Human Intestinal Parasite Burden and Poor Sanitation in Rural Alabama

Autochthonous Ascariasis, Mississippi, USA

We describe a case of a 2-year-old child who expelled a single adult female Ascaris lumbricoides worm. The patient is from a rural county in Mississippi, USA, with no reported travel outside of the United States. The caregivers in the home practice good sanitation. Exposure to domestic pigs is the likely source of infection.

Social barriers to safe sanitation access among housed populations in the United States: A systematic review

BACKGROUND

Nearly six million people residing in the United States do not have access to safely managed sanitation. Housed populations may lack access to centralized wastewater treatment systems or functioning onsite wastewater treatment systems, which subsequently places them at higher risk for adverse health outcomes associated with unsafe sanitation.

OBJECTIVES

We sought to understand the various social barriers that impact access to safe sanitation in the United States.

METHODS

We included peer-reviewed studies published between January 2000 and March 2023. The publication search was conducted using Scopus, ProQuest Social Science Database, and HeinOnline. We extracted data on social barriers and physical factors associated with access to sanitation.

RESULTS

Twenty publications met the inclusion criteria, and data relating to 11 social barriers and two physical factors were extracted. The social barriers to safe sanitation access mentioned most frequently were found to be socioeconomic status and race-based discrimination. Studies discussed sanitation in communities in five states.

DISCUSSION

Barriers pertained to lack of access to centralized wastewater treatment system, inadequate repair or replacement of septic systems, and lack of safely managed onsite sanitation systems. We discuss the intersectionality of the barriers, the underlying policy and history that leads to them, and make recommendations to address inequitable access to safe sanitation. Legislation and policy must be critically reviewed at national, state, and local levels to limit or eliminate ability for utilities to be extended on the basis of a community's income and property values or racial makeup. Policy recommendations also include additional community engagement, onsite sanitation system monitoring, and knowledge dissemination and education of septic system users. More geographically diverse research and research on sanitation in specific communities such as those of migrant farmworkers, undocumented persons, and tenants are recommended.

Nationwide USA re-analysis of amplicon metabarcoding targeting β-tubulin isoform-1 reveals absence of benzimidazole resistant SNPs in Ancylostoma braziliense, Ancylostoma tubaeforme and Uncinaria stenocephala

Nationwide sampling by Venkatesan and colleagues (2023) described the resistance status of the canine hookworm, Ancylostoma caninum, to benzimidazoles across the USA via β-tubulin isotype-1 amplicon metabarcoding. In this study, we aimed to use the existing public amplicon metabarcoding data and mine it for the presence of β-tubulin isotype-1 sequences that belong to hookworm species other than A. caninum. Through bioinformatics analysis we assigned species to A. caninum, Ancylostoma braziliense, Ancylostoma tubaeforme and Uncinaria stenocephala. All non-A. caninum sequences contained only the benzimidazole susceptible residues of β-tubulin isotype-1. Using two β-tubulin isotype-1 metabarcoding sequence data (assay targeting 134 and 167 codons, and assay targeting 198 and 200 codons), 2.0% (6/307) and 2.9% (9/310) individual samples had hookworms other than A. caninum (A. braziliense n = 5, A. tubaeforme n = 4 and U. stenocephala n = 2), respectively. We identified one sample containing A. braziliense in each of the Northeastern region and Midwestern region, and in three samples from the Southern region. Presence of A. tubaeforme in dog faeces is considered as pseudoparasitism. There were no statistically significant regional differences for the distribution of each species, for either of the two assays independently or combined (χ2 tests, P > 0.05). Our work demonstrates the utility of the amplicon metabarcoding for the identification of species through antemortem assays, thus resolving the dilemma of assigning hookworm species based on either post-mortem or egg sizes for the identification of hookworms.

The magnitude and predictors of self-medication amongst street dwellers in Ethiopia: a multicentre study

Background

Low levels of living standards amongst street dwellers worldwide limit their access to conventional healthcare services, resulting in self-medication use for the treatment of an illness. Nevertheless, self-medication use has risks, including adverse drug reactions, increased polypharmacy, drug resistance, drug dependence, drug interactions and incorrect diagnosis. Ethiopia has a large street-dwelling community; however, there are no studies conducted in Ethiopia assessing self-medication use amongst street dwellers. This study provides insight into self-medication use and predictors amongst street dwellers in Ethiopia.

Methods

A community-based, multicentre cross- sectional study was conducted amongst street dwellers from 1 September 2022 to 1 February 2023 at community drug-retail outlets in the three major cities in the Amhara region of Ethiopia. The data were obtained using an interviewer-administered questionnaire. Frequencies and percentages of descriptive statistics were calculated. Bivariable and multivariable logistic regression analyses were employed to indicate predictors of self-medication use. To determine statistical significance, a 95% confidence interval with a p value below 0.05 was utilized.

Results

The prevalence of self-medication use was 67.4%. Time and financial savings were reported as the reasons for most self-medication use. The most commonly reported illnesses for which people sought self-medication were gastrointestinal diseases. Low monthly income (adjusted OR 3.72, 95% CI 2.34-5.91) and residing near sewage areas (adjusted OR 3.37, 95% CI 2.03-5.58) were significantly associated with self-medication use.

Conclusion

Street dwellers had a high rate of self- medication use. Residing near sewage areas and having a low level of income were factors in self-medication use. Gastrointestinal diseases, respiratory ailments and dermatological conditions were the most frequently reported complaints, whereas antimicrobials and anthelmintics were the most commonly used medications. We recommend that healthcare services enhance outreach programmes to the most vulnerable people, such as street dwellers, especially those with lower monthly incomes and who live near sewage areas, to reduce self-medication rates.

Parasitism in viviparous vertebrates: an overview

The reproductive mode of viviparity has independently evolved in various animal taxa. It refers to the condition in which the embryos or young develop inside the female's body during gestation, providing advantages such as protection, nutrition, and improved survival chances. However, parasites and diseases can be an evolutionary force that limit the host's resources, leading to physiological, morphological, and behavioral changes that impose additional costs on both the pregnant female and her offspring. This review integrates the primary literature published between 1980 and 2021 on the parasitism of viviparous hosts. We describe aspects such as reproductive investment in females, offspring sex ratios, lactation investment in mammals, alterations in birth intervals, current reproductive investment, variations between environments, immune system activity in response to immunological challenges, and other factors that can influence the interaction between viviparous females and parasites. Maintaining pregnancy incurs costs in managing the mother's resources and regulating the immune system's responses to the offspring, while simultaneously maintaining an adequate defense against parasites and pathogens. Parasites can significantly influence this reproductive mode: parasitized females adjust their investment in survival and reproduction based on their life history, environmental factors, and the diversity of encountered parasites.

