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Journal of Medicine in the Tropics (2015) 17:2:91‑96
Journal of
Medicine in the
Tropics Original Article
Prevalence of malaria parasitaemia among residents proximal to environmental waste dumpsites in Gwagwalada metropolis, Abuja, Nigeria Idris Abdullahi Nasir, Maryam Aliyu Muhammad1, Anthony Uchenna Emeribe2, Adamu Babayo3, Muhammad Sagir Shehu3 Departments of Medical Microbiology and Parasitology and 2Medical Laboratory Services, University of Abuja Teaching Hospital, Abuja, 1Department of Medical Microbiology, Ahmadu Bello University Teaching Hospital, Shika, Zaria, Kaduna State, 3Department of Medical Laboratory Science, College of Medical Sciences, University of Maiduguri, Borno State, Nigeria
Abstract Background: Malaria is a widely explored public health topic which has been documented to constitute more burden among communities residing in proximity to environmental waste dumpsites and poor drainage systems. Objective: This present study sets to examine and compare whether there are more cases of malaria parasitemia burden among people residing proximal and those not proximal to dump sites at Gwagwalada metropolis. Materials and Methods: This was a cross‑sectional comparative survey which involved 100 blood samples collected from 25 households proximal to environmental waste dumpsites (test subjects) and another 100 from 25 households that are not proximal to dumpsites (control subjects) in Gwagwalada metropolis of Federal Capital Territory Abuja. These samples were analyzed using standard malaria microscopy. Results: Prevalence of malaria parasitemia was 82.0% among test subjects and 26.0% among control subjects. The highest malaria density recorded was >10,000 parasites/µL in 34 test subjects whereas none was observed from control subjects. Malaria parasitemia among test subjects was common among children (1–10 years) and least among 41–50 years. There was statistical relationship between malaria parasitemia among residents proximal to environmental waste dumpsites, more so with their age distribution (P 0.05). Conclusion: The findings of this study are a clear demonstration that accumulation of waste dumpsites in proximity to residential areas constitutes a pathway to malaria burden, consequently dumpsites should be properly located and managed to minimize their effects on the environment and health of man. Key words: Environmental dumpsites, Gwagwalada, public health, Malaria parasitaemia
Introduction Solid waste and drainage systems remained an intractable environmental sanitation problem in Nigeria.[1] This problem has manifested in the form of Access this article online Quick Response Code:
Website: www.jmedtropics.org
DOI: 10.4103/2276-7096.161511
piles of indiscriminately disposed heaps of uncovered waste and illegal dumpsites along major roads and at street corners in cities and urban areas. This problem is compounded by the rapid urbanization and population growth which has led to the generation of enormous quantities of solid waste which are often discarded by open dumping.[1] These waste dumps may contain a mixture of general waste and toxic, infectious or radioactive wastes and are susceptible to burning and exposure to scavengers. There are a number of major risks and impacts of the dump sites in the environment which include breeding sites for arthropods causing infections and diseases.[2]
Address for correspondence: Mr. Idris Abdullahi Nasir, Department of Medical Microbiology and Parasitology, University of Abuja Teaching Hospital, PMB 228, Gwagwalada, Abuja, Nigeria. E‑mail:
[email protected] Journal of Medicine in the Tropics | Vol. 17 | Issue 2 | Jul-Dec 2015
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Malaria is transmitted by the bite of female mosquitoes of the genus Anopheles. The transmission cycle is only between man and mosquitoes.[3] Man acts as the intermediate host or reservoir and the mosquitoes as the vector. Protozoan parasites of the genus Plasmodium have to undergo complex development and multiplication processes both in man and mosquito before they can be further transmitted. Only the female mosquitoes are of importance for transmission, as they need a blood meal for oviposition.[4] Malaria covers not only all developing countries, but is present on almost the entire land surface between the latitudes 40°N and 60°S. However, the distribution is not uniform and depends mainly on climate, altitude, population density, and the specific environmental requirements of the mosquitos’ species. Highly endemic areas are Sub‑Saharan Africa, Central America and the northern part of South America, the Indian subcontinent and Southeast Asia.[4] In the last two decades, a growing number of malaria cases have been observed.[4] This cannot only be explained by the increasing population, to a large extent, this is also due to the increasing numbers of environmental activities such as irrigation, waste dump sites and drainage schemes or hydro‑electric dams. With the introduction of new open water surfaces in the form of canals, ponds and artificial lakes, new mosquito breeding sites have been created.[5] However, the persistence of the disease is also due to the absence of effective long‑lasting vaccines, and the growing resistance of malaria pathogens and mosquitoes to treatment and insecticides, respectively.