Fall 2001; Volume 2, Number 2|
Malaria: Its Human Impact, Challenges, and Control Strategies in NigeriaArrese Carrington, MD, MPH
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Malaria is one of the most serious health problems facing the world today. The World Health Organization estimates that over 300 million new cases of malaria arise a year, with approximately two to three million deaths resulting from contraction. Malaria is endemic in tropical Africa, with an estimated 90% of the total malaria incidence and deaths occurring there, particularly amongst pregnant women and children. More specifically, malaria is causing various problems in Nigeria. Malaria is the only vector borne disease to be placed on World Health Organization’s Disability Adjusted Life Years (DALYS ) list. It is important to look at health problems like malaria that grossly affect the morbidity and mortality rates, as well as the economy of a developing country, such as Nigeria. Nigeria has a population of about 123.9 million people . A large percentage of its population lives in extreme poverty in rural areas, without access to potable water and adequate healthcare. Nigeria is also a low-income country already saddled with a huge foreign debt burden. It risks sinking further into debt as it struggles with a sick populace whose good health is essential for its economic growth. Traditionally, Chloroquine was a common treatment for Malaria. However, with the increase in chloroquine resistant malaria, additional methods of control must be employed. A multidimensional approach should be used in the control strategy, such as good management of clinical malaria, the use of insecticide-treated bed nets (ITBN), education and training programs in malaria prevention, vaccine research and the use of insecticide spraying such as DDT on breeding sites. It is also necessary to explore the use of indigenous natural mosquito repellant plant species. Pharmaceutical companies should study local anti-malarial herbs to determine their efficacy on malaria and effective and safe dosages should be found. The answer to malaria control may lie within local communities. Policies pertaining to the use of impregnated (soaked in insecticide) bed nets would be doubly advantageous and economical in rural areas. Culturally, the two most susceptible groups of people, pregnant mothers and infant children, tend to sleep together. Walls of mud huts in rural areas should be white washed to avoid attracting mosquitoes. Cracks and crevices where stagnant water can collect should be sealed. Partial funding for malaria control projects could be generated internally if the Nigerian government collected a levy from companies that are involved in activities that pollute the environment. Oil companies working in the Niger Delta areas, where there are many marshy swamps and a high prevalence of malaria, should also be asked to contribute to a general malaria control fund.
The Issue of MalariaMalaria is caused by four different protozoa in the plasmodium genus: either Plasmodium Vivax, which is more prevalent in low endemic areas, Plasmodium ovale, Plasmodium malaria, and the Plasmodium falciparum, the most dangerous of the four. The Plasmodium falciparum has a life cycle in the mosquito vector and also in the human host. The anopheles gambiae mosquito is the vector responsible for the transmission of malaria. The prevalence of malaria is dependent on the abundance of the female anopheles species, the propensity of the mosquito to bite, the rate at which it bites, its longevity and the rate of development of the plasmodium parasite inside the mosquito. When the female mosquito bites and sucks the blood of a person infected with malaria parasites she becomes infected; she then transmits the parasites to the next human host she bites. Malaria incubates in the human host for about eight to ten days. The spread of malaria needs conditions favorable to the survival of the mosquito and the plasmodium parasite. Temperatures of approximately 70 - 90 degrees Fahrenheit and a relative humidity of at least 60 percent are most conducive for the mosquito . The development of the malarial parasite inside the mosquito is more rapid as the temperature rises and ceases entirely below 60 degrees Fahrenheit . Increased rainfall and stagnant pools of water or surface water provide hospitable breeding grounds for the mosquito. It is important to understand how malaria transmission is affected using the “ basic reproduction number.” In an entirely susceptible host (non-immune) population from each primary malaria infection arises a varying number of secondary infections, referred to as the Basic Reproductive Number. That number is directly proportional to the populations’ risk for contracting malaria and can be increased by the following factors: an increase in the abundance of mosquitoes relative to the human population, an increase in the propensity of the mosquito to bite its human host, an increase in the proportion of the infective mosquito bites, an increase in the length of illness and an increase in survival rates or longevity of the mosquito .
