Hookworm infection

The effect of novel aromatic heterocycle substituted aminamidine derivatives on Necator americanus

BACKGROUND

The efficacy of current drugs against hookworms at a single dose is highly variable across regions, age groups and infection intensity. Extensive and repeated use of these drugs also leads to potential drug resistance. Therefore, novel drugs are required for sustained disease control.

OBJECTIVES

Novel aromatic heterocycle substituted aminamidine derivatives (AADs) were synthesized based on tribendimine (TBD), and their in vivo potency against Necator americanus was tested.

METHODS

The efficacy of the AADs was tested in male hamsters. Oral and IV pharmacokinetic parameters were determined in male Sprague-Dawley rats. The proteomic profiles of N. americanus samples treated with AADs were compared using tandem mass tag-based quantitative proteomic analyses.

RESULTS

Most AADs exhibited better anthelmintic activity than TBD at a single oral dose. Compound 3c exhibited improved solubility (>50×), and the curative dose was as low as 25 mg/kg. Similar to TBD, 3c was rapidly metabolized after oral administration and transformed into p-(1-dimethylamino ethylimino)aniline (dADT), an active metabolite against intestinal nematodes. dADT from 3c had better pharmacokinetic profiles than that from TBD and achieved an oral bioavailability of 99.5%. Compound 3c possessed rapid anthelmintic activity, clearing all worms within 24 h after an oral dose of 50 mg/kg. Quantitative proteomic analysis indicated that it might be related to ATP metabolism and cuticle protein synthesis.

CONCLUSIONS

Compound 3c is a novel and promising compound against N. americanus in vivo.

Safety and immunogenicity of the co-administered Na-APR-1 and Na-GST-1 hookworm vaccines in school-aged children in Gabon: a randomised, controlled, observer-blind, phase 1, dose-escalation trial

BACKGROUND

A human hookworm vaccine is being developed to protect children against iron deficiency and anaemia associated with chronic infection with hookworms. Necator americanus aspartic protease-1 (Na-APR-1) and N americanus glutathione S-transferase-1 (Na-GST-1) are components of the blood digestion pathway critical to hookworm survival in the host. Recombinant Na-GST-1 and catalytically inactive Na-APR-1 (Na-APR-1[M74]) adsorbed to Alhydrogel were safe and immunogenic when delivered separately or co-administered to adults in phase 1 trials in non-endemic and endemic areas. We aimed to investigate the safety and immunogenicity of these antigens in healthy children in a hookworm-endemic area.

METHODS

This was a randomised, controlled, observer-blind, phase 1, dose-escalation trial, conducted in a clinical research centre, in 60 children aged six to ten years in Lambaréné, a hookworm-endemic region of Gabon. Healthy children (determined by clinical examination and safety laboratory testing) were randomised 4:1 to receive co-administered Na-GST-1 on Alhydrogel plus Na-APR-1(M74) on Alhydrogel and glucopyranosyl lipid A in aqueous formulation (GLA-AF), or co-administered ENGERIX-B hepatitis B vaccine (HBV) and saline placebo, injected into the deltoid of each arm. Allocation to vaccine groups was observer-masked. In each vaccine group, children were randomised 1:1 to receive intramuscular injections into each deltoid on two vaccine schedules, one at months 0, 2, and 4 or at months 0, 2, and 6. 10 μg, 30 μg, and 100 μg of each antigen were administered in the first, second, and third cohorts, respectively. The intention-to-treat population was used for safety analyses; while for immunogenicity analyses, the per-protocol population was used (children who received all scheduled vaccinations). The primary outcome was to evaluate the vaccines' safety and reactogenicity in healthy children aged between six and ten years. The secondary outcome was to measure antigen-specific serum IgG antibody levels at pre-vaccination and post-vaccination timepoints by qualified ELISAs. The trial is registered with ClinicalTrials.gov, NCT02839161, and is completed.

FINDINGS

Between Jan 23 and Oct 3, 2017, 137 children were screened, of whom 76 were eligible for this trial. 60 children were recruited, and allocated to either 10 μg of the co-administered antigens (n=8 for each injection schedule), 30 μg (n=8 for each schedule), 100 μg (n=8 for each schedule), or HBV and placebo (n=6 for each schedule) in three sequential cohorts. Co-administration of the vaccines was well tolerated; the most frequent solicited adverse events were mild-to-moderate injection-site pain, observed in up to 12 (75%) of 16 participants per vaccine group, and mild headache (12 [25%] of 48) and fever (11 [23%] of 48). No vaccine-related serious adverse events were observed. Significant anti-Na-APR-1(M74) and anti-Na-GST-1 IgG levels were induced in a dose-dependent manner, with peaks seen 14 days after the third vaccinations, regardless of dose (for Na-APR-1[M74], geometric mean levels [GML]=2295·97 arbitrary units [AU] and 726·89 AU, while for Na-GST-1, GMLs=331·2 AU and 21·4 AU for the month 0, 2, and 6 and month 0, 2, and 4 schedules, respectively). The month 0, 2, and 6 schedule induced significantly higher IgG responses to both antigens (p=0·01 and p=0·04 for Na-APR-1[M74] and Na-GST-1, respectively).

INTERPRETATION

Co-administration of recombinant Na-APR-1(M74) and Na-GST-1 to school-aged Gabonese children was well tolerated and induced significant IgG responses. These results justify further evaluation of this antigen combination in proof-of-concept controlled-infection and efficacy studies in hookworm-endemic areas.

FUNDING

European Union Seventh Framework Programme.

Factors associated with hookworm and Schistosoma mansoni infections among school-aged children in Mayuge district, Uganda

BACKGROUND

Hookworm infection and schistosomiasis are two of sub-Saharan Africa's most common neglected tropical diseases. An annual mass drug administration (MDA) program against schistosomiasis and soil-transmitted helminths (STHs), including hookworm, has been implemented in Mayuge district, Uganda, since 2003 to date. However, hookworm and schistosomiasis remain prevalent in Mayuge district. Understanding the factors that predispose children to these infections in the context of MDA could inform interventions to reduce prevalence in Uganda and similar settings.

METHOD

This cross-sectional study took place in 33 randomly selected primary schools in the Mayuge district from January to February 2022. Children in primary classes 4 or 5, in the selected schools provided single stool samples and completed questionnaires. Stool specimens were examined using the Kato-Katz method to determine the prevalence of hookworm and schistosomiasis. We performed univariable and multivariable logistic regression to assess the associations of each infection with potential risk factors.

RESULT

A total of 1,617 students (mean age 12.1 years, 50.1% male) were enrolled. The prevalence of hookworm infection and schistosomiasis was 21.8% (95% confidence interval (CI): 19.8-23.9%) and 18.7% (95% CI: 16.8-20.7%), respectively. In multivariable analysis, longer water fetching time (over 30 min versus less than 30 min) and working daily in the soil were associated with increased odds of hookworm infection (adjusted odds ratio (AOR): 1.49, 95% CI: 1.13-1.96 and 1.37, 95% CI: 1.03-1.82, respectively). Higher odds of schistosomiasis were linked to proximity to water bodies within a one-hour walking distance (AOR: 1.84, 95% CI: 1.35-2.50), and not always washing hands before eating (AOR: 2.00, 95% CI: 1.50-2.67). Swimming, bathing, or washing in water bodies twice a week, compared to never, also increased schistosomiasis odds (AOR: 2.91, 95% CI: 1.66-5.13).

CONCLUSION

Consistent with the mechanisms of acquisition, hookworm infection increased with exposure to soil, and schistosomiasis increased with exposure to unclean water. Our findings highlight the importance of Water, Sanitation, and Hygiene programs and strategies aimed at reducing exposure within the framework of Neglected Tropical Disease elimination programs.

Hookworm infection as a model for deepen knowledge of iron metabolism and erythropoiesis in anemia

Over the years, there has been progress in understanding the molecular aspects of iron metabolism and erythropoiesis. However, despite research conducted both in laboratories and living organisms, there are still unanswered questions due to the complex nature of these fields. In this study we investigated the effects of hookworm infection on iron metabolism and how the hosts response to anemia is affected using hamsters infected with Ancylostoma ceylanicum as a model. Our data revealed interesting relationships between infection-induced anemia, erythropoiesis, iron metabolism, and immune modulation, such that the elevated production of erythropoietin (EPO) in renal tissue indicated intensified erythropoiesis in response to anemia. Additionally, the increased expression of the erythroferrone (ERFE) gene in the spleen suggested its involvement in iron regulation and erythropoiesis. Gene expression patterns of genes related to iron metabolism varied in different tissues, indicating tissue-specific adaptations to hypoxia. The modulation of pro-inflammatory and anti-inflammatory cytokines highlighted the delicate balance between immune response and erythropoiesis. Data derived from the investigation of changes induced in iron metabolism and stress erythropoiesis following anemia aid in our understanding of mechanisms related to blood spoliation and anemia, which could potentially be extrapolated or compared to other types or causes of anemia. These findings also contribute to our understanding of the pathophysiology of erythropoiesis in the context of blood loss.

