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Travel Medicine and Infectious Disease 2022To elucidate the relationship between CYP2D6 polymorphisms and Plasmodium vivax recurrence in patients receiving primaquine-based treatment through systematic review and... (Meta-Analysis)
Meta-Analysis
OBJECTIVES
To elucidate the relationship between CYP2D6 polymorphisms and Plasmodium vivax recurrence in patients receiving primaquine-based treatment through systematic review and meta-analysis.
METHODS
We searched the PubMed, EMBASE, Cochrane Library, and Web of Science databases for eligible studies published up to August of 2021. We included studies investigating the associations between CYP2D6 polymorphisms and P. vivax recurrence. We evaluated the pooled odds ratio (OR) and 95% confidence interval (CI).
RESULTS
Data from nine studies, including 970 patients, were analyzed. We found that CYP2D6 poor metabolizers (PMs), intermediate metabolizers (IMs), or normal metabolizers slow (NM-Ss) were associated with a 1.8-fold (95% CI, 1.34-2.45; P = 0.0001) higher recurrence of P. vivax than normal metabolizers fast (NM-Fs), extensive metabolizers (EMs), or ultrarapid metabolizer (UMs). Subgroup analysis showed that studies on both Brazilian and Southeast or East Asian individuals had similar results to the main results. Sensitivity analysis by sequentially excluding individual studies also showed robust results (OR range: 1.63-2.01).
CONCLUSIONS
This meta-analysis confirmed that CYP2D6 PMs, IMs, or NM-Ss increased the risk of P. vivax recurrence compared to NM-Fs, EMs, or UMs. The results of this study could be used to predict P. vivax recurrence and suggest CYP2D6 genotype-based primaquine dosing.
Topics: Antimalarials; Cytochrome P-450 CYP2D6; Genotype; Humans; Malaria, Vivax; Plasmodium vivax; Primaquine; Recurrence
PubMed: 35452835
DOI: 10.1016/j.tmaid.2022.102333 -
SAGE Open Medicine 2022Active detection of asymptomatic malaria cases and resolution of associated factors are essential for malaria elimination. There are no nationwide estimates for... (Review)
Review
Active detection of asymptomatic malaria cases and resolution of associated factors are essential for malaria elimination. There are no nationwide estimates for asymptomatic malaria and associated factors in Ethiopia. Therefore, this study aims to generate comprehensive and conclusive evidence from various studies conducted in Ethiopia. Published articles from various electronic databases such as PubMed, Google Scholar, CINAHL, Scopes, Cochrane Library, the Web of Science, and African Journals Online were accessed. Also, unpublished studies from Addis Ababa digital library were identified. All observational study designs were included in the search. Data were extracted on the Microsoft Excel spreadsheet and analyzed using STATA version 14.1. A random-effects model was fitted to estimate the pooled prevalence of asymptomatic malaria. A meta-regression and subgroup analysis was computed to see heterogeneity. The publication bias was assessed by the funnel plots and Egger's statistical tests. The analysis found that the pooled burden of asymptomatic malaria was 6.7 (95% confidence interval = 4.60, 8.79). The pooled prevalence of Plasmodium falciparum was 3.75 (95% confidence interval = 2.25, 5.18), and that of Plasmodium vivax was 2.22 (95% confidence interval = 1.46, 2.99). Factors such indoor residual spray service (odds ratio = 0.46; 95% confidence interval = 0.26, 0.81), never used insecticide-treated nets (odds ratio = 6.36; 95% confidence interval = 4.01, 10.09), and presence of stagnant water in the vicinity (odds ratio = 3.24; 95% confidence interval = 1.20, 8.71) were found to have a significant association with asymptomatic malaria. This study highlighted that pooled prevalence of asymptomatic malaria is high and varied by population groups. Prevalence of asymptomatic malaria was increased among those who never used insecticide-treated nets and were living near stagnant water by six and three times, respectively. The use of more sensitive diagnostic methods could yield a higher burden of the disease. Furthermore, active case detection is recommended for effective intervention toward elimination.
