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International Journal For Parasitology Jun 2020The ectoparasitic mite Varroa destructor is the most significant pathological threat to the western honey bee, Apis mellifera, leading to the death of most colonies if... (Review)
Review
The ectoparasitic mite Varroa destructor is the most significant pathological threat to the western honey bee, Apis mellifera, leading to the death of most colonies if left untreated. An alternative approach to chemical treatments is to selectively enhance heritable honey bee traits of resistance or tolerance to the mite through breeding programs, or select for naturally surviving untreated colonies. We conducted a literature review of all studies documenting traits of A. mellifera populations either selectively bred or naturally selected for resistance and tolerance to mite parasitism. This allowed us to conduct an analysis of the diversity, distribution and importance of the traits in different honey bee populations that can survive V. destructor globally. In a second analysis, we investigated the genetic bases of these different phenotypes by comparing 'omics studies (genomics, transcriptomics, and proteomics) of A. mellifera resistance and tolerance to the parasite. Altogether, this review provides a detailed overview of the current state of the research projects and breeding efforts against the most devastating parasite of A. mellifera. By highlighting the most promising traits of Varroa-surviving bees and our current knowledge on their genetic bases, this work will help direct future research efforts and selection programs to control this pest. Additionally, by comparing the diverse populations of honey bees that exhibit those traits, this review highlights the consequences of anthropogenic and natural selection in the interactions between hosts and parasites.
Topics: Animals; Bees; Genomics; Host-Parasite Interactions; Phenotype; Varroidae
PubMed: 32380096
DOI: 10.1016/j.ijpara.2020.03.005 -
Acta Parasitologica Sep 2020Toxocariasis is one of the neglected zoonosis with considerable public health importance around the world. The current study aimed to elucidate the overall prevalence of... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Toxocariasis is one of the neglected zoonosis with considerable public health importance around the world. The current study aimed to elucidate the overall prevalence of Toxocara infection in human and definitive hosts and also the contamination of soil and raw vegetables with the ova of these parasites, in Iran, using systematic review and meta-analysis.
METHODS
Six English and Persian databases were explored from 2000 to 2017 using the terms toxocariasis, Toxocara spp., visceral larva migrans, Iran, epidemiology, and prevalence. This meta-analysis conducted using STATA, and for all statistical tests, a p value less than 0.05 was considered significant. The random-effects model was used to the report of the pooled prevalence with a 95% confidence interval (CI).
RESULTS
The pooled prevalence of toxocariasis in human was calculated as 11% (95% CI 8-13%). In terms of definitive hosts, the pooled prevalence of Toxocara infection in dogs and cats were calculated as 17% (95% CI 14-20%) and 37% (95% CI 26-48%), respectively. Also, the pooled prevalence of Toxocara spp. eggs in the soil and raw vegetable samples were calculated as 18% (95% CI 13-23%) and 2% (95% CI 1-3%), respectively.
CONCLUSIONS
The results of current study demonstrate that toxocariasis should be taken more seriously by health authorities. Implementing an appropriate control program is necessary to reduce the incidence of this disease in Iran.
Topics: Animals; Cat Diseases; Cats; Dog Diseases; Dogs; Humans; Incidence; Iran; Prevalence; Public Health; Toxocara; Toxocariasis; Zoonoses
PubMed: 32319035
DOI: 10.2478/s11686-020-00195-1 -
Parasitology Sep 2016Parasitic infections are among the leading global public health problems with very high economic and mortality burdens. Unfortunately, the available treatment drugs are... (Review)
Review
Parasitic infections are among the leading global public health problems with very high economic and mortality burdens. Unfortunately, the available treatment drugs are beset with side effects and continuous parasite drug resistance is being reported. However, new findings reveal more promising compounds especially of plant origin. Among the promising leads are the pentacyclic triterpenes (PTs) made up of the oleanane, ursane, taraxastane, lupane and hopane types. This paper reviews the literature published from 1985 to date on the in vitro and in vivo anti-parasitic potency of this class of phytochemicals. Of the 191 natural and synthetic PT reported, 85 have shown high anti-parasitic activity against various species belonging to the genera of Plasmodium, Leishmania, Trypanosoma, as well as various genera of Nematoda. Moreover, structural modification especially at carbon 3 (C3) and C27 of the parent backbone of PT has led to improved anti-parasitic activity in some cases and loss of activity in others. The potential of this group of compounds as future alternatives in the treatment of parasitic diseases is discussed. It is hoped that the information presented herein will contribute to the full exploration of this promising group of compounds as possible drugs for parasitic diseases.