Carbon dioxide shapes parasite-host interactions in a human-infective nematode

Skin-penetrating nematodes infect nearly one billion people worldwide. The developmentally arrested infective larvae (iL3s) seek out hosts, invade hosts via skin penetration, and resume development inside the host in a process called activation. Activated infective larvae (iL3as) traverse the host body, ending up as parasitic adults in the small intestine. Skin-penetrating nematodes respond to many chemosensory cues, but how chemosensation contributes to host seeking, intra-host development, and intra-host navigation - three crucial steps of the parasite-host interaction - remains poorly understood. Here, we investigate the role of carbon dioxide (CO2) in promoting parasite-host interactions in the human-infective threadworm Strongyloides stercoralis. We show that S. stercoralis exhibits life-stage-specific preferences for CO2: iL3s are repelled, non-infective larvae and adults are neutral, and iL3as are attracted. CO2 repulsion in iL3s may prime them for host seeking by stimulating dispersal from host feces, while CO2 attraction in iL3as may direct worms toward high-CO2 areas of the body such as the lungs and intestine. We also identify sensory neurons that detect CO2; these neurons are depolarized by CO2 in iL3s and iL3as. In addition, we demonstrate that the receptor guanylate cyclase Ss-GCY-9 is expressed specifically in CO2-sensing neurons and is required for CO2-evoked behavior. Ss-GCY-9 also promotes activation, indicating that a single receptor can mediate both behavioral and physiological responses to CO2. Our results illuminate chemosensory mechanisms that shape the interaction between parasitic nematodes and their human hosts and may aid in the design of novel anthelmintics that target the CO2-sensing pathway.

Effects of Iron-Fortified Foods on the Nutritional Status of Children Residing in Regions Vulnerable to Parasitic Diseases: A Systematic Review

Parasitic infections (PIs) remain a public health concern among school-age children living in areas of greater socioeconomic vulnerability, especially in Brazil, Russia, India, China, and South Africa. PIs can promote nutritional deficiencies, increasing the risk of anemia and impaired physical and cognitive development. Thus, fortified foods have been considered as a promising strategy for improving the nutritional status of children and preventing PI complications. This systematic review aimed to present the effects of iron-fortified foods for deworming and improving blood parameters in schoolchildren residing in areas that are vulnerable to PIs. This review is based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines of randomized clinical trials addressing the use of fortified foods and micronutrients in children living in areas endemic for PIs. The PubMed, LILACS, Scopus, and Cochrane databases were searched to identify articles published between 2000 and 2020. A total of 153 records were retrieved from the databases, 10 of which were considered eligible for this study. On the basis of our analysis, most of the selected studies showed that the inclusion of fortified foods in the diet improved blood and infectious parameters. Therefore, fortified foods can be used as an important tool for controlling the adverse outcomes of PIs among children living in areas of greater vulnerability. However, more studies on this topic are needed to provide more evidence and consolidate strategies using iron-fortified food.

A Journey in Science: Molecular vaccines for global child health in troubled times of anti-science

My scientific life in translational medicine runs in two parallel, yet often converging paths. The first, is four-decade-long commitment to develop new vaccines for parasitic and neglected tropical diseases, as well as pandemic threats. This includes a vaccine for human hookworm infection that I began as an MD-PhD student in New York City in the 1980s, and a new low-cost COVID vaccine that reached almost 100 million people in low- and middle-income countries. Alongside this life in scientific research, is one in public engagement for vaccine and neglected disease diplomacy to ensure that people who live in extreme poverty can benefit from access to biomedical innovations. A troubling element has been the daunting task of countering rising antivaccine activism, which threatens to undermine our global vaccine ecosystem. Yet, this activity may turn out to become just as important for saving lives as developing new vaccines.

The effectiveness of albendazole against hookworm infections and the impact of bi-annual treatment on anaemia and body mass index of school children in the Kpandai district of northern Ghana

The impact of the Global Programme to Eliminate Lymphatic Filariasis (GPELF) (initiated in 2000 in Ghana and ran for 12 years) in mitigating soil-transmitted helminth (STH) infections in LF-endemic areas is unknown. During a 1-year hiatus which ensued between 2011 and 2012, a longitudinal study was conducted to determine GPELF effect on hookworm infections in selected communities involved in the programme since its inception, while measuring the effectiveness of biannual ALB treatments on schoolchildren living in such communities. A total of 399 school children aged 3 to 18 years were randomly selected from four communities in the Kpandai district of northern Ghana. Each presented a single stool sample at baseline, 21 days post-treatment, at the 3rd and 6th months, 21 days post-second intervention (i.e. following sample collection and treatment with ALB in the 6th month), and in the ninth month of the study period. Haemoglobin (hb) levels were also measured at all time points using finger prick blood samples and a URIT digital test kit. Each participant submitting a sample, was treated with a single-dose ALB (400mg) at baseline and in the sixth month. Stool samples were processed by preparing duplicate Kato-Katz slides per sample, and examined by microscopy. The Body Mass Index-for-age z-scores (BAZ) of participants were assessed following the determination of BMIs at each time point by measuring their height and weight with a stadiometer and weighing scale. Overall hookworm prevalences were 25.68% (95% CI = 20.51-31.75) at baseline, 11.18% (95% CI = 7.87-15.41) 21 days post-treatment, 11.78% (95% CI = 8.38-16.11) and 6.95% (95% CI = 4.41-10.43) in the 3rd and 6th months, 0.91% (95% CI = 0.19-2.65) 21 days post-second intervention, and 8.46% (95% CI = 5.62-12.23) in the ninth month. Observed overall faecal egg count reduction rates (ERRs) were 94.21% (95% CI = 81.50%- 100.00%) 21 days after baseline treatment, 97.70% (95% CI = 85.08-100.00) and 96.95% (95% CI = 84.18%- 100.00%) in the 3rd and 6th months, 99.98% (95% CI = 86.42%- 100.00%) 21 days post-second intervention, and 17.18% (95% CI = 14.07%- 20.67%) in the 9th month. Respective cure rates (CRs) were 62.35% (95% CI = 46.71-81.56%), 85.88% (95% CI = 67.32-100.00%), 87.06% (95% CI = 68.36%- 100.00%), 98.82% (95% CI = 78.83%- 100.00%), and 36.36% (95% CI = 9.91%- 93.11%). Additionally, increases in the percent frequency of 'normal hb' (p < 0.01) were observed across the study time points, whilst 'normal BAZ' cases remained high (from 94.87% to 98.87%) throughout the study period. These findings primarily indicate satisfactory effectiveness of ALB which may be maintainable in mass drug administration programmes by the modification of treatment strategies from annual to bi-annual regimes. This could minimize the likelihood of emerging poorly-responding hookworm phenotypes in Ghana. Additionally, a positive impact of bi-annual treatment on participant anaemia status is herein indicated with particular regard to the school children in our cohort.

A comprehensive assessment of deworming coverage among pregnant women in low- and middle-income countries, 2000-30

Background

Intestinal parasitic infections pose a significant global public health issue, particularly among pregnant women, who are generally more susceptible due to their elevated need for iron and nutrients. Deworming stands as a secure and efficacious public health intervention. The World Health Organization (WHO) set a target for the national deworming coverage rate among pregnant women at 75% by 2030. Nonetheless, the existing body of evidence on deworming among pregnant women in low- and middle-income countries (LMICs) remains limited.

Methods

Based on Demographic Health Survey (DHS) data from 56 LMICs (n = 924 277) between 2000 and 2022, we used Bayesian hierarchical models to estimate trends of deworming coverage up to 2030 and to analyse determinant factors of deworming.

Results

We found that, despite progress in deworming coverage estimates for most countries, only 11 (<20%) are on track to achieve the WHO target coverage at the national level. Inequality gaps were projected to increase in most LMICs. A multilevel model showed that increased numbers of antenatal care, access to safe water, and a higher wealth index were associated with higher odds of deworming.

Conclusions

The progress on deworming coverage and inequality in many countries remains insufficient for achieving the WHO target by 2030. Additional investments in the health sector towards the expansion of deworming programmes, along with integration with existing health services, are urgently required, as is the introduction of effective policies and strengthening programmes within the context of the 'Leave No One Behind' agenda.

Endoscopic Diagnosis of Hookworm Disease in a Patient with Severe Iron Deficiency Anemia: A Case Report

Hookworm infection is an important cause of iron deficiency anemia, especially in heavily infected high-risk populations residing in underdeveloped tropical countries. Stool examination is the main method used for hookworm diagnosis; however, its sensitivity is relatively low. Hookworm infections have been incidentally diagnosed during routine upper gastrointestinal endoscopies. We present the case of a 60-year-old Ethiopian farmer who had severe iron deficiency anemia and positive occult blood in the stool. Repeated stool examinations revealed no ova or parasites. Esophagogastroduodenoscopy revealed the presence of hookworms in the duodenum. The patient was treated with albendazole and ferrous sulfate. Careful endoscopic examination of the duodenum is crucial for identifying unsuspected hookworm infection responsible for chronic gastrointestinal bleeding and iron deficiency anemia.

Protective efficacy of short-term infection with Necator americanus hookworm larvae in healthy volunteers in the Netherlands: a single-centre, placebo-controlled, randomised, controlled, phase 1 trial

BACKGROUND

Vaccine development against hookworm is hampered by the absence of the development of protective immunity in populations repeatedly exposed to hookworm, limiting identification of mechanisms of protective immunity and new vaccine targets. Immunisation with attenuated larvae has proven effective in dogs and partial immunity has been achieved using an irradiated larvae model in healthy volunteers. We aimed to investigate the protective efficacy of immunisation with short-term larval infection against hookworm challenge.

METHODS

We did a single-centre, placebo-controlled, randomised, controlled, phase 1 trial at Leiden University Medical Center (Leiden, Netherlands). Healthy volunteers (aged 18-45 years) were recruited using advertisements on social media and in publicly accessible areas. Volunteers were randomly assigned (2:1) to receive three short-term infections with 50 infectious Necator americanus third-stage filariform larvae (50L3) or placebo. Infection was abrogated with a 3-day course of albendazole 400 mg, 2 weeks after each exposure. Subsequently all volunteers were challenged with two doses of 50L3 at a 2-week interval. The primary endpoint was egg load (geometric mean per g faeces) measured weekly between weeks 12 and 16 after first challenge, assessed in the per-protocol population, which included all randomly assigned volunteers with available data on egg counts at week 12-16 after challenge. This study is registered with ClinicalTrials.gov, NCT03702530.