PubMed: 35433001
DOI: 10.1177/20503121221088085 -
Scientific Reports Mar 2022A better understanding of the occurrence and risk of Plasmodium vivax infection among Duffy-negative individuals is required to guide further research on these... (Meta-Analysis)
Meta-Analysis
A better understanding of the occurrence and risk of Plasmodium vivax infection among Duffy-negative individuals is required to guide further research on these infections across Africa. To address this, we used a meta-analysis approach to investigate the prevalence of P. vivax infection among Duffy-negative individuals and assessed the risk of infection in these individuals when compared with Duffy-positive individuals. This study was registered with The International Prospective Register of Systematic Reviews website (ID: CRD42021240202) and followed Preferred Reporting Items for Systematic review and Meta-Analyses guidelines. Literature searches were conducted using medical subject headings to retrieve relevant studies in Medline, Web of Science, and Scopus, from February 22, 2021 to January 31, 2022. Selected studies were methodologically evaluated using the Joanna Briggs Institute (JBI) Critical Appraisal Tools to assess the quality of cross-sectional, case-control, and cohort studies. The pooled prevalence of P. vivax infection among Duffy-negative individuals and the odds ratio (OR) of infection among these individuals when compared with Duffy-positive individuals was estimated using a random-effects model. Results from individual studies were represented in forest plots. Heterogeneity among studies was assessed using Cochrane Q and I statistics. We also performed subgroup analysis of patient demographics and other relevant variables. Publication bias among studies was assessed using funnel plot asymmetry and the Egger's test. Of 1593 retrieved articles, 27 met eligibility criteria and were included for analysis. Of these, 24 (88.9%) reported P. vivax infection among Duffy-negative individuals in Africa, including Cameroon, Ethiopia, Sudan, Botswana, Nigeria, Madagascar, Angola, Benin, Kenya, Mali, Mauritania, Democratic Republic of the Congo, and Senegal; while three reported occurrences in South America (Brazil) and Asia (Iran). Among studies, 11 reported that all P. vivax infection cases occurred in Duffy-negative individuals (100%). Also, a meta-analysis on 14 studies showed that the pooled prevalence of P. vivax infection among Duffy-negative individuals was 25% (95% confidence interval (CI) - 3%-53%, I = 99.96%). A meta-analysis of 11 studies demonstrated a decreased odds of P. vivax infection among Duffy-negative individuals (p = 0.009, pooled OR 0.46, 95% CI 0.26-0.82, I = 80.8%). We confirmed that P. vivax infected Duffy-negative individuals over a wide prevalence range from 0 to 100% depending on geographical area. Future investigations on P. vivax infection in these individuals must determine if Duffy-negativity remains a protective factor for P. vivax infection.
Topics: Brazil; Cross-Sectional Studies; Humans; Kenya; Malaria, Vivax; Plasmodium vivax; Prevalence
PubMed: 35256675
DOI: 10.1038/s41598-022-07711-5 -
PLoS Medicine Jan 2022Plasmodium vivax infects an estimated 7 million people every year. Previously, vivax malaria was perceived as a benign condition, particularly when compared to... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Plasmodium vivax infects an estimated 7 million people every year. Previously, vivax malaria was perceived as a benign condition, particularly when compared to falciparum malaria. Reports of the severe clinical impacts of vivax malaria have been increasing over the last decade.
METHODS AND FINDINGS
We describe the main clinical impacts of vivax malaria, incorporating a rapid systematic review of severe disease with meta-analysis of data from studies with clearly defined denominators, stratified by hospitalization status. Severe anemia is a serious consequence of relapsing infections in children in endemic areas, in whom vivax malaria causes increased morbidity and mortality and impaired school performance. P. vivax infection in pregnancy is associated with maternal anemia, prematurity, fetal loss, and low birth weight. More than 11,658 patients with severe vivax malaria have been reported since 1929, with 15,954 manifestations of severe malaria, of which only 7,157 (45%) conformed to the World Health Organization (WHO) diagnostic criteria. Out of 423 articles, 311 (74%) were published since 2010. In a random-effects meta-analysis of 85 studies, 68 of which were in hospitalized patients with vivax malaria, we estimated the proportion of patients with WHO-defined severe disease as 0.7% [95% confidence interval (CI) 0.19% to 2.57%] in all patients with vivax malaria and 7.11% [95% CI 4.30% to 11.55%] in hospitalized patients. We estimated the mortality from vivax malaria as 0.01% [95% CI 0.00% to 0.07%] in all patients and 0.56% [95% CI 0.35% to 0.92%] in hospital settings. WHO-defined cerebral, respiratory, and renal severe complications were generally estimated to occur in fewer than 0.5% patients in all included studies. Limitations of this review include the observational nature and small size of most of the studies of severe vivax malaria, high heterogeneity of included studies which were predominantly in hospitalized patients (who were therefore more likely to be severely unwell), and high risk of bias including small study effects.