Topics: Animals; Humans; Leishmania; Leishmaniasis; Malaria; Mice; Nematode Infections; Parasitic Diseases; Pentacyclic Triterpenes; Plasmodium; Tropical Climate; Trypanosoma; Trypanosomiasis
PubMed: 27240847
DOI: 10.1017/S0031182016000718 -
Infectious Diseases of Poverty Sep 2023Strongyloidiasis, caused by the nematodes Strongyloides stercoralis and Strongyloides fuelleborni, is estimated to affect over 600 million individuals worldwide. The... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Strongyloidiasis, caused by the nematodes Strongyloides stercoralis and Strongyloides fuelleborni, is estimated to affect over 600 million individuals worldwide. The disease is endemic in Southeast Asia, where a warm-humid climate and socio-economic conditions maintain the parasite's life cycle and transmission. However, the current diagnostic methods may not be sufficiently sensitive, suggesting that the true prevalence of strongyloidiasis could be seriously underestimated in this. This study aims to determine the prevalence of strongyloidiasis in Southeast Asia through a systematic review and meta-analysis and to discuss the implications of the estimated prevalence on diagnostic approaches and control strategies.
METHODS
Following PRISMA guidelines, we conducted a systematic literature search in PubMed and Google Scholar databases to identify studies reporting Strongyloides prevalence data in the 11 Southeast Asian countries up to December 2022. A random effects model was employed to estimate the pooled prevalence of S. stercoralis at both regional and country levels.
RESULTS
Out of 3722 articles identified, 224 met our inclusion criteria. For S. stercoralis specifically, we found 187 articles, of which 52.4% were from Thailand. All Southeast Asian countries, except Brunei, had at least one study on Strongyloides prevalence. The estimated pooled prevalence of S. stercoralis regionally was 12.7% (95% CI 10.70-14.80%), ranging from 0.4 to 24.9% at the country level. Cambodia had the highest pooled prevalence (24.9%, 95% CI 15.65-35.38%), followed by Lao PDR (16.5%, 95% CI 9.50-24.95%). Moreover, we obtained a pooled prevalence of 10% (95% CI 7.06-13.52%) in a group comprising immigrants, workers, and veterans from Southeast Asian countries. S. stercoralis infects various host types, including nonhuman primates, domestic dogs and cats, rodents, and transport carriers such as cockroaches and vegetables.
CONCLUSIONS
A high prevalence of strongyloidiasis in Southeast Asia was revealed, highlighting the importance of the region's ongoing research, surveillance, and control efforts. Factors contributing to the strongyloidiasis transmission include the role of animal hosts, the impact of global connectivity, and the significance of the co-endemicity of other Strongyloides species. Based on these findings, a multi-pronged One-Health approach is essential for sustainable intervention and control.
Topics: Animals; Cats; Dogs; Public Health; Strongyloidiasis; Cat Diseases; Prevalence; Dog Diseases; Cambodia; Strongyloides stercoralis
PubMed: 37705080
DOI: 10.1186/s40249-023-01138-4 -
Revista Do Instituto de Medicina... 2022Cryptosporidiosis is a disease caused by the Cryptosporidium spp parasite. As some species of Cryptosporidium have a wide host spectrum, the characterization of the... (Meta-Analysis)
Meta-Analysis
Cryptosporidiosis is a disease caused by the Cryptosporidium spp parasite. As some species of Cryptosporidium have a wide host spectrum, the characterization of the pathogen at the species or genotype level is of great importance to define the sources of infection for humans and the potential for public health. This study investigated the diversity of the genus Cryptosporidium spp. in humans from all over the American continent and observed whether the method used to search for the parasite influenced the prevalence found in the Americas. This systematic review was carried out using the Pubmed, Science direct, Lilacs, Scielo, and Scopus databases with publications from January 1, 2010, to December 31, 2020. For data synthesis, the PRISMA flowchart was used and for the meta-analysis we used the MetaXL program. Of the selected publications, 57, 9 and 16 belonged to the region of South, Central and North America, respectively. The prevalence found for South, Central, and North America was 7%, 7%, and 8%, respectively, when analyzing publications that used only the microscopy method. When we analyzed the publications that used immunological and molecular methods, we found prevalences of 10%, 9%, and 21% for South, Central, and North America, respectively. The C. hominis subtype IbA10G2 was the most reported in the American continent, followed by subtype IeA11G3T3 and, for C. parvum, subtype IIaA15G2RI was the most reported. In conclusion, Cryptosporidium spp. is present throughout the American continent and its prevalence is higher when immunological and/or molecular methods are used, in addition to direct microscopic examination.
