MALARIA CONTROL: THE NEED FOR TARGETING MOSQUITO BREEDING HABITATS

ABSTRACT
In the early 1990s, malaria was controlled using environmental management for vector control in cities in sub-Sahara Africa. However this approach lacked effectiveness due to unsustainability as compared with the residual insecticides that appeared in the 1950s. Today, malaria control in Africa is entirely focused on the use of anti-malarials and insecticide-treated bed nets and not on biophysical environmental modifications or on strengthened social systems to perform effective environmental manipulation. Even though drugs and insecticides are extremely effective weapons, the development of resistance by the parasite and the vector mosquitoes, respectively, are a growing concern for the long-term costs and in addition, the environmental impacts of insecticides have been a challenge. The present study assessed the impact of controlling malaria in two communities by means of targeting the habitat of the vector mosquito. The overall goal was to assess the impact of mosquito habitat reduction on malaria incidence and prevalence in two selected endemic communities in the Agortime-Ziope district of the Volta Region. Kakadedzi and Takuve are both rural communities in the town of Ziope. They experience a tropical climate with rain fall throughout much of the year. Data on malaria cases recorded was collected from the Ziope Health Centre, the only health facility serving the two rural communities in order to review the diagnosed malaria cases in the selected communities. The selected communities were surveyed and the mosquito breeding grounds identified. Interventions involving manipulation and elimination of the breeding habitats were introduced in the two identified communities. Data collected before and after the interventions were compared. The diagnosed malaria cases in the health centre were again reviewed monthly for seven months. The inhabitants and school pupils were interviewed during the study period in order to determine their level of knowledge on malaria and its control. Results from both Kakadedzi and Takuve communities revealed the breeding habitats of mosquitoes to be open water tanks, depressions on farm lands, drinking pots and dams. The reviewed malaria cases in the health centre indicated that malaria cases were more prevalent during the rainy season than during the dry season. The arithmetic means of the number of mosquitoes collected from each room before the interventions were carried out, were significantly more ( p value of 0.0002) than those collected after the interventions. The number of the malaria cases recorded in the Health centre after post- interventions also reduced significantly (p value of 0.0019). The interviews conducted in the communities revealed that 20% of the total population of the elders lacked basic knowledge on malaria and how it could be controlled. The pupils from the community school could not transfer the knowledge they acquired on malaria and its control during school lessons to control malaria in their homes. The findings from this study suggest that managing the environment by practising good sanitation can reduce the breeding habitats of mosquitoes. This in turn can reduce the human-vector contact leading to the control of the disease, malaria.


CHAPTER ONE
1.0 INTRODUCTION
1.1 Background Information
Malaria is a serious health problem in many developing countries, infecting between 300 and 500 million people annually, and the disease is a leading cause of infant and child mortality in sub-Saharan Africa (Walker 2002). In addition to children, pregnant women and migrating populations are most vulnerable to malaria. Miscarriage, stillbirth, and low birth weight are common among pregnant women who are infected with the disease. It is also a highly complex disease caused by five different pathogens and vectored by many different mosquito species of the genus Anopheles. The disease causes a huge burden on many countries. Malaria remains one of the worst killers in the world today and is the cause of even greater suffering in human, social and economic terms (Wadhwa. et al.2010).

Malaria is caused by a Protozoan parasite of the genus Plasmodium .The genus that causes the disease is of five species, namely Plasmodium falciparum, P. vivax, P.malariae, P.ovale and P.knowlesi.

Malaria begins with a bite from an infected female Anopheles mosquito, which introduces sporozoites (cells that cause infections) through saliva into the human circulatory system. In the human bloodstream, the sporozoites are carried to the liver to mature and reproduce. In the liver, the sporozoites firstly grow into trophozoites (active feeding- stage cells) and then into schizonts (mother cells) which are for asexual reproduction. The schizonts go on to divide into merozoites (daughter cells), invade red blood corpuscles (RBCs) and eventually break out of the damaged RBCs and invade new ones. This causes the typical malaria symptoms of chills, fever and headache, which in severe cases can progress to coma or death. After a time, some of the merozoites entering the red blood cells develop and differentiate into male and female gametocytes, which enter the mosquito as it feeds on humans again. Male and female gametes produced by the gametocytes undergo fertilization in the stomach of the mosquito to form a zygote which grows and transforms into a motile and but short-lived diploid of diploid ookinete which migrates and embeds in the mid-gut wall of the mosquito and forms oocyst. Within the oocyst further divisions occur resulting in the formation of sporozoites, which then move to the salivary glands of the mosquito and the entire cycle begins again. Parasite viability depends upon favourability of environmental conditions for the vector (mosquito), on the availability of food, or access to human blood (Wadhwa et al.2010).The vast majority of deaths are caused by P.falciparum and P.vivax. It is a disease that can be treated in just 48 hours, yet it can cause fatal complications if the diagnosis and treatment are delayed.

