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PLoS Neglected Tropical Diseases Jun 2023Schistosomiasis is a water-borne parasitic disease which affects over 230 million people globally. The relationship between contact with open freshwater bodies and the... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Schistosomiasis is a water-borne parasitic disease which affects over 230 million people globally. The relationship between contact with open freshwater bodies and the likelihood of schistosome infection remains poorly quantified despite its importance for understanding transmission and parametrising transmission models.
METHODS
We conducted a systematic review to estimate the average effect of water contact duration, frequency, and activities on schistosome infection likelihood. We searched Embase, MEDLINE (including PubMed), Global Health, Global Index Medicus, Web of Science, and the Cochrane Central Register of Controlled Trials from inception until May 13, 2022. Observational and interventional studies reporting odds ratios (OR), hazard ratios (HR), or sufficient information to reconstruct effect sizes on individual-level associations between water contact and infection with any Schistosoma species were eligible for inclusion. Random-effects meta-analysis with inverse variance weighting was used to calculate pooled ORs and 95% confidence intervals (CIs).
RESULTS
We screened 1,411 studies and included 101 studies which represented 192,691 participants across Africa, Asia, and South America. Included studies mostly reported on water contact activities (69%; 70/101) and having any water contact (33%; 33/101). Ninety-six percent of studies (97/101) used surveys to measure exposure. A meta-analysis of 33 studies showed that individuals with water contact were 3.14 times more likely to be infected (OR 3.14; 95% CI: 2.08-4.75) when compared to individuals with no water contact. Subgroup analyses showed that the positive association of water contact with infection was significantly weaker in children compared to studies which included adults and children (OR 1.67; 95% CI: 1.04-2.69 vs. OR 4.24; 95% CI: 2.59-6.97). An association of water contact with infection was only found in communities with ≥10% schistosome prevalence. Overall heterogeneity was substantial (I2 = 93%) and remained high across all subgroups, except in direct observation studies (I2 range = 44%-98%). We did not find that occupational water contact such as fishing and agriculture (OR 2.57; 95% CI: 1.89-3.51) conferred a significantly higher risk of schistosome infection compared to recreational water contact (OR 2.13; 95% CI: 1.75-2.60) or domestic water contact (OR 1.91; 95% CI: 1.47-2.48). Higher duration or frequency of water contact did not significantly modify infection likelihood. Study quality across analyses was largely moderate or poor.
CONCLUSIONS
Any current water contact was robustly associated with schistosome infection status, and this relationship held across adults and children, and schistosomiasis-endemic areas with prevalence greater than 10%. Substantial gaps remain in published studies for understanding interactions of water contact with age and gender, and the influence of these interactions for infection likelihood. As such, more empirical studies are needed to accurately parametrise exposure in transmission models. Our results imply the need for population-wide treatment and prevention strategies in endemic settings as exposure within these communities was not confined to currently prioritised high-risk groups such as fishing populations.
Topics: Adult; Child; Animals; Humans; Schistosoma; Schistosomatidae; Odds Ratio; Probability; Waterborne Diseases
PubMed: 37315020
DOI: 10.1371/journal.pntd.0011377 -
Infectious Diseases of Poverty Apr 2023Urogenital schistosomiasis is endemic in Mali and is a major cause of serious morbidity in large parts of the world. This disease is responsible for many socio-economic...
BACKGROUND
Urogenital schistosomiasis is endemic in Mali and is a major cause of serious morbidity in large parts of the world. This disease is responsible for many socio-economic and public health issues. The aim of this study was to investigate the impact of the disease on morbidity and to describe demographic and socioeconomic factors in relation to the status of children with urogenital schistosomiasis in Mali.
METHODS
We conducted a cross-sectional study in November 2021 of 971 children aged 6 to 14 years selected at random from six schools in three districts in the Kayes Region of Mali. Demographic and socioeconomic data were collected on survey forms. Clinical data were collected following a medical consultation. Hematuria was systematically searched for through the use of strips. The search for Schistosoma haematobium eggs in urine was done via the filtration method. The urinary tract was examined by ultrasound. Associations between each of these variables and disease infection were tested using multivariate logistic regression.
