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Ticks and Tick-borne Diseases Jan 2024Published data on tick-borne pathogens (TBPs) in camels worldwide have been collected to provide an overview of the global prevalence and species diversity of camelid... (Meta-Analysis)
Meta-Analysis Review
Published data on tick-borne pathogens (TBPs) in camels worldwide have been collected to provide an overview of the global prevalence and species diversity of camelid TBPs. Several TBPs have been detected in dromedary camels, raising concerns regarding their role as natural or maintenance hosts for tick-borne pathogens. Insubstantial evidence exists regarding the natural infection of camels with Babesia spp., Theileria spp., Anaplasma spp., and Ehrlichia spp., particularly because most of the camels were considered healthy at the time of sampling. Based on polymerase chain reaction (PCR) testing, a pooled prevalence of 35.3% (95% CI: 22.6-48.1%) was estimated for Anaplasma, which was the most frequently tested TBP in dromedaries, and DNA of Anaplasma marginale, Anaplasma centrale, Anaplasma ovis, Anaplasma platys, and A. platys-like were isolated, of which ruminants and dogs are reservoirs. Similarly, the estimated pooled prevalence for the two piroplasmid genera; Babesia and Theileria was approximately equal (10-12%) regardless of the detection method (microscopy or PCR testing). Nevertheless, Babesia caballi, Theileria equi, and Theileria annulata DNA have frequently been detected in camels but they have not yet been proven to be natural hosts. Scarce data detected Babesia microti, Anaplasma phagocytophilum, and Borrelia burgdorferi sensu lato (s.l.) DNA in blood of dromedaries, although ticks of the genus Ixodes are distributed in limited areas where dromedaries are raised. Interestingly, a pooled seroprevalence of 47.7% (26.3-69.2%) was estimated for Crimean-Congo hemorrhagic fever virus, and viral RNA was detected in dromedary blood; however, their contribution to maintain the viral transmission cycles requires further experimental investigation. The substantially low incidence and scarcity of data on Rickettsia and Ehrlichia species could imply that camels were accidentally infected. In contrast, camels may play a role in the spread of Coxiella burnetii, which is primarily transmitted through the inhalation of aerosols emitted by diseased animals and contaminated environments. Bactrian camels showed no symptoms due to the examined TBPs, meanwhile, clinical disease was seen in alpacas infected with A. phagocytophilum. Similar to dromedaries, accidental tick bites may be the cause of TBP DNA found in the blood of Bactrian camels.
Topics: Animals; Dogs; Camelus; Prevalence; Seroepidemiologic Studies; Ehrlichia; Rickettsia; Anaplasma; Babesia; Ixodes; Theileria annulata; DNA; Tick-Borne Diseases; Dog Diseases
PubMed: 37769585
DOI: 10.1016/j.ttbdis.2023.102268 -
Journal of Infection in Developing... Dec 2014Although toxoplasmosis in immunocompetent individuals is generally asymptomatic, in immunocompromised patients (HIV/AIDS, cancer, and transplant patients), it can lead... (Meta-Analysis)
Meta-Analysis Review
Although toxoplasmosis in immunocompetent individuals is generally asymptomatic, in immunocompromised patients (HIV/AIDS, cancer, and transplant patients), it can lead to serious pathological effects. This study included a systematic review and meta-analysis to comprehensively assess the seroprevalence rate of Toxoplasma infection in immunocompromised patients in Iran. Electronic English and Persian databases (PubMed, Google Scholar, ScienceDirect, Scopus, Magiran, Scientific Information Database [SID], IranMedex, and IranDoc), parasitology congresses, and projects and theses of Iranian medical universities, were systematically searched from 1997 to 2013 (published or unpublished data). In this paper, several studies that used serological methods for diagnosis of toxoplasmosis were selected. Analysis of seroprevalence estimates was pooled using a random-effects meta-analysis. Twenty-two studies, comprising 2,805 individuals, were included in the meta-analysis. Overall seroprevalence rate of Toxoplasma infection in Iranian immunocompromised patients was 50.01% (95% confidence interval, 43.85 to 56.17); however, there was significant heterogeneity among study groups. The results showed that seroprevalence rate of toxoplasmosis among transplant recipients, HIV/AIDS, and cancer patients in Iran was 55.1%, 50.05%, and 45.06%, respectively. In addition, IgM seroprevalence rate was estimated to be 4.85% (95% confidence interval, 2.22 to 8.41). This systematic review and meta-analysis identified a high seroprevalence rate of Toxoplasma infection among immunocompromised patients (50%). Consideration of management, design and provision of appropriate control measures of toxoplasmosis is highly recommended.
