-
The American Journal of Tropical... Jul 2020Hookworm infections are classified as the most impactful of the human soil-transmitted helminth (STH) infections, causing a disease burden of ∼4 million...
Hookworm infections are classified as the most impactful of the human soil-transmitted helminth (STH) infections, causing a disease burden of ∼4 million disability-adjusted life years, with a global prevalence of 406-480 million infections. Until a decade ago, epidemiological surveys largely assumed and as the relevant human hookworm species implicated as contributing to iron-deficiency anemia. This assumption was based on the indistinguishable morphology of the spp. eggs in stool and the absence of awareness of a third zoonotic hookworm species, . The expanded use of molecular diagnostic assays for differentiating hookworm species infections during STH surveys has now implicated , a predominant hookworm of dogs in Asia, as the second most common hookworm species infecting humans in Southeast Asia and the Pacific. Despite this, with the exception of sporadic case reports, there is a paucity of data available on the impact of this emerging zoonosis on human health at a population level. This situation also challenges the current paradigm, necessitating a One Health approach to hookworm control in populations in which this zoonosis is endemic. Here, we have summarized the available research studies and case reports on human infections in Southeast Asia and the Pacific after 2013 using a systematic review approach. We summarized eight research articles and five clinical case studies, highlighting the importance of future in-depth investigation of zoonotic infections using sensitive and cost-effective diagnostic tools.
Topics: Ancylostoma; Ancylostomiasis; Animals; Asia, Southeastern; Dog Diseases; Dogs; Feces; Humans; Neglected Diseases; One Health; Pacific Islands; Parasite Egg Count; Zoonoses
PubMed: 32342850
DOI: 10.4269/ajtmh.20-0060 -
Transactions of the Royal Society of... Nov 2016Qualitative evidence suggests that inadequate water, sanitation and hygiene (WASH) may affect diarrheal and helminthic infection in women disproportionately. We... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Qualitative evidence suggests that inadequate water, sanitation and hygiene (WASH) may affect diarrheal and helminthic infection in women disproportionately. We systematically searched PubMed in June 2014 (updated 2016) and the WHO website, for relevant articles.
METHODS
Articles dealing with the public health relevance of helminthic and diarrheal diseases, and highlighting the role of gender in WASH were included. Where possible, we carried out a meta-analysis.
RESULTS
In studies of individuals 5 years or older, cholera showed lower prevalence in males (OR 0.56; 95% CI 0.34-0.94), while Schistosoma mansoni (1.38; 95% CI 1.14-1.67), Schistosoma japonicum (1.52; 95% CI 1.13-2.05), hookworm (1.43; 95% CI 1.07-1.89) and all forms of infectious diarrhea (1.21; 95% CI 1.06-1.38) showed a higher prevalence in males. When studies included all participants, S. mansoni and S. japonicum showed higher prevalence with males (OR 1.40; 95% CI 1.27-1.55 and 1.84; 95% CI 1.27-2.67, respectively). Prevalence of Trichiuris and hookworm infection showed effect modification with continent.
CONCLUSIONS
Evidence of gender differences in infection may reflect differences in gender norms, suggesting that policy changes at the regional level may help ameliorate gender related disparities in helminthic and diarrheal disease prevalence.
Topics: Diarrhea; Female; Helminthiasis; Humans; Hygiene; Male; Sex Factors; Water Supply
PubMed: 28115686
DOI: 10.1093/trstmh/trw080 -
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 -
Nature Communications Sep 2019Agriculture has been implicated as a potential driver of human infectious diseases. However, the generality of disease-agriculture relationships has not been... (Meta-Analysis)
Meta-Analysis
Agriculture has been implicated as a potential driver of human infectious diseases. However, the generality of disease-agriculture relationships has not been systematically assessed, hindering efforts to incorporate human health considerations into land-use and development policies. Here we perform a meta-analysis with 34 eligible studies and show that people who live or work in agricultural land in Southeast Asia are on average 1.74 (CI 1.47-2.07) times as likely to be infected with a pathogen than those unexposed. Effect sizes are greatest for exposure to oil palm, rubber, and non-poultry based livestock farming and for hookworm (OR 2.42, CI 1.56-3.75), malaria (OR 2.00, CI 1.46-2.73), scrub typhus (OR 2.37, CI 1.41-3.96) and spotted fever group diseases (OR 3.91, CI 2.61-5.85). In contrast, no change in infection risk is detected for faecal-oral route diseases. Although responses vary by land-use and disease types, results suggest that agricultural land-uses exacerbate many infectious diseases in Southeast Asia.
