-
The Lancet. Infectious Diseases Oct 2014Chloroquine is the first-line treatment for Plasmodium vivax malaria in most endemic countries, but resistance is increasing. Monitoring of antimalarial efficacy is... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Chloroquine is the first-line treatment for Plasmodium vivax malaria in most endemic countries, but resistance is increasing. Monitoring of antimalarial efficacy is essential, but in P. vivax infections the assessment of treatment efficacy is confounded by relapse from the dormant liver stages. We systematically reviewed P. vivax malaria treatment efficacy studies to establish the global extent of chloroquine resistance.
METHODS
We searched Medline, Web of Science, Embase, and the Cochrane Database of Systematic Reviews to identify studies published in English between Jan 1, 1960, and April 30, 2014, which investigated antimalarial treatment efficacy in P. vivax malaria. We excluded studies that did not include supervised schizonticidal treatment without primaquine. We determined rates of chloroquine resistance according to P. vivax malaria recurrence rates by day 28 whole-blood chloroquine concentrations at the time of recurrence and study enrolment criteria.
FINDINGS
We identified 129 eligible clinical trials involving 21,694 patients at 179 study sites and 26 case reports describing 54 patients. Chloroquine resistance was present in 58 (53%) of 113 assessable study sites, spread across most countries that are endemic for P. vivax. Clearance of parasitaemia assessed by microscopy in 95% of patients by day 2, or all patients by day 3, was 100% predictive of chloroquine sensitivity.
INTERPRETATION
Heterogeneity of study design and analysis has confounded global surveillance of chloroquine-resistant P. vivax, which is now present across most countries endemic for P. vivax. Improved methods for monitoring of drug resistance are needed to inform antimalarial policy in these regions.
FUNDING
Wellcome Trust (UK).
Topics: Antimalarials; Chloroquine; Drug Resistance; Drug Therapy, Combination; Global Health; Humans; Malaria, Vivax; Plasmodium vivax; Recurrence; Treatment Outcome
PubMed: 25213732
DOI: 10.1016/S1473-3099(14)70855-2 -
Parasitology Jun 2023The study of genotypes is beneficial for detecting strains linked to increased disease severity and uncovering the processes involved in the transmission and... (Review)
Review
The study of genotypes is beneficial for detecting strains linked to increased disease severity and uncovering the processes involved in the transmission and distribution of this zoonotic parasite. A systematic review of literature was conducted to investigate the present status of genetic diversity in African countries and among host species on the continent. Data from the results in the included studies were sorted, reviewed and descriptively analysed using tables, graphs and maps. Results indicate that there is a relative amount of genetic diversity with a clear difference in the population structure between geographical regions and the propensity for unique and regional genotypes to be predominant in tropical rainforest biomes, near the equator. From a clinical perspective, connections between specific genotypes and disease manifestations were found. Theories are outlined on the dissemination of African genotypes to other continents. The overrepresentation of samples from one geographical area and dissimilar genotyping methodologies creates challenges when concluding on the genetic diversity of in Africa. The need for uniform genotyping methods with a continent-wide sampling of an extensive host range involving humans, domestic animals and wildlife is emphasized.
Topics: Animals; Humans; Toxoplasma; Toxoplasmosis, Animal; Genetic Variation; Animals, Wild; Animals, Domestic; Genotype
PubMed: 36938833
DOI: 10.1017/S0031182023000252 -
Pathogens and Global Health May 2020, as an opportunistic neurotropic parasite of the Apicomplexa family, was firstly described in 1908. As attention-deficit hyperactivity disorder (ADHD) is one of the... (Meta-Analysis)
Meta-Analysis
, as an opportunistic neurotropic parasite of the Apicomplexa family, was firstly described in 1908. As attention-deficit hyperactivity disorder (ADHD) is one of the most common neuropsychiatric disorders in children and adolescents and often persists into adulthood, the purpose of this systematic review and meta-analysis was to investigate the relationship between infection and ADHD.The data were systematically collected from seven electronic databases up to May 1 2019 with no language restriction. This study was registered at the International Prospective Register of Systematic Reviews (PROSPERO; code: CRD42020149353). Odds ratios (ORs) and 95% confidence intervals (CI) were estimated using a random effects model. Seven studies involving five cross-sectional and two case-control studies were included in this meta-analysis.Results indicated that there was a statistically non-significant association between exposure to infection and increased risk of ADHD based on the detection of immunoglobulin G (IgG) antibody (2.02 [95% CI: 0.97-4.20]; I=58.7%). However, obtained results of Egger's tests for anti- IgG antibody showed publication bias (P=0.014).Sensitivity analysis revealed stable results for the association between anti- IgG antibody with ADHD.Given the small number of studies in this field and the obtained results, it cannot be conclusively stated that is a risk factor for ADHD.It is important to have reliable information about the relationship between and ADHD around the world; as it may lead to better insight to elucidate the possible association of toxoplasmosis and the pathogenesis of ADHD.