Topics: Antibodies, Protozoan; HIV Infections; Humans; Immunocompromised Host; Immunoglobulin G; Iran; Neoplasms; Seroepidemiologic Studies; Toxoplasma; Toxoplasmosis; Transplant Recipients
PubMed: 25500647
DOI: 10.3855/jidc.4796 -
Scientific Reports Apr 2017Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency overlaps with malaria endemicity although it predisposes carriers to hemolysis. This fact supports the protection... (Meta-Analysis)
Meta-Analysis Review
Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency overlaps with malaria endemicity although it predisposes carriers to hemolysis. This fact supports the protection hypothesis against malaria. The aim of this systematic review is to assess the presence and the extent of protective association between G6PD deficiency and malaria. Thirteen databases were searched for papers reporting any G6PD alteration in malaria patients. Twenty-eight of the included 30 studies were eligible for the meta-analysis. Results showed absence of negative association between G6PD deficiency and uncomplicated falciparum malaria (odds ratio (OR), 0.77; 95% confidence interval (CI), 0.59-1.02; p = 0.07). However, this negative association happened in Africa (OR, 0.59; 95% CI, 0.40-0.86; p = 0.007) but not in Asia (OR, 1.24; 95% CI, 0.96-1.61; p = 0.10), and in the heterozygotes (OR, 0.70; 95% CI, 0.57-0.87; p = 0.001) but not the homo/hemizygous (OR, 0.70; 95% CI, 0.46-1.07; p = 0.10). There was no association between G6PD deficiency and total severe malaria (OR, 0.82; 95% CI, 0.61-1.11; p = 0.20). Similarly, there was no association with other malaria species. G6PD deficiency can potentially protect against uncomplicated malaria in African countries, but not severe malaria. Interestingly, this protection was mainly in heterozygous, being x-linked thus related to gender.
Topics: Glucosephosphate Dehydrogenase; Glucosephosphate Dehydrogenase Deficiency; Heterozygote; Humans; Malaria, Falciparum; Plasmodium falciparum; Species Specificity
PubMed: 28382932
DOI: 10.1038/srep45963 -
Actas Espanolas de Psiquiatria Apr 2024Toxoplasmosis is a worldwide parasitic zoonosis caused by the protozoan Toxoplasma gondii. In cases of vertical infection, and in immunosuppressed people by the human...
BACKGROUND
Toxoplasmosis is a worldwide parasitic zoonosis caused by the protozoan Toxoplasma gondii. In cases of vertical infection, and in immunosuppressed people by the human immunodeficiency virus (HIV) serious clinical conditions may appear, while immunocompetent people do not present symptoms. However, T. gondii infection has been linked to several mental disorders for decades.
OBJECTIVE
To substantiate the possible relationship between T. gondii and mental disorders and suggest control and prevention strategies.
MATERIAL AND METHODS
A systematic review has been carried out to analyze the relationship between T. gondii exposure (presence of IgG) and the onset of mental disorders in minors and adults. The etiopathogenic mechanisms described by the authors have also been included and the systems of surveillance, prevention and control of infection have been evaluated.