FINDINGS

Between Nov 8 and Dec 14, 2018, 26 volunteers were screened, of whom 23 enrolled in the trial. The first immunisation was conducted on Dec 18, 2018. 23 volunteers were randomly assigned (15 to the intervention group and eight to the placebo group). Egg load after challenge was lower in the intervention group than the placebo group (geometric mean 571 eggs per g [range 372-992] vs 873 eggs per g [268-1484]); however, this difference was not statistically significant (p=0·10). Five volunteers in the intervention group developed a severe skin rash, which was associated with 40% reduction in egg counts after challenge (geometric mean 742 eggs per g [range 268-1484] vs 441 eggs per g [range 380-520] after challenge; p=0·0025) and associated with higher peak IgG1 titres.

INTERPRETATION

To our knowledge, this is the first study to describe a protective effect of short-term exposure to hookworm larvae and show an association with skin response, eosinophilic response, and IgG1. These findings could inform future hookworm vaccine development.

FUNDING

Dioraphte Foundation.

Cross-Sectional Study of Soil-Transmitted Helminthiases in Black Belt Region of Alabama, USA

We conducted a cross-sectional study to determine the prevalence of soil-transmitted helminthiases (STH) in areas of rural Alabama, USA, that have sanitation deficits. We enrolled 777 children; 704 submitted stool specimens and 227 a dried blood spot sample. We microscopically examined stool specimens from all 704 children by using Mini-FLOTAC for helminth eggs. We tested a subset by using molecular techniques: real-time PCR analysis for 5 STH species, TaqMan Array Cards for enteric helminths, and digital PCR for Necator americanus hookworm. We analyzed dried blood spots for Strongyloides stercoralis and Toxocara spp. roundworms by using serologic testing. Despite 12% of our cohort reporting living in homes that directly discharge untreated domestic wastewater, stool testing for STH was negative; however, 5% of dried blood spots were positive for Toxocara spp. roundworms. Survey data suggests substantial numbers of children in this region may be exposed to raw sewage, which is itself a major public health concern.

Prevalence and Determinants of Geohelminthiasis among School-Age Children in Jimma City, Ethiopia

School-age children (SAC) are at a higher risk of geohelminth or soil-transmitted helminth (STH) infections due to their practice of walking and playing barefoot, lack of adequate sanitary facilities, and poor personal hygiene. In Ethiopia, periodic deworming has been implemented since 2013 with the aim of interrupting the transmission of STH in children by 2025. To evaluate the likely success of such a control program, it is crucial to monitor the transmission of STH, especially in peri-urban settings where environmental sanitation is modest. The aim of this study was to determine the prevalence and determinants of STH infections among SAC in peri-urban areas of Jimma City, Southwestern Ethiopia. A community-based cross-sectional study was conducted in five peri-urban Kebeles of Jimma City from July to September, 2021. Systematic random sampling was used to select 522 households with at least one child, and 478 children (5-15 years old) were recruited randomly from the households. Data on sociodemographic and potential risk factors were collected using a structured questionnaire. Stool samples from each study participant were collected and examined microscopically using the Kato-Katz technique. Multivariate logistic regression model was used to identify risk factors associated with STH infections. The prevalence of any STH among SAC was 23.4%, with Ascaris lumbricoides being the predominant STH species (15.7%), followed by Trichuris trichiura (9%) and hookworm (2.1%). Most (86.6%) of the STH-positive SAC had a single infection and a light infection intensity (88.2%), with a mean intensity of 367.4 eggs per gram. Location of Kebele (AOR = 2.73; 95% CI: 1.21-6.16, p=0.016), lack of hand washing after defecation (AOR = 6.39; 95% CI: 3.16-12.95, p < 0.001), untrimmed fingernails (AOR = 2.65; 95% CI: 1.56-4.51, p < 0.001), and lack of previous deworming (AOR = 2.90; 95% CI: 1.47-5.74, p=0.002) were significant predictors for STH infections among SAC. In conclusion, the study revealed that STH infections are significant health problem in the peri-urban areas of Jimma City. Strengthening periodic deworming and improving children's hygiene through health education are required to reduce the transmission.

Cutaneous larva migrans: A One Health Perspective on Familial Infection Among Tourists Returning from Southeast Asia

Cutaneous larva migrans (CLM) is a dermatosis caused by accidental infestation with animal hookworms and is widely distributed in tropical and subtropical regions. Humans become infected when their skin comes into contact with soil contaminated with dog faeces. The filariform larvae penetrate and burrow into human skin, causing a condition known as "creeping eruption". We describe a case, well-documented by photos, of CLM infection in a family of three who returned from Thailand.

Inflicting Significant Losses in Slaughtered Animals: Exposing the Hidden Effects of Parasitic Infections

We started a campaign in the heart of Faisalabad, Punjab, Pakistan, to expose the hidden threats of parasitic illnesses in ruminants and the severe financial consequences associated with them. Our in-depth investigations focused on the prevalence, impact, and astounding financial losses brought on by organ contamination in slaughtered animals. Of the 384 slaughtered ruminants examined for gastrointestinal parasites, a prevalence of 44.79% was recorded. It is interesting to note that we found no conclusive association between parasitic infection and the various ruminant species under study (p > 0.05). However, goats (52.0%) had the highest numerical prevalence of parasitic infection, followed by cattle (46.1%), buffalo (46.0%), and sheep (34.7%) in that order. A significant finding (p < 0.05) showed that the majority of animals had light parasitism (46.5%), as opposed to those with moderate (30.2%) or severe loads (23.2%). Our research revealed substantial (p < 0.05) relationships between ruminant age, sex, and parasitic infection prevalence. In comparison to females (56.4%) and adults (48.1%), males (36.1%) and young (36.9%) ruminants showed considerably decreased infection rates (p < 0.05). On the other hand, we discovered a non-significant (p > 0.05) association between the months and the prevalence of parasitic infection. As a result of the condemnation of contaminated organs such as the rumen, lungs, and liver, an estimated financial loss of PKR 133,731,400 (USD = 466,939.2) was incurred. The yearly economic losses caused by liver condemnation were much greater than those caused by rumen and lung condemnation (p < 0.05). Our research not only reported a significantly higher abundance but also economic threats of the parasitic diseases among the slaughtered animals in Faisalabad, Punjab, Pakistan. Our findings highlighted the critical need for preventive and therapeutic interventions for parasitic infections in animals, in order to mitigate the economic losses through strengthened animal health.

Sewerage as a protective factor for prevalence of hookworm infection in schoolchildren in Brazil: A multilevel ecological analysis of national prevalence surveys (1950-2018)

INTRODUCTION

The prevalence of hookworm infection in Brazil has decreased considerably in recent decades. However, there is no definitive consensus as to which changes have contributed to this reduction. A hypothesis is that improvements in environmental factors have contributed to lowering the parasite load and the level of host-parasite contact.

METHODS

This is an ecological study using unbalanced panel data from two Brazilian surveys (1947-1953 and 2010-2015), with municipalities as the analysis unit. The sample comprised 1428 municipalities, in which a total of 745,983 schoolchildren aged 7 to 14 were examined. Zero-inflated Poisson regression models, with fixed and random effects were estimated to evaluate the association of potential explanatory variables with the prevalence of hookworm infection at a significance level of 5 %.

RESULTS

We identified a significant decrease in the prevalence between the first and last analyzed periods (RR 0.096; CI 0.086-0.107); The following variables were found to have a protective effect: access to sanitary sewage systems (RR 0.984, CI 0.982-0.986), urbanization (RR 0.995, CI 0.993-0.997), and gross domestic product (RR 0.929, CI 0.912-0.945).

CONCLUSION

The findings of this study show a decrease in the prevalence of hookworm infections over six decades in schoolchildren in the Brazilian municipalities. Environmental, demographic, and economic factors were associated with this trend. A historical analysis indicates that interventions aimed at improving sanitation contributed to reducing the disease prevalence.

Molecular variability of the Ancylostoma secreted Protein-2 (Aca-asp-2) gene from Ancylostoma caninum contributes to expand information on population genetic studies of hookworms

Hookworm infection is a major public health problem in many regions of the world. Given the high levels of host morbidity and even mortality of the host caused by these infections, it is crucial to understand the genetic structure of hookworm populations. This understanding can provide insights into the ecology, transmission patterns, mechanisms of drug resistance, and the development of vaccines and immunotherapeutic strategies. Previously, we examined presumably neutral molecular markers, such as microsatellites and COI (Cytochrome C oxidase subunit 1) in Brazilian populations of Ancylostoma caninum. Here we analyze the molecular variability of a genomic fragment of the Aca-asp-2 (Ancylostoma secreted protein-2) gene from Ancylostoma caninum. This gene is a highly expressed and activated following the infection of the L3 larvae in the host. We obtained individuals of A. caninum from five different geographic locations in Brazil, sequenced and analyzed parts of the gene. The results revealed extensive polymorphism at this fragment, especially in the intronic region, indicating low selective pressure acting on these sequences. However, we also observed irregular distributions of nucleotides and polymorphisms in the coding region of this gene, resulting in the identification of 27 alleles. The data presented here contribute to expanding the understanding of population genetic studies of hookworms.

Preschool child growth attainment and velocity during an agriculture intervention in rural Panama may be diminished by soil-transmitted helminths

Background

Agricultural interventions are often recommended to address undernutrition in subsistence farming communities. However, intensified agriculture exposure can increase soil transmitted helminth (STH) infections, which are linked with poor child growth. This study examined impacts of the VERASAN public health and agricultural intervention program on preschool child growth attainment (HAZ and WAZ) and relative growth velocity over 7 months [change in height-for-age (∆HAD) and weight-for-age (∆WAD) difference].