Topics: Agriculture; Animals; Asia, Southeastern; Communicable Diseases; Databases, Factual; Ecosystem; Humans; Risk Factors
PubMed: 31541099
DOI: 10.1038/s41467-019-12333-z -
Journal of Travel Medicine Mar 2020Gestational helminth infections are correlated to adverse outcomes including maternal anaemia; as such, treatment is recommended. However, little published high-quality... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Gestational helminth infections are correlated to adverse outcomes including maternal anaemia; as such, treatment is recommended. However, little published high-quality data exist around the efficacy, safety and tolerability of anti-helminthics in pregnancy. We therefore conducted a systematic review and synthesized the available data on maternal outcomes following gestational treatment of intestinal nematodes to help guide clinical decision-making.
METHODS
Five electronic databases were searched for studies reporting the efficacy, safety or tolerability of anti-helminthic drugs for gestational treatment of intestinal nematodes. Studies were systematically screened followed by data extraction. Trial quality was assessed using the Grading of Recommendations Assessment, Development and Evaluation approach. We conducted a narrative synthesis followed by meta-analyses using random effects models as appropriate. Data were summarized using qualitative and quantitative measures for specific parasitic infections as well as efficacy and safety of anti-parasitic agents. Outcomes of interest included maternal anaemia, minor adverse outcomes, pregnancy loss, pre-mature delivery, prevalence of infection and cure rate.
RESULTS
Twenty-three studies were included. Gestational treatment with albendazole had cure rates up to 90% for hookworm and Ascaris, but only 50% for Trichuris. Mebendazole had an overall cure rate of ≤ 70% for Ascaris, hookworm and Trichuris. Pooled relative risk reduction of hookworm prevalence at delivery with albendazole compared to placebo was 90% (95% confidence interval, 0.09-0.15; n = 2; I2 = 0%). Rate of pregnancy loss and haemoglobin concentration did not differ between albendazole or mebendazole vs placebo, and rates of pre-term delivery were similar in albendazole-treated pregnant women vs controls. Ivermectin demonstrated a cure rate of 29% for hookworm and 56% for Trichuris in pregnant women. No serious adverse events were attributable to any drug studied.
CONCLUSIONS
With increased international travel and migration of vulnerable populations, practitioners will encounter nematode infections in pregnant patients. Our analysis supports that albendazole in pregnancy has high cure rates for soil-transmitted helminths and is safe for the mother.
Topics: Albendazole; Animals; Anthelmintics; Female; Helminthiasis; Helminths; Humans; Pregnancy; Soil; Travel-Related Illness
PubMed: 31641774
DOI: 10.1093/jtm/taz079 -
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 -
PloS One 2020The effect of nutritional supplements on the re-infection rate of species-specific soil-transmitted helminth infections in school-aged children remains complex and... (Meta-Analysis)
Meta-Analysis
BACKGROUND
The effect of nutritional supplements on the re-infection rate of species-specific soil-transmitted helminth infections in school-aged children remains complex and available evidence on the subject matter has not been synthesized.
METHODS
The review included randomised controlled trials (RCTs) and cluster RCTs investigating food supplements on school-aged children between the age of 4-17 years. A search for RCTs was conducted on eight databases from inception to 12th June 2019. Cochrane Risk of Bias tool was used to assess the risk of bias in all included studies. Meta-analysis and narrative synthesis were conducted to describe and analyze the results of the review. Outcomes were summarized using the mean difference or standardized mean difference where appropriate.
RESULTS
The search produced 1,816 records. Six studies met the inclusion criteria (five individually RCTs and one cluster RCT). Four studies reported data on all three STH species, while one study only reported data on Ascaris lumbricoides infections and the last study reported data on only hookworm infections. Overall, the risk of bias in four individual studies was low across most domains. Nutritional supplementation failed to statistically reduce the re-infection rates of the three STH species. The effect of nutritional supplements on measures of physical wellbeing in school-aged children could not be determined.