RESULTS
Several processes linked to the presence of cysts and the reactivation of the parasite in certain situations produce an immune and inflammatory response. Also, direct and indirect actions on different neurotransmitters. These mechanisms, together with other environmental and genetic factors, would predispose to different psychiatric pathologies.
CONCLUSIONS
Due to the limits of the study, no conclusions can be drawn in childhood and adolescence. However, the results of this systematic review show a possible association of schizophrenia, bipolar disorder and compulsive disorder with T. gondii infection in adults. There is a need to improve control, integrated surveillance and extend prevention measures to the entire population.
Topics: Adult; Adolescent; Humans; Toxoplasmosis; Mental Disorders; Toxoplasma; Bipolar Disorder; Schizophrenia
PubMed: 38622004
DOI: 10.62641/aep.v52i2.1658 -
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 -
Parasitology Research Oct 2018Studies suggest that the protozoan Toxoplasma gondii can disturb human behavior. This study aimed to systematically review the scientific literature on the possible... (Review)
Review
Studies suggest that the protozoan Toxoplasma gondii can disturb human behavior. This study aimed to systematically review the scientific literature on the possible associations between Toxoplasma gondii infection and neurobehavioral abnormalities in humans. We reviewed and summarized the studies published since 1990. The descriptors used were related to T. gondii infection and behavioral outcomes in humans; the main databases of the medical literature were accessed. The results of eight original articles published between 1994 and 2016 were evaluated and described. The most common serological method was the enzyme immunoassay. Most of the researchers used validated instruments for behavioral evaluation. Seven studies reported some association between the prevalence of anti-T. gondii antibodies and some altered behavioral aspects in adult humans; these studies focused on adult population in Europe and the USA. The most reported behavioral deviations are related to greater impulsivity and aggressiveness. There are very few studies on this subject, which present some limitations for inference and conclusions: most were cross-sectional studies, with a small sample size and in similar populations. Investigations with a larger sample size of different population groups should be performed to evaluate multiple factors.
Topics: Adult; Antibodies, Protozoan; Europe; Female; Humans; Immunoenzyme Techniques; Immunoglobulin G; Male; Mental Disorders; Nervous System Diseases; Personality Tests; Prevalence; Seroepidemiologic Studies; Toxoplasma; Toxoplasmosis
PubMed: 30109417
DOI: 10.1007/s00436-018-6040-2 -
Scientific Reports Jun 2023Asymptomatic Plasmodium infection raises a problem for the persistent transmission of malaria in low-endemic areas such as Asia. This systematic review was undertaken to... (Meta-Analysis)
Meta-Analysis
Asymptomatic Plasmodium infection raises a problem for the persistent transmission of malaria in low-endemic areas such as Asia. This systematic review was undertaken to estimate the prevalence and proportion of asymptomatic Plasmodium infection in Asia. The systematic review was registered at PROSPERO (ID: CRD42022373664). The research followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. A comprehensive search of five databases, Ovid, Scopus, MEDLINE, PubMed, and Embase, was conducted to identify studies of asymptomatic Plasmodium infection in Asian countries. The pooled prevalence of asymptomatic Plasmodium infection, the pooled proportion of asymptomatic Plasmodium infection among all parasitised individuals, and the associated 95% confidence intervals were estimated using a random-effects model. A total of 916 articles were retrieved, and 87 articles that met the criteria were included in the systematic review. The pooled prevalence of asymptomatic Plasmodium infection among enrolled participants in Southeast Asia, South Asia, and Western Asia was 5.8%, 9.4%, and 8.4%, respectively. The pooled proportion of asymptomatic Plasmodium infection among all parasitised individuals in Southeast Asia, South Asia, and Western Asia was 89.3%, 87.2%, and 64.8%, respectively. There was a low prevalence of asymptomatic Plasmodium infection, but there was a high proportion of asymptomatic Plasmodium infection per all parasitised individuals in different parts of Asia. These results may support and facilitate elimination and control programs for asymptomatic Plasmodium infection in Asia.