The Burden of MalariaAs malaria’s incidence increases, so too will morbidity and mortality rates. Malaria is endemic in Nigeria, and the population at highest risk includes children, pregnant women, and the non-immune. Along with malarial morbidity and mortality come economic losses. Social and economic consequences are directly related to the severity of the malaria’s increased morbidity and mortality. As a result of malaria, children spend days away from school and adults lose workdays. Age distribution of the population also has an effect on the burden of disease. In highly endemic areas, the older population develops some collective immunity to malaria so the severity of malaria attacks is less than in children under five. Plasmodium ovale is less fatal than Plasmodium falciparum. Since Plasmodium ovale is more prevalent in non-endemic areas, in these areas the burden of disease is less than in endemic areas where malaria is due to the fatal Plasmodium falciparum. Currently, studies show that any increase in the disease burden of malaria as expressed in terms of DALYS is an unsustainable development. The level of socio-economic development in a country usually affects how much is invested in health care, which in turn affects the health outcomes and severity of diseases like malaria. Like a vicious cycle, the health outcomes affect income and capital, which in turn affects the economic development of the country. Nigeria’s 6% allocation of its annual national budget to the healthcare sector is low and has resulted in poor health outcomes and an increase in the severity of diseases like malaria. These poor health outcomes are partially responsible for its low gross national income per capita (GNI) of US$260.  In the cause and effect relationship between malaria and economic growth, it is also possible that the severity of malaria leads to poor health outcomes which in turn leads to a low gross national income and poor economic growth.
Risk Control strategies; Implications and Cost EffectsPolicy makers need to aggressively pursue malaria control strategies because malaria infections are attacking Africa’s most populous country, Nigeria, at an alarming pace. Factors that are also responsible for the increase in the resurgence of malaria must be addressed in malaria transmission control. These factors include the large-scale resettlement of people usually associated with ecological changes, increasing urbanization disproportionate to the infrastructure, drug resistant malaria, insecticide resistant mosquitoes, inadequate vector control operations and public health practices. Vector control is significant in the light of increasing drug resistant malaria, as well as for cost effective reasons. Insecticide treated bed net trials are being conducted in some parts of Nigeria and the results so far have been promising for the reduction in severity and prevalence of malaria in children. The cost effectiveness of using insecticide treated bed nets in reducing pediatric admissions also reduces the personal costs that family and friends bear during a hospital admission. Such costs include out of pocket expenses, travel, family input into treatment, and productive time lost by mothers who have to take their children to the clinic or stay with them in hospital. A trusted method of controlling the mosquito is spraying breeding sites with insecticide such as DDT. Although some studies have reported the presence of DDT resistant mosquitoes, it is still one of the most effective and economical forms of insecticide in the control of malaria. The use of DDT was partly responsible for the reduction of malaria in areas where it is now mainly eradicated. Environmental laws are leading towards the total ban of the use of DDT. Due to its persistence in the environment and its effect on the ecosystem, it is regarded as a persistent organic pollutant. A total ban on the use of DDT, however, could prove disastrous to poor countries that still rely heavily on its use for malaria control. A more widely agreed upon solution is that there should be mass campaigns for education training in malaria prevention. In addition, research for a vaccine for malaria would be a noble gift to Africa and other areas where malaria is endemic and should be intensified. At the April 2000 Malaria Summit hosted in Nigeria, a pledge was made by African countries to reduce or waive taxes and tariffs for mosquito nets, insecticides, anti-malarial drugs, and other tools used for malaria control. Since Nigeria is the most populous country in Africa, the success of its malaria control programs will have a significant impact on the overall control of malaria in the region. Because a large proportion of the population in Nigeria’s rural areas lives in poverty, a control plan focused on those areas should be initiated.
A Summary of Problems Affecting Malarial Control in Rural NigeriaMost of the rural areas do not have access to good health care systems. Usually there are no accessible roads to the health centers, which in turn are poorly equipped and have inadequate drugs for malaria treatment. Drug resistant malaria is common and anti malarial drugs are becoming less effective as the plasmodium parasite develops resistance to affordable drugs. This poses a serious threat to clinical management and treatment of malaria. People cannot afford anti-malarial drugs so they tend to self medicate with local herbs. Children wear little clothing during the day and at night due to heat and humidity, thus leaving their bodies exposed to mosquito bites. Rural dwellers cannot afford to purchase bed nets. Mud houses are poorly constructed and are surrounded by bushes. Water is collected from streams and wells and left standing in open clay pots since there are usually no running taps. Recommendations to Control Malaria in Rural Nigeria Within the control strategy for malaria, a multi-dimensional approach is needed. Resources collected for a general malaria control fund could be used to implement some of these strategies.
1. Management of clinical malaria
• Accessibility to primary health care centers and affordability must be guaranteed. Units within primary health care centers should be set up to diagnose, treat and monitor malaria cases. These centers will need the basic equipment required to check blood films for malaria parasites and a full blood count. All drug resistant cases should be reported and referred to tertiary health centers where alternative lines of management, such as radical drug treatment combinations, can be established.
• Epidemiological surveillance is highly essential in any control strategy, and is an essential guide in developing a multi-dimensional approach. The malarial control units set up should keep data on the epidemiological surveillance and the information should be sent to the national malaria control center.
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