Surveillance for Soil-Transmitted Helminths in High-Risk County, Mississippi, USA

Recent reports of hookworm infection in Alabama, USA, has prompted surveillance in Mississippi, given the states' similar environmental conditions. We collected stool specimens from 277 children in Rankin County, Mississippi. Kato-Katz microscopic smear, agar plate culture, and quantitative PCR indicated no soil-transmitted helminths. Nevertheless, further surveillance in other high-risk Mississippi counties is warranted.

Risk Factors for Enteric Pathogen Exposure among Children in Black Belt Region of Alabama, USA

We collected stool from school-age children from 352 households living in the Black Belt region of Alabama, USA, where sanitation infrastructure is lacking. We used quantitative reverse transcription PCR to measure key pathogens in stool that may be associated with water and sanitation, as an indicator of exposure. We detected genes associated with > 1 targets in 26% of specimens, most frequently Clostridioides difficile (6.6%), atypical enteropathogenic Escherichia coli (6.1%), and enteroaggregative E. coli (3.9%). We used generalized estimating equations to assess reported risk factors for detecting > 1 pathogen in stool. We found no association between lack of sanitation and pathogen detection (adjusted risk ratio 0.95 [95% CI 0.55–1.7]) compared with specimens from children served by sewerage. However, we did observe an increased risk for pathogen detection among children living in homes with well water (adjusted risk ratio 1.7 [95% CI 1.1–2.5]) over those reporting water utility service.

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.

Vaccine value profile for Hookworm

Hookworm, a parasitic infection, retains a considerable burden of disease, affecting the most underprivileged segments of the general population in endemic countries and remains one of the leading causes of mild to severe anemia in Low and Middle Income Countries (LMICs), particularly in pregnancy and children under 5. Despite repeated large scale Preventive Chemotherapy (PC) interventions since more than 3 decades, there is broad consensus among scholars that elimination targets set in the newly launched NTD roadmap will require additional tools and interventions. Development of a vaccine could constitute a promising expansion of the existing arsenal against hookworm. Therefore, we have evaluated the biological and implementation feasibility of the vaccine development as well as the added value of such a novel tool. Based on pipeline landscaping and the current knowledge on key biological aspects of the pathogen and its interactions with the host, we found biological feasibility of development of a hookworm vaccine to be moderate. Also, our analysis on manufacturing and regulatory issues as well as potential uptake yielded moderate implementation feasibility. Modelling studies suggest a that introduction of a vaccine in parallel with ongoing integrated interventions (PC, WASH, shoe campaigns), could substantially reduce burden of disease in a cost - saving mode. Finally a set of actions are recommended that might impact positively the likelihood of timely development and introduction of a hookworm vaccine.

The Landscape of Parasitic Infections in the United States

The landscape of parasitic infections in the United States has shifted dramatically over the past century. Although infections such as malaria have been successfully eliminated, others remain endemic and pose a significant public health risk. Numerous parasitic infections are also imported each year. This article focuses on endemic parasitic infections that may be commonly seen in anatomical pathology preparations and discusses their biology, diagnostic histopathological features, and epidemiology.

Minimizing the Risk of Donor-Derived Events and Maximizing Organ Utilization Through Education and Policy Development

Herein, we review the current knowledge of donor-derived disease and current US Organ Procurement and Transplantation Network policies to minimize the risk. During the process, we also consider actions to further mitigate the risk of donor-derived disease. The overarching goal is to provide an infectious disease perspective on the complex decision of organ acceptance for transplant programs and candidates.

Coinfection with Strongyloides and SARS-CoV-2: A Systematic Review

BACKGROUND

Treatments for COVID-19, including steroids, might exacerbate Strongyloides disease in patients with coinfection. We aimed to systematically review clinical and laboratory features of SARS-CoV-2 and Strongyloides coinfection, investigate possible interventions, assess outcomes, and identify research gaps requiring further attention.

METHODS

We searched two electronic databases, LitCOVID and WHO, up to August 2022, including SARS-CoV-2 and Strongyloides coinfection studies. We adapted the World Health Organization-Uppsala Monitoring Centre (WHO-UMC) system for standardized case causality assessment to evaluate if using corticosteroids or other immunosuppressive drugs in COVID-19 patients determined acute manifestations of strongyloidiasis.

RESULTS

We included 16 studies reporting 25 cases of Strongyloides and SARS-CoV-2 coinfection: 4 with hyperinfection syndrome; 2 with disseminated strongyloidiasis; 3 with cutaneous reactivation of strongyloidiasis; 3 with isolated digestive symptoms; and 2 with solely eosinophilia, without clinical manifestations. Eleven patients were asymptomatic regarding strongyloidiasis. Eosinopenia or normal eosinophil count was reported in 58.3% of patients with Strongyloides reactivation. Steroids were given to 18/21 (85.7%) cases. A total of 4 patients (19.1%) received tocilizumab and/or Anakirna in addition to steroids. Moreover, 2 patients (9.5%) did not receive any COVID-19 treatment. The causal relationship between Strongyloides reactivation and COVID-19 treatments was considered certain (4% of cases), probable (20% of patients), and possible (20% of patients). For 8% of cases, it was considered unlikely that COVID-19 treatment was associated with strongyloidiasis reactivations; the relationship between the Strongyloides infection and administration of COVID-19 treatment was unassessable/unclassifiable in 48% of cases. Of 13 assessable cases, 11 (84.6%) were considered to be causally associated with Strongyloides, ranging from certain to possible.

CONCLUSIONS

Further research is needed to assess the frequency and risk of Strongyloides reactivation in SARS-CoV-2 infection. Our limited data using causality assessment supports recommendations that clinicians should screen and treat for Strongyloides infection in patients with coinfection who receive immunosuppressive COVID-19 therapies. In addition, the male gender and older age (over 50 years) may be predisposing factors for Strongyloides reactivation. Standardized guidelines should be developed for reporting future research.