Topics: Humans; Malaria, Falciparum; Prevalence; Malaria; Plasmodium; Asia; Asymptomatic Infections
PubMed: 37369862
DOI: 10.1038/s41598-023-37439-9 -
PloS One 2023Toxoplasma gondii, a ubiquitous parasitic protozoan, may be an important cause of neurological and psychiatric diseases. The present systematic review and meta-analysis,... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Toxoplasma gondii, a ubiquitous parasitic protozoan, may be an important cause of neurological and psychiatric diseases. The present systematic review and meta-analysis, therefore, was conducted to investigate the scientific evidence regarding the potential association between T. gondii infection and psychiatric disorders in Iran.
METHODS
We systematically reviewed articles from world-wide databases, including PubMed, Scopus, Science Direct, Web of Science, Google Scholar, and Iranian national databases up to July 30th, 2021. The Newcastle Ottawa Scale (NOS) was used to assess the quality of included studies. The common odds ratio (OR) was estimated using inverse variance and a random-effects model. Heterogeneity was assessed using the χ2-based Cochrane test (Q) and the I2 index. Also, sensitivity analyses and publication bias were calculated. Moreover, subgroup analysis was performed based on the type of disorder and quality score of different eligible studies.
RESULTS
16 studies were included in this meta-analysis. Our meta-analyses found that the OR of the risk of anti- T. gondii IgG and IgM in psychiatric patients compared to the control group was 1.56 (95% CI; 1.23-1.99) and 1.76 (95% CI: 1.19-2.61), respectively. Subgroup analysis based on the type of disorder showed that the OR of the risk of anti- T. gondii IgG in Iranian schizophrenia patients and other psychiatric disorders compared to the control group were 1.50 (95% CI; 1.09-2.07) and 2.03 (95% CI: 1.14-3.60), respectively, which are statistically significant. Also, the OR of the risk of anti- T. gondii IgM in Iranian schizophrenia and depression patients compared to the control group was 1.54 (95% CI; 0.9-2.64) and 1.03 (95% CI: 0.2-5.24), respectively, which are not statistically significant. Additionally, subgroup analysis based on quality scores showed no significant influence on the results according to the moderate quality studies. However, this association was significant according to the high quality studies. The obtained results of Egger's test were 1.5 (95% CI; -0.62-3.73, P = 0.15) and 0.47 (95% CI; -0.82-1.76, P = 0.45), respectively, indicating publication bias. The significant results of the heterogeneity analysis confirmed a high level of heterogeneity in the IgG test (P = 0.000, I2 = 66.6%). However, no significant results from the test of heterogeneity were detected in the IgM test (P = 0.15, I2 = 27.5%). The results of the sensitivity analysis showed that the impact of each study on the meta-analysis was not significant on overall estimates.
CONCLUSIONS
Despite the limited number of studies, these outcomes supported a possible link between T. gondii infection and psychiatric disorders in Iran. However, more high-quality investigations are needed in the future.
Topics: Humans; Iran; Toxoplasmosis; Toxoplasma; Schizophrenia; Immunoglobulin G; Immunoglobulin M; Seroepidemiologic Studies
PubMed: 37552680
DOI: 10.1371/journal.pone.0284954 -
BMC Medicine Sep 2014Identifying Plasmodium vivax antigen-specific antibodies associated with P. vivax infection and protective immunity is key to the development of serosurveillance tools... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Identifying Plasmodium vivax antigen-specific antibodies associated with P. vivax infection and protective immunity is key to the development of serosurveillance tools and vaccines for malaria. Antibody targets of P. vivax can be identified by seroepidemiological studies of individuals living in P. vivax-endemic areas, and is an important strategy given the limited ability to culture P. vivax in vitro. There have been numerous studies investigating the association between P. vivax antibody responses and P. vivax infection, but there has been no standardization of results to enable comparisons across populations.