CONCLUSIONS
Young children and pregnant women are particularly vulnerable to adverse clinical impacts of vivax malaria, and preventing infections and relapse in this groups is a priority. Substantial evidence of severe presentations of vivax malaria has accrued over the last 10 years, but reporting is inconsistent. There are major knowledge gaps, for example, limited understanding of the underlying pathophysiology and the reason for the heterogenous geographical distribution of reported complications. An adapted case definition of severe vivax malaria would facilitate surveillance and future research to better understand this condition.
Topics: Anemia; Humans; Malaria, Vivax; Prevalence
PubMed: 35041650
DOI: 10.1371/journal.pmed.1003890 -
International Emergency Nursing Jan 2022Malaria is a life-threatening disease. Prior to the pandemic, over a million people annually from non-endemic, high income countries such as Europe and North America... (Review)
Review
BACKGROUND
Malaria is a life-threatening disease. Prior to the pandemic, over a million people annually from non-endemic, high income countries such as Europe and North America visited countries with a risk of malaria transmission. Emergency care nurses in non-endemic countries frequently encounter returning travellers, presenting with symptoms suggestive of malaria. While rapid diagnostic tests are used in countries with endemic malaria, in countries such as the United Kingdom diagnosis is undertaken by microscopy and three negative tests are required to exclude.
QUESTION
Are rapid diagnostic tests effective for diagnosing imported malaria in non-endemic, high income countries?
METHOD
A systematic review of published research (January 2009 - November 2020) comparing rapid diagnostic tests with microscopy.
RESULTS
Fourteen studies were included, conducted in five countries with 14 different RDTs evaluated. Mean sensitivity and specificity for Plasmodium Falciparum was 91.8% and 97.7% and Plasmodium Vivax 81.6% and 99.2%. Higher sensitivities were related to higher parasite densities.
CONCLUSIONS
International travel will return post-pandemic and rapid, accurate and cost-efficient tests will be required. The rapid diagnostic tests in these studies showed significant variation and were not as accurate as microscopy. Consequently, it cannot be recommended that rapid diagnostic tests replace the gold standard of microscopy. Further research is required.
Topics: Developed Countries; Diagnostic Tests, Routine; Humans; Malaria; Plasmodium vivax; Sensitivity and Specificity
PubMed: 34953438
DOI: 10.1016/j.ienj.2021.101110 -
Malaria Journal Dec 2021Ethiopia is one of the few countries in Africa where Plasmodium vivax commonly co-exists with Plasmodium falciparum, and which accounts for ~ 40% of the total number... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Ethiopia is one of the few countries in Africa where Plasmodium vivax commonly co-exists with Plasmodium falciparum, and which accounts for ~ 40% of the total number of malaria infections in the country. Regardless of the growing evidence over many decades of decreasing sensitivity of this parasite to different anti-malarial drugs, there has been no comprehensive attempt made to systematically review and meta-analyse the efficacy of different anti-malarial drugs against P. vivax in the country. However, outlining the efficacy of available anti-malarial drugs against this parasite is essential to guide recommendations for the optimal therapeutic strategy to use in clinical practice. The aim of this study was to synthesize evidence on the efficacy of anti-malarial drugs against clinical P. vivax malaria in Ethiopia.
METHODS
All potentially relevant, peer-reviewed articles accessible in PubMed, Scopus, Web of Science, and Clinical Trial.gov electronic databases were retrieved using a search strategy combining keywords and related database-specific subject terms. Randomized controlled trials (RCTs) and non-randomized trials aiming to investigate the efficacy of anti-malarial drugs against P. vivax were included in the review. Data were analysed using Review Manager Software. Cochrane Q (χ) and the I tests were used to assess heterogeneity. The funnel plot and Egger's test were used to examine risk of publication bias.
