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Parasites & Vectors Jan 2016Preventive chemotherapy (PCT) programmes are used to control five of the highest burden neglected tropical diseases (NTDs): soil-transmitted helminth infections... (Review)
Review
Preventive chemotherapy (PCT) programmes are used to control five of the highest burden neglected tropical diseases (NTDs): soil-transmitted helminth infections (hookworm, ascariasis, and trichuriasis), lymphatic filariasis, schistosomiasis, onchocerciasis, and trachoma. Over the past decade, new resource commitments for the NTDs have enabled such programmes to intensify their control efforts, and for some diseases, to shift from goals of morbidity control to the interruption of transmission and elimination. To successfully eliminate the parasite reservoir, these programmes will undoubtedly require prolonged, high treatment coverage. However, it is important to consider that even when coverage levels reach an acceptable proportion of the target population, there may be a considerable gap between coverage (those who receive the drug) and compliance (those who actually consume the drug)-a topic of fundamental and perhaps underestimated importance. We conducted a systematic review of published literature that investigated compliance to PCT programmes for NTD control and elimination. Databases searched included PubMed/Medline, Web of Knowledge (including Web of Science), OVID, and Scopus. Data were collected on compliance rates, reasons for non-compliance, as well as the heterogeneity of compliance definitions and calculations across programmes and studies. A total of 112 studies were selected for inclusion. The findings of the review revealed substantial heterogeneity across compliance terms and definitions; an imbalance of available studies for particular disease areas and countries; and finally, a lack of longitudinal compliance studies to properly investigate the role of systematic non-compliance. The lack of consistency among reporting of compliance data can result in under- or over-estimating compliance in a population, and therefore has serious implications for setting and reaching elimination targets. Reframing of the guidelines on compliance definitions coupled with an urgent call for longitudinal research in systematic non-compliance should be essential elements in the programmatic shift from control to elimination.
Topics: Animals; Anthelmintics; Chemoprevention; Disease Eradication; Elephantiasis, Filarial; Helminthiasis; Neglected Diseases; Schistosomiasis; Tropical Medicine
PubMed: 26813098
DOI: 10.1186/s13071-016-1311-1 -
Transactions of the Royal Society of... Nov 2023The aberrant migration of Ascaris lumbricoides may cause extra-intestinal ascariasis (EIA) involving hepato-biliary-pancreatic (HBP) or other extra-gastro-intestinal... (Meta-Analysis)
Meta-Analysis
The aberrant migration of Ascaris lumbricoides may cause extra-intestinal ascariasis (EIA) involving hepato-biliary-pancreatic (HBP) or other extra-gastro-intestinal (EGI) organs. We performed a systematic review and meta-analysis to study the risk factors and clinical presentations of EIA, and differences in HBP and EGI ascariasis. Medline, Web of Science and Embase were searched for cases of EIA in the English language from India. From 1204 articles, 86 studies (105 cases) were included. The majority of the cases involved the HBP system (78%). Among HBP ascariasis, the most commonly involved site was the bile duct (53.6%). Females had 11.3 times higher odds (95% CI 2.852 to 44.856; p=0.001) of HBP ascariasis, while the pediatric population had lower odds (OR=0.323). Previous gallbladder disease was significantly associated with HBP ascariasis in adults (p=0.046), while a significantly higher number of cases of EGI ascariasis were observed among pediatric patients (p=0.003). Ocular symptoms occurred exclusively in the pediatric population (p=0.017). Overall, death was reported in 3.8% of patients (n=4). This review emphasizes the importance of the complications of EIA. It encourages future research into issues such as the reasons of higher gall bladder ascariasis in females and the implications of Ascaris-related complications following biliary tract interventions. It also suggests considering Ascaris as a differential diagnosis for airway obstuction in intubated critically ill patients.
