By Ekwebene Onyeka Chukwudalu
Malaria has been known from antiquity as seasonal and intermittent fevers with chills and shivering, which had been detected through religious and medical means in the ancient India, China and Assyria. Charaka and Susruka have described the disease and noted its association with mosquitoes. Hippocrates in Greece in the 5th century BC gave a detailed account of the clinical picture and observed the prevalence of the disease in certain places and season. The relation between the disease and stagnant waters, swamps marshy lands was recognised, and measures to control the disease has been effective drainage and was practiced in Rome and Greece by the 6th century AD. The name malaria (bad air) was given in the 15th century in Italy as it was believed to be caused by foul emanations from the marshy soil. The recent demonstration of a specific parasitic antigen in Egyptian mummies indicates that malaria was present thousands of years ago.
Malaria is the most prevalent tropical disease in the world today. Each year, it causes disease in approximately 650million people and kills between one and three million, most of them, young children in sub-Saharan Africa. Nigeria is known for high prevalence of malaria and it is a leading cause of morbidity and mortality in the country. Records have shown that at least 60percent of the Nigerian population suffers from at least one episode of malaria each year. It accounts for over 60 percent out patients visit and 30percent hospital admissions in Nigeria. The disease has impacted negatively on the economy with about N132 billion lost as the cost of treatment. Malaria, which is a severe disease, is a major cause of absenteeism from work and school. It also contributes to poverty and results in poor pregnancy outcome. Malaria impedes human development and is both cause and consequence of underdevelopment.
Malaria is an infectious disease caused by the parasite of genus plasmodium. The four identified species of this parasite causing human malaria are Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale and Plasmodium malariae. In Nigeria, 98 percent of all cases of malaria is due to Plasmodium falciparum. This is the specie that is responsible for the severe form of this disease that leads to death. It is transmitted from bite of an infected female anopheles mosquito to man.
Malaria remains one of the world’s greatest childhood killers and is substantial obstacle to social and economic development in the tropics. Plasmodium falciparium infection is the major cause of morbidity and mortality especially among the vulnerable groups with children aged less than five years been more vulnerable. The disease accounts for 25percent of infants mortality and 30percent of childhood mortality in Nigeria, thereby imposing great burden on the country in terms of pains and trauma suffered by its victims as well as loss in output and cost of treatment.
Consequences of severe malaria include coma and death if untreated, young children are especially vulnerable in endemic areas. Treatment is often less satisfactory and the overall fatality rate for all cases of malaria can be as high as one in ten. Children with malaria frequently exhibit abnormal posturing, a sign indicating severe brain damage. It causes cognitive impairment, which is more in children. Malaria causes widespread anemia during a rapid brain development and also direct brain damage; neurologic damage results from cerebral malaria to which children are more vulnerable. Considering the above complication of malaria infection in children, a study was carried out to assess the prevalence of malaria parasite infection among children between 0-12 years of age in relation to attitudes and social pattern of living as factors affecting their exposure to malaria parasite infection by Dept of Biological Sciences, Covenant University, Ota, Ogun State and Dept of Medical Micro Biology and Parasitology, LAUTECH Teaching Hospital, Oshogbo in Nigeria. The result showed that the distribution of malaria parasite according to method use for prevention of mosquito bite by patient reveals that those who did not use any method to prevent the bites of mosquito have the prevalence rate of 90.9percent.
In areas of stable malaria transmission, most adult women have developed sufficient immunity that even during pregnancy, malaria infection does not usually result in fever or other clinical symptoms. The impact of this malaria infection is anemia which results in the mother and the presence of plasmodium parasite in the placenta. The resulting impairment of foetal nutrition contributes to low birth weight and it leads to poor infant’s survival and development which may lead to congenital malaria in which the brain of the child is affected. This is the main reason why the World Health Organisation, WHO, recommends that pregnant women in malaria endemic area should receive two doses of sulphadoxine-pyrimethamine given at therapeutic doses at scheduled interval during the index pregnancy, which some hospital do not recommend and some shy away with the reason of low proper orientation and poverty. In other words, pregnant women should be educated properly on the effects of this disease.
Treatment and control measures
Anti-malaria therapy should ideally destroy all sexual forms of the parasite in order to cure the clinical illness, eliminating sporozoites and exo-erythrocytic forms to relapses and kill gametocytes to block transmission from the vector (mosquito). Effective, affordable and safe treatment of malaria particularly falciparum malaria is becoming increasingly difficult as resistance to chloroquine and other anti-malaria drugs continue to spread throughout the tropics. Most resistant strains of Plasmodium falciparum has developed due to inadequate drug doses mainly as a result of unregulated drug distribution and prescribing, lack of adequate drugs, poor quality of drugs, incorrect taking of drugs by patients and when insufficient drugs is taking to kill the malaria parasite.
Therefore chemotherapy is due to the problem of drug resistance in the treatment of malaria, combination therapy is the current therapeutic approach and this involves the intake of Artemisinin based Combination Therapy, ACT, the malaria vaccine production is yet to be fully successful and three stage vaccines are available but blocking vaccines against the parasite is most ideal but still has challenges to be examined.
Measures against the vectors
Spraying residual insecticides such as DDT
Spraying the breeding sites with petroleum oil and Paris green as larvicides
Flooding and flushing breeding sites
Eliminating breeding places such as lagoons and swamps
Prevention of man-mosquito contact through the use of insecticide treated net while sleeping
Biological control of larva guppy fish(Poecilia reticulate) and Gambusia affilis to control the larvae
Avoiding exposure to mosquito bite by wearing long sleeve clothing and trouser after sunset, when the insects are most active
Application of mosquito repellant containing diethyltoluamide to exposed skin
Early diagnosis and prompt treatment of patients
Use of genetic control
In conclusion, despite the efforts in the control of malaria among infants and pregnant women in Nigeria, behavioural and monetary factor still pose a great challenge in the successful control of malaria.
Ekwebene is a Parasitology and Entomology student of Nnamdi Azikiwe University Awka.