Methods

VERASAN was initiated in 15 subsistence farming communities in rural Panama experiencing chronic undernutrition. Activities targeted improved household food security, preschool child diets and growth by intensifying and diversifying household agriculture. Our objectives were to explore the relationship between VERASAN and preschool child growth attainment (HAZ and WAZ) and velocity (∆HAD and ∆WAD) during one agricultural cycle in 238 households. We compared those new to VERASAN with those involved for 1 or 5 years, and identified if agricultural practices, food security, diet diversity and treatment of pre-existing STH infection were associated with growth attainment or velocity.

Results

Prior participation in VERASAN did not directly influence WAZ, HAZ or ΔHAD but VERASAN-related benefits had an indirect influence. ΔHAD was positively associated with VERASAN-associated improvements in diet diversity and food security. HAZ and WAZ during land preparation were positively associated with diet diversity and HAZ with food security during harvest. HAZ was negatively associated with children visiting the agricultural plot, consuming leafy green vegetables and pre-existing hookworm infections. Both agricultural season and STH influenced ΔWAD. Children in VERASAN for 1 or 5 years experienced growth faltering between land preparation and growing season, but not those new to VERASAN. In contrast, between growing and harvest, ∆WAD declined in children new to VERASAN compared to children in VERASAN for longer. ΔWAD from land preparation to harvest was higher with pre-existing Ascaris infection whereas it was lower between growing season and harvest for pre-existing hookworm infection.

Conclusion

In a context of preschool child growth faltering, malnutrition and STH infections, improved food security, agricultural production and diet diversity associated with VERASAN were associated with improved growth. In contrast, STH infections were negatively associated with some, but not all, growth outcomes.

[Schistosomiasis, soil-transmitted helminthiases and sanitation in Latin America and the Caribbean: a systematic reviewRelación entre la prevalencia de esquistosomiasis y geohelmintiasis y las condiciones sanitarias en América Latina y el Caribe: una revisión sistemática]

Objective

To investigate the relationship between the prevalence of schistosomiasis and soil-transmitted helminthiasis with variables related to access to water, sanitation and solid waste in Latin American and Caribbean (LAC) countries.

Method

A systematic review was performed in the LILACS, PubMed, Web of Science, and SciELO databases. Studies published between 1950 and August 2021, with an ecological design and a focus on population groups (states, municipalities and/or districts), having the prevalence of infection by Schistosoma mansoni, Ancylostoma sp., Necator americanus, Ascaris lumbricoides or Trichuris trichiura as primary variable and access to water, sewage and/or solid waste as explanatory variables were included. Open access articles with full text available in English, Spanish, or Portuguese were considered. The risk of bias and the quality of the studies were assessed according to the Joanna Briggs Institute manual.

Results

Of 2 714 articles, nine were eligible, published between 1994 and 2021 and covering 22 LAC countries and 14 350 municipalities. All articles had moderate methodological quality. Environmental variables indicated an association between water supply and solid waste collection with schistosomiasis; water supply with ascariasis, trichuriasis and hookworm; and sewage with ascariasis and hookworm. Except for one article, which had regional coverage for LAC, all the others were developed in Brazil.

Conclusion

There is a clear need to expand research on the association between household and collective health conditions and parasitic diseases for all endemic countries in LAC to support environmental strategies to control these diseases.

Microbiota and parasite relationship

The diversity of microbiota is different in each person. Many health problems such as autoimmune diseases, diabetes, cardiovascular diseases, and depression can be caused by microbiota imbalance. Since the parasite needs a host to survive, it interacts closely with the microbiota elements. Blastocystis acts on the inflammatory state of the intestine and may cause various gastrointestinal symptoms, on the contrary, it is more important for gut health because it causes bacterial diversity and richness. Blastocystis is associated with changes in gut microbiota composition, the ultimate indicator of which is the Firmicutes/Bacteroidetes ratio. The Bifidobacterium genus was significantly reduced in IBS patients and Blastocystis, and there is a significant decrease in Faecalibacterium prausnitzii, which has anti-inflammatory properties in Blastocystis infection without IBS. Lactobacillus species reduce the presence of Giardia, and the produced bacteriocins prevent parasite adhesion. The presence of helminths has been strongly associated with the transition from Bacteroidetes to Firmicutes and Clostridia. Contrary to Ascaris, alpha diversity in the intestinal microbiota decreases in chronic Trichuris muris infection, and growth and nutrient metabolism efficiency can be suppressed. Helminth infections indirectly affect mood and behavior in children through their effects on microbiota change. The main and focus of this review is to address the relationship of parasites with microbiota elements and to review the data about what changes they cause. Microbiota studies have gained importance recently and it is thought that it will contribute to the treatment of many diseases as well as in the fight against parasitic diseases in the future.

Cutaneous larva migrans: A case report diagnosed using teledermatology

Teledermatology is a branch of dermatology that transmits medical data over several miles using telecommunications technologies. It involves the diagnosis of skin lesions using digital photographs and related patient data, and it can be especially helpful for patients in remote areas who might not have convenient access to dermatologists. Cutaneous larva migrans (CLM) is a zoonotic parasitic disease found in tropical and subtropical areas that are sunny and hot; however, cases of allocated resources have been disclosed in Saudi Arabia. There is little information about the frequency of CLM as a work-related illness among employees who are exposed to potentially polluted soil or have close contact with pets. In this paper, we present an ancestral case of CLM in Saudi Arabia, explaining the hazards of CLM infection. CLM may pose a challenge for physicians in non-endemic areas regarding assessment, therapeutic interventions, and protection, especially at work. The holistic strategy to CLM assessment, which includes the participation of numerous science competencies (e.g., veterinarians, dermatologists, and occupational physicians), may contribute to a better understanding of the expansion of human CLM and related risk factors, lowering the chance of infection.

Emodepside for Trichuris trichiura and Hookworm Infection

BACKGROUND

Current treatments for soil-transmitted helminth infections in humans have low efficacy against Trichuris trichiura. Emodepside - a drug in veterinary use and under development for the treatment of onchocerciasis in humans - is a leading therapeutic candidate for soil-transmitted helminth infection.

METHODS

We conducted two phase 2a, dose-ranging, randomized, controlled trials to evaluate the efficacy and safety of emodepside against T. trichiura and hookworm infections. We randomly assigned, in equal numbers, adults 18 to 45 years of age in whom T. trichiura or hookworm eggs had been detected in stool samples to receive emodepside, at a single oral dose of 5, 10, 15, 20, 25, or 30 mg; albendazole, at a single oral dose of 400 mg; or placebo. The primary outcome was the percentage of participants who were cured of T. trichiura or hookworm infection (the cure rate) with emodepside 14 to 21 days after treatment, determined with the use of the Kato-Katz thick-smear technique. Safety was assessed 3, 24, and 48 hours after the receipt of treatment or placebo.

RESULTS

A total of 266 persons were enrolled in the T. trichiura trial and 176 in the hookworm trial. The predicted cure rate against T. trichiura in the 5-mg emodepside group (85% [95% confidence interval {CI}, 69 to 93]; 25 of 30 participants) was higher than the predicted cure rate in the placebo group (10% [95% CI, 3 to 26]; 3 of 31 participants) and the observed cure rate in the albendazole group (17% [95% CI, 6 to 35]; 5 of 30 participants). A dose-dependent relationship was shown in participants with hookworm: the observed cure rate was 32% (95% CI, 13 to 57; 6 of 19 participants) in the 5-mg emodepside group and 95% (95% CI, 74 to 99.9; 18 of 19 participants) in the 30-mg emodepside group; the observed cure rates were 14% (95% CI, 3 to 36; 3 of 21 participants) in the placebo group and 70% (95% CI, 46 to 88; 14 of 20 participants) in the albendazole group. In the emodepside groups, headache, blurred vision, and dizziness were the most commonly reported adverse events 3 and 24 hours after treatment; the incidence of events generally increased in a dose-dependent fashion. Most adverse events were mild in severity and were self-limited; there were few moderate and no serious adverse events.

CONCLUSIONS

Emodepside showed activity against T. trichiura and hookworm infections. (Funded by the European Research Council; ClinicalTrials.gov number, NCT05017194.).

Excretory/Secretory Proteome of Females and Males of the Hookworm Ancylostoma ceylanicum

The dynamic host-parasite mechanisms underlying hookworm infection establishment and maintenance in mammalian hosts remain poorly understood but are primarily mediated by hookworm's excretory/secretory products (ESPs), which have a wide spectrum of biological functions. We used ultra-high performance mass spectrometry to comprehensively profile and compare female and male ESPs from the zoonotic human hookworm Ancylostoma ceylanicum, which is a natural parasite of dogs, cats, and humans. We improved the genome annotation, decreasing the number of protein-coding genes by 49% while improving completeness from 92 to 96%. Compared to the previous genome annotation, we detected 11% and 10% more spectra in female and male ESPs, respectively, using this improved version, identifying a total of 795 ESPs (70% in both sexes, with the remaining sex-specific). Using functional databases (KEGG, GO and Interpro), common and sex-specific enriched functions were identified. Comparisons with the exclusively human-infective hookworm Necator americanus identified species-specific and conserved ESPs. This is the first study identifying ESPs from female and male A. ceylanicum. The findings provide a deeper understanding of hookworm protein functions that assure long-term host survival and facilitate future engineering of transgenic hookworms and analysis of regulatory elements mediating the high-level expression of ESPs. Furthermore, the findings expand the list of potential vaccine and diagnostic targets and identify biologics that can be explored for anti-inflammatory potential.