Helminth Lessons in Inflammatory Bowel Diseases (IBD)

Helminths are multicellular invertebrates that colonize the gut of many vertebrate animals including humans. This colonization can result in pathology, which requires treatment. It can also lead to a commensal and possibly even a symbiotic relationship where the helminth and the host benefit from each other's presence. Epidemiological data have linked helminth exposure to protection from immune disorders that include a wide range of diseases, such as allergies, autoimmune illnesses, and idiopathic inflammatory disorders of the gut, which are grouped as inflammatory bowel diseases (IBD). Treatment of moderate to severe IBD involves the use of immune modulators and biologics, which can cause life-threatening complications. In this setting, their safety profile makes helminths or helminth products attractive as novel therapeutic approaches to treat IBD or other immune disorders. Helminths stimulate T helper-2 (Th2) and immune regulatory pathways, which are targeted in IBD treatment. Epidemiological explorations, basic science studies, and clinical research on helminths can lead to the development of safe, potent, and novel therapeutic approaches to prevent or treat IBD in addition to other immune disorders.

Using Google Trends to Estimate the Geographic Distribution of Soil-Transmitted Helminthiasis in the United States from 2016 to 2021

Soil-transmitted helminth infections are assumed to be uncommon in the US, despite numerous studies in the past few decades showing high burdens in Appalachia and the southern states. We assessed trends of interest in the Google search engine to gauge spatiotemporal patterns of potential soil-transmitted helminth transmission. We conducted a further ecological study comparing Google search trends to risk factors for soil-transmitted helminth transmission. Google search trends for terms related to soil-transmitted helminths were clustered in Appalachia and the south, with seasonal surges suggestive of endemic transmission for hookworm, roundworm (Ascaris), and threadworm. Furthermore, lower access to plumbing, increased septic tank use, and more rural environments were associated with increased soil-transmitted helminth-related Google search terms. Together, these results suggest that soil-transmitted helminthiasis remains endemic in parts of Appalachia and the south.

COVID-19 morbidity in lower versus higher income populations underscores the need to restore lost biodiversity of eukaryotic symbionts

The avoidance of infectious disease by widespread use of 'systems hygiene', defined by hygiene-enhancing technology such as sewage systems, water treatment facilities, and secure food storage containers, has led to a dramatic decrease in symbiotic helminths and protists in high-income human populations. Over a half-century of research has revealed that this 'biota alteration' leads to altered immune function and a propensity for chronic inflammatory diseases, including allergic, autoimmune and neuropsychiatric disorders. A recent Ethiopian study (EClinicalMedicine 39: 101054), validating predictions made by several laboratories, found that symbiotic helminths and protists were associated with a reduced risk of severe COVID-19 (adjusted odds ratio = 0.35; p<0.0001). Thus, it is now apparent that 'biome reconstitution', defined as the artificial re-introduction of benign, symbiotic helminths or protists into the ecosystem of the human body, is important not only for alleviation of chronic immune disease, but likely also for pandemic preparedness.

Evidence and potential drivers of neglected parasitic helminth and protist infections among a small preliminary sample of children from rural Mississippi

INTRODUCTION

Intestinal infections with helminths (parasitic worms) and protists (single-celled eukaryotes) may be neglected health issues in low-resource communities across the United States. Because they predominantly infect school-aged children and can lead to nutritional deficiencies and developmental delays, these infections can affect lifelong health. More research is needed to understand the prevalence and risk factors of these parasitic infections in the United States.

METHODS

A total of 24 children (ages 0.5-14 years) from a low-resource, rural Mississippi Delta community provided stool samples for 18s rRNA amplification and sequencing to determine infection presence. Parent/guardian interviews provided age, sex, and household size to test for associations with infection.

RESULTS

Infections were found in 38% (n = 9) of the samples. 25% (n = 6) of participants were infected with helminths (platyhelminths [n = 5]; nematodes [n = 2]), while 21% (n = 5) were infected with protists (Blastocystis [n = 4]; Cryptosporidium [n = 1]). There were no associations between infection status and age, sex, or household size. Problematically, analytical methods did not allow for more specific classifications for helminth species.

CONCLUSIONS

These preliminary findings suggest parasitic infections may be overlooked health issues in the rural Mississippi Delta and emphasize the need for more research on potential health outcomes within the United States.

Strongyloides and COVID-19: Challenges and Opportunities for Future Research

Strongyloides stercoralis is a soil transmitted helminth endemic to tropical and subtropical areas that can persist for decades in immunocompetent human hosts as a chronic asymptomatic infection. The use of corticosteroids, a mainstay of treatment for patients hospitalized with severe coronavirus disease (COVID-19), can trigger a life-threatening Strongyloides hyperinfection syndrome and disseminated disease. We identified 22 previously published cases of strongyloidiasis occurring in individuals with COVID-19, with one death reported among the seven patients who had Strongyloides hyperinfection syndrome. A total of seventeen patients had previously received corticosteroids, and of the five with no prior corticosteroid use, one presented with hyperinfection syndrome. We identify the key challenges in the diagnosis and treatment of Strongyloides within the context of COVID-19, including our imprecise knowledge of the global distribution of Strongyloides, the overlapping symptoms and signs of COVID-19 and Strongyloides hyperinfection syndrome, the limited utility of eosinophilia as a clinical marker for strongyloidiasis in this setting, the lack of validated algorithms to screen for Strongyloides prior to corticosteroid use, and the paucity of treatment options for critically ill patients with COVID-19 who cannot take oral ivermectin. Future research should focus on improved diagnostic methods and population prevalence estimates, optimizing the approaches for Strongyloides screening in persons with COVID-19 (including clinical trial participants and strategies for resource-limited settings) and better defining the role of pre-emptive treatment.

Rural Embodiment and Community Health: an Anthropological Case Study on Biocultural Determinants of Tropical Disease Infection and Immune System Development in the USA

Purpose of Review

Biocultural methods are critically important for identifying environmental and socioeconomic factors linked with tropical disease risk and outcomes. For example, embodiment theory refers to the process by which lived experiences impact individual biology. Increased exposure to pathogens, chronic psychosocial stress, and unequal resource access are all outcomes linked with discrimination and poverty. Through lived experiences, race and socioeconomic inequality can literally become embodied-get under the skin and affect physiology-impacting immune responses and contributing to lifelong health disparities. Yet, few studies have investigated tropical disease patterns and associated immune function using embodiment theory to understand lasting physiological impacts associated with living in a high-pathogen environment.

Recent Findings

Here, we use preliminary data drawn from the Rural Embodiment and Community Health (REACH) study to assess whether pathogen exposure and immune stimulation within a sample of children from the Mississippi Delta are associated with household income. We also test whether immune marker levels-assessed with enzyme-linked immunosorbent assays using dried blood spot samples-vary between the REACH sample and a similarly aged nationally representative NHANES sample. Immune marker levels did not differ significantly between REACH participants living below vs. above the federal poverty line, yet immunoglobulin E levels-a marker of macroparasite infection-were higher among REACH study participants compared to the NHANES sample.