[3,5] Furthermore, malaria transmission is not only related to illegal waste dumpsites. Deforestation, mining, road construction and all the negative consequences of rapid, and uncontrolled urbanization are also contributing to the creation of mosquito breeding sites. In this context, urban waste dump sites play two key roles. On the one hand, it is an essential and effective tool for reducing and eliminating mosquito breeding sites by advocating against rampant dumpsites and by eliminating unnecessary scattered and numerous dump sites, these can represent potential breeding sites for various mosquito species if they are permanently flooded and heaped by household disposals.[5] Solid waste disposal sites are found on the outskirts of the urban areas, turning into the sources of contamination due to the incubation and proliferation of f lies, mosquitoes, and rodents; that in turn transmits malaria, cholera, dengue, onchocerciasis and some filariasis that affect population’s health. The said situation produces gastrointestinal, dermatological, respiratory, genetic, and several other kinds of infectious diseases such as malaria. Consequently, dumping sites and poor drainages have a
very high economic and social cost in the public health services and have not yet been completely estimated by governments, industries, and families.[6] Apart from proximity to solid waste, other determinants of high susceptibility to malaria include quality of housing, household income, use of anti‑mosquitoes measures (e.g., long lasting insecticide treated nets), access to treatment, and rural travel.[7] Gwagwalada is one of the fast‑growing and influential towns in Federal Capital Territory (FCT) of Nigeria. Over the years, the town is threatened by environmental waste dump sites and pollution making the inhabitant vulnerable to health hazards with malaria infections. The situation is likely to be exacerbated by poor economic situation of the inhabitant, poor planning system, high standard of living caused by proximity of the town to the FCT and being the University town of the FCT. Due to poor adherence to proper environmental waste disposal and its health implications on the inhabitants of the town, this study was instigated. The inappropriate environmental waste disposal and drainage system in Gwagwalada area council has led to the presence of stagnant water bodies which serve as breeding sites for this mosquito vectors and indeed are the agent of malaria transmission. The increase in numbers of these solid waste dump sites might increase the risk of mosquitos’ activities (e.g., laying/hatching so many eggs and night bites); hence making close‑by residents much vulnerable to malaria parasitemia.[7] An estimated 200 million persons in Sub‑Sahara Africa live currently in urban centers in malaria endemic areas[7] and 24–103 million clinical attacks occur annually in those areas.[8] In addition, Nigeria has highest malaria prevalence, with about 97% of its estimated 150 million population at risk and about 100 million cases and 300,000 deaths annually.[4,8] Malaria is endemic in Nigeria as high‑intensity transmission occurs all year round, with rates of transmission higher in the wet season than in the dry season, and with more victims in the northern than in the southern part. A number of studies have investigated the incidence of malaria all over the world.[9‑12] It is estimated that the annual death resulting from this disease is between 1.1 and 2.7 million people out of which over 1 million are children under the age of five in the Sub‑Sahara Africa.[13] Much attention was focused on pregnant women and children due to their high vulnerability and exposure to conditions that malaria can cause. There is limited evidence from the results of all these studies to suggest that the breeding and Journal of Medicine in the Tropics | Vol. 17 | Issue 2 | Jul-Dec 2015
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multiplication of mosquitoes on solid waste dumps can lead to increase in the incidence of malaria.[14] The World Health Organization (WHO) recommends a parasite‑based diagnosis of malaria infection. [14] Microscopic examination using Giemsa‑stained blood slides for detection of malaria parasites remains, in spite of the availability of the other various methods, the reference standard and it is routinely relied upon as a primary endpoint measurement for patient care, epidemiological studies, operational research, intervention studies, as well as clinical trials.[15] It is the only method that is widely and practically available for quantifying malaria parasite density by comparing the ratio of counted parasites within a given number of microscopic fields, against either counted white blood cells (WBCs) or counted red blood cells (RBCs) within those same fields, and then multiplying that ratio by either the measured or estimated/assumed density of the patient’s actual WBCs or RBCs.[15] This present study examined and compared whether there are more cases of malaria parasitemia burden among people residing proximal to waste dump sites compared to those residing far away or not proximal to dump sites at Gwagwalada metropolis. The outcome of this study might therefore justify the need to encourage periodic surveillance of mosquito activities and their effects on health in the community.
