2.5. Diagnosis of malariaMalaria is febrile illness which requires accurate and timely diagnosis accompaniedby immediate treatment for proper management and control (Endeshaw et al., 2008). Accurate diagnosis is alsoimportant when realistic estimates of malaria burden are needed to guide oninformed interventions (Wongsrichanalai et al., 2007; Fancony et al., 2013) Parasite based diagnosis has been recommendedby World Health Organization as the best option towards malaria case management(WHO, 2015b). This is to minimize indiscriminate administration ofantimalarials in unconfirmed cases which may contribute to increasing resistance of parasites to the existingdrugs.
Various diagnostic tools have been in practise with microscopy being thegold standard for laboratory diagnosis of malaria (Makler et al.,1998; Ndao et al., 2004). In regions where laboratories lack requiredfacilities, Clinicaldiagnosis has been widely used; however, this type of diagnosis is unreliabledue to the non-specific nature of signs and symptoms of malaria (Bardaji et al.
, 2008; Endeshaw et al.,2008; Juma andZurovac, 2011). In recent years, otheraffordable, fast and simple diagnostic techniques such as application of RapidDiagnostic Test kits (RDT) are being introduced in endemic settings especiallyin regions with few experienced microscopists (Lubell et al., 2007). Unfortunately, theinability of RDTs to quantify the parasite load and its tendency to detectgametocytes especially in Parasite LactateDehydrogenase (pLDH)-based RDTs may confound treatment outcomes (Mueller et al., 2007). Other parasite-based diagnostic methods such asPolimerase chain reaction (PCR), flow cytometry, ELISA and indirectimmunofluorescence antibody assay (IFA) have been developed to help inreduction of morbidity and mortality associated with malaria. However, most ofthem are not frequently used in diagnosis of malaria especially in Kenyanhospitals.
Unlike microscopy and RDTs, molecular detection techniques have agreater sensitivity that can reveal widespread presence of infections with verylow parasite densities (Snounou, Viriyakosol, Zhu, et al., 1993). Due to high detection ofboth parasites and gametocytes, they are being introduced in many laboratoriesin endemic countries and are widely used in interventions and field surveys (Andrade et al., 2010; Kamau et al.,2011). These molecular detectiontechniques are valuable in areas experiencing perennial malaria transmissionbecause majority of infections may be submicroscopic rendering microscopyinefficient. Therefore, to accurately determine the proportion of individuals harboringgametocytes and to quantify the actual burden of submicroscopic infection,molecular techniques will be of utmost importance. 2.
6. Malaria control strategies Intensificationof concerted efforts to control malaria has greatly minimized malaria burden andtransmission most countries (Gething et al., 2010; Murray et al., 2012; Cotter et al.
,2013) Various strategies that have been put in place for management andcontrol of malaria include; use of insecticide-treated bednets (ITNs),widespread application of Indoor Residual Spray (IRS) and availability ofeffective treatment of clinical malaria (Lindblade et al., 2013). Early treatment with effective antimalarial drugs hasremained main intervention but treatment is threatened by the growingresistance of parasites to the existing drugs (Laxminarayan et al.
,2006). Currently, artemisinins are the most effective remainingantimalarial. These drugs caneffectively clear asexual blood stagesand P.
falciparum gametocytes at manageable concentrations (Maude et al., 2010). Efficacy of chloroquine, Sulphadoxine-Pyrimethamine (SP),amodiaquine and quinine diminished after reported cases of emerging drugresistant parasites (Trampuz et al.
, 2003; Achan et al.,2011; Shujatullah et al., 2012; Wongsrichanalai and Sibley, 2013). Both ITNs an IRS remain the major controlinterventions against the malaria vectors.
For successful implementation, WorldHealth Organization has intensified campaign to cover all population at riskwith either ITNs or indoor residual spraying (IRS) (WHO, 2008). Study findings further indicate that both ITNs andIRS are capable of cutting down malaria transmission when applied independently(Lengeler, 2004; Pluess et al., 2010; Kim et al., 2012).As a result, many countries have adopted both interventions (Raghavendra et al., 2011). In Africa, the ownership ofITNs per household increased from 3% in 2000 to 54% in 2013 while theproportion of the population protected by IRS increased from below 5% in 2005to 8% in 2012 (WHO, 2013; West et al.
, 2014).In western Kenya, malaria control activities have been intensified for morethan 10 years but parasite prevalence in children under the age of 5, onlyreduced from 83% in 1999 to 41% in 2009 by microscopy (Hamel et al., 2011). To improve efficiency ofthese intervention strategies, asymptomatic individuals should be targeted tointerrupt continuous transmission. This is possible with adoption of verysensitive detection tools.