Topics: Adult; Animals; Female; Child; Humans; Ascariasis; Ascaris lumbricoides; Intestines; Gastrointestinal Tract; India
PubMed: 37264906
DOI: 10.1093/trstmh/trad033 -
Le Infezioni in Medicina 2022Intestinal helminthiasis are a common public health problem in developed and developing countries. It is thought that they can influence pregnancy by causing gestational... (Review)
Review
Intestinal helminthiasis are a common public health problem in developed and developing countries. It is thought that they can influence pregnancy by causing gestational anemia. The aim of this study was to determine if there is a relationship between helminth infection and gestational anemia. A structured review of scientific literature was conducted through active search in the electronic databases MEDLINE and LILACS until December 2021, following 2020 PRISMA statement. The studies were reviewed independently by two authors, extracting the most relevant information from each study. Cross-sectional studies, case-control and ecological studies were included, with no date or language limit. Randomized clinical trials were excluded. A total of 38 studies were included in the systematic review. The study populations of all studies belonged to low- and middle-income countries: 28 studies from Africa, 6 from Asia, 3 from Latin America and 1 from Oceania. Overall, the average prevalence of gestational anemia among the included studies was 40% (95% CI 34-46%). Hookworm was the predominant species detected in most studies (19/38; 50%), followed by (15/38; 39.5%). Gestational anemia was positively associated with (OR 1.86, 95% CI 1.12-3.08) and hookworms (OR 3.09, 95% CI 1.99-4.78). Prevalence of malaria was not associated with the magnitude of the effect of hookworm on anemia risk during meta-regression (p=0.5182). The results of this review indicate that there is a statistically significant association between helminthiasis and gestational anemia. Although hookworm is the main species associated with the outcome, prevalence of malaria was not associated with the magnitude of the effect of hookworm on anemia risk. The impact of other species needs to be defined given the expected bias that arises from polyparasitism when defining comparison groups.
PubMed: 36908393
DOI: 10.53854/liim-3101-6 -
PLoS Neglected Tropical Diseases Jan 2018Soil-transmitted helminth (STH) infections are among the most prevalent neglected tropical diseases (NTD) worldwide. Since the publication of the WHO road map to combat...
BACKGROUND
Soil-transmitted helminth (STH) infections are among the most prevalent neglected tropical diseases (NTD) worldwide. Since the publication of the WHO road map to combat NTD in 2012, there has been a renewed commitment to control STH. In this study, we analysed the geographical distribution and effect of community type on prevalence of hookworm, Trichuris and Ascaris in south Asia and south east Asia.
METHODOLOGY
We conducted a systematic review of open-access literature published in PubMed Central and the Global Atlas of Helminth Infection. A total of 4182 articles were available and after applying selection criteria, 174 studies from the region were retained for analysis.
PRINCIPAL FINDINGS
Ascaris was the commonest STH identified with an overall prevalence of 18% (95% CI, 14-23%) followed by Trichuris (14%, 9-19%) and hookworm (12%, 9-15%). Hookworm prevalence was highest in Laos, Vietnam and Cambodia. We found a geographical overlap in countries with high prevalence rates for Trichuris and Ascaris (Malaysia, Philippines, Myanmar, Vietnam and Bangladesh). When the effect of community type was examined, prevalence rates of hookworm was comparable in rural (19%, 14-24%) and tribal communities (14%, 10-19%). Tribal communities, however, showed higher prevalence of Trichuris (38%, 18-63%) and Ascaris (32%, 23-43%) than rural communities (13%, 9-20% and 14%, 9-20% respectively). Considerable between and within country heterogeneity in the distribution of STH (I2 >90%) was also noted. When available data from school aged children (SAC) were analysed, prevalence of Ascaris (25% 16-31%) and Trichuris (22%, 14-34%) were higher than among the general population while that of hookworm (10%, 7-16%) was comparable.
CONCLUSIONS/SIGNIFICANCE
Our analysis showed significant variation in prevalence rates between and within countries in the region. Highlighting the importance of community type in prevalence and species mix, we showed that tribal and rural communities had higher hookworm infections than urban communities and for ascariasis and trichuriasis, tribal populations had higher levels of infection than rural populations. We also found a higher prevalence of ascariasis and trichuriasis in SAC compared to the general population but comparable levels of hookworm infections. These key findings need to be taken into account in planning future MDA and other interventions.
Topics: Ascariasis; Asia, Southeastern; Humans; Prevalence; Rural Population; Topography, Medical; Trichuriasis; Urban Population
PubMed: 29346440
DOI: 10.1371/journal.pntd.0006153 -
PLoS Neglected Tropical Diseases Feb 2016Neglected Tropical Diseases (NTDs) not only cause health and life expectancy loss, but can also lead to economic consequences including reduced ability to work. This... (Review)
Review
BACKGROUND
Neglected Tropical Diseases (NTDs) not only cause health and life expectancy loss, but can also lead to economic consequences including reduced ability to work. This article describes a systematic literature review of the effect on the economic productivity of individuals affected by one of the five worldwide most prevalent NTDs: lymphatic filariasis, onchocerciasis, schistosomiasis, soil-transmitted helminths (ascariasis, trichuriasis, and hookworm infection) and trachoma. These diseases are eligible to preventive chemotherapy (PCT).