Modeling the effectiveness of One Health interventions against the zoonotic hookworm Ancylostoma ceylanicum

Hookworm disease is a major global public health concern, annually affecting 500-700 million of the world's poorest people. The World Health Organization is targeting the elimination of hookworm as a public health problem by 2030 using a strategy of mass drug administration (MDA) to at-risk human populations. However, in Southeast Asia and the Pacific the zoonotic hookworm species, Ancylostoma ceylanicum, is endemic in dogs and commonly infects people. This presents a potential impediment to the effectiveness of MDA that targets only humans. Here, we develop a novel multi-host (dog and human) transmission model of A. ceylanicum and compare the effectiveness of human-only and "One Health" (human plus dog) MDA strategies under a range of eco-epidemiological assumptions. We show that One Health interventions-targeting both dogs and humans-could suppress prevalence in humans to ≤ 1% by the end of 2030, even with only modest coverage (25-50%) of the animal reservoir. With increasing coverage, One Health interventions may even interrupt transmission. We discuss key unresolved questions on the eco-epidemiology of A. ceylanicum, the challenges of delivering MDA to animal reservoirs, and the growing importance of One Health interventions to human public health.

Trends of intestinal parasites among the patients attended at Yabelo General Hospital, Borena Zone, Southern Ethiopia

Objectives

Intestinal parasitic infections (IPIs) still cause a major public health problem in developing countries. The most affected populations are those with low socioeconomic status, lack of latrines, inadequate water supply, and poor hygiene like in pastoralist community areas in Ethiopia. Therefore, the study assessed the trends of intestinal parasites among the patients attended at Yabelo General Hospital, Southern Ethiopia, from 2019 to 2021.

Methods

This retrospective study was conducted on 6108 patients and recorded data from Yabelo General Hospital, which were extracted using a checklist. The complete data of sex, age, and laboratory stool examination result in the record book were included in the study. The data were double-entered using EpiData version 3 and exported to the Statistical Package for Social Sciences version 16 for analysis. The associated factors were analyzed using chi-square and a p-value <0.05 was considered statistically significant. The results were presented in tables, pie charts, and graphs.

Results

The overall prevalence of intestinal parasites among the patients who attended Yabelo General Hospital was 48%. Of these, 37.8% (2310) were intestinal protozoa, and 10.2% (624) were intestinal helminths. The study indicates that 59% of patients aged above 45 years were seen infected with intestinal parasites. Of the total suspected patients, 2% (123) were found to have mixed parasite infections. The most reported parasites were Entamoeba histolytica/Entamoeba Dispar 22.6%, Giardia lamblia 15.3%, and Ascaris lumbricoides 1.8%. The trend analysis of intestinal parasites revealed that the overall prevalence declined from 55% in 2019 to 42.3% in 2021.

Conclusion

The prevalence of IPI was high among patients seen at Yabelo General Hospital. The analysis showed that the prevalence declined from 2019 to 2021. To sustain the decrease in prevalence, all intestinal parasite prevention measures should be continuously exercised in the area.

Policy stakeholder perspectives on barriers and facilitators to launching a community-wide mass drug administration program for soil-transmitted helminths

BACKGROUND

Recent evidence suggests that soil-transmitted helminth (STH) transmission interruption may be feasible through community-wide mass drug administration (cMDA) that deworms community members of all ages. A change from school-based deworming to cMDA will require reconfiguring of STH programs in endemic countries. We conducted formative qualitative research in Benin, India, and Malawi to identify barriers and facilitators to successfully launching a cMDA program from the policy-stakeholder perspective.

METHODS

We conducted 40 key informant interviews with policy stakeholders identified as critical change agents at national, state/district, and sub-district levels. Participants included World Health Organization country office staff, implementing partners, and national and sub-national government officials. We used the Consolidated Framework for Implementation Research to guide data collection, coding, and analysis. Heat maps were used to organize coded data and differentiate perceived facilitators and barriers to launching cMDA by stakeholder.

RESULTS

Key facilitators to launching a cMDA program included availability of high-quality, tailored sensitization materials, and human and material resources that could be leveraged from previous MDA campaigns. Key barriers included the potential to overburden existing health workers, uncertainty of external funding to sustain a cMDA program, and concerns about weak intragovernmental coordination to implement cMDA. Cross-cutting themes included the need for rigorous trial evidence on STH transmission interruption to gain confidence in cMDA, and implementation evidence to effectively operationalize cMDA. Importantly, if policy stakeholders anticipate a cMDA program cannot be sustained due to cost and human resource barriers in the long term they may be less likely to support the launch of a program in the short term.

CONCLUSIONS

Overall, policy stakeholders were optimistic about implementing cMDA primarily because they believe that the tools necessary to successfully implement cMDA are already available. Policy stakeholders in this study were cautiously optimistic about launching cMDA to achieve STH transmission interruption and believe that it is feasible to implement. However, launching cMDA as an alternative policy to school-based deworming will require addressing key resource and evidence barriers. Trial registration This study was registered in the U.S. National Library of Medicine Clinical Trials registry (NCT03014167).

Impact of a 5-Year Mass Drug Administration Programme for Soil-Transmitted Helminthiases on the Spatial Distribution of Childhood Anaemia in Burundi from 2007 to 2011

Background: Childhood anaemia affects 1.8 billion people globally. Little is known about the long-term impact of mass drug administration (MDA) for the control of soil-transmitted helminthiases (STH) on the spatiotemporal variation of anaemia prevalence and severity. We describe the long-term spatiotemporal impact of a 5-year STH MDA programme (2007−2011) on the prevalence of anaemia and anaemia severity in school-aged children (SAC) in Burundi. Methodology/Principal Findings: We used annual haemoglobin concentration and STH data collected during 2007−2011 in 31 schools in Burundi. Spatial dependence in prevalence and severity of anaemia was assessed using semivariograms. Bayesian geostatistical models were developed to (a) quantify the role of STH (adjusted for other anaemia determinants) in the spatiotemporal distribution of anaemia prevalence/severity, and (b) predict the geographical variation of both outcomes across Burundi. Adjusted population data were used to estimate the geographical distribution of the number of SAC at risk of anaemia and with low and moderate/severe anaemia. Infections with Ascaris lumbricoides and Trichuris trichiura were positively and significantly associated with childhood anaemia; hookworm infections were not. A significant decrease in anaemia prevalence, from 40−50% (2008) to 10−20% (2011) was predicted in western areas. The predicted prevalence of low-severity anaemia decreased from 40−50% (2008) to <20% (2011) in southern and eastern areas. Moderate/high-severity anaemia was concentrated in western regions of Burundi, with pockets of moderate/high-severity anaemia in central and northern regions in 2008. The overall number of predicted anaemic children decreased from 443,657 (2008) to 232,304 (2011), with a resurgence after MDA disruption in 2010 (to 480,605). Prevalence of low- and moderate-severity anaemia was higher in boys than in girls. Conclusions/Significance: Despite ongoing MDA, the prevalence of anaemia in SAC remained high and increased in certain parts of the country. It is recommended that MDA programmes targeting STH are complemented with specific anaemia interventions.

Phenotypic characterization and multiple resistance analysis in an experimentally selected albendazole-resistant hookworm isolate

For some nematodes, alterations that leads to a resistance genotype may be accompanied by other modifications, causing changes in the biology of the parasite, although the exact mechanisms of this relationship are still not very clear. These alterations can have deleterious effects on their survival or even potentiate their pathogenicity. In this study a phenotypic characterization was carried out to compare two Ancylostoma ceylanicum isolates, a wild type one, kept in the laboratory and an albendazole selected resistant isolate (AceyBZR2). Differences in some analyzed parameters, between the two strains, were registered, as patency period, number and size of the recovered worms, including differences in the body structures. The AceyBZR2 isolate showed to be less adapted to the host, leading to a smaller number of recovered worms. However, no difference on the female egg content was observed between the two isolates. Concerning blood evaluation, no differences were found between the wild type and AceyBZR2 isolates, related to hemoglobin and hematocrit levels. However, animals in the group infected with the wild type isolate had lower serum iron concentrations than animals in the AceyBZR2 group. The possibility that the AceyBZR2 isolate might be resistant to other drugs was evaluated and it was demonstrated that it does not present cross-resistance to ivermectin and nitazoxanide. However, when animals infected with the AceyBZR2 were treated with another drug from the benzimidazoles group (mebendazole), the cross-resistance effect was observed. Morphometric analyses were performed comparing female and male adult worms from the two isolates. The results presented here allow a better understanding of the parasite-host relationship and may constitute a useful basis for establishing future control strategies for soil-transmitted helminths.

Intestinal Helminth Infection, Anemia, Undernutrition and Academic Performance among School Children in Northwestern Ethiopia

This study examined the prevalence and intensity of intestinal helminth infections and their association with anemia, undernutrition, and academic performance among school children in Maksegnit, northwestern Ethiopia. A total of 1205 school children, who attended Maksegnit Number Two Elementary School between May and July 2021, participated in this study. To determine helminth infection status, two thick Kato–Katz slides were examined for each child. Hemoglobin level was measured using a HemoCue machine. Academic performance was assessed using the mean score of all subjects children have taken for the Spring 2020/2021 academic term. Out of 1205 children examined, 45.4% were infected with at least one helminth species, 7.9% were anemic, and 35.8% were undernourished. The means for hemoglobin level and z-scores of weight for age, height for age, body mass index for age, and academic scores were lower among helminth-infected children than the uninfected. Children infected with intestinal helminths showed higher odds of anemia than those uninfected with helminths. In conclusion, there was a moderate prevalence of intestinal helminth infection and undernutrition among school children in Maksegnit. Intestinal helminth infection could increase the risk of anemia, undernutrition, and poor academic performance.