METHODS
We performed a systematic review with meta-analysis of population-based, cross-sectional, case-control, and cohort studies of individuals living in P. vivax-endemic areas. We searched 6 databases and identified 18 studies that met predefined inclusion and quality criteria, and examined the association between antibody responses to P. vivax antigens and P. vivax malaria.
RESULTS
The majority of studies were published in South America (all from Brazil) and the rest from geographically diverse areas in the Asia-Pacific region. Considerable heterogeneity in estimates was observed, but IgG responses to PvCSP, PvMSP-119, PvMSP-9RIRII, and PvAMA1 were associated with increased odds of P. vivax infection in geographically diverse populations. Potential sources of heterogeneity included study design, different transmission intensities and transmigrant populations. Protective associations were observed for antibodies to PvMSP-119, PvMSP-1NT, PvMSP-3α and PvMSP-9NT antigens, but only in single geographical locations.
CONCLUSIONS
This systematic review revealed several antigen-specific antibodies that were associated with active infection and protective immunity, which may be useful biomarkers. However, more studies are needed on additional antigens, particularly cohort studies to increase the body of evidence for protective immunity. More studies representing diverse geographical regions encompassing varying P. vivax endemicities are needed to validate the generalizability of the findings and to provide a solid evidence base for the use of P. vivax antigens in vaccines and serosurveillance tools.
Topics: Antibodies, Protozoan; Antigens, Protozoan; Biomarkers; Female; Humans; Malaria, Vivax; Male; Plasmodium vivax; Protozoan Proteins; Seroepidemiologic Studies
PubMed: 25199532
DOI: 10.1186/s12916-014-0150-1 -
Cancer Epidemiology Apr 2022Brain tumors are among the most fatal cancers with substantial morbidity and mortality worldwide. Epidemiologic evidence suggests that infectious agents, especially,... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Brain tumors are among the most fatal cancers with substantial morbidity and mortality worldwide. Epidemiologic evidence suggests that infectious agents, especially, protozoan parasite Toxoplasma gondii could be a possible risk factor or contributor. Here, we performed a systematic review and meta-analysis to evaluate the possible association between T. gondii infection/exposure and risk of brain tumors.
METHODS
We searched the PubMed, Embase, Scopus, and Web of Science collection databases from inception through 1st of December 2021. Pooled estimates of odds ratios (ORs) and 95% confidence intervals (CIs) were generated using random effects models. We did the subgroup analysis according to tumor types. Statistical tests for heterogeneity and sensitivity analyses were applied.
RESULTS
A total of seven eligible studies comprising 2323 patients diagnosed with brain tumors and 5131 healthy controls were included in the meta-analysis. T. gondii infection/exposure prevalence was 24.2% (95%CI, 12.7%-41.2) in cases and 12.9% (95%CI, 7.0-22.6%) in control subjects. Pooled analysis showed an overall OR of 1.96 (95%CI, 1.37-2.80), indicating a significant increased risk of brain tumors associated with T. gondii infection/exposure. In subgroup analysis T. gondii infection/exposure was significantly associated with gliomas (OR: 1.64, 95%CI, 1.15-2.33), meningioma (OR: 2.30, 95%CI, 1.0-5.27) and other types of brain tumors (OR: 2.19, 95%CI, 1.02-4.71).
CONCLUSION
This study provides suggestive evidence for an association between T. gondii infection/exposure and brain tumors. Our findings should be further confirmed by well-designed cohort studies with strict control of confounders. Moreover, we suggest that future studies also focus on the effect of T. gondii infection/exposure to the types of brain tumors.
Topics: Brain Neoplasms; Humans; Meningeal Neoplasms; Risk Factors; Seroepidemiologic Studies; Toxoplasma; Toxoplasmosis
PubMed: 35152168
DOI: 10.1016/j.canep.2022.102119