Summary

These results may suggest community-level pathogenic exposures (i.e., parasitic infections) are embodied by REACH participants with implications for long-term immune function, potentially resulting in immune aspects that differ from nationally representative samples.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40475-023-00282-z.

Strongyloides stercoralis: Uncommon yet not to be missed cause of eosinophilia

Strongyloides stercoralis is a soil-transmitted nematode that is estimated to infect millions of people per year worldwide. However, cases are less commonly seen in the United States. This report highlights the importance of when to include Strongyloides stercoralis in the differential diagnosis of patients presenting eosinophilia within the United States.

Evaluation of a Geographic Screening Protocol for Chronic Parasitic Infections Before Kidney Transplant: An Institutional Experience in Minnesota

Pretransplant recommendations advise risk-based screening for strongyloidiasis, schistosomiasis, and Chagas disease. We evaluated the implementation of a chronic parasite screening protocol at a health system in a nonendemic region serving a large foreign-born population. Candidates listed for kidney transplant at Hennepin Healthcare (Minneapolis, MN) between 2010 and 2020 were included. Country of birth and serologic screening for strongyloidiasis, schistosomiasis, and Chagas disease were retrospectively obtained from electronic medical records. Parasite screening frequency and seropositivity was assessed before and after implementation of a geographic risk factor-based screening protocol in 2014. Cost-efficiency of presumptive treatment was modeled. Of 907 kidney transplant candidates, 312 (34%) were born in the United States and 232 (26%) outside the United States, with the remainder missing country of birth information. The 447 (49%) candidates evaluated after implementation of the screening protocol had fewer unidentified countries of birth (53%-27%, P < 0.001) and were more frequently screened for strongyloidiasis, schistosomiasis, and Chagas disease (14%-44%, 8%-22%, and 1-14%, respectively, all Ps < 0.001). The number of identified seropositive candidates increased after protocol implementation from two to 14 for strongyloidiasis and from one to 11 for schistosomiasis, with none seropositive for Chagas disease. The cost-efficiency model favored presumptive ivermectin when strongyloidiasis prevalence reaches 30% of those screened. Implementing a geographic risk screening protocol before kidney transplant increases attention to infectious disease risk associated with country of birth and identification of chronic parasitic infections. In populations with higher strongyloidiasis prevalence or lower ivermectin costs, presumptive treatment may be cost-efficient.

Prevalence and Associated Risk Factors of Human Intestinal Helminths Parasitic Infections in Ethiopia: A Systematic Review and Meta-Analysis

Background

Intestinal helminth infections are still public health problems in tropical and subtropical countries including Ethiopia. This review and meta-analysis aimed to produce the pooled prevalence and associated risk factors of human intestinal helminth parasitic infections (HIHPIs) in Ethiopia.

Methods

Articles written in English were searched from online databases. Sixty-seven studies were included. Meta-analysis was computed using STATA version 14.

Result

The pooled prevalence of HIHPIs was (33.35%, 95% CI: 28.85%, 37.86%). Ascaris lumbricoides (10.84%, 95% CI: 9.34, 12.34), hookworm spp. (8.89%, 95% CI: 7.75, 10.04), Schistosoma mansoni (4.22%, 95% CI: 3.64, 4.81), Trichuris trichiura (2.51%, 95% CI: 2.17, 2.86), Hymenolepis nana (2.29%, 95% CI: 1.96, 2.63), Taenia species (1.01%, 95% CI: 0.80, 1.22), Strongyloides stercoralis (1.17%, 95% CI: 0.92, 1.41), and Enterobius vermicularis(0.71%, 95% CI: 0.52, 0.90) were recorded. Handwashing before food (OR: 5.22,95% CI: 3.49, 6.94), handwashing after toilet (OR: 3.03, 95%; CI: 1.01, 5.05), age (OR: 1.66, 95% CL. 1.09, 2.23), open defecation (OR: 2.42, 95% CI: 1.60, 3.24), eating raw and unwashed vegetables/fruits (OR: 1.98, 95%; CI: 1.30, 2.66), maternal education (OR: 1.81, 95% CI: 0.91, 2.72), family income (OR: 2.00, 95% CI: 0.87, 3.31), source of drinking water (OR: 3.12, 95% CI: 1.96, 4.27), swimming/contact with river water (OR: 1.90, 95% CI: 1.11, 2.69), barefoot (OR: 3.28, 95% CI: 1.67, 4.88), playing with soil (OR: 2.64, 95% CI: 1.40, 3.88), and family size (OR: 3.75, 95% CI: 2.03, 5.46) were factors associated with HIHPIs in Ethiopia. High heterogeneity of the prevalence of HIHPIs was observed among the studies within and among regions (I² > 99.6% and P ≤ 0.001).

Conclusion

HIHPIs in Ethiopia were significantly high. Therefore, special attention should be given by all stakeholders to minimize HIHPIs in Ethiopia.

Bottled and Well Water Quality in a Small Central Appalachian Community: Household-Level Analysis of Enteric Pathogens, Inorganic Chemicals, and Health Outcomes in Rural Southwest Virginia

Consumption of unsafe drinking water is associated with a substantial burden of disease globally. In the US, ~1.8 million people in rural areas lack reliable access to safe drinking water. Our objective was to characterize and assess household-level water sources, water quality, and associated health outcomes in Central Appalachia. We collected survey data and water samples (tap, source, and bottled water) from consenting households in a small rural community without utility-supplied water in southwest Virginia. Water samples were analyzed for physicochemical parameters, total coliforms, E. coli, nitrate, sulfate, metals (e.g., arsenic, cadmium, lead), and 30+ enteric pathogens. Among the 69% (n = 9) of households that participated, all had piped well water, though 67% (n = 6) used bottled water as their primary drinking water source. Total coliforms were detected in water samples from 44.4% (n = 4) of homes, E. coli in one home, and enteric pathogens (Aeromonas, Campylobacter, Enterobacter) in 33% (n = 3) of homes. Tap water samples from 11% (n = 1) of homes exceeded the EPA MCL for nitrate, and 33% (n = 3) exceeded the EPA SMCL for iron. Among the 19 individuals residing in study households, reported diarrhea was 25% more likely in homes with measured E. coli and/or specific pathogens (risk ratio = 1.25, cluster-robust standard error = 1.64, p = 0.865). Although our sample size was small, our findings suggest that a considerable number of lower-income residents without utility-supplied water in rural areas of southwest Virginia may be exposed to microbiological and/or chemical contaminants in their water, and many, if not most, rely on bottled water as their primary source of drinking water.