Topics: Humans; Cryptosporidiosis; Cryptosporidium; Prevalence; Genotype; Americas; Feces
PubMed: 36383892
DOI: 10.1590/S1678-9946202264070 -
Malaria Journal Oct 2011During pregnancy, malaria infection with Plasmodium falciparum or Plasmodium vivax is related to adverse maternal health and poor birth outcomes. Diagnosis of malaria,... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
During pregnancy, malaria infection with Plasmodium falciparum or Plasmodium vivax is related to adverse maternal health and poor birth outcomes. Diagnosis of malaria, during pregnancy, is complicated by the absence or low parasite densities in peripheral blood. Diagnostic methods, other than microscopy, are needed for detection of placental malaria. Therefore, the diagnostic accuracy of rapid diagnostic tests (RDTs), detecting antigen, and molecular techniques (PCR), detecting DNA, for the diagnosis of Plasmodium infections in pregnancy was systematically reviewed.
METHODS
MEDLINE, EMBASE and Web of Science were searched for studies assessing the diagnostic accuracy of RDTs, PCR, microscopy of peripheral and placental blood and placental histology for the detection of malaria infection (all species) in pregnant women.
RESULTS
The results of 49 studies were analysed in metandi (Stata), of which the majority described P. falciparum infections. Although both placental and peripheral blood microscopy cannot reliably replace histology as a reference standard for placental P. falciparum infection, many studies compared RDTs and PCR to these tests. The proportion of microscopy positives in placental blood (sensitivity) detected by peripheral blood microscopy, RDTs and PCR are respectively 72% [95% CI 62-80], 81% [95% CI 55-93] and 94% [95% CI 86-98]. The proportion of placental blood microscopy negative women that were negative in peripheral blood microscopy, RDTs and PCR (specificity) are 98% [95% CI 95-99], 94% [95% CI 76-99] and 77% [95% CI 71-82]. Based on the current data, it was not possible to determine if the false positives in RDTs and PCR are caused by sequestered parasites in the placenta that are not detected by placental microscopy.
CONCLUSION
The findings suggest that RDTs and PCR may have good performance characteristics to serve as alternatives for the diagnosis of malaria in pregnancy, besides any other limitations and practical considerations concerning the use of these tests. Nevertheless, more studies with placental histology as reference test are urgently required to reliably determine the accuracy of RDTs and PCR for the diagnosis of placental malaria. P. vivax-infections have been neglected in diagnostic test accuracy studies of malaria in pregnancy.
Topics: Antigens, Protozoan; DNA, Protozoan; Diagnostic Tests, Routine; Female; Histocytochemistry; Humans; Malaria, Falciparum; Malaria, Vivax; Microscopy; Parasitemia; Placenta; Plasmodium falciparum; Plasmodium vivax; Polymerase Chain Reaction; Pregnancy; Pregnancy Complications, Infectious
PubMed: 22035448
DOI: 10.1186/1475-2875-10-321 -
Malaria Journal Dec 2017There is no agreed standard method to assess the efficacy of anti-malarials for uncomplicated falciparum in pregnancy despite an increased risk of adverse outcomes for... (Meta-Analysis)
Meta-Analysis Review
Systematic literature review and meta-analysis of the efficacy of artemisinin-based and quinine-based treatments for uncomplicated falciparum malaria in pregnancy: methodological challenges.