The disease is widespread in tropical and subtropical regions in a broad band around the equator including much of Sub-Sahara Africa, Asia, and the Americas. Malaria is prevalent in tropical and subtropical regions because rainfall, warm temperatures and stagnant waters provide habitats for mosquito larvae. Malaria is also more common in rural areas than in cities; for example, cities in Asia are malaria –free, but the disease is prevalent in many rural areas including along international borders and forest fringes (Kar et al, 2014).

In contrast, malaria in Africa is present in both rural and urban areas though the risk is lower in the larger cities (Donnelly et al. 2005). Only female mosquitoes feed on blood, male mosquitoes feed on plant nectar, and so do not transmit the disease. The female of the Anopheles genus of mosquitoes prefer to feed at night. They usually start searching for a meal at dusk and will continue throughout the night until a meal is taken. The malaria parasite can also be transmitted by blood transfusions although this is rare.

According to the World Malaria Report (2008), 109 countries or territories were malaria prone in 2006, placing 3.3 billion people at risk of malaria transmission. Every year, several 100 million cases of malaria occur, and cause an estimated death toll of over a million of which over 90% occur in Africa. The World Malaria Report estimates that the number of cases of malaria rose from 233 million in 2000 to 244 million in 2005 but decreased to 225 million in 2009. Also, according to this report, the number of deaths due to malaria decreased from 985,000 in 2000 to 781,000 in 2009.

On World Malaria Day in 2008, the United Nations Secretary-General called for efforts to ensure universal coverage with malaria prevention and treatment programmes by the end of 2010. In 2005, the World Health Assembly established a goal, that the Roll Back Malaria (RBM) Partnership should reduce the number of malaria cases and death recorded in 2000 by 50 % or more by the end of 2010 and by 75% or more by 2015. Also, in September 2008, the RBM Partnership launched the Global Malaria Action Plan which defineds the steps required to accelerate achievement of the 2010 and 2015 targets for malaria control and elimination (Aregawi et al. 2009).

The goals set have not been achieved yet; instead, over the past 35 years, the incidence of malaria has increased 2-3 fold and this continuing upsurge has come from several factors such as the weakening of public health systems in some poor countries, continuing poverty and political instability, drug-resistant parasites, insecticide-resistant mosquitoes, deforestation, global climate change, population movements into malarious regions, changing agricultural practices including the building of dams and irrigation schemes, etc.(Raval, 2013).

Malaria is a major cause of illness and death in Ghana, particularly among children and pregnant women. In 2006, it accounted for 38.6% of all outpatient illnesses and 36.9% of all admissions (Pharm, 2013). Malaria prevalence per thousand population was 171 and 2,835 malaria attributable deaths representing 19% of all deaths were recorded. As many as 13.7% of all admissions of pregnant women in 2006 was as a result of malaria whilst 9.0% of them died from the disease (Pharm., 2013).

In most areas, malaria and poverty co-exist, with the average GDP and average growth of per capita GDP in malarious countries being about one fifth of those in non-malarious countries. The economic burden of malaria is huge, estimated to be $12 billion a year in Africa alone. However, the global spending on malaria control is only meager, with US$ 652 million disbursed in 2007 and US$ 1.7 billion committed in 2009. (In comparison, in the year 2008, HIV/AIDS accounted for 33.4 million of cases prevalence and 2 million deaths but a total global spending of US$ 13.7 billion).

More than 30,000 cases of malaria are reported annually among travelers from the developed world visiting malarious areas. With the increasing globalization, perennially prevalent malaria, therefore, remains an ever existing danger for humanity, in every part of the globe (Raval, 2013).

Many malaria control initiatives have been implemented by Governments, NGOs, WHO, Roll Back Malaria, Bill & Melinda Gates Foundation and other Charitable Organizations, Academic and Research Institutes, Corporate and other Private Organizations in different parts of the world. Some progress has been made due to the initiatives put in place. Malaria mortality rates have been estimated to have decreased by forty five percent globally across all age groups between 2000 and 2012, and by fifty one percent in children under five years of age. In the Africa Region alone, malaria death rates decreased by forty nine percent across all age groups and by fifty four percent in children under five years of age ( W.H.O., 2009).

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Item Type: Ghanaian Project Material  |  Attribute: 81 pages  |  Chapters: 1-5
Format: MS Word  |  Price: GH50  |  Delivery: Within 30Mins.
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