Using newly optimized genetic tools to probe Strongyloides sensory behaviors

The oft-neglected human-parasitic threadworm, Strongyloides stercoralis, infects roughly eight percent of the global population, placing disproportionate medical and economic burden upon marginalized communities. While current chemotherapies treat strongyloidiasis, disease recrudescence and the looming threat of anthelminthic resistance necessitate novel strategies for nematode control. Throughout its life cycle, S. stercoralis relies upon sensory cues to aid in environmental navigation and coordinate developmental progression. Odorants, tastants, gases, and temperature have been shown to shape parasite behaviors that drive host seeking and infectivity; however, many of these sensory behaviors remain poorly understood, and their underlying molecular and neural mechanisms are largely uncharacterized. Disruption of sensory circuits essential to parasitism presents a promising strategy for future interventions. In this review, we describe our current understanding of sensory behaviors - namely olfactory, gustatory, gas sensing, and thermosensory behaviors - in Strongyloides spp. We also highlight the ever-growing cache of genetic tools optimized for use in Strongyloides that have facilitated these findings, including transgenesis, CRISPR/Cas9-mediated mutagenesis, RNAi, chemogenetic neuronal silencing, and the use of fluorescent biosensors to measure neuronal activity. Bolstered by these tools, we are poised to enter an era of rapid discovery in Strongyloides sensory neurobiology, which has the potential to shape pioneering advances in the prevention and treatment of strongyloidiasis.

The neural basis of heat seeking in a human-infective parasitic worm

Soil-transmitted parasitic nematodes infect over one billion people and cause devastating morbidity worldwide. Many of these parasites have infective larvae that locate hosts using thermal cues. Here, we identify the thermosensory neurons of the human threadworm Strongyloides stercoralis and show that they display unique functional adaptations that enable the precise encoding of temperatures up to human body temperature. We demonstrate that experience-dependent thermal plasticity regulates the dynamic range of these neurons while preserving their ability to encode host-relevant temperatures. We describe a novel behavior in which infective larvae spontaneously reverse attraction to heat sources at sub-body temperatures and show that this behavior is mediated by rapid adaptation of the thermosensory neurons. Finally, we identify thermoreceptors that confer parasite-specific sensitivity to body heat. Our results pinpoint the parasite-specific neural adaptations that enable parasitic nematodes to target humans and provide the foundation for drug development to prevent human infection.

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.

Structural Racism, Place, and COVID-19: A Narrative Review Describing How We Prepare for an Endemic COVID-19 Future

Background:

Place is a social determinant of health, as recently evidenced by COVID-19. Previous literature surrounding health disparities in the United States often fails to acknowledge the role of structural racism on place-based health disparities for historically marginalized communities (i.e., Black and African American communities, Hispanic/Latinx communities, Indigenous communities [i.e., First Nations, Native American, Alaskan Native, and Native Hawaiian], and Pacific Islanders). This narrative review summarizes the intersection between structural racism and place as contributors to COVID-19 health disparities.

Methods:

This narrative review accounts for the unique place-based health care experiences influenced by structural racism, including health systems and services and physical environment. We searched online databases for peer-reviewed and governmental sources, published in English between 2000 and 2021, related to place-based U.S. health inequities in historically marginalized communities. We then narrate the link between the historical trajectory of structural racism and current COVID-19 health outcomes for historically marginalized communities.

Results:

Structural racism has infrequently been named as a contributor to place as a social determinant of health. This narrative review details how place is intricately intertwined with the results of structural racism, focusing on one's access to health systems and services and physical environment, including the outdoor air and drinking water. The role of place, health disparities, and structural racism has been starkly displayed during the COVID-19 pandemic, where historically marginalized communities have been subject to greater rates of COVID-19 incidence and mortality.

Conclusion:

As COVID-19 becomes endemic, it is crucial to understand how place-based inequities and structural racism contributed to the COVID-19 racial disparities in incidence and mortality. Addressing structurally racist place-based health inequities through anti-racist policy strategies is one way to move the United States toward achieving health equity.

Pediatric Medicaid Visits for Soil-Transmitted Helminth Infections in the Black Belt Region-Alabama, 2010-2018

Areas of rural Alabama may be at risk for re-emergence of soil-transmitted helminthiasis (STH) where environmental conditions are favorable for STH transmission, including in the agricultural Black Belt region. We describe pediatric Medicaid STH visits in Alabama and compare STH visit rates in Black Belt counties with those of non-Black Belt counties. Alabama Medicaid visit claims among children aged 0-18 years who received an STH diagnosis during January 2010-December 2018 were examined. STH-related pediatric visits were uncommon, but several counties with higher STH rates were identified. Visit rates did not differ meaningfully when comparing Black Belt with non-Black Belt region counties (rate ratio: 1.10; 95% CI: 0.73-1.64). Additional studies examining STH prevalence among children living in communities at risk for STH in Alabama can further clarify STH burden and identify communities experiencing environmental and sanitation conditions favorable to STH endemicity.

Networks, cultures, and institutions: Toward a social immunology

This paper calls for increased attention to the ways in which immune function – including its behavioral aspects – are responsive to social contexts at multiple levels. Psychoneuroimmunology has demonstrated that the quantity and quality of social connections can affect immune responses, while newer research is finding that sickness temporarily affects these same social networks and that some aspects of culture can potentially “get under the skin” to affect inflammatory responses. Social immunology, the research framework proposed here, unifies these findings and also considers the effects of structural factors – that is, a society's economic, political, and environmental landscape – on exposure to pathogens and subsequent immune responses. As the COVID-19 pandemic has highlighted, a holistic understanding of the effects of social contexts on the patterning of morbidity and mortality is critically important. Social immunology provides such a framework and can highlight important risk factors related to impaired immune function.

A community-engaged approach to understanding environmental health concerns and solutions in urban and rural communities

Background

Focus groups and workshops can be used to gain insights into the persistence of and potential solutions for environmental health priorities in underserved areas. The objective of this study was to characterize focus group and workshop outcomes of a community-academic partnership focused on addressing environmental health priorities in an urban and a rural location in Alabama between 2012 and 2019.

Methods

Six focus groups were conducted in 2016 with 60 participants from the City of Birmingham (urban) and 51 participants from Wilcox County (rural), Alabama to discuss solutions for identified environmental health priorities based on previous focus group results in 2012. Recorded focus groups were transcribed and analyzed using the grounded theory approach. Four follow-up workshops that included written survey instruments were conducted to further explore identified priorities and determine whether the priorities change over time in the same urban (68 participants) and rural (72 participants) locations in 2018 and 2019.