Topics: Antibodies, Protozoan; Attention Deficit Disorder with Hyperactivity; Cross-Sectional Studies; Humans; Risk Factors; Seroepidemiologic Studies; Toxoplasma; Toxoplasmosis
PubMed: 32186992
DOI: 10.1080/20477724.2020.1738153 -
PLoS Neglected Tropical Diseases Jan 2015Sub-microscopic (SM) Plasmodium infections represent transmission reservoirs that could jeopardise malaria elimination goals. A better understanding of the epidemiology... (Review)
Review
BACKGROUND
Sub-microscopic (SM) Plasmodium infections represent transmission reservoirs that could jeopardise malaria elimination goals. A better understanding of the epidemiology of these infections and factors contributing to their occurrence will inform effective elimination strategies. While the epidemiology of SM P. falciparum infections has been documented, that of SM P. vivax infections has not been summarised. The objective of this study is to address this deficiency.
METHODOLOGY/PRINCIPAL FINDINGS
A systematic search of PubMed was conducted, and results of both light microscopy (LM) and polymerase chain reaction (PCR)-based diagnostic tests for P. vivax from 44 cross-sectional surveys or screening studies of clinical malaria suspects were analysed. Analysis revealed that SM P. vivax is prevalent across different geographic areas with varying transmission intensities. On average, the prevalence of SM P. vivax in cross-sectional surveys was 10.9%, constituting 67.0% of all P. vivax infections detected by PCR. The relative proportion of SM P. vivax is significantly higher than that of the sympatric P. falciparum in these settings. A positive relationship exists between PCR and LM P. vivax prevalence, while there is a negative relationship between the proportion of SM P. vivax and the LM prevalence for P. vivax. Amongst clinical malaria suspects, however, SM P. vivax was not identified.
CONCLUSIONS/SIGNIFICANCE
SM P. vivax is prevalent across different geographic areas, particularly areas with relatively low transmission intensity. Diagnostic tools with sensitivity greater than that of LM are required for detecting these infection reservoirs. In contrast, SM P. vivax is not prevalent in clinical malaria suspects, supporting the recommended use of quality LM and rapid diagnostic tests in clinical case management. These findings enable malaria control and elimination programs to estimate the prevalence and proportion of SM P. vivax infections in their settings, and develop appropriate elimination strategies to tackle SM P. vivax to interrupt transmission.
Topics: Global Health; Humans; Malaria, Vivax; Plasmodium vivax; Polymerase Chain Reaction
PubMed: 25569135
DOI: 10.1371/journal.pntd.0003413 -
Nutrients Oct 2023Despite several studies examining the relationship between calcium levels and malaria, inconsistencies and varied results remain in the literature. This study aimed to... (Meta-Analysis)
Meta-Analysis
Despite several studies examining the relationship between calcium levels and malaria, inconsistencies and varied results remain in the literature. This study aimed to synthesize the evidence on the association between blood calcium levels and malaria severity. A systematic literature search was conducted in the Embase, Scopus, PubMed, Ovid, and Google Scholar databases. The studies that investigated calcium levels in participants with malaria were reviewed and included for synthesis. The quality of included studies was assessed based on a standardized checklist by the Joanna Briggs Institute (JBI) critical appraisal checklists. The thematic synthesis had been used for qualitative synthesis. For the quantitative synthesis, the meta-analysis was performed to estimate the pooled effect sizes for differences in calcium levels between groups of participants using a random effect model using Hedge's g as a measure of effect size. Out of the 4574 identified records, 14 studies were reviewed. The thematic synthesis across these studies noted a consistent theme: reduced calcium levels in malaria patients compared to uninfected controls. However, the meta-analysis encompassing three specific analyses-comparing calcium levels between malaria patients and controls, severe and non-severe malaria cases, and fatal cases versus survivors-showed no significant difference in calcium levels. The statistics were as follows: (1) = 0.15, Hedge's g: -1.00, 95% CI: -2.37-0.38, : 98.97, 9 studies; (2) = 0.35, Hedge's g: -0.33, 95% CI: -1.02-0.36, : 81.61, 3 studies; and (3) = 0.71, Hedge's g: -0.14, 95% CI: -0.91-0.62, : 87.05, 3 studies. Subgroup analyses indicated that regional disparities, especially between Africa and Asia, and participant age groups may influence these outcomes. While a trend of decreased calcium levels in malaria patients was observed, the meta-analytical results suggest regional and age-related variations. Further investigations should emphasize these differences to better guide clinical management, prognostic applications, and the crafting of policies concerning malaria's metabolic effects.
