causes fever! But this is not true.”
She added that it is well known that when we walk or work for a long period under hot sun, we are bound to become tired and weak because we lose fluids in the form of sweat. These two signs of weakness and tiredness, she said, are also found in a person with malaria; but the cause in this case is not the sun but the pathology due to the presence of plasmodium falciparum (most times) in the blood.
She said further, “Malaria is an infection caused by a parasite called plasmodium which can only be transmitted through a female anopheles mosquito from the blood of an infected person to another. So, the myth that the heat of the sun causes malaria is to be discarded. The sun does not and cannot harbour the plasmodium that causes malaria neither can it transfer blood from one person to another.”
Also according to the CDC published report, the blood stage parasites are those that cause the symptoms of malaria. When specific kinds of blood stage parasites (gametocytes, which happen in male and female forms) are absorbed during blood feeding by a female Anopheles mosquito, they mate in the gut of the mosquito and begin a pattern of development and increase in the mosquito. After 10-18 days, a form of the parasite named ‘sporozoite’ migrates to the mosquito’s salivary glands. When the Anopheles mosquito takes a blood meal on another human, anticoagulant saliva is injected alongside the sporozoites, which move to the liver, thereby starting a new cycle. Thus the infected mosquito carries the illness from an individual to another (acting as a “vector”), while infected individuals transmit the parasite to the mosquito, In contrast to the human host, the mosquito vector has no problems with the presence of the parasites.
Also, Malaria parasites are microorganisms that belong to the genus Plasmodium. There are more than 100 species of Plasmodium, which can infect many animal species such as reptiles, birds, and various mammals. Four species of Plasmodium have long been recognized to infect humans in nature. In addition there is one species that naturally infects macaques which has recently been recognized to be a cause of zoonotic malaria in humans. (There are some additional species which can, exceptionally or under experimental conditions, infect humans.)
A Professor of Epidemiology and Family Physician at the Department of Epidemiology and Medical Statistics at the University of Ibadan, Professor Ajayi, in a report published by Nigerian Tribune also said “malaria is not caused by stress or walking in the sun.” She said malaria is an infection caused by a parasite (plasmodium) that is only transmitted by the female anopheles mosquito from an infected person’s blood to another person through its bite.
Prof. Ajayi noted that “there has been this notion by many people that stress or exposure to too much sun causes malaria. This is not true. The only thing that causes malaria is the malaria parasite. Nonetheless, people under severe stress can have the symptoms that somebody who has malaria also has, like tiredness, feeling unwell and loss of appetite for food. This is similar to a person that after walking in the sun for long feels tired, dehydrated or hot in the body. All the symptoms make them think that they have malaria.”
She added that if the blood of many people living in malaria-endemic areas like Nigeria are tested, it may contain malaria parasites even though they do not have signs and symptoms of malaria. She, however, said under severe stress, such individuals already with malaria parasites in their blood stand a higher risk of developing malaria.
Professor Ajayi added that: “It has been shown that when people are stressed, the body immunity comes down. The lower immunity now affords the malaria parasites in the blood to exhibit itself in the form of signs and symptoms of malaria. So whether it is stress arising from daily living or walking in the sun, you must have that parasite in your body for stress to precipitate malaria infection.”
The issue with the popular myth about prolonged exposure to sun as a cause of malaria can also be explained with a Yoruba adage that says “Bí ìyà ńlá bá gbénisánlẹ̀, kékeré á g’orí ẹni,” meaning that when there’s a major breakdown, little issues can be really overwhelming. Because prolonged exposure to the sun does break human immunity, one’s immune system becomes weak to fight malaria once a female mosquito carrying the disease bites one. Hence, prolonged exposure to the sun cannot cause malaria, except a female mosquito carrying the disease.
The researcher produced this fact-check per the Dubawa 2020 Fellowship partnership with the Broadcastings Corporation of Oyo State, to facilitate the ethos of “truth” in Journalism and enhance Media Literacy in the Country.