Results

Consistent with focus groups in 2012, all six focus groups in 2016 in Birmingham identified abandoned houses as the primary environmental priority. Four groups listed attending city council meetings, contacting government agencies and reporting issues as individual-level solutions. Identified city-level solutions included city-led confiscation, tearing down and transferring of abandoned property ownership. In Wilcox County, all six groups agreed the top priority was drinking water quality, consistent with results in 2012. While the priority was different in Birmingham versus Wilcox County, the top identified reason for problem persistence was similar, namely unresponsive authorities. Additionally, individual-level solutions identified by Wilcox County focus groups were similar to Birmingham, including contacting and pressuring agencies and developing petitions and protesting to raise awareness, while local policy-level solutions identified in Wilcox County included government-led provision of grants to improve septic systems, and transparency in allocation of funds. Workshops in 2018 and 2019 further emphasized water quality as the top priority in Wilcox County, while participants in Birmingham transitioned from abandoned houses as a top priority in 2018 to drinking water quality as a new priority in 2019.

Conclusions

Applying a community-engaged approach in both urban and rural locations provided better understanding of the unique opportunities and challenges for identifying potential interventions for environmental health priorities in both locations. Results can help inform future efforts to address locally defined environmental health issues and solutions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11799-1.

Broadening the range of use cases for ivermectin - a review of the evidence

Ivermectin is a broad-spectrum antiparasitic agent that interferes with glutamate-gated chloride channels found in invertebrates but not in vertebrate species. Mass drug administration (MDA) with ivermectin-based regimes has been a mainstay of elimination efforts targeting onchocerciasis and lymphatic filariasis for more than 3 decades. More recently, interest in the use of ivermectin to control other neglected tropical diseases (NTDs) such as soil-transmitted helminths and scabies has grown. Interest has been further stimulated by the fact that ivermectin displays endectocidal efficacy against various Anopheles species capable of transmitting malaria. Therefore there is growing interest in using ivermectin MDA as a tool that might aid in the control of both malaria and several NTDs. In this review we outline the evidence base to date on these emerging indications for ivermectin MDA with reference to clinical and public health data and discuss the rationale for evaluating the range of impacts of a malaria ivermectin MDA on other NTDs.

Parasitic Disease Surveillance, Mississippi, USA

Surveillance for soil-transmitted helminths, strongyloidiasis, cryptosporidiosis, and giardiasis was conducted in Mississippi, USA. PCR performed on 224 fecal samples for all soil-transmitted helminths and on 370 samples for only Necator americanus and Strongyloides stercoralis identified 1 S. stercoralis infection. Seroprevalences were 8.8% for Toxocara, 27.4% for Cryptosporidium, 5.7% for Giardia, and 0.2% for Strongyloides parasites.

Arboviral diseases and poverty in Alabama, 2007-2017

Mosquito-borne viruses cause diseases of great public health concern. Arboviral disease case distributions have complex relationships with socioeconomic and environmental factors. We combined information about socio-economic (population, and poverty rate) and environmental (precipitation, and land use) characteristics with reported human cases of arboviral disease in the counties of Alabama, USA, from 2007–2017. We used county level data on West Nile virus (WNV), dengue virus (DENV), chikungunya virus (CHIKV), Zika virus (ZIKV), California serogroup virus, Eastern equine encephalitis virus, and Saint Louis encephalitis virus to provide a detailed description of their spatio-temporal pattern. We found a significant spatial convergence between incidence of WNV and poverty rate clustered in the southern part of Alabama. DENV, CHIKV and ZIKV cases showed a different spatial pattern, being mostly located in the northern part, in areas of high socioeconomic status. The results of our study establish that poverty-driven inequities in arboviral risk exist in the southern USA, and should be taken into account when planning prevention and intervention strategies.

Mosquito-borne arboviruses like West Nile virus (WNV), dengue virus (DENV), chikungunya virus (CHIKV), Zika virus (ZIKV), California serogroup virus (CSV), Eastern equine encephalitis virus (EEE), and Saint Louis encephalitis virus (SLE) are on the rise globally. Socioeconomic and environmental conditions have played a role in directing in this expansion by creating conditions ideal for mosquito vectors and transmission. In this study, we used 10 years (2007–2017) of county level human arboviral case data from the US state of Alabama to better understand the roles socioeconomics (poverty rate) and environmental (land use, precipitation, land cover) conditions may play in driving patterns of arboviral disease in the southern US. We found a significant association between poverty rate and incidence of WNV, an arbovirus primarily transmitted by Culex spp. mosquitoes, which are known for thriving in contaminated water sources and sewage overflow. Conversely, cases of DENV, CHIKV, and ZIKV, arboviruses primarily transmitted by Aedes spp. mosquitoes, were reported in areas of high socioeconomic status. These findings suggest differential distribution of arboviruses relevant to human health in Alabama, and that poverty in the southern US is a significant factor that should be considered when planning WNV prevention and intervention strategies.

Social Justice as a Tool to Eliminate Inequities in Kidney Disease

Kidney disease has disparate effects on racial and ethnic minority groups, who have higher rates of chronic kidney disease and generally poorer outcomes. These disparate rates and outcomes have been attributed to social determinants of health; however, these social determinants of health are related to governmental and societal structural barriers that have created inequities not only in kidney disease, but also in other chronic diseases and in maternal/fetal health outcomes. The societal barriers to health equity include income inequality, inadequate education, environmental injustice, mass incarceration, and the enduring effects of the legacy of slavery. The approach to reducing disparities in kidney outcomes must be viewed through the lens of social justice to address these societal barriers.

Physician Perception and Diagnosis of Intestinal Parasitic Infections among Patients with Gastrointestinal Symptoms in Ghana

This study evaluated physicians' perception and diagnosis of intestinal parasitic infections (IPI) in patients with gastrointestinal (GI) symptoms. This cross-sectional survey used a Google form questionnaire distributed online. Demographic and clinical practice information was solicited, including if “IPI was considered as a diagnosis in the last patient seen,” “if stool investigation was requested among the last patients seen,” and physicians' perception of the burden of IPI in the country. Using Pearson chi-square and multivariate logistic regression analysis, we tested the significance of the associations of the job cadre of the physicians and their perception of the IPI burden with consideration of IPI as a diagnosis in the last patient seen, request for stool investigation in the last patient seen, and overall frequency of the request for stool investigation. Ultimately, 184 physicians responded. The majority agreed to “often seeing patients with GI symptoms” (156, 84.7%), “not considering IPI among the last patient seen” (106, 57.6%), and “not requesting stool investigation among the last patient seen with symptoms” (136, 73.9%). House officers (81, 44.2%) constituted the highest proportion of physicians who considered IPI as a diagnosis among the last patient seen (39, 48.1%, p = 0.05). Most physicians (138, 75%) considered IPI as a burden in Ghana. They constituted significant proportions of the physicians who considered IPI as a diagnosis among their last patients seen (65, 83.3%, p = 0.02) and were twice more likely to consider IPI as a diagnosis among the last patients seen than their colleagues who did not consider IPI as a burden in Ghana (AOR 2.26, p = 0.04). The consideration of IPI as a diagnosis among patients with GI symptoms and request for stool investigations was low among physicians in this study. Further engagements with physicians in Ghana are needed to help improve their diagnosis of IPI in patients with GI symptoms.