RESULTS
The overall prevalence of urinary schistosomiasis detected was 50.2%. The average intensity of infection was 36 eggs/10 ml of urine. The associated risk factors for urogenital schistosomiasis showed that children who bathed, used the river/pond as a domestic water source, and who habitually urinated in the river/pond were more affected (P < 0.05). Children with farming parents were most affected (P = 0.032). The collection of clinical signs revealed that boys had more pollakiuria (58.6%) and dysuria (46.4%) than girls. Ultrasound data showed that focal lesion rates were recorded in all villages with the lowest rate in Diakalel (56.1%). Ultrasound and parasitological findings showed that irregularity and thickening were strongly associated with urinary schistosomiasis (P < 0.0001).
CONCLUSIONS
Schistosoma haematobium infection was still endemic in the study site despite more than a decade of mass treatment with praziquantel. However, the high percentage of symptoms associated with high intensity reinforces the idea that further studies in terms of schistosomiasis-related morbidity are still needed.
Topics: Male; Female; Animals; Humans; Child; Schistosomiasis haematobia; Mali; Cross-Sectional Studies; Schistosoma haematobium; Prevalence; Risk Factors; Schools
PubMed: 37081494
DOI: 10.1186/s40249-023-01071-6 -
PLoS Neglected Tropical Diseases Mar 2023Taenia solium is a tapeworm that causes taeniosis in humans and cysticercosis in humans and pigs. Within Eastern and Southern Africa (ESA), information on the presence...
BACKGROUND
Taenia solium is a tapeworm that causes taeniosis in humans and cysticercosis in humans and pigs. Within Eastern and Southern Africa (ESA), information on the presence of human taeniosis and cysticercosis seems scarce. This systematic review aimed to describe the current information available and gaps in the epidemiology of human T. solium infections in ESA.
METHODS/PRINCIPLE FINDINGS
Scientific literature published between 1st January 2000 and 20th June 2022 in international databases [MEDLINE (Ovid), Embase (Ovid), Global Health (Ovid), Scopus (Elsevier), African Index Medicus (via WHO Global Index Medicus), and Open Grey] was systematically reviewed for ESA. The study area included 27 countries that make up the ESA region. Information on either taeniosis, cysticercosis or NCC was available for 16 of 27 countries within the region and a total of 113 reports were retained for the review. Most case reports for cysticercosis and NCC were from South Africa, while Tanzania had the most aggregated cysticercosis reports. Eleven countries reported on NCC with seven countries reporting data on NCC and epilepsy. Unconfirmed human T. solium taeniosis cases were reported in nine countries while two countries (Madagascar and Zambia) reported confirmed T. solium cases. The cysticercosis seroprevalence ranged between 0.7-40.8% on antigen (Ag) ELISA and between 13.1-45.3% on antibody (Ab) ELISA. Based on immunoblot tests the Ab seroprevalence was between 1.7-39.3%, while the proportion of NCC-suggestive lesions on brain CT scans was between 1.0-76% depending on the study population. The human taeniosis prevalence based on microscopy ranged between 0.1-14.7%. Based on Copro Ag-ELISA studies conducted in Kenya, Rwanda, Tanzania, and Zambia, the highest prevalence of 19.7% was reported in Kenya.
CONCLUSIONS
Despite the public health and economic impact of T. solium in ESA, there are still large gaps in knowledge about the occurrence of the parasite, and the resulting One Health disease complex, and monitoring of T. solium taeniosis and cysticercosis is mostly not in place.
Topics: Humans; Swine; Animals; Seroepidemiologic Studies; Taeniasis; Cysticercosis; Taenia solium; Africa, Southern; Tanzania; Prevalence; Swine Diseases
PubMed: 37000841
DOI: 10.1371/journal.pntd.0011042 -
Acta Tropica May 2023Schistosoma japonicum remains endemic in China and the Philippines. Substantial progress has been made in the control of Japonicum in both China and the Philippines.... (Review)
Review
BACKGROUND
Schistosoma japonicum remains endemic in China and the Philippines. Substantial progress has been made in the control of Japonicum in both China and the Philippines. China is reaching elimination thanks to a concerted effort of control strategies. Mathematical modelling has been a key tool in the design of control strategies, in place of expensive randomised-controlled trials. We conducted a systematic review to investigate mathematical models of Japonicum control strategies in China and the Philippines.