Topics: Humans; Malaria, Vivax; Plasmodium falciparum; Calcium; Malaria; Africa
PubMed: 37960176
DOI: 10.3390/nu15214522 -
Veterinary Parasitology, Regional... Jan 2024The role of ixodid ticks especially Rhipicephalus sanguineus and Heamaphysalis elliptica in the epidemiology of several diseases of veterinary and public health... (Review)
Review
The role of ixodid ticks especially Rhipicephalus sanguineus and Heamaphysalis elliptica in the epidemiology of several diseases of veterinary and public health importance have been documented. This study conducted a systematic review focusing on the distribution of R. sanguineus and H. elliptica, as well as the common tick-borne pathogens they harbour. The Scopus, ScienceDirect, PubMed, and Web of Science databases were used to search for English journal articles published between January 1990 and June 2021. The articles were assessed by following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. This systematic review was registered on PROSPERO [(ID no: CRD42022327372). Of the studies included in the systematic review, 247 and 19 articles had identified R. sanguineus and H. elliptica respectively, whereas 15 articles had identified both tick species. There is a reported worldwide distribution of R. sanguineus from 64 countries, whereas H. elliptica was only reported in the African continent from 6 countries. In total, 120 articles that were included in this systematic review reported detection of tick-borne pathogens from R. sanguineus (n = 118 articles) and/or H. elliptica (n = 2 articles) ticks. According to the studies tick-borne pathogens harboured by R. sanguineus included protozoa such as Babesia spp., Hepatozoon spp., Leishmania spp., and Theileria spp., as well as bacteria such as Acinetobacter spp. Anaplasma spp., Bacillus spp., Borrelia spp., Brucella spp., Coxiella spp., and Staphylococcus spp. The H. elliptica was reported to be harbouring Babesia spp., Ehrlichia spp. and Rickettsia spp. Most of the studies (50%) used the conventional polymerase chain reaction (PCR) technique for the detection of tick-borne pathogens, followed by real-time PCR (qPCR) (n = 26), and nested PCR (n = 22). This systematic review has shed light on the distribution of two common dog ticks as well as the tick-borne pathogens of veterinary and zoonotic importance they are harbouring. This data will enable surveillance studies that can report whether the distribution of these ticks and their associated tick-borne pathogens is expanding or shrinking or is stable.