Plasmodium falciparum coinfection is associated with improved IgE and IgG3 response against hookworm antigens

Background

Plasmodium falciparum and Hookworm infections are prevalent in West Africa and they cause iron deficiency anemia and protein malnutrition in Children. Immune response of these parasites interact and their interactions could have repercussions on vaccine development and efficacy. The current goal of hookworm eradication lies on vaccination. We evaluated the effect of P. falciparum coinfection and albendazole treatment on naturally acquired antibody profile against hookworm L3 stage larvae antigen.

Methods

In a longitudinal study, 40 individuals infected with Necator americanus only, 63 participants infected with N. americanus and P. falciparum, and 36 nonendemic controls (NECs) were recruited. The study was done in the Kintampo North Metropolis of Ghana. Stool and blood samples were taken for laboratory analyses. Serum samples were obtained before hookworm treatment and 3 weeks after treatment.

Results

The malaria-hookworm (N. americanus and P. falciparum) coinfected subjects had significantly higher levels of IgE (β = 0.30, 95% CI = [0.12, 0.48], p = 0.023) and IgG3 (β = 0.15, 95% CI = [0.02, 0.52], p = 0.004) compared to those infected with hookworm only (N. americanus). The N. americanus groups had significantly higher levels of IgG3 (β = 0.39, 95% CI = [0.14-0.62], p = 0.002) compared to the control group. Similarly, N. americanus and P. falciparum coinfected participants had significantly higher levels of IgE (β = 0.35, 95% CI = [0.70-0.39], p = 0.002) and IgG3 (β = 0.54, 95% CI = [0.22-0.76], p = 0.002). Moreover, albendazole treatment led to a significant reduction in IgE, IgA, IgM, and IgG3 antibodies against hookworm L3 stage larvae (p < 0.05).

Conclusion

P. falciparum is associated with improved IgE and IgG response against hookworm L3 stage larvae. Treatment with single dose of albendazole led to reduction in naturally acquired immune response against hookworm infection. Thus, P. falciparum infection may have a boosting effect on hookworm vaccine effectiveness.

National surveillance of hookworm disease in China: A population study

Background

Hookworm disease is endemic in China and is widespread globally. The disease burden to humans is great.

Methods

The study described the national surveillance of hookworm implemented in 31 provinces/autonomous regions/municipalities (P/A/Ms) of China in 2019. Each P/A/M determined the number and location of surveillance spots (counties). A unified sampling method was employed, and at least 1000 subjects were investigated in each surveillance spot. The modified Kato-Katz thick smear method was employed for stool examination. Fifty samples positive with hookworm eggs were cultured in each surveillance spot to discriminate species between A. duodenale and N. americanus. Twenty-five soil samples were collected from each surveillance spot and examined for hookworm larva. The 2019 surveillance results were analyzed and compared with that of 2016–2018.

Results

A total of 424766 subjects were investigated in 31 P/A/Ms of China in 2019, and the overall hookworm infection rate was 0.85% (3580/424766). The weighted infection and standard infection rates were 0.66% (4288357/648063870) and 0.67% (4343844/648063870), respectively. Sichuan province had the highest standard infection rate (4.75%) in 2019, followed by Chongqing (2.54%) and Hainan (2.44%). The standard infection rates of other P/A/Ms were all below 1%, with no hookworm detected in 15 P/A/Ms. The standard hookworm infection rate in the males and the females were 0.61% (2021216/330728900) and 0.71% (2267141/317334970), respectively, with a significant difference between different genders (χ2 = 17.23, P<0.0001). The highest standard hookworm infection rate (1.97%) was among age ≥ 60 years, followed by 45~59 years (0.77%), 15~44 years (0.37%), and 7~14 years (0.20%). The lowest standard infection rate was among the 0~6 years age group (0.12%). A significant difference was observed among different age groups (χ2 = 2 305.17, P<0.0001). The constitute ratio for N. americanus, A. duodenale, and coinfection was 78.70% (1341/1704), 2.03% (346/1704), and 1.00% (17/1704), respectively. The detection rate of hookworm larva from soil was 3.45% (71/2056).

Conclusion

The national surveillance showed that the hookworm infection rate has been decreasing annually from 2016 to 2019, and it is now below 1%. China has made significant progress in controlling hookworm. The national surveillance system is an important way to understand the endemic status and provide important information in this process and thus needs to be continually optimized.

Hookworm disease is endemic in China. The national surveillance system on important parasitic diseases including hookworm infection has been established in China. Stool samples were collected from participants, and the Kato-Katz method was applied to detect helminth eggs while samples with hookworm eggs were further cultured to differentiate the species of the parasite. Additionally, soil samples were collected and examined for hookworm larva. In 2019, the overall infection rate of hookworm in China was 0.85% (3580/424766). High prevalence was demonstrated in Western and Southern China, including Sichuan (4.75%), Chongqing (2.54%) and Hainan (2.44%). The prevalence was high in the females (0.71%) than in the males (0.61%), while it was high in older population especially those age over 60 years. N. americanus dominated the hookworm species. The prevalence of hookworm in soil was 3.45%. Overally, hookworm infection decreased to a low level in China. However, there still exist high endemic areas. Thus, intervention needs to be applied in the high endemic areas and elder population.

Mapping the global distribution of Strongyloides stercoralis and hookworms by ecological niche modeling

Background

The WHO has established a control strategy for Strongyloides stercoralis in school-aged children as well as targets and to maintain control programs for Ascaris lumbricoides, Trichuris trichiura and hookworms. For an efficient development of control programs, it is necessary to know the target countries around the world, as well as the areas within each country where efforts should be focused. Therefore, maps that provide information on the areas at risk for soil-transmitted helminth (STH) infections on a national and sub-national scale would allow for a better allocation of resources.

Methods

We used the ecological niche models MaxEnt and Kuenm R library to estimate the global distribution of S. stercoralis and hookworms. We used occurrence points of both species extracted from surveys of two literature reviews and from the Global Atlas of Helminth Infection database, together with 14 raster maps of environmental variables.

Results

We obtained two raster maps with the presence probability of S. stercoralis and hookworm infections at a global level and then estimated the global population at risk to be 2.6 and 3.4 billion, respectively. The population at risk was also estimated at the country level using estimations for areas as small as 25 km². A relationship was found between the probability of the presence of S. stercoralis and its prevalence, and a raster map was generated. Annual precipitation, annual temperature, soil carbon content and land cover were the main associated environmental variables. The ecological niches of Strongyloides stercoralis and hookworms had an overlap of 68%.

Conclusions

Here we provide information that can be used for developing more efficient and integrated control strategies for S. stercoralis and hookworm infections. This information can be annexed to the study of other risk factors or even other diseases to assess the health status of a community.

Graphical Abstarct

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05284-w.

Novel High-Throughput Fluorescence-Based Assay for the Identification of Nematocidal Compounds That Target the Blood-Feeding Pathway

Hookworm infections cause a neglected tropical disease (NTD) affecting ~740 million people worldwide, principally those living in disadvantaged communities. Infections can cause high morbidity due to their impact on nutrient uptake and their need to feed on host blood, resulting in a loss of iron and protein, which can lead to severe anaemia and impaired cognitive development in children. Currently, only one drug, albendazole is efficient to treat hookworm infection and the scientific community fears the rise of resistant strains. As part of on-going efforts to control hookworm infections and its associated morbidities, new drugs are urgently needed. We focused on targeting the blood-feeding pathway, which is essential to the parasite survival and reproduction, using the laboratory hookworm model Nippostrongylus brasiliensis (a nematode of rodents with a similar life cycle to hookworms). We established an in vitro-drug screening assay based on a fluorescent-based measurement of parasite viability during blood-feeding to identify novel therapeutic targets. A first screen of a library of 2654 natural compounds identified four that caused decreased worm viability in a blood-feeding-dependent manner. This new screening assay has significant potential to accelerate the discovery of new drugs against hookworms.

Soil-Transmitted Helminths and Anaemia: A Neglected Association Outside the Tropics

Anaemia is an important cause of morbidity and mortality globally. Among infectious agents responsible for anaemia, helminthic infections are often neglected, particularly in non-endemic countries. However, they should not be neglected in this setting, as international travel and migration are on the rise. In this narrative review, we aimed to describe soil-transmitted helminths as a cause of or contributing factor to anaemia, focusing on hookworms (Necator americanus and Ancylostoma duodenale), the whipworm (Trichuris trichiura), the roundworm (Ascaris lumbricoides), and the threadworm (Strongyloides stercoralis). A general review on the epidemiology, lifecycle, and clinical spectrum of anaemia is proposed, with a special focus on helminthic infections’ association with anaemia as well as the diagnostic approach, which are both particularly important in non-endemic settings.

Occupational risk of cutaneous larva migrans: A case report and a systematic literature review

Cutaneous larva migrans (CLM) is a parasitic zoonosis of warm tropical and subtropical areas, although autochthonous cases have been increasingly reported in Western European countries. Data on the prevalence of CLM as an occupational disease in workers exposed to potentially contaminated soil or in close contact with dogs and cats are scant. Herein, we report an autochthonous case of CLM in a dog breeder from southern Italy (Apulia region), along with a systematic literature review describing the risk of CLM infection, mainly according to job categories. The patient was referred to the dermatology unit presenting a serpiginous lesion on his hand, raising the suspected CLM diagnosis. In non-endemic areas, CLM might represent a challenge for physicians in terms of diagnosis, treatment, and prevention, particularly in workplaces. The multidisciplinary approach in the diagnosis of CLM with the involvement of different scientific competences (i.e., dermatologists, veterinarians, and occupational physicians) may contribute to further assess the distribution of human CLM and associated risk factors, toward reducing the risk for the infection.