RESULTS
Out of 1294 identified citations, 14 articles that presented data on 29 treatment options were included in the analysis. These studies enrolled 2144 clinical vivax malaria patients. The pooled estimate of in vivo efficacy of anti-malarial drugs against vivax malaria in Ethiopia was 97.91% (95% CI: 97.29-98.52%), with significant heterogeneity (I = 86%, p < 0.0001) and publication bias (Egger's test = -12.86, p < 0.001). Different anti-malarial drugs showed varied efficacies against vivax malaria. The duration of follow-up significantly affected the calculated efficacy of any given anti-malarial drug, with longer duration of the follow-up (42 days) associated with significantly lower efficacy than efficacy reported on day 28. Also, pooled PCR-corrected efficacy and efficacy estimated from altitudinally lower transmission settings were significantly higher than PCR-uncorrected efficacy that estimated for moderate transmission settings, respectively.
CONCLUSION
The overall efficacy of anti-malarial drugs evaluated for the treatment of vivax malaria in Ethiopia was generally high, although there was wide-ranging degree of efficacy, which was affected by the treatment options, duration of follow-up, transmission intensity, and the confirmation procedures for recurrent parasitaemia. Regardless of evidence of sporadic efficacy reduction reported in the country, chloroquine (CQ), the first-line regimen in Ethiopia, remained highly efficacious, supporting its continuous utilization for confirmed P. vivax mono-infections. The addition of primaquine (PQ) to CQ is recommended, as this is the only approved way to provide radical cure, and thus ensure sustained efficacy and longer protection against P. vivax. Continuous surveillance of the efficacy of anti-malarial drugs and clinical trials to allow robust conclusions remains necessary to proactively act against possible emergence and spread of drug-resistant P. vivax in Ethiopia.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Antimalarials; Child; Child, Preschool; Ethiopia; Female; Humans; Infant; Malaria, Vivax; Male; Middle Aged; Non-Randomized Controlled Trials as Topic; Plasmodium vivax; Randomized Controlled Trials as Topic; Young Adult
PubMed: 34952581
DOI: 10.1186/s12936-021-04016-2 -
Biology Dec 2021The understanding of platelet biology under physiological and pathological conditions like malaria infection is critical importance in the context of the disease outcome... (Review)
Review
The understanding of platelet biology under physiological and pathological conditions like malaria infection is critical importance in the context of the disease outcome or model systems used. The importance of severe thrombocytopenia (platelet count < 50,000 cells (µL) and profound thrombocytopenia (platelet count < 20,000 cells/µL) in malaria patients remains unclear. This study aimed to synthesize evidence regarding the risks of severe and profound thrombocytopenia in patients with severe non- malaria. Our overall aim was to identify potential indicators of severe non- malaria and the species that cause severe outcomes. This systematic review was registered at the International Prospective Register of Systematic Reviews (PROSPERO) under registration ID CRD42020196541. Studies were identified from previous systematic reviews ( = 5) and the MEDLINE, Scopus, and Web of Science databases from 9 June 2019 to 9 June 2020. Studies were included if they reported the outcome of severe non-Plasmodium species infection, as defined by the World Health Organization (WHO) criteria, in patients with known platelet counts and/or severe and profound thrombocytopenia. The risk of bias was assessed using the Newcastle-Ottawa Scale (NOS). Data were pooled, and pooled prevalence (PP) and pooled odds ratios (ORs) were calculated using random effects models. Of the 118 studies identified from previous meta-nalyses, 21 met the inclusion criteria. Of the 4807 studies identified from the databases, three met the inclusion criteria. Nine studies identified from reference lists and other sources also met the inclusion criteria. The results of 33 studies reporting the outcomes of patients with severe and infection were pooled for meta-analysis. The PP of severe thrombocytopenia (reported in 21 studies) was estimated at 47% (95% confidence interval (CI): 33-61%, I: 96.5%), while that of profound thrombocytopenia (reported in 13 studies) was estimated at 20% (95% CI: 14-27%, 85.2%). The pooled weighted mean difference (WMD) in platelet counts between severe uncomplicated infections (reported in 11 studies) was estimated at -28.51% (95% CI: -40.35-61%, I: 97.7%), while the pooled WMD in platelet counts between severe non- and severe infections (reported in eight studies) was estimated at -3.83% (95% CI: -13.90-6.25%, I: 85.2%). The pooled OR for severe/profound thrombocytopenia comparing severe to uncomplicated infection was 2.92 (95% CI: 2.24-3.81, I: 39.9%). The PP of death from severe and profound thrombocytopenia was estimated at 11% (95% CI: 0-22%). These results suggest that individuals with severe non- infection (particularly and ) who exhibit severe or profound thrombocytopenia should be regarded as high risk, and should be treated for severe malaria according to current WHO guidelines. In addition, severe or profound thrombocytopenia coupled with other clinical and microscopic parameters can significantly improve malaria diagnosis, enhance the timely treatment of malaria infections, and reduce the morbidity and mortality of severe non- malaria.
