Malaria prevalence in asymptomatic and symptomatic children in Kiwangwa, Bagamoyo district, Tanzania

Abstract

BackgroundMalaria prevalence continues to decline across sub-Saharan Africa as a result of various intervention strategies. However, the diseases still poses a public health concern in the region. While symptomatic malaria is recognized and treated, asymptomatic infections become increasingly important for interrupting transmission. A cross-sectional survey was conducted to assess malaria prevalence in symptomatic and asymptomatic children in Kiwangwa ward in Bagamoyo District in Tanzania.MethodsFour hundred school-aged children in Kiwanga ward were recruited in the study; 200 from Kiwangwa dispensary and 200 from nearby schools. Primary health parameters were examined and blood samples collected and examined for Plasmodium falciparum prevalence using rapid diagnostic test (RDT), light microscopy (LM) and reverse transcription quantitative PCR (RT-qPCR) targeting transcripts of A-type 18s rRNA of P. falciparum. Gametocytes were detected by LM and RT-qPCR targeting transcripts of gametocyte specific marker, Pfs25.ResultsOverall P. falciparum prevalence was 73.3, 40.8 and 36.3% by RT-qPCR, RDT and LM in the study area, respectively (P < 0.001). As expected symptomatic children had a significantly higher prevalence of 89, 67.5 and 64.5% by qPCR, RDT and LM, compared to 57.5, 14 and 8% in the asymptomatic group, respectively. However, gametocyte prevalence in asymptomatic individuals was higher by both LM (2%) and qPCR (14%) than in symptomatic individuals LM (0.5%) and qPCR (3%).ConclusionsA substantial difference in prevalence of symptomatic and asymptomatic infections observed in Kiwangwa ward underpins the use of molecular tools in malaria surveillance aiming at estimating prevalence and transmission. Notably, the higher gametocytaemia observed in asymptomatic children indicates the reservoir infections and points to the need for detection and treatment of both asymptomatic and symptomatic malaria.

Reactive Case Detection of Asymptomatic Malaria in Households and Neighbors of Laboratory Confirmed Cases in Raya Kobo District, Northeast Ethiopia

“…However, this figure is lower than previous studies in Kenya 12.6% (28) and Tanzania 8% (29). Lower findings than the current study were reported in Malo, Southwest Ethiopia with no case (17), Myanmar 1.4% (30), and Haiti with 2.8% (24).…”

Prevalence of Asymptomatic Malaria among Children in the Tamale Metropolis: How Does the PfHRP2 CareStart™ RDT Perform against Microscopy?

“…Using microscopy in the current study, the overall prevalence of malaria was lower compared to RDT. is is consistent with recent studies by Sumari et al [11] and Huang et al [21] but contrary to results of a study in Myanmar where microscopy produced a higher prevalence than RDT [22]. e microscopic prevalence found in this current study is far lower than the 56% reported in 2010 and 27.5% in 2017 during a similar dry season study in the northern part of Ghana [18,23].…”

“…Individuals with asymptomatic infection carry very low parasite densities for extended periods and usually go untreated. As such, they contribute to malaria transmission especially in areas with seasonal transmission by serving as Plasmodium reservoirs [10][11][12]. Identifying and eliminating these reservoirs (through chemopreventive methods like mass drug administration) therefore will play a critical role in the fight against malaria.…”

Evaluation of decreased haematocrit and haemoglobin levels in <i>Plasmodium falciparum</I> infected individuals from South-western Nigeria

“…Probing further into the practices of the study population (which is outside the scope of this present study) would have revealed if drugs were used prior to hospital visitation and as such substantiate the claim of drug reaction on the parasite. Other studies showing same trend of lower prevalence by microscopy as against RDT where both were used include that carried out in Lagos, Nigeria (Olusegun-Joseph et al, 2016) and also in Tanzanian, though among children (Sumari et al, 2017). Such results however need validation by PCR in order to ascertain the true diagnostic status of the individuals.…”