METHODOLOGY/PRINCIPAL FINDINGS
Eleven bibliographic databases were searched using different names of all NTDs and various keywords relating to productivity. Additional references were identified through reference lists from relevant papers. Of the 5316 unique publications found in the database searches, thirteen papers were identified for lymphatic filariasis, ten for onchocerciasis, eleven for schistosomiasis, six for soil-transmitted helminths and three for trachoma. Besides the scarcity in publications reporting the degree of productivity loss, this review revealed large variation in the estimated productivity loss related to these NTDs.
CONCLUSIONS
It is clear that productivity is affected by NTDs, although the actual impact depends on the type and severity of the NTD as well as on the context where the disease occurs. The largest impact on productivity loss of individuals affected by one of these diseases seems to be due to blindness from onchocerciasis and severe schistosomiasis manifestations; productivity loss due to trachoma-related blindness has never been studied directly. However, productivity loss at an individual level might differ from productivity loss at a population level because of differences in the prevalence of NTDs. Variation in estimated productivity loss between and within diseases is caused by differences in research methods and setting. Publications should provide enough information to enable readers to assess the quality and relevance of the study for their purposes.
Topics: Animals; Chemoprevention; Humans; Neglected Diseases; Tropical Medicine; Work
PubMed: 26890487
DOI: 10.1371/journal.pntd.0004397 -
PLoS Neglected Tropical Diseases Nov 2017Human excreta is a low cost source of nutrients vital to plant growth, but also a source of pathogens transmissible to people and animals. We investigated the... (Meta-Analysis)
Meta-Analysis Review
Human excreta is a low cost source of nutrients vital to plant growth, but also a source of pathogens transmissible to people and animals. We investigated the cost-savings and infection risk of soil transmitted helminths (STHs) in four scenarios where farmers used either inorganic fertilizer or fresh/composted human excreta supplemented by inorganic fertilizer to meet the nutrient requirements of rice paddies in the Red River Delta, Vietnam. Our study included two main components: 1) a risk estimate of STH infection for farmers who handle fresh excreta, determined by systematic review and meta-analysis; and 2) a cost estimate of fertilizing rice paddies, determined by nutrient assessment of excreta, a retailer survey of inorganic fertilizer costs, and a literature review to identify region-specific inputs. Our findings suggest that farmers who reuse fresh excreta are 1.24 (95% CI: 1.13-1.37, p-value<0.001) times more likely to be infected with any STH than those who do not handle excreta or who compost appropriately, and that risk varies by STH type (Ascaris lumbricoides RR = 1.17, 95% CI = 0.87-1.58, p-value = 0.29; Hookworm RR = 1.02, 95% CI = 0.50-2.06, p-value = 0.96; Trichuris trichiura RR = 1.38, 95% CI = 0.79-2.42, p-value = 0.26). Average cost-savings were highest for farmers using fresh excreta (847,000 VND) followed by those who composted for 6 months as recommended by the WHO (312,000 VND) and those who composted for a shorter time (5 months) with lime supplementation (37,000 VND/yr); however, this study did not assess healthcare costs of treating acute or chronic STH infections in the target group. Our study provides evidence that farmers in the Red River Delta are able to use a renewable and locally available resource to their economic advantage, while minimizing the risk of STH infection.
Topics: Agriculture; Ancylostomatoidea; Animals; Ascariasis; Ascaris lumbricoides; Body Fluids; Cost-Benefit Analysis; Feces; Hookworm Infections; Humans; Linear Models; Soil; Trichuriasis; Trichuris; Vietnam
PubMed: 29176840
DOI: 10.1371/journal.pntd.0006088 -
Clinical Infectious Diseases : An... Jan 2019Periodic mass distribution of benzimidazole anthelminthic drugs is the key strategy to control soil-transmitted helminths (STHs) globally. However, benzimidazoles have... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Periodic mass distribution of benzimidazole anthelminthic drugs is the key strategy to control soil-transmitted helminths (STHs) globally. However, benzimidazoles have low efficacy against Trichuris trichiura, and there are concerns about benzimidazole resistance potentially emerging in humans. Therefore, identifying alternative drug regimens is a pressing priority. We present a systematic review and network meta-analysis comparing the efficacy of 21 different anthelminthic drug regimens, including standard, novel, and combination treatments.