BACKGROUND
There is no agreed standard method to assess the efficacy of anti-malarials for uncomplicated falciparum in pregnancy despite an increased risk of adverse outcomes for the mother and the fetus. The aim of this review is to present the currently available evidence from both observational and interventional cohort studies on anti-malarial efficacy in pregnancy and summarize the variability of assessment and reporting found in the review process.
METHODS
Efficacy methodology and assessment of artemisinin-based treatments (ABT) and quinine-based treatments (QBT) were reviewed systematically using seven databases and two clinical trial registries (protocol registration-PROSPERO: CRD42017054808). Pregnant women in all trimesters with parasitologically confirmed uncomplicated falciparum malaria were included irrespective of symptoms. This review attempted to re-calculate proportions of treatment success applying the same definition as the standard WHO methodology for non-pregnant populations. Aggregated data meta-analyses using data from randomized control trials (RCTs) comparing different treatments were performed by random effects model.
RESULTS
A total of 48 eligible efficacy studies were identified including 7279 treated Plasmodium falciparum episodes. While polymerase chain reaction (PCR) was used in 24 studies for differentiating recurrence, the assessment and reporting of treatment efficacy was heterogeneous. When the same definition could be applied, PCR-corrected treatment failure of ≥ 10% at any time points was observed in 3/30 ABT and 3/7 QBT arms. Ten RCTs compared different combinations of ABT but there was a maximum of two published RCTs with PCR-corrected outcomes for each comparison. Five RCTs compared ABT and QBT. Overall, the risk of treatment failure was significantly lower in ABT than in QBT (risk ratio 0.22, 95% confidence interval 0.07-0.63), although the actual drug combinations and outcome endpoints were different. First trimester women were included in 12 studies none of which were RCTs of ABT.
CONCLUSIONS
Efficacy studies in pregnancy are not only limited in number but use varied methodological assessments. In five RCTs with comparable methodology, ABT resulted in higher efficacy than QBT in the second and third trimester of pregnancy. Individual patient data meta-analysis can include data from observational cohort studies and could overcome some of the limitations of the current assessment given the paucity of data in this vulnerable group.
Topics: Antimalarials; Artemisinins; Drug Therapy, Combination; Female; Humans; Malaria, Falciparum; Pregnancy; Pregnancy Complications, Parasitic; Quinine
PubMed: 29237461
DOI: 10.1186/s12936-017-2135-y -
Preventive Veterinary Medicine Jun 2022Giardia duodenalis is an important intestinal parasite responsible for diarrhea in humans and animals worldwide. Up to now, G. duodenalis infections in cattle have been... (Meta-Analysis)
Meta-Analysis Review
Giardia duodenalis is an important intestinal parasite responsible for diarrhea in humans and animals worldwide. Up to now, G. duodenalis infections in cattle have been reported in many studies around the world. Hence, the aim of the present study is to report on the distribution of G. duodenalis in cattle at global scale and to evaluate the global prevalence, risk factors and genetic characterization of G. duodenalis infection among cattle worldwide. International databases were systematically searched to identify relevant studies. A random-effects meta-analysis model was used to estimate the overall and the subgroup-pooled prevalence of G. duodenalis across studies, and the variance between studies (heterogeneity) was quantified by I index. One hundred and fifty-eight articles (including 195 datasets), from 48 countries met eligibility criteria for analysis. Considering detection methods, the pooled prevalence was estimated to be 24% (95% confidence interval (CI), 19-30%) using copro-antigen techniques, 22% (95% CI, 17-28%) using molecular, and 16% (95% CI, 12-20%) using microscopic detection. Molecular methods showed that the highest number of reports were associated with assemblage E (45/46; 97.83% studies), assemblage A (33/46; 71.74% studies) and assemblage A+E (10/46; 21.74% studies). The pooled prevalence different of subgroups (WHO regions, countries, and type of cattle) were analyzed separately. Moreover, a significant association was observed between G. duodenalis infection with cattle suffering from diarrhea (odds ratio (OR), 2.61; 95% CI, 1.50-4.55) and pre-weaned calves (OR, 1.79; 95% CI, 1.08-2.95). These results suggest that the corresponding control scheme and effective management measures should be formulated to reduce the transmission of G. duodenalis infection according to the difference of geographical conditions in different areas.