CONCLUSIONS
The findings from this systematic review suggest that nutritional supplements for treatment of STH in children should not be encouraged unless better evidence emerges. Conclusion of earlier reviews on general populations may not necessarily apply to children since children possibly have a higher re-infection rate.
Topics: Ascariasis; Child; Dietary Supplements; Humans; Micronutrients; Randomized Controlled Trials as Topic; Soil; Trichuriasis; Vitamins
PubMed: 32790693
DOI: 10.1371/journal.pone.0237112 -
International Health Jan 2024Patients with diabetes are at an increased risk of intestinal parasitic infections (IPIs). We evaluated the pooled prevalence and OR of IPIs in patients with diabetes... (Meta-Analysis)
Meta-Analysis
Patients with diabetes are at an increased risk of intestinal parasitic infections (IPIs). We evaluated the pooled prevalence and OR of IPIs in patients with diabetes through a systematic review and meta-analysis. A systematic search was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol for studies reporting IPIs in patients with diabetes through 1 August 2022. The collected data were analyzed using comprehensive meta-analysis software version 2. Thirteen case-control studies and nine cross-sectional studies were included in this study. The overall prevalence of IPIs in patients with diabetes was calculated to be 24.4% (95% CI 18.8 to 31%). Considering the case-control design, the prevalence of IPIs in case (25.7%; 95% CI 18.4 to 34.5%) was higher than controls (15.5%; 95% CI 8.4 to 26.9%) and a significant correlation was observed (OR, 1.80; 95% CI 1.08 to 2.97%). Moreover, a significant correlation was seen in the prevalence of Cryptosporidium spp. (OR, 3.30%; 95% CI 1.86 to 5.86%), Blastocystis sp. (OR, 1.57%; 95% CI 1.11 to 2.22%) and hookworm (OR, 6.09%; 95% CI 1.11 to 33.41%) in the cases group. The present results revealed a higher prevalence of IPIs in patients with diabetes than in controls. Therefore, the results of this study suggest a proper health education program to preventing measures for the acquisition of IPIs in patients with diabetes.
Topics: Humans; Prevalence; Cross-Sectional Studies; Cryptosporidiosis; Cryptosporidium; Feces; Intestinal Diseases, Parasitic; Diabetes Mellitus
PubMed: 37052134
DOI: 10.1093/inthealth/ihad027 -
The Cochrane Database of Systematic... Oct 2019Rice fortification with vitamins and minerals has the potential to increase the nutrition in rice-consuming countries where micronutrient deficiencies exist. Globally,... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Rice fortification with vitamins and minerals has the potential to increase the nutrition in rice-consuming countries where micronutrient deficiencies exist. Globally, 490 million metric tonnes of rice are consumed annually. It is the dominant staple food crop of around three billion people.
OBJECTIVES
To determine the benefits and harms of rice fortification with vitamins and minerals (iron, vitamin A, zinc or folic acid) on micronutrient status and health-related outcomes in the general population.
SEARCH METHODS
We searched CENTRAL, MEDLINE, Embase, CINAHL, and 16 other databases all up to 10 December 2018. We searched ClinicalTrials.gov, and World Health Organization International Clinical Trials Registry Platform (ICTRP) on 10 December 2018.
SELECTION CRITERIA
We included randomised and quasi-randomised trials (with either individual or cluster randomisation) and controlled before-and-after studies. Participants were populations older than two years of age (including pregnant women) from any country. The intervention was rice fortified with at least one micronutrient or a combination of several micronutrients (iron, folic acid, zinc, vitamin A or other vitamins and minerals) compared with unfortified rice or no intervention.
DATA COLLECTION AND ANALYSIS
We used standard methodological procedures expected by Cochrane. Two review authors independently screened studies and extracted data.