PubMed: 34943190
DOI: 10.3390/biology10121275 -
The Cochrane Database of Systematic... Sep 2021Studies evaluating mass drug administration (MDA) in malarious areas have shown reductions in malaria immediately following the intervention. However, these effects vary... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Studies evaluating mass drug administration (MDA) in malarious areas have shown reductions in malaria immediately following the intervention. However, these effects vary by endemicity and are not sustained. Since the 2013 version of this Cochrane Review on this topic, additional studies have been published.
OBJECTIVES
Primary objectives To assess the sustained effect of MDA with antimalarial drugs on: - the reduction in malaria transmission in moderate- to high-transmission settings; - the interruption of transmission in very low- to low-transmission settings. Secondary objective To summarize the risk of drug-associated adverse effects following MDA.
SEARCH METHODS
We searched several trial registries, citation databases, conference proceedings, and reference lists for relevant articles up to 11 February 2021. We also communicated with researchers to identify additional published and unpublished studies.
SELECTION CRITERIA
Randomized controlled trials (RCTs) and non-randomized studies comparing MDA to no MDA with balanced co-interventions across study arms and at least two geographically distinct sites per study arm.
DATA COLLECTION AND ANALYSIS
Two review authors independently assessed trials for eligibility and extracted data. We calculated relative risk (RR) and rate ratios with corresponding 95% confidence intervals (CIs) to compare prevalence and incidence, respectively, in MDA compared to no-MDA groups. We stratified analyses by malaria transmission and by malaria species. For cluster-randomized controlled trials (cRCTs), we adjusted standard errors using the intracluster correlation coefficient. We assessed the certainty of the evidence using the GRADE approach. For non-randomized controlled before-and-after (CBA) studies, we summarized the data using difference-in-differences (DiD) analyses.
MAIN RESULTS
Thirteen studies met our criteria for inclusion. Ten were cRCTs and three were CBAs. Cluster-randomized controlled trials Moderate- to high-endemicity areas (prevalence ≥ 10%) We included data from two studies conducted in The Gambia and Zambia. At one to three months after MDA, the Plasmodium falciparum (hereafter, P falciparum) parasitaemia prevalence estimates may be higher compared to control but the CIs included no effect (RR 1.76, 95% CI 0.58 to 5.36; Zambia study; low-certainty evidence); parasitaemia incidence was probably lower (RR 0.61, 95% CI 0.40 to 0.92; The Gambia study; moderate-certainty evidence); and confirmed malaria illness incidence may be substantially lower, but the CIs included no effect (rate ratio 0.41, 95% CI 0.04 to 4.42; Zambia study; low-certainty evidence). At four to six months after MDA, MDA showed little or no effect on P falciparum parasitaemia prevalence (RR 1.18, 95% CI 0.89 to 1.56; The Gambia study; moderate-certainty evidence) and, no persisting effect was demonstrated with parasitaemia incidence (rate ratio 0.91, 95% CI 0.55 to 1.50; The Gambia study). Very low- to low-endemicity areas (prevalence < 10%) Seven studies from Cambodia, Laos, Myanmar (two studies), Vietnam, Zambia, and Zanzibar evaluated the effects of multiple rounds of MDA on P falciparum. Immediately following MDA (less than one month after MDA), parasitaemia prevalence was reduced (RR 0.12, 95% CI 0.03 to 0.52; one study; low-certainty evidence). At one to three months after MDA, there was a reduction in both parasitaemia incidence (rate ratio 0.37, 95% CI 0.21 to 0.55; 1 study; moderate-certainty evidence) and prevalence (RR 0.25, 95% CI 0.15 to 0.41; 7 studies; low-certainty