Topics: Animals; Cattle; Cattle Diseases; Diarrhea; Feces; Genotype; Giardia lamblia; Giardiasis; Prevalence
PubMed: 35427916
DOI: 10.1016/j.prevetmed.2022.105632 -
Parasites & Vectors Jan 2016Soil-transmitted helminth (STH) infections of humans fall within the World Health Organization's (WHO) grouping termed the neglected tropical diseases (NTDs). It is... (Review)
Review
Soil-transmitted helminth (STH) infections of humans fall within the World Health Organization's (WHO) grouping termed the neglected tropical diseases (NTDs). It is estimated that they affect approximately 1.4 billion people worldwide. A significant proportion of these infections are in the population of Southeast Asia. This review analyses published data on STH prevalence and intensity in Southeast Asia over the time period of 1900 to the present to describe age related patterns in these epidemiological measures. This is with a focus on the four major parasite species affecting humans; namely Ascaris lumbricoides, Trichuris trichiura and the hookworms; Necator americanus and Ancylostoma duodenale. Data were also collected on the diagnostic methods used in the published surveys and how the studies were designed to facilitate comparative analyses of recorded patterns and changes therein over time. PubMed, Google Scholar, EMBASE, ISI Web of Science, Cochrane Database of Systematic Reviews and the Global Atlas of Helminth Infections search engines were used to identify studies on STH in Southeast Asia with the search based on the major key words, and variants on, "soil-transmitted helminth" "Ascaris" "Trichuris" "hookworm" and the country name. A total of 280 studies satisfied the inclusion criteria from 11 Southeast Asian countries; Brunei, Cambodia, Indonesia, Lao People's Democratic Republic (Lao PDR), Malaysia, Myanmar, Philippines, Singapore, Thailand, Timor-Leste and Vietnam. It was concluded that the epidemiological patterns of STH infection by age and species mix in Southeast Asia are similar to those reported in other parts of the world. In the published studies there were a large number of different diagnostic methods used with differing sensitivities and specificities, which makes comparison of the results both within and between countries difficult. There is a clear requirement to standardise the methods of both STH diagnosis in faecal material and how the intensity of infection is recorded and reported in future STH research and in monitoring and evaluation (M&E) of the impact of continuing and expanding mass drug administration (MDA) programmes.
Topics: Ancylostoma; Ancylostomatoidea; Animals; Ascariasis; Ascaris lumbricoides; Asia, Southeastern; Feces; Helminthiasis; Helminths; Hookworm Infections; Humans; Prevalence; Research; Soil; Surveys and Questionnaires; Trichuriasis; Trichuris
PubMed: 26813007
DOI: 10.1186/s13071-016-1310-2 -
F1000Research 2022: Climatic change is an inescapable fact that implies alterations in seasons where weather occurrences have their schedules shift from the regular and magnitudes...
: Climatic change is an inescapable fact that implies alterations in seasons where weather occurrences have their schedules shift from the regular and magnitudes intensify to more extreme variations over a multi-year period. Southeast Asia is one of the many regions experiencing changes in climate and concurrently still has endemicities of malaria. Given that previous studies have suggested the influence of climate on malaria's vector the mosquitoes and parasite the Plasmodium group, this study was conducted to review the evidence of associations made between malaria cases and climatic variables in Southeast Asia throughout a multi-year period. : Our systematic literature review was informed by the PRISMA guidelines and registered in PROSPERO: CRD42022301826 on 5 February 2022. We searched for original articles in English and Indonesian that focused on the associations between climatic variables and malaria cases. : The initial identification stage resulted in 535 records of possible relevance and after abstract screening and eligibility assessment we included 19 research articles for the systematic review. Based on the reviewed articles, changing temperatures, precipitation, humidity and windspeed were considered for statistical association across a multi-year period and are correlated with malaria cases in various regions throughout Southeast Asia. : According to the review of evidence, climatic variables that exhibited a statistically significant correlation with malaria cases include temperatures, precipitation, and humidity. The strength of each climatic variable varies across studies. Our systematic review of the limited evidence indicates that further research for the Southeast Asia region remains to be explored.
Topics: Animals; Climate Change; Mosquito Vectors; Malaria; Anopheles; Asia, Southeastern; Asia, Eastern
PubMed: 37867624
DOI: 10.12688/f1000research.125294.2