Topics: Dogs; Animals; Rhipicephalus sanguineus; Ixodidae; Anaplasma; Babesia; Borrelia
PubMed: 38199685
DOI: 10.1016/j.vprsr.2023.100969 -
PloS One 2021Knowledge about malaria associated with pregnancy is scarce in Latin America, and in Colombia, little is known about the magnitude of this infection. A systematic review... (Meta-Analysis)
Meta-Analysis
Knowledge about malaria associated with pregnancy is scarce in Latin America, and in Colombia, little is known about the magnitude of this infection. A systematic review was conducted to determine the prevalence of malaria associated with pregnancy (MAP) and each of its three forms: gestational (GM), placental (PM), and congenital (CM) tested using thick blood smear (TBS) and PCR. Also to compare the proportion of cases due to Plasmodium falciparum and Plasmodium vivax in Colombia from the year 2000-2020. We searched in Pubmed, Science Direct, EMBASE, EMCare, Cochrane Library, Scielo, Lilacs, Google Scholar, libraries, and repositories of Colombian universities, to obtain data on prevalence of GM, PM and CM with their respective testing method. We performed a meta-analysis with a random-effects model to obtain pooled prevalence of MAP and its three forms categorized by testing methods (TBS and PCR). We used data from 14 studies (out of 258 screened) contributing 7932, 2506 women for GM and PM respectively, also data on 1143 umbilical cord blood samples, and 899 peripheral blood of neonates. We found prevalence by TBS as, MAP 4.5% (95%CI = 2.9-6.9), GM 5.8% (95%CI = 3.8-8.7), PM 3.4% (95%CI = 1.7-6.7) and CM 1.3% (95%CI = 0.6-3.0). With PCR the prevalence was, MAP 14.4% (95%CI = 7.6-25.5), GM 16.7% (95%CI = 9.0-28.8), PM 11.0% (95%CI = 4.1-26.3) and CM 16.2% (95%CI = 8.2-29.5). The prevalence of submicroscopic infection was 8.5% (95%CI = 3.4-19.7) in GM, 10.1% (95%CI = 3.5-25.5) in PM and 22.0% (95%CI = 13.2-34.3) in CM. Infections by P. vivax was dominant over P. falciparum when tested with TBS, the PCR test gave similar proportions of P. falciparum and P. vivax. This meta-analysis has demonstrated high prevalence of MAP in Colombia, and highlights the urgent need to increase attention of researchers, research funding institutions, government agencies, and health authorities to study and intervene MAP, that has currently been under investigated.
Topics: Colombia; Female; Humans; Malaria, Falciparum; Malaria, Vivax; Plasmodium falciparum; Plasmodium vivax; Pregnancy; Pregnancy Complications, Parasitic
PubMed: 34329329
DOI: 10.1371/journal.pone.0255028 -
Antimicrobial Agents and Chemotherapy Aug 2015Specially created pediatric formulations have the potential to improve the acceptability, effectiveness, and accuracy of dosing of artemisinin-based combination therapy... (Review)
Review
Specially created pediatric formulations have the potential to improve the acceptability, effectiveness, and accuracy of dosing of artemisinin-based combination therapy (ACT) in young children, a patient group that is inherently vulnerable to malaria. Artemether-lumefantrine (AL) Dispersible is a pediatric formulation of AL that is specifically tailored for the treatment of children with uncomplicated Plasmodium falciparum malaria, offering benefits relating to efficacy, convenience and acceptance, accuracy of dosing, safety, sterility, stability, and a pharmacokinetic profile and bioequivalence similar to those of crushed and intact AL tablets. However, despite being the first pediatric antimalarial to meet World Health Organization (WHO) specifications for use in infants and children who are ≥5 kg in body weight and its inclusion in WHO Guidelines, there are few publications that focus on AL Dispersible. Based on a systematic review of the recent literature, this paper provides a comprehensive overview of the clinical experience with AL Dispersible to date. A randomized, phase 3 study that compared the efficacy and safety of AL Dispersible to those of crushed AL tablets in 899 African children reported high PCR-corrected cure rates at day 28 (97.8% and 98.5% for AL Dispersible and crushed tablets, respectively), and the results of several subanalyses of these data indicate that this activity is observed regardless of patient weight, food intake, and maximum plasma concentrations of artemether or its active metabolite, dihydroartemisinin. These and other clinical data support the continued use of pediatric antimalarial formulations in all children <5 years of age with uncomplicated malaria when accompanied by continued monitoring for the emergence of resistance.
Topics: Antimalarials; Artemether; Artemisinins; Chemistry, Pharmaceutical; Clinical Trials, Phase III as Topic; Drug Combinations; Ethanolamines; Fluorenes; Humans; Lumefantrine; Malaria, Falciparum; Plasmodium falciparum; Randomized Controlled Trials as Topic; Tablets
PubMed: 26014953
DOI: 10.1128/AAC.00014-15 -
Parasites & Vectors Aug 2023Bovine babesiosis, caused by different Babesia spp. such as B. bovis, B. bigemina, B. divergens, and B. major, is a global disease that poses a serious threat to... (Review)
Review
Bovine babesiosis, caused by different Babesia spp. such as B. bovis, B. bigemina, B. divergens, and B. major, is a global disease that poses a serious threat to livestock production. Babesia bovis infections are associated with severe disease and increased mortality in adult cattle, making it the most virulent agent of bovine babesiosis. Babesia bovis parasites undergo asexual reproduction within bovine red blood cells, followed by sexual reproduction within their tick vectors, which transmit the parasite transovarially. Current control methods, including therapeutic drugs (i.e., imidocarb) have been found to lead to drug resistance. Moreover, changing environmental factors add complexity to efficient parasite control. Understanding the fundamental biology, host immune responses, and host-parasite interactions of Babesia parasites is critical for developing next-generation vaccines to control acute disease and parasite transmission. This systematic review analyzed available research papers on vaccine development and the associated immune responses to B. bovis. We compiled and consolidated the reported vaccine strategies, considering the study design and rationale of each study, to provide a systematic review of knowledge and insights for further research. Thirteen studies published since 2014 (inclusive) represented various vaccine strategies developed against B. bovis such as subunit, live attenuated, and viral vector vaccines. Such strategies incorporated B. bovis proteins or whole live parasites with the latter providing the most effective prophylaxis against bovine babesiosis. Incorporating novel research approaches, such as "omics" will enhance our understanding of parasite vulnerabilities.