Twenty-year economic impacts of deworming

The belief that investing in child health and nutrition can generate improvements in individuals’ future quality of life is the rationale for many policy initiatives around the world. Yet there remains limited evidence on the causal impacts of child health gains on adult living standards, especially in developing countries. This study contributes evidence that addresses leading methodological concerns, by using variation in child health via a randomized health intervention that provided deworming treatment to Kenyan children. We estimate impacts on individual living standards up to 20 y later among a representative sample of participants, and find those in the deworming treatment group experience meaningful gains in adult living standards and earnings, and shifts in sectors of residence and employment.

Estimating the impact of child health investments on adult living standards entails multiple methodological challenges, including the lack of experimental variation in health status, an inability to track individuals over time, and accurately measuring living standards and productivity in low-income settings. This study exploits a randomized school health intervention that provided deworming treatment to Kenyan children, and uses longitudinal data to estimate impacts on economic outcomes up to 20 y later. The effective respondent tracking rate was 84%. Individuals who received two to three additional years of childhood deworming experienced a 14% gain in consumption expenditures and 13% increase in hourly earnings. There are also shifts in sectors of residence and employment: treatment group individuals are 9% more likely to live in urban areas, and experience a 9% increase in nonagricultural work hours. Most effects are concentrated among males and older individuals. The observed consumption and earnings benefits, together with deworming’s low cost when distributed at scale, imply that a conservative estimate of its annualized social internal rate of return is 37%, a high return by any standard.

Centering the Voices of Black Parasitologists During America's Racial Awakening

During the fall of 2020, several panel discussions were held to highlight the perspectives of Black parasitologists. Here, I summarize the themes from three such discussions, held at the Molecular Parasitology Meeting, Black in Microbiology Week, and the Annual Meeting of the American Society of Tropical Medicine & Hygiene, respectively.

Making waves: Right in our backyard- surface discharge of untreated wastewater from homes in the United States

Roughly ¼ of U.S. residents (80 million people) lack access to sanitary sewers and are required to treat their wastewater through a permitted onsite wastewater treatment system (OWTS). The vast majority use conventional septic systems with subsurface infiltration, which work well under most conditions. However, certain geologic conditions (e.g., impermeable soil, high water table) can preclude use of septic systems, requiring investment in expensive advanced OWTS. The confluence of lack of sewer, unsuitable geology, and poverty can lead households to have no feasible option for treating wastewater. In many such communities households discharge raw sewage onto the ground through what are commonly called "straight pipes." Here, we present the first effort to synthesize available evidence documenting the scope of straight pipe use in the U.S., including estimates of close to 50% straight pipe use in some counties. Despite reports that straight pipes are widespread and troubling preliminary evidence of adverse health effects, there has been no national effort to estimate the use or impacts of straight pipes. There are various disincentives that discourage the reporting of straight pipes by both residents and government actors. We propose ways to improve quantification of straight pipes and increase knowledge of their adverse effects. We identify the characteristics of areas with large proportions of straight pipes and describe the role of new and pending government programs in encouraging reporting and providing solutions.

Soil-Transmitted Helminths in the USA: a Review of Five Common Parasites and Future Directions for Avenues of Enhanced Epidemiologic Inquiry

Purpose of Review

The aim of this review is to present a comprehensive look at five intestinal soil-transmitted helminths (STHs) of global health importance that may continue to plague low-income and rural areas of the USA and argue the need for enhanced surveillance of these infections, which primarily affect the nation’s most vulnerable groups.

Recent Findings

Human STH infections in middle- and high-income countries are at particular risk for being undiagnosed; as common symptoms are non-specific, differentials require a high index of clinical suspicion, and cases are concentrated in areas of poverty where access to care is limited. Although autochthonous STHs are thought to be rare in the USA, infections were once common in the American South and Appalachia and robust epidemiologic surveillance is limited post 1980s. However, recent community studies and case reports from small-scale farms and areas of high rural or inner-city poverty reveal the potential for persisting helminth infections in distinct populations of the country.

Summary

STHs are among the most common neglected tropical diseases globally causing significant morbidity in underserved communities and contributing to the continuation of cycles of poverty within vulnerable populations. Due to possible severe disease sequalae and their ability to perpetuate poverty and poverty-associated health outcomes within already vulnerable groups, it is vital that surveillance for these infections is enhanced to bolster health equity in the USA.

COVID-19 and Corticosteroids: Unfamiliar but Potentially Fatal Infections That Can Arise following Short-Course Steroid Treatment

Corticosteroid use is increasing worldwide as recent studies confer survival benefit of corticosteroids in the management of patients with severe COVID-19. Strongyloides and amebic infections are neglected diseases that can progress to catastrophic complications in patients exposed to corticosteroids, even with short treatment courses. To prevent lethal outcomes, clinicians should be aware of the threat these two parasitic infections pose to at-risk patients receiving corticosteroids, especially in the era of COVID-19.

Impact of Anthelmintic Price Increases on Practice Patterns of Healthcare Providers Caring for Immigrant and Refugee Populations in the United States

In the United States, prices of long-established, generic anthelmintic medications have markedly risen. In the past decade, albendazole and mebendazole have increased in price by > 8,000%, whereas praziquantel has increased by > 500%. To determine the effect of these price increases on the practice patterns of healthcare providers, we conducted a cross-sectional electronic survey of clinics in the United States that primarily care for immigrant and refugee patient populations. Among 32 clinics, 53.1% reported that price increases impacted how providers diagnosed and treated helminth infections. A third (34.4%) of clinics reported that price increases have left them unable to treat known helminth infections. Other ways in which price increases impacted practice patterns included prescribing anthelmintics other than albendazole, mebendazole, or praziquantel when possible (34.4%); avoiding screening asymptomatic patients for helminth infections (15.6%); advising patients to acquire medications from another country (15.6%) or the patient's home country (9.4%); reducing anthelmintic dosing regimens to fewer pills (9.4%); and advising patients to purchase medications on the Internet (6.3%). These findings suggest price increases have negatively impacted the diagnosis and treatment of helminth infections in this population, and have resulted in the inability to treat known helminth infections. These findings have significant implications for the morbidity and mortality of infected individuals, as well as for public health in the United States.