Developing Immune Profiles of Endangered Australian Sea Lion (Neophoca cinerea) Pups Within the Context of Endemic Hookworm (Uncinaria sanguinis) Infection

As a top predator, the endangered Australian sea lion (Neophoca cinerea) is a sentinel of ecosystem change, where population trends can reflect broader shifts in the marine environment. The population of this endemic pinniped was historically diminished by commercial sealing, and recovery has been slowed by fishery interactions, disease and, potentially, pollutants. Hookworm infects 100% of neonatal pups and has been identified as a contributor to population decline. Here, a multivariable approach using traditional serological and novel molecular tools such as qPCR and ddPCR was used to examine immune phenotypes of developing Australian sea lion pups infected with the endemic hookworm (Uncinaria sanguinis) from two South Australian colonies. Results show changing immunophenotypes throughout the patent period of infection represented by pro-inflammatory cytokines (IL-6), IgG and acute-phase proteins. Although cytokines may prove useful as markers of resistance, in this study, IL-6 is determined to be an early biomarker of inflammation in Australian sea lion pups, excluding the alternative hypothesis. Additionally, immunological differences between animals from high- and low-intensity hookworm seasons, as well as ivermectin-treated animals, indicate hookworm infection modulation of the host immune response, as evidenced by a lower IL-6 mRNA expression in the non-treated groups. This study of the Australian sea lion is an example of an ecoimmunological approach to disease investigation, which can be applied to evaluate the impact of environmental and anthropogenic factors on susceptibility to infectious diseases in free-ranging species

The first report on the prevalence of soil-transmitted helminth infections and associated risk factors among traditional pig farmers in Bali Province, Indonesia

Background and Aim:

Pigs are the main livestock commodity in Bali Province, Indonesia, where traditional farming practices are widely used. Traditional pig farmers are often closely associated with poverty and a perceived lack of knowledge regarding health and hygiene. Data on soil-transmitted helminthiasis (STH) and risk factors associated with STH worm infection among traditional pig farmers in Bali were previously unavailable. This study aimed to analyze the prevalence and risk factors for STH infections among traditional pig farmers in Bali Province, Indonesia.

Materials and Methods:

This study involved the fecal examination of 238 traditional pig farmers from all areas of Bali Province in Indonesia. In addition, several pig feces samples were combined into one pooled sample belonging to each farm. All fresh fecal samples were stored in a 5% formaldehyde solution before being analyzed using concentration flotation techniques. Subsequently, risk factors were determined through an interview and a questionnaire. The odds ratio (OR) and Chi-square tests were used to determine the risk factors associated with STH infections.

Results:

The result showed that there was a high prevalence of STH infections among traditional pig farmers and pig farms in Bali, with rates of 21.8% and 76.5%, respectively. This could be due to risk factors, such as personal hygiene (OR: 5.756; confidence interval [CI]: 2.96-11.193; p=0.00), sanitation (OR: 1.914; CI: 1.024-3.576; p=0.042), education level (OR: 7.579; CI: 2.621-21.915; p=0.00), household income (OR: 2.447; CI: 1.122-5.338; p=0.025), and occupation (OR: 2.95; CI: 1.356-6.415; p=0.006).

Conclusion:

The infections seen in farmers were distributed among hookworm, Ascaris spp., and Trichuris spp., at 15.1%, 9.2%, and 4.2%, respectively. The risk factors associated with infections of STH and Ascaris spp. were personal hygiene, home sanitation, education level, household income, and having a primary occupation as a traditional pig farmer. In contrast, personal hygiene, education level, and primary occupation were the only risk factors for hookworm infection, while personal hygiene and home sanitation were the risk factors associated with Trichuris spp. infection. The limitation of this study was that the number of samples was relatively small due to the difficulty of obtaining stool samples from traditional pig farmers, with many individuals refusing to provide their stool for inspection. We suggest that future research focus on identifying the species of worms that infect traditional pig farmers and to better identify the zoonotic link of STH transmission from pigs to humans.

Prevalence and effect of Plasmodium spp. and hookworm co-infection on malaria parasite density and haemoglobin level: a meta-analysis

The dual effects of co-infection of Plasmodium spp. and hookworm on malaria remain under debate. This study investigated prevalence, prevalence odds ratio (POR) of co-infection and impact of co-infection on malaria parasite density and haemoglobin levels in comparison to Plasmodium mono-infection. The protocol for this systematic review and meta-analysis is registered at PROPERO under ID: CRD42020202156. Relevant literatures were obtained from PubMed, ISI Web of Science, and Scopus on 25 December 2020. Mean difference (MD) and confidence interval (CI) of malaria parasite density and haemoglobin were compared using a random effect model. Heterogeneity was assessed using Cochrane Q and I² statistics. Publication bias was determined by visualising funnel plot asymmetry. Of 1756 articles examined, 22,191 malaria cases across 37 studies included 6096 cases of co-infection of Plasmodium spp. and hookworm. The pooled prevalence was 20% (95% CI 15–26%, I² 99.6%, 37 studies) and was varied in terms of geographical region. Co-infection occurred by chance (OR 0.97, p 0.97, 95% CI 0.73–1.27, I² 95%, 30 studies). The mean malaria parasite density for co-infection (478 cases) was similar to Plasmodium mono-infection (920 cases) (p 0.24, MD 0.86, 95% CI − 0.58–2.29, I² 100%, 7 studies). The mean haemoglobin level for co-infection (90 cases) was similar to Plasmodium mono-infection (415 cases) (p 0.15, MD − 0.63, 95% CI − 1.49–0.23, I² 98%, 4 studies). Co-infection was common and occurred by chance but varied by geographic region. Further studies are required to investigate the mechanism of hookworm infection on malaria severity. Additionally, detection of hookworm infections among patients with malaria in endemic areas of both diseases is recommended to prevent severe malaria.

IL-27 Enhances γδ T Cell–Mediated Innate Resistance to Primary Hookworm Infection in the Lungs

IL-27 is a heterodimeric IL-12 family cytokine formed by noncovalent association of the promiscuous EBI3 subunit and selective p28 subunit. IL-27 is produced by mononuclear phagocytes and unfolds pleiotropic immune-modulatory functions through ligation to IL-27 receptor α (IL-27RA). Although IL-27 is known to contribute to immunity and to limit inflammation after various infections, its relevance for host defense against multicellular parasites is still poorly defined. Here, we investigated the role of IL-27 during infection with the soil-transmitted hookworm, Nippostrongylus brasiliensis, in its early host intrapulmonary life cycle. IL-27(p28) was detectable in bronchoalveolar lavage fluid of C57BL/6J wild-type mice on day 1 after s.c. inoculation. IL-27RA expression was most abundant on lung-invading γδ T cells. Il27ra^-/- mice showed increased lung parasite burden together with aggravated pulmonary hemorrhage and higher alveolar total protein leakage as a surrogate for epithelial-vascular barrier disruption. Conversely, injections of recombinant mouse (rm)IL-27 into wild-type mice reduced lung injury and parasite burden. In multiplex screens, higher airway accumulations of IL-6, TNF-α, and MCP-3 (CCL7) were observed in Il27ra^-/- mice, whereas rmIL-27 treatment showed a reciprocal effect. Importantly, γδ T cell numbers in airways were enhanced by endogenous or administered IL-27. Further analysis revealed a direct antihelminthic function of IL-27 on γδ T cells as adoptive intratracheal transfer of rmIL-27-treated γδ T cells during primary N. brasiliensis lung infection conferred protection in mice. In summary, this report demonstrates protective functions of IL-27 to control the early lung larval stage of hookworm infection.

Nutritional status, intestinal parasitic infections, and socio-environmental conditions in Mbyá-guaraní children: The current situation in communities in central Misiones, Argentina

OBJECTIVES

Our previous research in Mbyá-guaraní communities of central Misiones showed high levels of growth stunting and intestinal parasites in children, as well as associations between these variables and deficient sanitary conditions. New studies were necessary to update the present health status of the previously studied Mbyá populations after around two decades. Therefore, we evaluated the current nutritional status, intestinal parasites, and socio-environmental conditions among Mbyá-guaraní children from these communities.

METHODS

Body weight and height of 102 individuals (aged 2-14) were measured and nutritional status was estimated according to the World Health Organization criteria. Serial fecal samples and anal swabs were analyzed from 75 children (aged 1-14). Socio-environmental data were obtained from questionnaires.

RESULTS

The prevalence of undernutrition was 31.4% and excess of weight was 10.8%. The prevalence of stunting and of overweight reached 30.4% and 8.8%, respectively. About 85% of the children were infected with at least one of the 14 species identified, and around 44% had multiple parasite infections. The most prevalent species were Enterobius vermicularis and hookworms. Among undernourished children, 88.2% were parasitized by at least one of the potentially pathogenic species detected. Most of the families lived in overcrowded conditions in precarious houses, defecated in latrines, and consumed well water. A higher risk of parasitosis was associated with the source of drinking water.

CONCLUSIONS

Although the prevalence of undernutrition and intestinal parasites decreased compared with our previous studies, we still observed the coexistence of stunting, excess weight, and parasitic infections, in a context of socio-environmental vulnerability.

“Using the same hand”: The complex local perceptions of integrated one health based interventions in East Africa

Background

Neglected Tropical Diseases (NTDs) such as soil transmitted helminths (STH) and human rabies represent a significant burden to health in East Africa. Control and elimination remains extremely challenging, particularly in remote communities. Novel approaches, such as One Health based integrated interventions, are gaining prominence, yet there is more to be learned about the ways in which social determinants affect such programmes.

Methodology

In 2015 a mixed method qualitative study was conducted in northern Tanzania to determine community perceptions towards integrated delivery of two distinct healthcare interventions: treatment of children for STH and dog vaccination for rabies. In order to assess the effectiveness of the integrated approach, villages were randomly allocated to one of three intervention arms: i) Arm A received integrated mass drug administration (MDA) for STH and mass dog rabies vaccination (MDRV); ii) Arm B received MDA only; iii) Arm C received MDRV only.