evidence). For confirmed malaria incidence, absolute rates were low, and it is uncertain whether MDA had an effect on this outcome (rate ratio 0.58, 95% CI 0.12 to 2.73; 2 studies; very low-certainty evidence). For P falciparum prevalence, the relative differences declined over time, from RR 0.63 (95% CI 0.36 to 1.12; 4 studies) at four to six months after MDA, to RR 0.86 (95% CI 0.55 to 1.36; 5 studies) at 7 to 12 months after MDA. Longer-term prevalence estimates showed overall low absolute risks, and relative effect estimates of the effect of MDA on prevalence varied from RR 0.82 (95% CI 0.20 to 3.34) at 13 to 18 months after MDA, to RR 1.25 (95% CI 0.25 to 6.31) at 31 to 36 months after MDA in one study. Five studies from Cambodia, Laos, Myanmar (2 studies), and Vietnam evaluated the effect of MDA on Plasmodium vivax (hereafter, P vivax). One month following MDA, P vivax prevalence was lower (RR 0.18, 95% CI 0.08 to 0.40; 1 study; low-certainty evidence). At one to three months after MDA, there was a reduction in P vivax prevalence (RR 0.15, 95% CI 0.10 to 0.24; 5 studies; low-certainty evidence). The immediate reduction on P vivax prevalence was not sustained over time, from RR 0.78 (95% CI 0.63 to 0.95; 4 studies) at four to six months after MDA, to RR 1.12 (95% CI 0.94 to 1.32; 5 studies) at 7 to 12 months after MDA. One of the studies in Myanmar provided estimates of longer-term effects, where overall absolute risks were low, ranging from RR 0.81 (95% CI 0.44 to 1.48) at 13 to 18 months after MDA, to RR 1.20 (95% CI 0.44 to 3.29) at 31 to 36 months after MDA. Non-randomized studies Three CBA studies were conducted in moderate- to high-transmission areas in Burkina Faso, Kenya, and Nigeria. There was a reduction in P falciparum parasitaemia prevalence in MDA groups compared to control groups during MDA (DiD range: -15.8 to -61.4 percentage points), but the effect varied at one to three months after MDA (DiD range: 14.9 to -41.1 percentage points). AUTHORS' CONCLUSIONS: In moderate- to high-transmission settings, no studies reported important effects on P falciparum parasitaemia prevalence within six months after MDA. In very low- to low-transmission settings, parasitaemia prevalence and incidence were reduced initially for up to three months for both P falciparum and P vivax; longer-term data did not demonstrate an effect after four months, but absolute risks in both intervention and control groups were low. No studies provided evidence of interruption of malaria transmission.
Topics: Antimalarials; Humans; Malaria; Malaria, Falciparum; Mass Drug Administration; Parasitemia
PubMed: 34585740
DOI: 10.1002/14651858.CD008846.pub3 -
Malaria Journal Sep 2021Rapid accurate diagnosis followed by effective treatment is very important for malaria control. Light microscopy remains the "golden standard" method for malaria... (Meta-Analysis)
Meta-Analysis
Performance of rapid diagnostic tests, microscopy, loop-mediated isothermal amplification (LAMP) and PCR for malaria diagnosis in Ethiopia: a systematic review and meta-analysis.
BACKGROUND
Rapid accurate diagnosis followed by effective treatment is very important for malaria control. Light microscopy remains the "golden standard" method for malaria diagnosis. Diagnostic test method must have sufficient level of accuracy for detecting malaria parasites. Therefore, this study aimed to investigate the diagnostic accuracy of rapid diagnostic tests (RDTs), microscopy, loop-mediated isothermal amplification (LAMP) and/or polymerase chain reaction (PCR) for the malaria diagnosis in Ethiopia.
METHODS
Data bases such as PubMed, PubMed central, Science direct databases, Google scholar, and Scopus were searched from September to October, 2020 for studies assessing the diagnostic accuracy of RDTs, microscopy, LAMP and PCR methods for malaria diagnosis.