METHODS
We searched PubMed, Medline, Embase, Web of Science, and Cochrane databases and identified studies comparing anthelminthic treatments to each other or placebo. The outcomes calculated were relative risk (RR) of cure and difference in egg reduction rates (dERR). We used an automated generalized pairwise modeling framework to generate mixed treatment effects against a common comparator, the current standard treatment (single-dose albendazole).
RESULTS
Our search identified 4876 studies, of which 114 were included in the meta-analysis. Results identified several drug combinations with higher efficacy than single-dose albendazole for T. trichiura, including albendazole-ivermectin (RR of cure, 3.22 [95% confidence interval {CI}, 1.84-5.63]; dERR, 0.97 [95% CI, .21-1.74]), albendazole-oxantel pamoate (RR, 5.07 [95% CI, 1.65-15.59]; dERR, 0.51 [95% CI, .50-.52]), mebendazole-ivermectin (RR, 3.37 [95% CI, 2.20-5.16]), and tribendimidine-oxantel pamoate (RR, 4.06 [95% CI, 1.30-12.64]).
CONCLUSIONS
There are several promising drug combinations that may enhance the impact of STH control programs on T. trichiura, without compromising efficacy against Ascaris lumbricoides and hookworm. We suggest further, large-scale trials of these drug combinations and consideration of their use in STH control programs where T. trichiura is present.
INTERNATIONAL PROSPECTIVE REGISTER OF SYSTEMATIC REVIEWS REGISTRATION
CRD42016050739.
Topics: Anthelmintics; Ascariasis; Drug Combinations; Humans; Mass Drug Administration; Placebos; Prospective Studies; Treatment Outcome; Trichuriasis
PubMed: 29788074
DOI: 10.1093/cid/ciy423 -
PLoS Neglected Tropical Diseases Aug 2019In South Asia, hundreds of millions of people are infected with soil-transmitted helminths (Ascaris lumbricoides, hookworm, and Trichuris trichiura). However,...
BACKGROUND
In South Asia, hundreds of millions of people are infected with soil-transmitted helminths (Ascaris lumbricoides, hookworm, and Trichuris trichiura). However, high-resolution risk profiles and the estimated number of people infected have yet to be determined. In turn, such information will assist control programs to identify priority areas for allocation of scarce resource for the control of soil-transmitted helminth infection.
METHODOLOGY
We pursued a systematic review to identify prevalence surveys pertaining to soil-transmitted helminth infections in four mainland countries (i.e., Bangladesh, India, Nepal, and Pakistan) of South Asia. PubMed and ISI Web of Science were searched from inception to April 25, 2019, without restriction of language, study design, and survey date. We utilized Bayesian geostatistical models to identify environmental and socioeconomic predictors, and to estimate infection risk at high spatial resolution across the study region.
PRINCIPAL FINDINGS
A total of 536, 490, and 410 georeferenced surveys were identified for A. lumbricoides, hookworm, and T. trichiura, respectively. We estimate that 361 million people (95% Bayesian credible interval (BCI) 331-395 million), approximately one-quarter of the South Asia population, was infected with at least one soil-transmitted helminth species in 2015. A. lumbricoides was the predominant species. Moderate to high prevalence (>20%) of any soil-transmitted helminth infection was predicted in the northeastern part and some northern areas of the study region, as well as the southern coastal areas of India. The annual treatment needs for the school-age population requiring preventive chemotherapy was estimated at 165 million doses (95% BCI: 146-185 million).
CONCLUSIONS/SIGNIFICANCE
Our risk maps provide an overview of the geographic distribution of soil-transmitted helminth infection in four mainland countries of South Asia and highlight the need for up-to-date surveys to accurately evaluate the disease burden in the region.