Ascaris and Toxocara as foodborne and waterborne pathogens

This is a review on the current status of Ascaris and Toxocara as agents of disease as a foodborne pathogen that is often transmitted onto produce via contaminated water. The paper introduces the parasites, their biology, disease caused, and mode of transmission. It summarizes recent research on methods for the detection of the parasites on crops, their prevalence in recent surveys of ready to eat plants in different parts of the world, and potential aspects of their means for remediation on vegetable crops. Also discussed is the ubiquitous nature of the presence of these eggs in the environment due to the many humans infected and means currently underway to control these parasites though improve water quality, sanitation, and hygiene.

Parasitic Infection Surveillance in Mississippi Delta Children

Some recent studies suggest ongoing transmission of parasitic diseases in the American South; however, surveys in Mississippi children are lacking. We enrolled 166 children (median age 8 years, range 4-13 years) from the Mississippi Delta region and carried out multi-parallel real-time polymerase chain reaction (PCR) for Necator americanus, Ascaris lumbricoides, and Strongyloides stercoralis on their stool samples. Dried blood spots were obtained for multiplex serology antibody detection. Of 166 children, all reported having flushable toilets, 11% had soil exposure, and 34% had a pet dog or cat. None had prior diagnosis or treatment of parasitic disease. Multi-parallel real-time PCRs were negative on the 89 stool DNA extracts available for testing. Dried blood spot testing of all 166 children determined the seroprevalence of IgG antibodies to Toxocara spp. (3.6%), Cryptosporidium (2.4%), S. stercoralis, Fasciola hepatica, and Giardia duodenalis (all 0%). In conclusion, parasitic infections and exposure were scarce in this population. Larger studies of at-risk populations are needed.

Historical analysis of inverse correlation between soil-transmitted helminthiasis and pancreatic cancer

In this descriptive epidemiological study, the soil-transmitted helminth (STH) burden and pancreatic cancer (PC) mortality rates of different countries and peoples are compared to demonstrate an inverse correlation. Formerly ubiquitous helminth infection possibly played a significant role in defending the human host against PC until the advancement of modern hygiene, with helminth eradication in recent times in developed countries and urban centers. It is posited that a high rate of infection by STH in developing countries and rural areas protects the human host from the development of PC, possibly by immune modulation. This hypothesis is used to explain increased PC rates in minority groups in the United States who had decreased helminth exposure in the late 20th century.

Modeling strongyloidiasis risk in the United States

OBJECTIVES

To provide a spatial risk assessment for the neglected disease strongyloidiasis in the United States by prioritizing areas with high probability of Strongyloides stercoralis presence and to offer recommendations for targeted screening and surveillance.

METHODS

The risk assessment was based on a species distribution model with parasite occurrence data and ecologically important environmental variables as input and local habitat suitability for the species as output. The model used a maximum entropy algorithm and occurrence records and environmental data from public sources. This ecological risk assessment was coupled to socioeconomic factors using multi-criteria analysis.

RESULTS

The model predicts suitable habitat for the parasite in ten states beyond the southeastern United States where it has been recorded including states in the south, east and northeast, and west coasts.

CONCLUSIONS

We recommend strongyloidiasis should be reportable in 16 states at high risk and uniform, near universal solid organ transplant screening should be implemented alongside approaches to heighten clinical suspicion.

Global COVID-19 Efforts as the Platform to Achieving the Sustainable Development Goals

Purpose of Review

In this commentary, we summarize and put into perspective the recent information that highlights the associations between coronavirus disease and poverty. We also bring attention to another dimension that will most likely exacerbate the severity and long-term sequelae of COVID-19 in impoverished populations, that is, the comorbidities and the presence of tropical infections.

Recent Findings

During this first half of 2020, the COVID-19 pandemic has emerged as a poverty-related neglected disease on at least two fronts. First, is its significant impact in low-income neighborhoods in the USA, the epicenter of the pandemic. Second, is its emergence in poor urban areas of South America, and now in Asia and Africa. In both fronts, the pandemic is contributing heavily towards the loss of public health gains that we managed to achieve globally during the last two decades. Specifically, any advances made as part of the United Nations Millennium Development Goals (United Nations, 2020) is eroding, and for the first time, the number of people entering extreme poverty is increasing. Adding to this descent into poverty are new disruptions in ongoing disease control programs, routine vaccination strategies, and a reduction of capacity building efforts globally. Therefore, and as highlighted by many others, we support the notion that a way forward to eliminate this coronavirus pandemic should include linking COVID-19 control to other tropical or poverty-related diseases.

Summary

COVID-19 is slowing or reversing global health and development gains. To be successful and achieve the global goals including the control of pandemics such as the one seen from the COVID-19, we must rely on strong leadership leading to impactful public policies and global collaborations, including global COVID-19 vaccinations, and potentially linking them to programs for childhood and adult vaccinations and programs for malaria, tuberculosis, HIV/AIDS, and neglected tropical disease treatments. Opportunities also include the creation of unique research opportunities and funding models and increase science engagement for international diplomacy. This can only be done with a better understanding of the relationships between coronavirus disease, poverty, and tropical diseases.

Chemosensory mechanisms of host seeking and infectivity in skin-penetrating nematodes

Approximately 800 million people worldwide are infected with one or more species of skin-penetrating nematodes. These parasites persist in the environment as developmentally arrested third-stage infective larvae (iL3s) that navigate toward host-emitted cues, contact host skin, and penetrate the skin. iL3s then reinitiate development inside the host in response to sensory cues, a process called activation. Here, we investigate how chemosensation drives host seeking and activation in skin-penetrating nematodes. We show that the olfactory preferences of iL3s are categorically different from those of free-living adults, which may restrict host seeking to iL3s. The human-parasitic threadworm Strongyloides stercoralis and hookworm Ancylostoma ceylanicum have highly dissimilar olfactory preferences, suggesting that these two species may use distinct strategies to target humans. CRISPR/Cas9-mediated mutagenesis of the S. stercoralis tax-4 gene abolishes iL3 attraction to a host-emitted odorant and prevents activation. Our results suggest an important role for chemosensation in iL3 host seeking and infectivity and provide insight into the molecular mechanisms that underlie these processes.