Investigation into the risk factors for Malaria transmission in the Omusati region select="/dri:document/dri:meta/dri:pageMeta/dri:metadata[@element='title']/node()"/>

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dc.contributor.advisor Haindongo, Erastus H. 2016-10-13T13:45:22Z 2016-10-13T13:45:22Z 2016
dc.description A thesis submitted in fulfilment of the requirements for the Degree of Master of Science en_US
dc.description.abstract Namibia has achieved great success in the reduction of malaria case numbers from over 500 per 1000 population in 2000 to between 1 -2 per 1000 population in 2013 (MoHSS-NVDCP, 2009). The gains in the reduction of malaria case numbers have seen the country transitioning from the control phase of malaria epidemiology to the pre-elimination phase, and has subsequently adopted the goal of malaria elimination by 2020 (MoHSS-NVDCP, 2010; Pindolia et al., 2012). Since the year 2008, there were no significant reductions in cases per annum, despite continued interventions (such as Indoor Residual spraying, Insecticide treated nets and larviciding) geared towards vector and parasite control. These interventions are aimed at the realization of malaria elimination. These uninformed and untargeted interventions leave certain groups or individuals at an increased risk of infection. Furthermore in a low transmission setting, parasite density decreases and a considerable number of people harboring Plasmodium parasites are asymptomatic. As a consequence, untargeted at risk populations continue to harbor parasites, which continues to fuel transmission and thus poses as a challenge to elimination. This highlights the need for establishing the unknown risk factors and detection of low parasite density asymptomatic infections with more sensitive molecular diagnostics since the current Point of Care (P.O.C) diagnostics, the Rapid Diagnostic Tests (RDTs) do not detect some of these low density infections. These will ultimately allow for evidence-based targeting of interventions, for the final drive to eliminate malaria. A household level cluster case-control study was carried out between January – May 2014 in the Oshikuku and Outapi health district of the Omusati Region, north central Namibia. Case households were identified by Re-Active Case Detection (RACD), a surveillance tool which involves the screening of individual residing in proximity of a case detected passively at a health facility. Control households were randomly selected from National Census Enumeration Areas (EA). A semi- structured questionnaire was administered to all eligible and consenting members. Questions pertaining to the demographics (age and gender), net ownership and usage, presence of breeding site, travel in the past 6 weeks, outdoor nocturnal behavior, household spraying, and treatment seeking behavior following the self-reported history of fever were elicited from all eligible study participants. RDT and Dried Blood Spots were collected and stored for analysis of the presence of Plasmodium parasites using Loop-mediated isothermal Amplification (LAMP) and Cytochrome B nested Polymerase Chain Reaction (nPCR). RACD identified 59 index case households for investigation and an additional randomly selected 77 households were investigated as controls. The distribution of males and females was comparable in both case and control households. The following factors were found to be associated with the increased risk of being a malaria case: Household with a low Socio-Economic status(SES); Long lasting insecticide treated bed net ownership (O.R=3.89, p-value: 0.05), net usage ( O.R=1.4, p-value:0.01); Age group: 35 – 45 (O.R=15.06, p-value: <0.001); Presence of breeding site (O.R=2.21, p-value= 0.01) ; distance of household to a Health facility (O.R=6.26, p-value:0.01) and poor treatment seeking behaviour. RDTs had a sensitivity and specificity of 76.47(95%CI:50.10-93.19) and 95.88 (95%CI:92.45-96.51), with its calculated Positive Predictive Value (PPV) being 35.14 (95%CI:18.57-49.13). Hence, when compared to LAMP and nPCR, the sensitivity and specificity of RDTs was the lowest. When using the reference method of nPCR, the sensitivity (100%) and specificity (97.89%) of LAMP was comparable to that of nPCR although LAMP detected 48% more positives than nPCR. However, LAMP had a PPV of 52% since most of its positives were considered false. This study indicates that RACD can be used as a tool to establish the risk factors associated with malaria at household level and can thus inform elimination programmes on the appropriate intervention tools that should be employed. LAMP had a higher sensitivity, specificity, PPV and NPV than RDT and may potentially perform better than RDTs in detecting low density infections. However, further research is required as LAMP results could not always be confirmed using PCR. en_US
dc.language.iso en en_US
dc.publisher University of Namibia en_US
dc.subject Malaria transmission en_US
dc.subject Omusati region en_US
dc.subject Breeding site en_US
dc.title Investigation into the risk factors for Malaria transmission in the Omusati region en_US
dc.type Thesis en_US

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