Topics: Ancylostomatoidea; Animals; Ascariasis; Ascaris lumbricoides; Asia; Bangladesh; Bayes Theorem; Databases, Factual; Helminthiasis; Helminths; Hookworm Infections; Humans; India; Nepal; Pakistan; Prevalence; Risk Factors; Socioeconomic Factors; Soil; Trichuriasis; Trichuris
PubMed: 31398200
DOI: 10.1371/journal.pntd.0007580 -
Scientific Reports Jul 2023Soil-transmitted Helminth (STH) infections have been found associated with people living with human immunodeficiency virus (HIV) but little is known about the overall... (Meta-Analysis)
Meta-Analysis
Soil-transmitted Helminth (STH) infections have been found associated with people living with human immunodeficiency virus (HIV) but little is known about the overall burden of STH coinfection in HIV patients. We aimed to assess the burden of STH infections among HIV patients. Relevant databases were systematically searched for studies reporting the prevalence of soil-transmitted helminthic pathogens in HIV patients. Pooled estimates of each helminthic infection were calculated. The odds ratio was also determined as a measure of the association between STH infection and the HIV status of the patients. Sixty-one studies were finally included in the meta-analysis, consisting of 16,203 human subjects from all over the world. The prevalence of Ascaris lumbricoides infection in HIV patients was found to be 8% (95% CI 0.06, 0.09), the prevalence of Trichuris trichiura infection in HIV patients was found to be 5% (95% CI 0.04, 0.06), the prevalence of hookworm infection in HIV patients was found to be 5% (95% CI 0.04, 0.06), and prevalence of Strongyloides stercoralis infection in HIV patients was found to be 5% (95% CI 0.04, 0.05). Countries from Sub-Saharan Africa, Latin America & Caribbean and Asia were identified with the highest burden of STH-HIV coinfection. Our analysis indicated that people living with HIV have a higher chance of developing Strongyloides stercoralis infections and decreased odds of developing hookworm infections. Our findings suggest a moderate level of prevalence of STH infections among people living with HIV. The endemicity of STH infections and HIV status both are partially responsible for the burden of STH-HIV coinfections.
Topics: Animals; Humans; Prevalence; HIV; Soil; HIV Infections; Helminthiasis; Ascariasis; Hookworm Infections; Helminths; Strongyloidiasis; Coinfection; Feces; Ascaris lumbricoides
PubMed: 37422549
DOI: 10.1038/s41598-023-38030-y -
Parasites & Vectors Jan 2018The human helminth infections include ascariasis, trichuriasis, hookworm infections, schistosomiasis, lymphatic filariasis (LF) and onchocerciasis. It is estimated that...
BACKGROUND
The human helminth infections include ascariasis, trichuriasis, hookworm infections, schistosomiasis, lymphatic filariasis (LF) and onchocerciasis. It is estimated that almost 2 billion people worldwide are infected with helminths. Whilst the WHO treatment guidelines for helminth infections are mostly aimed at controlling morbidity, there has been a recent shift with some countries moving towards goals of disease elimination through mass drug administration, especially for LF and onchocerciasis. However, as prevalence is driven lower, treating entire populations may no longer be the most efficient or cost-effective strategy. Instead, it may be beneficial to identify individuals or demographic groups who are persistently infected, often termed as being "predisposed" to infection, and target treatment at them.
METHODS
The authors searched Embase, MEDLINE, Global Health, and Web of Science for all English language, human-based papers investigating predisposition to helminth infections published up to October 31st, 2017. The varying definitions used to describe predisposition, and the statistical tests used to determine its presence, are summarised. Evidence for predisposition is presented, stratified by helminth species, and risk factors for predisposition to infection are identified and discussed.
RESULTS
In total, 43 papers were identified, summarising results from 34 different studies in 23 countries. Consistent evidence of predisposition to infection with certain species of human helminth was identified. Children were regularly found to experience greater predisposition to Ascaris lumbricoides, Schistosoma mansoni and S. haematobium than adults. Females were found to be more predisposed to A. lumbricoides infection than were males. Household clustering of infection was identified for A. lumbricoides, T. trichiura and S. japonicum. Ascaris lumbricoides and T. trichiura also showed evidence of familial predisposition. Whilst strong evidence for predisposition to hookworm infection was identified, findings with regards to which groups were affected were considerably more varied than for other helminth species.
CONCLUSION
This review has found consistent evidence of predisposition to heavy (and light) infection for certain human helminth species. However, further research is needed to identify reasons for the reported differences between demographic groups. Molecular epidemiological methods associated with whole genome sequencing to determine 'who infects whom' may shed more light on the factors generating predisposition.
Topics: Adult; Age Factors; Ascariasis; Child; Disease Susceptibility; Feces; Female; Helminthiasis; Hookworm Infections; Humans; Intestinal Diseases, Parasitic; Male; Prevalence; Risk Factors; Sex Factors; Soil; Trichuriasis
PubMed: 29382360
DOI: 10.1186/s13071-018-2656-4