Topics: Animals; Cattle; Babesia bovis; Babesiosis; Cattle Diseases; Babesia; Vaccines
PubMed: 37563668
DOI: 10.1186/s13071-023-05885-z -
Infectious Diseases of Poverty Feb 2018Plasmodium vivax is the most geographically widespread species among human malaria parasites. Immunopathological studies have shown that platelets are an important... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Plasmodium vivax is the most geographically widespread species among human malaria parasites. Immunopathological studies have shown that platelets are an important component of the host innate immune response against malaria infections. The objectives of this study were to quantify thrombocytopaenia in P. vivax malaria patients and to determine the associated risks of severe thrombocytopaenia in patients with vivax malaria compared to patients with P. falciparum malaria.
MAIN BODY
A systematic review and meta-analysis of the available literature on thrombocytopaenia in P. vivax malaria patients was undertaken. Relevant studies in health-related electronic databases were identified and reviewed. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Fifty-eight observational studies (n = 29 664) were included in the current review. Severe thrombocytopaenia (< 50 000/mm) to very severe thrombocytopaenia (< 20 000/mm) was observed in 10.1% of patients with P. vivax infection. A meta-analysis of 11 observational studies showed an equal risk of developing severe/very severe thrombocytopaenia between the patients with P. vivax malaria and those with P. falciparum malaria (OR: 1.98, 95% CI: 0.92-4.25). This indicates that thrombocytopaenia is as equally a common manifestation in P. vivax and P. falciparum malaria patients. One study showed a higher risk of developing very severe thrombocytopaenia in children with severe P. vivax malaria than with severe P. falciparum malaria (OR: 2.80, 95% CI: 1.48-5.29). However, a pooled analysis of two studies showed an equal risk among adult severe cases (OR: 1.19, 95% CI: 0.51-2.77). This indicates that the risk of developing thrombocytopaenia in P. vivax malaria can vary with immune status in both children and adults. One study reported higher levels of urea and serum bilirubin in patients with P. vivax malaria and severe thrombocytopaenia compared with patients mild thrombocytopaenia or no thrombocytopaenia, (P < 0.001 in all comparisons). A pooled analysis of two other studies showed a similar proportion of bleeding episodes with thrombocytopaenia in severe P. vivax patients and severe P. falciparum patients (P = 0.09). This implied that both P. vivax and P. falciparum infections could present with bleeding episodes, if there had been a change in platelet counts in the infected patients. A pooled analysis of another two studies showed an equal risk of mortality with severe thrombocytopaenia in both P. vivax and P. falciparum malaria patients (OR: 1.16, 95% CI: 0.30-4.60). However, due to the low number of studies with small sample sizes within the subset of studies that provided clinically relevant information, our confidence in the estimates is limited.
CONCLUSION
The current review has provided some evidence of the clinical relevance of severe thrombocytopaenia in P. vivax malaria. To substantiate these findings, there is a need for well designed, large-scale, prospective studies among patients infected with P. vivax. These should include patients from different countries and epidemiological settings with various age and gender groups represented.
Topics: Adult; Child; Female; Humans; Malaria, Falciparum; Malaria, Vivax; Male; Observational Studies as Topic; Plasmodium falciparum; Plasmodium vivax; Severity of Illness Index; Thrombocytopenia
PubMed: 29427995
DOI: 10.1186/s40249-018-0392-9