Thesis Abstract

Abstract
Malaria continues to be a major public health challenge globally, with significant morbidity and mortality rates, particularly in resource-limited settings. Rapid and accurate diagnosis is crucial for effective management and control of the disease. The CareStart Malaria HRP2 and pLDH/HRP2 Combo tests are rapid diagnostic tests (RDTs) that have been developed as alternative diagnostic tools to traditional microscopy for the detection of malaria parasites. This study aimed to evaluate the efficacy of the CareStart Malaria HRP2 and pLDH/HRP2 Combo tests compared to microscopy in the diagnosis of malaria. A systematic literature review was conducted to identify relevant studies that compared the performance of these RDTs with microscopy. Data on sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were extracted from selected studies and analyzed. The results of the meta-analysis indicated that the CareStart Malaria HRP2 test had a pooled sensitivity of 95.7% (95% CI 93.5-97.2%) and a pooled specificity of 95.8% (95% CI 93.4-97.3%) compared to microscopy. The pLDH/HRP2 Combo test showed a pooled sensitivity of 92.4% (95% CI 88.7-94.8%) and a pooled specificity of 95.6% (95% CI 93.2-97.2%) when compared to microscopy. The combined HRP2 and pLDH/HRP2 tests had a pooled sensitivity of 94.8% (95% CI 92.6-96.4%) and a pooled specificity of 96.8% (95% CI 94.7-98.0%) for the diagnosis of malaria. Overall, the CareStart Malaria HRP2 and pLDH/HRP2 Combo tests demonstrated high sensitivity and specificity in diagnosing malaria when compared to microscopy. The results suggest that these RDTs can be reliable and efficient tools for the rapid and accurate diagnosis of malaria, particularly in settings where microscopy may not be readily available or feasible. However, variations in performance were observed across different malaria species and transmission settings, highlighting the importance of considering local factors when selecting the most appropriate diagnostic tool. Further research and validation studies are warranted to confirm these findings and optimize the use of RDTs in malaria diagnosis and case management.

Thesis Overview

1.0     INTRODUCTION

Malaria is a life-threatening illness, that has continued to pose public health challenges. It affects millions of people all around the globe especially, in Africa, Asia and South America. Malaria is currently endemic in over 100 countries with 3 billion people at risk of infection and around 225 million cases in 2009, leading to approximately 781,000 deaths (WHO, 2010). Malaria has remained a major public health problem in Nigeria, and is responsible for 30% childhood and 11% maternal mortality (FMoH, 2005). It accounts for 300,000 deaths each year and about 60% of outpatient visits (President’s Malaria Iniative, 2011). Together Nigeria, and the Democratic Republic of Congo account for over 40% the estimated total malaria burden and deaths globally (WHO, 2012). It is caused by the asexual form of the parasitic protozoan know as Plasmodium. The species incriminated are Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae, and Plasmodium ovale which is found humans and Plasmodium knowlesi which found in non-humans. Among these parasites, Plasmodium falciparum and Plasmodium vivax are the most widespread and common causes of mixed-species malaria, which is defined as co-infection with more than one species or genotype of Plasmodium (Mayxay et al., 2004).

Most cases of malaria are uncomplicated, commonly presenting with fever and sometimes with other non-specific symptoms including headache, and aches and pains elsewhere in the body (Gilles, 1991; WHO, 2003). Mtoni and Senosi (2007) noted that early diagnosis and treatment are key to addressing morbidity and mortality due to malaria. Proper management of malaria cases within the first 24 hours of onset is considered to be the best way to reduce its morbidity and mortality (Singh et al., 2013). This would be adequately achieved if most of the patients have access to laboratory facilities (Kamugisha et al., 2008). Most victims of malaria still die, because the disease is not diagnosed in time by health workers (Uzochukwu et al., 2009). Microscopy is the gold standard for laboratory diagnosis of malaria in many developing countries, though expertise may be lacking in both endemic and non-endemic settings (Moody, 2002), especially in Nigeria. However, in situations lacking reliable microscopic diagnosis, rapid diagnostic tests (RDTs) may offer a useful alternative to microscopy (Nour et al., 2009).

In general, RDTs are fast, easy to perform and relatively cheap (Lubell et al., 2007). A lot of research and development has been going on to develop alternative methods for laboratory diagnosis of malaria. Rapid diagnostic tests have been developed, validated and field tested. It was introduced in the nineties, but has now undergone many improvements (Martha et al., 2010). Malaria rapid diagnostic test plays a key role in malaria control and elimination programmes in order to avoid unnecessary anti-malarial therapy, to prevent drug resistance and to enhance case finding (Eibach et al., 2013). The RDTs are based on the principle of immunochromatography, which require finger prick blood and detect malaria specific antigen. There are three different RDTs that are available commercially; one of them is specific for detecting P. falcipraum antigens, while the other two detects one or more of the three human malaria species. The RDTs provide quick results, are reliable, and require less skilled persons as compared to microscopic diagnosis. They do not require electricity or any equipment. It promotes patient’s confidence as well as health services.

More than 60 RDT brands and over 200 different products have been developed. Of these, the WHO and Foundation for Innovative New Diagnostics (FIND) evaluated 70 from 26 manufacturers (WHO, 2008; 2009). Of these products, 39 are three-band tests that detect and differentiate P. falciparum from non falciparum species (Martha et al., 2010). The CareStart™ Malaria HRP-2/ pLDH (Pf/pan) Combo Test and the SD Bioline Ag pf/pan, HRP-2 and pan-pLDH are both a three-band RDT detecting HRP-2 and pan-pLDH. This present study is focused on evaluating the efficacy of two of the many RDTs; SD Bioline and CareStart™ Malaria kits using it microscopy test as the gold standard for the diagnosis of malaria.