METHODS
We conducted a systematic review on July 5, 2020, in four electronic bibliographic databases - PubMed, Web of Science, SCOPUS and Embase. Articles were screened for relevance and for meeting the inclusion criteria. Data extracted included authors, year of publication, year of data collection, setting and ecological context, objectives, control strategies, main findings, the form and content of the model including its background, type, representation of population dynamics, heterogeneity of hosts, simulation period, source of parameters, model validation and sensitivity analysis. Results After screening, 19 eligible papers were included in the systematic review. Seventeen considered control strategies in China and two in the Philippines. Two frameworks were identified; the mean-worm burden framework and the prevalence-based framework, the latter of which increasingly common. Most models considered human and bovine definitive hosts. There were mixed additional elements included in the models, such as alternative definitive hosts and the role of seasonality and weather. Models generally agreed upon the need for an integrated control strategy rather than reliance on mass drug administration alone to sustain reductions in prevalence.
CONCLUSIONS
Mathematical modelling of Japonicum has converged from multiple approaches to modelling using the prevalence-based framework with human and bovine definitive hosts and find integrated control strategies to be most effective. Further research could investigate the role of other definitive hosts and model the effect of seasonal fluctuations in transmission.
Topics: Animals; Cattle; Humans; Schistosoma japonicum; Schistosomiasis japonica; Models, Theoretical; Computer Simulation; China
PubMed: 36907291
DOI: 10.1016/j.actatropica.2023.106873 -
PloS One 2023Traditional diagnostic tests for schistosome infections are suboptimal, particularly when the parasite burden is low. In the present review we sought to identify...
Diagnostic performances of Schistosoma haematobium and Schistosoma mansoni recombinant proteins, peptides and chimeric proteins antibody based tests. Systematic scoping review.
BACKGROUND
Traditional diagnostic tests for schistosome infections are suboptimal, particularly when the parasite burden is low. In the present review we sought to identify recombinant proteins, peptides, and chimeric proteins with potential to be used as sensitive and specific diagnostic tools for schistosomiasis.
METHODS
The review was guided by PRISMA-ScR guidelines, Arksey and O'Malley's framework, and guidelines from the Joanna Briggs Institute. Five databases were searched: Cochrane library, PubMed, EMBASE, PsycInfo and CINAHL, alongside preprints. Identified literature were assessed by two reviewers for inclusion. A narrative summary was used to interpret the tabulated results.
RESULTS
Diagnostic performances were reported as specificities, sensitivities, and AUC. The AUC for S. haematobium recombinant antigens ranged from 0.65 to 0.98, and 0.69 to 0.96 for urine IgG ELISA. S. mansoni recombinant antigens had sensitivities ranging from 65.3% to 100% and specificities ranging from 57.4% to 100%. Except for 4 peptides which had poor diagnostic performances, most peptides had sensitivities ranging from 67.71% to 96.15% and specificities ranging from 69.23% to 100%. S. mansoni chimeric protein was reported to have a sensitivity of 86.8% and a specificity of 94.2%.
CONCLUSION
The tetraspanin CD63 antigen had the best diagnostic performance for S. haematobium. The tetraspanin CD63 antigen Serum IgG POC-ICTs had a sensitivity of 89% and a specificity of 100%. Peptide Smp_150390.1 (216-230) serum based IgG ELISA had the best diagnostic performance for S. mansoni with a sensitivity of 96.15% and a specificity of 100%. Peptides were reported to demonstrate good to excellent diagnostic performances. S. mansoni multi-peptide chimeric protein further improved the diagnostic accuracy of synthetic peptides. Together with the advantages associated with urine sampling technique, we recommend development of multi-peptide chimeric proteins urine based point of care tools.
Topics: Animals; Schistosoma haematobium; Schistosoma mansoni; Tetraspanin 30; Peptides; Blood Group Antigens; Recombinant Proteins; Recombinant Fusion Proteins; Immunoglobulin G
PubMed: 36862712
DOI: 10.1371/journal.pone.0282233 -
International Journal of Infectious... Apr 2023The lack of subnational mapping of the zoonotic cestode Taenia solium in endemic countries presents a major challenge to achieving intensified T. solium control...
OBJECTIVES
The lack of subnational mapping of the zoonotic cestode Taenia solium in endemic countries presents a major challenge to achieving intensified T. solium control milestones, as outlined in the "World Health Organization neglected tropical disease roadmap by 2030". We conducted a mapping study in Uganda, considered to be endemic, to identify subnational high-risk areas.
METHODS
T. solium prevalence data, adjusted for diagnostic sensitivity and specificity in a Bayesian framework, were identified through a systematic review. Spatial autocorrelation and interpolation techniques were used to transform demographic and health survey cluster-level sanitation and poverty indicators, overlaid onto a pig density map for Uganda into modelled porcine cysticercosis (PCC) risk maps.