Principle findings

Integrated interventions were looked upon favourably by communities with respondents in all arms stating that they were more likely to either get their dogs vaccinated if child deworming was delivered at the same time and vice versa. Participants appreciated integrated interventions, due to time and cost savings and increased access to essential health care. Analysis of qualitative data allowed deeper exploration of responses, revealing why people appreciated these benefits as well as constraints and barriers to participation in integrated programmes.

Conclusions/significance

An interdisciplinary One Health approach that incorporates qualitative social science can provide key insights into complex local perceptions for integrated health service delivery for STH and human rabies. This includes providing insights into how interventions can be improved while acknowledging and addressing critical issues around awareness, participation and underlying health disparities in remote pastoralist communities.

Important Nematodes in Children

Intestinal nematode infections caused by soil-transmitted helminths (STH), such as the roundworm Ascaris lumbricoides, the whipworm Trichuris trichiura, and the hookworms Ancylostoma duodenale, and Necator americanus, infect more than 1 billion people throughout the world. School-aged children tend to harbor the greatest numbers of intestinal worms, and as a result, experience more adverse health consequences, such as poor growth, anemia, and cognitive decline. Clinicians should maintain a high degree of suspicion in endemic areas when patients present with surgical abdomens, particularly children. Current antihelminthic drugs are moderately effective, but reinfection is possible. Global efforts are needed to eradicate STH infections.

Helminth-virus interactions: determinants of coinfection outcomes

Viral infections are often studied in model mammalian organisms under specific pathogen-free conditions. However, in nature, coinfections are common, and infection with one organism can alter host susceptibility to infection with another. Helminth parasites share a long coevolutionary history with mammalian hosts and have shaped host physiology, metabolism, immunity, and the composition of the microbiome. Published studies suggest that helminth infection can either be beneficial or detrimental during viral infection. Here, we discuss coinfection studies in mouse models and use them to define key determinants that impact outcomes, including the type of antiviral immunity, the tissue tropism of both the helminth and the virus, and the timing of viral infection in relation to the helminth lifecycle. We also explore the current mechanistic understanding of how helminth-virus coinfection impacts host immunity and viral pathogenesis. While much attention has been placed on the impact of the gut bacterial microbiome on immunity to infection, we suggest that enteric helminths, as a part of the eukaryotic macrobiome, also represent an important modulator of disease pathogenesis and severity following virus infection.

Rapidly progressive respiratory failure after helminth larvae ingestion

BACKGROUND

Self-administration of helminths has gained attention among patients as a potential but unproven therapy for autoimmune disease. We present a case of rapidly progressive respiratory failure in a patient with systemic sclerosis (SSc) and pulmonary arterial hypertension (PAH) as a result of self-administration of parasitic organisms.

CASE

A 45-year-old woman with a history of interstitial lung disease and PAH due to limited cutaneous SSc presented to pulmonary clinic with worsening dyspnea, cough, and new onset hypoxemia. Three months prior to presentation she started oral helminth therapy with Necator americanus as an alternative treatment for SSc. Laboratory evaluation revelaed eosinophilia and elevated IgE levels. IgG antibodies to Strongyloides were detected. High resolution computed tomography of the chest revealed progressive ILD and new diffuse ground glass opacities. Transthoracic echocardiogram and right heart catheterization illustrated worsening PAH and right heart failure. The patient was admitted to the hospital and emergently evaluated for lung transplantation but was not a candidate for transplantation due to comorbidities. Despite aggressive treatment for PAH and right heart failure, her respiratory status deteriorated, and the patient transitioned to comfort-focused care.

CONCLUSION

Although ingestion of helminths poses a risk of infection, helminth therapy has been investigated as a potential treatment for autoimmune diseases. In this case, self-prescribed helminth ingestion precipitated fatal acute worsening of lung inflammation, hypoxemia, and right heart dysfunction, highlighting the risk of experimental helminth therapy in patients, especially those with underlying respiratory disease.

Molecular modelling and de novo fragment-based design of potential inhibitors of beta-tubulin gene of Necator americanus from natural products

The emergence of drug resistance against the known hookworm drugs namely albendazole and mebendazole and their reduced efficacies necessitate the need for new drugs. Chemically diverse natural products present plausible templates to augment hookworm drug discovery. The present work utilized pharmacoinformatics techniques to predict African natural compounds ZINC95486082, ZINC95486052 and euphohelionon as potential inhibitory molecules of the hookworm Necator americanus β tubulin gene. A library of 3390 compounds was screened against a homology-modelled structure of β tubulin. The docking results obtained from AutoDock Vina was validated with an acceptable area under the curve (AUC) of 0.714 computed from the receiver operating characteristic (ROC) curve. The three selected compounds had favourable binding affinities and were predicted to form no interactions with the resistance-associated mutations Phe167, Glu198 and Phe200. The compounds were predicted as anthelmintics using a Bayesian-based technique and were pharmacologically profiled to be druglike. Further molecular dynamics simulations and MM-PBSA calculations showed the compounds as promising anthelmintic drug leads. Novel critical residues comprising Leu246, Asn247 and Asn256 were also predicted for binding. Euphohelionon was selected as a template for the de novo fragment-based design of five compounds labelled A1, A2, A3, A4 and A5; with four of them having SAscore values below 6, denoting easy synthesis. All the five de novo molecules docked firmly in the binding pocket of the β tubulin with no binding interactions with the three known resistance mutation residues. Binding energies of −8.2, −7.6, −7.3, −7.2 and −6.8 kcal/mol were obtained for A1, A2, A3, A4 and A5, respectively. The identified compounds can serve as treasure troves from which future potent anthelmintics can be designed. The current study strives to assuage the hookworm disease burden, especially making available molecules with the potential to circumvent the chemoresistance.

An annotated checklist of the eukaryotic parasites of humans, exclusive of fungi and algae

The classification of "parasites" in the medical field is a challenging notion, a group which historically has included all eukaryotes exclusive of fungi that invade and derive resources from the human host. Since antiquity, humans have been identifying and documenting parasitic infections, and this collective catalog of parasitic agents has expanded considerably with technology. As our understanding of species boundaries and the use of molecular tools has evolved, so has our concept of the taxonomy of human parasites. Consequently, new species have been recognized while others have been relegated to synonyms. On the other hand, the decline of expertise in classical parasitology and limited curricula have led to a loss of awareness of many rarely encountered species. Here, we provide a comprehensive checklist of all reported eukaryotic organisms (excluding fungi and allied taxa) parasitizing humans resulting in 274 genus-group taxa and 848 species-group taxa. For each species, or genus where indicated, a concise summary of geographic distribution, natural hosts, route of transmission and site within human host, and vectored pathogens are presented. Ubiquitous, human-adapted species as well as very rare, incidental zoonotic organisms are discussed in this annotated checklist. We also provide a list of 79 excluded genera and species that have been previously reported as human parasites but are not believed to be true human parasites or represent misidentifications or taxonomic changes.

The Influence of Helminth Immune Regulation on COVID-19 Clinical Outcomes: Is it Beneficial or Detrimental?

Immunologically, chronic worm infections prevent themselves from strong immune responses by skewing the host response towards a T helper 2 (Th2) type. The regulatory response initiated by helminth infections is supposed to temper responses to non-helminth antigens including viral infections which will, in turn, alter the clinical outcomes of infections. In view of this, recent reports highlighted the possible negative associations of severe COVID-19 and helminth co-infections in helminth-endemic regions. As the pathology of COVID-19 is primarily mediated by an excessive immune response and subsequent cytokine storm, which contributes to the poor prognosis of COVID-19, helminth-driven immune modulation will hypothetically contribute to the less severe outcomes of COVID-19. Nevertheless, emerging reports also stated that COVID-19 and helminth co-infections may have more hidden outcomes than predictable ones. Herein, the current knowledge on the interaction of COVID-19 and helminth co-infections will be discussed.

Benefits and Risks of Smallholder Livestock Production on Child Nutrition in Low- and Middle-Income Countries

Livestock production may improve nutritional outcomes of pregnant women and children by increasing household income, availability of nutrient-dense foods, and women's empowerment. Nevertheless, the relationship is complex, and the nutritional status of children may be impaired by presence of or proximity to livestock and their pathogens. In this paper, we review the benefits and risks of livestock production on child nutrition. Evidence supports the nutritional benefits of livestock farming through income, production, and women's empowerment. Increasing animal source food consumption requires a combination of efforts, including improved animal management so that herd size is adequate to meet household income needs and consumption and addressing sociocultural and gendered norms. Evidence supports the inclusion of behavior change communication strategies into livestock production interventions to facilitate the sustainability of nutritional benefits over time, particularly interventions that engage women and foster dimensions of women's empowerment. In evaluating the risks of livestock production, evidence indicates that a broad range of enteric pathogens may chronically infect the intestines of children and, in combination with dietary deficits, may cause environmental enteric dysfunction (EED), a chronic inflammation of the gut. Some of the most important pathogens associated with EED are zoonotic in nature with livestock as their main reservoir. Very few studies have aimed to understand which livestock species contribute most to colonization with these pathogens, or how to reduce transmission. Control at the point of exposure has been investigated in a few studies, but much less effort has been spent on improving animal husbandry practices, which may have additional benefits. There is an urgent need for dedicated and long-term research to understand which livestock species contribute most to exposure of young children to zoonotic enteric pathogens, to test the potential of a wide range of intervention methods, to assess their effectiveness in randomized trials, and to assure their broad adaptation and sustainability. This review highlights the benefits and risks of livestock production on child nutrition. In addition to identifying research gaps, findings support inclusion of poor gut health as an immediate determinant of child undernutrition, expanding the established UNICEF framework which includes only inadequate diet and disease.