RESULTS
A total of 29 studies published between 2001 and 2020 were analysed using review manager, Midas (Stata) and Meta-disc. The sensitivity and specificity of studies comparing RDT with microscopy varies from 79%-100% to 80%-100%, respectively. The sensitivity of LAMP (731 tests) was 100% and its specificity was varies from 85 to 99% when compared with microscopy and PCR. Considerable heterogeneity was observed between studies included in this meta-analysis. Meta-regression showed that blinding status and target antigens were the major sources of heterogeneity (P < 0.05). RDT had an excellent diagnostic accuracy (Area under the ROC Curve = 0.99) when compared with microscopy. Its specificity was quite good (93%-100%) except for one outlier (28%), but lower "sensitivity" was observed when PCR is a reference test. This indicates RDT had a good diagnostic accuracy (AUC = 0.83). Microscopy showed a very good diagnostic accuracy when compared with PCR.
CONCLUSIONS
The present study showed that microscopy and RDTs had high efficiency for diagnosing febrile malaria patients. The diagnostic accuracy of RDT was excellent when compared with microscopy. This indicates RDTs have acceptable sensitivities and specificities to be used in resource poor settings as an alternative for microscopy. In this study, LAMP showed an excellent sensitivities and specificities. Furthermore, the need of minimum equipment and relatively short time for obtaining results can made LAMP one of the best alternatives especially for accurate diagnosis of asymptomatic malaria.
Topics: Diagnostic Tests, Routine; Ethiopia; Humans; Malaria; Microscopy; Molecular Diagnostic Techniques; Nucleic Acid Amplification Techniques; Polymerase Chain Reaction
PubMed: 34579729
DOI: 10.1186/s12936-021-03923-8 -
PLoS Neglected Tropical Diseases Sep 2021Ethiopia is one of the scarce African countries where Plasmodium vivax and P. falciparum co-exist. There has been no attempt to derive a robust prevalence estimate of P.... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Ethiopia is one of the scarce African countries where Plasmodium vivax and P. falciparum co-exist. There has been no attempt to derive a robust prevalence estimate of P. vivax in the country although a clear understanding of the epidemiology of this parasite is essential for informed decisions. This systematic review and meta-analysis, therefore, is aimed to synthesize the available evidences on the distribution of P. vivax infection by different locations/regions, study years, eco-epidemiological zones, and study settings in Ethiopia.
METHODS
This study was conducted in accordance with Preferred Reposting Items for Systematic Reviews and Meta Analyses (PRISMA) guidelines. Studies conducted and published over the last two decades (2000 to 2020) that reported an estimate of P. vivax prevalence in Ethiopia were included. The Cochrane Q (χ2) and the I2 tests were used to assess heterogeneity, and the funnel plot and Egger's test were used to examine publication bias. A p-value of the χ2 test <0.05 and an I2 value >75% were considered presence of considerable heterogeneity. Random effect models were used to obtain pooled estimate of P. vivax infection prevalence. This study is registered with PROSPERO (International Prospective Register of Systematic Reviews): ID CRD42020201761.
RESULTS
We screened 4,932 records and included 79 studies that enrolled 1,676,659 confirmed malaria cases, from which 548,214 (32.69%) were P. vivax infections and 1,116,581 (66.59%) were due to P. falciparum. The rest were due to mixed infections. The pooled estimate of P. vivax prevalence rate was 8.93% (95% CI: 7.98-9.88%) with significant heterogeneity (I2 = 100%, p<0.0001). Regional differences showed significant effects (p<0.0001, and I2 = 99.4%) on the pooled prevalence of P. vivax, while study years (before and after the scaling up of interventional activities) did not show significant differences (p = 0.9, I2 = 0%). Eco-epidemiological zones considered in the analysis did show a significant statistical effect (p<0.001, I2 = 78.5%) on the overall pooled estimate prevalence. Also, the study setting showed significant differences (p = 0.001, and I2 = 90.3%) on the overall prevalence, where significant reduction of P. vivax prevalence (4.67%, 95%CI: 1.41-7.93%, p<0.0001) was observed in studies conducted at the community level. The studies included in the review demonstrated lack of publication bias qualitatively (symmetrical funnel plot) and quantitatively [Egger's test (coefficient) = -2.97, 95% CI: -15.06-9.13, p = 0.62].
CONCLUSION
The estimated prevalence of P. vivax malaria in Ethiopia was 8.93% with P. vivax prevailing in the central west region of Ethiopia, but steadily extending to the western part of the country. Its distribution across the nation varies according to geographical location, study setting and study years.
Topics: Ethiopia; Humans; Malaria, Vivax; Plasmodium vivax
PubMed: 34525091
DOI: 10.1371/journal.pntd.0009781