MAIN RESULTS
We included 17 studies (10,483 participants) and identified two ongoing studies. Twelve included studies were randomised-controlled trials (RCTs), with 2238 participants after adjusting for clustering in two cluster-RCTs, and five were non-randomised studies (NRS) with four controlled before-and-after studies and one cross-sectional study with a control (8245 participants). Four studies were conducted in India, three in Thailand, two in the Philippines, two in Brazil, one each in Bangladesh, Burundi, Cambodia, Indonesia, Mexico and the USA. Two studies involved non-pregnant, non-lactating women and 10 involved pre-school or school-age children. All 17 studies reported fortification with iron. Of these, six studies fortified rice with iron only; 11 studies had other micronutrients added (iron, zinc and vitamin A, and folic acid). One study had one arm each with vitamin A alone and carotenoid alone. Elemental iron content ranged from 0.2 to 112.8 mg/100 g uncooked rice given for a period varying from two weeks to 48 months. Thirteen studies did not clearly describe either sequence generation or allocation concealment. Eleven studies had a low attrition rate. There was no indication of selective reporting in the studies. We considered two RCTs at low overall risk of bias and 10 at high overall risk of bias. One RCT was at high or unclear risk of bias for most of the domains. All controlled before-and-after studies had a high risk or unclear risk of bias in most domains. The included studies were funded by Government, private and non-governmental organisations, along with other academic institutions. The source of funding does not appear to have altered the results. We used the NRS in the qualitative synthesis but we excluded them from the quantitative analysis and review conclusions since they provided mostly contextual information and limited quantitative information. Rice fortified with iron alone or in combination with other micronutrients versus unfortified rice (no micronutrients added) Fortification of rice with iron (alone or in combination with other micronutrients) may make little or no difference in the risk of having anaemia (risk ratio (RR) 0.72, 95% confidence interval (CI) 0.54 to 0.97; I = 74%; 7 studies, 1634 participants; low-certainty evidence) and may reduce the risk of iron deficiency (RR 0.66, 95% CI 0.51 to 0.84; 8 studies, 1733 participants; low-certainty evidence). Rice fortification may increase mean haemoglobin (mean difference (MD) 1.83, 95% CI 0.66 to 3.00; I = 54%; 11 studies, 2163 participants; low-certainty evidence) and it may make little or no difference to vitamin A deficiency (with vitamin A as one of the micronutrients in the fortification arm) (RR 0.68, 95% CI 0.36 to 1.29; I = 37%; 4 studies, 927 participants; low-certainty evidence). One study reported that fortification of rice (with folic acid as one of the micronutrients) may improve serum or plasma folate (nmol/L) (MD 4.30, 95% CI 2.00 to 6.60; 215 participants; low-certainty evidence). One study reported that fortification of rice with iron alone or with other micronutrients may slightly increase hookworm infection (RR 1.78, 95% CI 1.18 to 2.70; 785 participants; low-certainty evidence). We are uncertain about the effect of fortified rice on diarrhoea (RR 3.52, 95% CI 0.18 to 67.39; 1 study, 258 participants; very low-certainty evidence). Rice fortified with vitamin A alone or in combination with other micronutrients versus unfortified rice (no micronutrients added) One study had one arm providing fortified rice with vitamin A only versus unfortified rice. Fortification of rice with vitamin A (in combination with other micronutrients) may increase mean haemoglobin (MD 10.00, 95% CI 8.79 to 11.21; 1 study, 74 participants; low-certainty evidence). Rice fortified with vitamin A may slightly improve serum retinol concentration (MD 0.17, 95% CI 0.13 to 0.21; 1 study, 74 participants; low-certainty evidence). No studies contributed data to the comparisons of rice fortification versus no intervention. The studies involving folic acid and zinc also involved iron in the fortification arms and hence we reported them as part of the first comparison.
AUTHORS' CONCLUSIONS
Fortification of rice with iron alone or in combination with other micronutrients may make little or no difference in the risk of having anaemia or presenting iron deficiency and we are uncertain about an increase in mean haemoglobin concentrations in the general population older than 2 years of age. Fortification of rice with iron and other micronutrients such as vitamin A or folic acid may make little or no difference in the risk of having vitamin A deficiency or on the serum folate concentration. There is limited evidence on any adverse effects of rice fortification.
Topics: Adolescent; Adult; Anemia, Iron-Deficiency; Avitaminosis; Child; Child, Preschool; Female; Food, Fortified; Humans; Male; Malnutrition; Micronutrients; Minerals; Oryza; Pregnancy; Randomized Controlled Trials as Topic; Vitamins; Young Adult
PubMed: 31684687
DOI: 10.1002/14651858.CD009902.pub2