Materials and Methods Study Area This study concentrates on Gwagwalada town of the FCT of Nigeria. The town is about 45 km away from the FCT. It is one of the six area council headquarters of the FCT. The town lies in the downstream of River Usuma and is located between latitude 8°55’ and 9°00’N and longitudinal 7°00’ and 7°05’E.[16] The centrality of this town in relation to other area councils’ headquarters makes it influential and important in various socio‑economic activities. Climate of this town is not farfetched from that of the tropics having several climatic elements in common; most especially the wet and dry season, characteristic. The temperature of the area ranges from 30°C to 37°C yearly, with the highest temperature experienced in the month of March and with mean total rainfall of approximately 1650 mm/annum. About 60% of this rain falls between the months of July to September. The area council is an industrial zone of FCT that stands out as the second most cosmopolitan city of the FCT, after the capital city with 10 political ward and consist of over 26 Federal agencies which includes Sharia court of Appeal, University of Abuja Teaching hospital etc., These have brought about the inflow of people into the council.[16] Journal of Medicine in the Tropics | Vol. 17 | Issue 2 | Jul-Dec 2015
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Gwagwalada Area Council had an estimated population of over 600,000 people. This comprises original settlers (indigenes) and immigrant population of other Nigerians and foreigners. Gwagwalada town records over 300 households.[16] Sample Collection Venous blood samples were collected from four residents from 50 houses residing close to environmental dump sites in Gwagwalada area council, FCT Abuja. The samples were then transported to parasitology unit of medical laboratory department at the university of Abuja teaching hospital for microscopy of stained slides for malaria parasite. A total of 200 blood samples were collected from these residents within the period of May 2013 to August 2013. Sample Size The sample size was determined using Hassan, 2012 [17] prevalence rate. This was calculated using Naing’s statistical expression. Thus, n = 349. However, due to noncompliance of some residents, we were able to recruit 200 subjects that consented to take part in the study. Residents Selection Process The study considered one important measure of exposure to malaria infection, the distance between residences from environmental waste dumpsite. Thus, in the study area, two residential areas were carefully delineated. The first area designated has households located within the range of distance between 100 and 500 m from waste dump sites. While 100 of our subjects reside in this area, the remaining 100 control subjects reside in the second area which was also in the same town but beyond 500 m from waste dump sites, this was considered essentially hygienic zone. Sample Collection and Storage Two milliliter of peripheral blood was collected from the residents by vein puncture from any of the cephalic, medial, or basilic veins with a sterile syringe and barrel into a new ethylene diamine tetra acetic acid (EDTA) anticoagulant container. The blood samples were then transported to the laboratory. Upon reaching the laboratory, Thick and thin blood films were made with each of the samples on a clean grease‑free slide using the appropriate laboratory number given to each and every individual. The smeared slides were allowed to air dry whilst arranged on slide holders. Malaria Parasite Microscopy Procedure Staining blood smears One set of smears was stained and the duplicate unstained. The latter will prove useful if a problem occurs
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during the staining process. Giemsa‑staining procedure was used for detect and quantify malaria parasites on thick films. Staining procedure To ensure that proper staining results be achieved, a positive smear (malaria) was included with each new batch of working Giemsa‑stain. Blood specimens were collected in an EDTA bottle, which has enough parasites so that at least one can be found in every two to three fields. Thick blood smears were stained using 1 in 10 dilution of the Giemsa‑stain for 10 min. Estimation of parasite density Parasite densities were recorded as a ratio of parasites to WBCs in thick films. Plasmodium parasites were counted against 200 WBC on the thick film. Five hundred WBCs were counted where 10,000 parasites/µL (in 34 individuals). This value was recorded among the test subjects and none from the control subjects, P 10000 parasites/µl of blood (severe) Total 100 (100) 100 (100) χ2=6.0, P=0.04
Table 4: Age distribution of malaria density count across test and control subjects Age Test Control ≤1000/µL (years) subjects subjects Test Control recruited recruited 0‑10 10 15 8 10 11‑20 12 26 2 5 21‑30 44 39 6 1 31‑40 18 14 4 1 41‑50 6 2 1 Total 100 22 18
1001‑10000/µL >10000 µL Test Control Test Control 12 5 6 0 3 26
6 0 0 2 0 8
14 14 2 4 0 34
0 0 0 0 0 0
χ2=2.22, P=0.0034
had the highest incidence of infection, 50 (25.0%). While only 6 (3.00%) individuals in the age range 41–50 had malaria parasite. There was a statistical relationship between the age distribution and malaria infection in this study (P