RESULTS
A total of 16 articles (n = 11 PCC and n = 5 human cysticercosis (HCC) and/or human taeniasis) were included in the final analysis. The observed HCC prevalence ranged from 0.01% to 6.0% (confidence interval range: 0.004-11.4%), whereas the adjusted PCC ranged from 0.3 to 93.9% (uncertainty interval range: 0-99.8%). There was substantial variation in the modelled PCC risk factors and prevalence across Uganda and over time.
CONCLUSION
The high PCC prevalence and moderate HCC exposure estimates indicate the need for urgent implementation of T. solium control efforts in Uganda.
Topics: Animals; Humans; Swine; Taenia solium; Uganda; Bayes Theorem; Swine Diseases; Cysticercosis; Taeniasis; Risk Factors
PubMed: 36805327
DOI: 10.1016/j.ijid.2023.02.001 -
PLoS Neglected Tropical Diseases Oct 2022Schistosomiasis is a parasitic disease that is endemic in 78 countries and affects almost 240 million people worldwide. It has been acknowledged that an integrated...
BACKGROUND
Schistosomiasis is a parasitic disease that is endemic in 78 countries and affects almost 240 million people worldwide. It has been acknowledged that an integrated approach that goes beyond drug treatment is needed to achieve control and eventual elimination of the disease. Improving hygiene has been encouraged by World Health Organisation, and one aspect of good hygiene is using soap during water-contact activities, such as bathing and doing laundry. This hygiene practice might directly reduce the skin exposure to cercariae at transmission sites. A systematic review was carried out to investigate the efficacy of soap against schistosome cercariae and to identify the knowledge gaps surrounding this topic.
METHODOLOGY
Six online databases were searched between 5th and 8th July of 2021. Records returned from these databases were screened to remove duplicates, and the remaining records were classified by reading titles, abstracts, and full texts to identify the included studies. The results were categorised into two groups based on two different protective mechanisms of soap (namely, damage to cercariae and protection of skin).
CONCLUSIONS
Limited research has been conducted on the efficacy of soap against schistosome cercariae and only 11 studies met the criteria to be included in this review. The review demonstrates that soap has the potential of protecting people against schistosome cercariae and there are two protective aspects: (1) soap affects cercariae adversely; (2) soap on the skin prevents cercariae from penetrating the skin, developing into adult worms and producing eggs. Both aspects of protection were influenced by many factors, but the differences in the reported experimental conditions, such as the cercarial endpoint measurement used and the cercaria numbers used per water sample, lead to low comparability between the previous studies. This review indicates that more evidence is needed to inform hygiene advice for people living in schistosomiasis endemic areas.
Topics: Animals; Cercaria; Schistosoma; Schistosomiasis; Soaps; Water
PubMed: 36191022
DOI: 10.1371/journal.pntd.0010820 -
Veterinary Medicine and Science Nov 2022Spirometra infection is aneglected food- and waterborne disease with worldwide distribution. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Spirometra infection is aneglected food- and waterborne disease with worldwide distribution.
OBJECTIVES
The present study aims to estimate the global prevalence of Spirometra species in snakes, frogs, dogs and cats.
METHODS
Multiple databases (PubMed, Scopus, ProQuest, Web of Science and Google Scholar) were searched for relevant literatures published up to March 2022.
RESULTS
Among 131 data sets (including 113 articles) that met the inclusion, 15 investigations reported Spirometra infection in snakes, 23 in frogs, 41 in dogs and 52 in cats. The pooled prevalence (95% confidence interval) in intermediate hosts and definitive hosts was found to be 0.313% and 0.089%, respectively. Based on continent, the infection was most prevalent in Asia for studies on snakes (0.696%) and frogs (0.181%), while Africa (0.224%) and Oceania (0.203%) were the regions with the highest pooled prevalence rates of the infection in dogs and cats, respectively. Among different diagnostic methods, the highest pooled prevalence was related to morphological method for studies on snakes, frog and cats with rate of 0.665%, 0.189% and 0.104%, respectively. Regarding studies on dogs, the highest pooled prevalence was observed for molecular technique (0.101%).
CONCLUSIONS
The results presented here revealed the importance of establishing a prevention and control measure focused on protection of aquaculture systems from being contaminated with faeces of dogs and cats, and raising awareness of parasitic zoonotic diseases to decrease the transmission risk.
Topics: Cats; Dogs; Animals; Spirometra; Parasites; Cat Diseases; Prevalence; Dog Diseases; Cestode Infections; Snakes
PubMed: 36084292
DOI: 10.1002/vms3.932 -
ELife Aug 2022Infection by poses a major burden across endemic countries. The World Health Organization (WHO) 2021-2030 Neglected Tropical Diseases roadmap has proposed that 30% of...
Infection by poses a major burden across endemic countries. The World Health Organization (WHO) 2021-2030 Neglected Tropical Diseases roadmap has proposed that 30% of endemic countries achieve intensified control in hyperendemic areas by 2030. Understanding geographical variation in age-prevalence profiles and force-of-infection (FoI) estimates will inform intervention designs across settings. Human taeniasis (HTT) and human cysticercosis (HCC) age-prevalence data from 16 studies in Latin America, Africa, and Asia were extracted through a systematic review. Catalytic models, incorporating diagnostic performance uncertainty, were fitted to the data using Bayesian methods, to estimate rates of antibody (Ab)-seroconversion, infection acquisition and Ab-seroreversion or infection loss. HCC FoI and Ab-seroreversion rates were also estimated across 23 departments in Colombia from 28,100 individuals. Across settings, there was extensive variation in all-ages seroprevalence. Evidence for Ab-seroreversion or infection loss was found in most settings for both HTT and HCC and for HCC Ab-seroreversion in Colombia. The average duration until humans became Ab-seropositive/infected decreased as all-age (sero)prevalence increased. There was no clear relationship between the average duration humans remain Ab-seropositive and all-age seroprevalence. Marked geographical heterogeneity in transmission rates indicate the need for setting-specific intervention strategies to achieve the WHO goals.
Topics: Animals; Bayes Theorem; Cysticercosis; Humans; Seroepidemiologic Studies; Swine; Swine Diseases; Taenia solium; Taeniasis
PubMed: 35984416
DOI: 10.7554/eLife.76988 -
PloS One 2022Cysticercosis and Neurocysticercosis (NCC) can be studied using several animal species in experimental models which contributes to the understanding of the human form of...
BACKGROUND
Cysticercosis and Neurocysticercosis (NCC) can be studied using several animal species in experimental models which contributes to the understanding of the human form of the disease. Experimental infections of Taenia spp. are vital in explaining the modes of transmission of the parasite and helps the understanding of transmission of the parasite in humans and thus may be useful in designing therapeutic and immune-prophylactic studies to combat the disease. Thus, this systematic review aims to explore the existing experimental animal models to the understanding of cysticercosis in both humans and animals and elucidate the risk factors of cysticercosis and identify the Taenia spp. used in these models.
METHODOLOGY
We systematically identified all publications from the Web of Science, Google Scholar, and Pubmed regarding experimental animal models using Taenia spp. that cause cysticercosis in both humans and animals. 58 studies were identified for eligibility. Of these, only 48 studies met the inclusion criteria from which data extraction was done and presented descriptively.
RESULTS
Pigs, cattle, gerbils, mice, rats, voles, monkeys, cats, dogs, and goats were used in which T. solium, T. saginata, T. saginata asiatica, T. crassiceps and T. asiatica were studied. The routes used to induce disease were; oral, intravenous, subcutaneous, intramuscular, intraperitoneal, intraarterial, intracranial, intraduodenal, and surgical routes using eggs, oncospheres, and proglottids. Besides, the establishment of infection using eggs and oncospheres was affected by the route used to induce infection in the experimental animals. The cysticerci recovery rate in all the experimental studies was low and the number of animals used in these experiments varied from 1 to 84. Although not analysed statistically, sex, age, and breed of animals influenced the cysticerci recovery rate. Additionally, the cysticerci recovery rate and antibody-antigen levels were shown to increase with an increase in the dose of oncospheres and eggs inoculated in the animals. Contrasting results were reported in which the cysticerci recovery rate decreased with an increase in the dose of eggs inoculated.
CONCLUSION
This review describes the various animal experiments using Taenia species that cause cysticercosis highlighting the animals used, age and their breed, the routes of infection used to induce disease and the sample size used, and the cysticerci recovery rate in these animal models.
Topics: Animals; Cattle; Cysticercosis; Cysticercus; Dogs; Humans; Mice; Models, Animal; Neurocysticercosis; Rats; Swine; Taenia; Taenia solium
PubMed: 35853079
DOI: 10.1371/journal.pone.0271232