Waterborne Diseases That Are Sensitive to Climate Variability and Climate Change

The potential impact of climate change on medication access and quality deserves far more attention

Notwithstanding the obvious interconnection between humans and the world that they share with non-human inhabitants, the impact of our changing climate on certain aspects of the public health ecosystem has been under-investigated. We briefly describe some of the possible climate-induced changes in the procurement, distribution, access and use of medications, including those for animals generally and livestock specifically. A fuller understanding of the effect of climate change on medicine supply, access, use and quality, including how these affect antimicrobial resistance, would contribute to the further development of the "One Health" and "One Health Systems" concepts. We suggest that this understanding is not yet available, even though the changing incidence of infectious diseases due to changing climate has been studied. There is a need for improved understanding of the impact of extremes of humidity and heat on medication quality and research into heat-stable medicines as well as strategies for the improving resilience of the pharmaceutical supply and distribution system in complex public health emergencies caused by aberrant weather patterns.

Occurrence of macrolides resistance in Legionella pneumophila ST188: Results of the Belgian epidemiology and resistome investigation of clinical isolates

OBJECTIVES

The incidence of Legionnaires' disease steadily increases worldwide. Although Legionella pneumophila is known as pathogenic, systematic investigations into antibiotic resistance are scarce, and reports of resistance in isolates are recently emerging.

METHODS

Clinical cases and metadata reported to the Belgian National Reference Centre between 2011 and 2022 were retrospectively analyzed. A total of 283 clinical isolates were typed by core genome multi-locus sequence typing (cgMLST). Acquired genes or mutations triggering resistance were extracted from all of them.

RESULTS

The number of Legionnaires' disease cases has increased in Belgium. Urinary antigen testing remains the main used test, but polymerase chain reaction and serology allow the diagnostic in 14.8% and 2.4% of cases, respectively. cgMLST showed a good discrimination between sequence typing (ST) and minimal variation for ST47 isolates, whereas ST1s were more diverse. Genotypic screening identified a 23S ribosomal RNA mutation linked to a high-level macrolide resistance in one isolate of ST188, which is genetically closed to resistant isolates from France.

CONCLUSION

The increase in incidence is of concern and likely an under-estimate due to the reliance on urine antigen testing. Routine typing by cgMLST allows good discrimination and the first clinical isolate reported as resistant for macrolides was cultured, underscoring the need to define resistance breakpoints and incorporate antimicrobial susceptibility testing as routine clinical investigation practice.

Fulminant Edwardsiella tarda bacteremia following near-drowning episode in a patient without cirrhosis: A case report

Edwardsiella tarda is a Gram-negative intracellular pathogen within the Enterobacterales order, recognized as a causative agent of hemorrhagic septicemia in fish but also pathogenic to humans. However, the clinical course and prognostic factors of E. tarda bacteremia are not fully understood. We present a case of fulminant E. tarda bacteremia in a 90-year-old Japanese man without significant immunosuppression, developing after exposure to freshwater. The patient was admitted to the intensive care unit with septic shock following an accidental fall into an irrigation ditch. Despite appropriate empiric treatment, he passed away within 18 hours of admission. Blood cultures identified E. tarda, while Aeromonas hydrophila was detected in sputum. This case highlights the rapid progression and high mortality risk associated with E. tarda bacteremia; prolonged exposure to contaminated water and delayed transport to medical care were likely contributory factors to the fatal outcome. Furthermore, the detection of waterborne pathogens like A. hydrophila in respiratory samples may serve as a clue to consider possible water exposure in diagnostic reasoning.

The effects of rain and drought on incidence of enteric disease in Pennsylvania (2010-2019)

BACKGROUND

Campylobacter, nontyphoidal Salmonella, Cryptosporidium, and Giardia cause an estimated 1 million cases of domestically acquired waterborne diseases annually in the United States. Acute symptoms can include diarrhea and vomiting; however, these illnesses can result in longer term complications such as reactive arthritis, Guillan Barré syndrome and death, particularly in immunocompromised individuals. Precipitation and drought can plausibly increase the risk of enteric infections, but consensus in the literature is lacking.

OBJECTIVES

To determine the effects of rain and drought on weekly counts of reportable enteric illness (due to Salmonella, Campylobacter, Giardia, or Cryptosporidium) in Pennsylvania, US between 2010 and 2019.

METHODS

We obtained 10-years of data on confirmed illness from 66 Pennsylvania counties due to: Salmonella (9,924), Campylobacter (15,854), Giardia (4,537), and Cryptosporidium (4,017). A zero-inflated negative binomial model with random-intercept for county was used to assess the relationship between illnesses caused by these pathogens between 2010 and 2019, and weekly rain (cm) and Palmer Drought Severity Index (PDSI) values from the National Weather Service. The lag times that were tested, between illness and weather event, were chosen by calculating the cross correlation between the statewide average weekly rain and the statewide number of weekly cases.

RESULTS

A positive association was found between rain and counts of campylobacteriosis, salmonellosis, and giardiasis. An increase in prior wetness (PDSI value) was associated with increased incidence rates of cryptosporidiosis and campylobacteriosis. The relationship between rain and PDSI and illness varied by organism type.

DISCUSSION

Complex relationships exist between enteric disease and precipitation and prior environmental wetness. Our findings suggest that rainfall may be contributing to increased waterborne exposure. Further investigation is needed to explore these relationships with factors such as drinking water source, local geological conditions, presence of combined sewer overflows and agricultural activities, recreational water use and irrigation water sources to better elucidate important waterborne transmission pathways.

Extreme rainfall disproportionately impacts E. coli concentrations in Texas recreational waterbodies

Waterborne pathogen contamination poses a significant threat to water resources globally and the exposure to waterborne pathogen contamination is widely recognized as unevenly distributed. Extreme weather events could exacerbate inequalities in waterborne disease as climate variability continues to escalate. However, there is a limited understanding of how extreme rainfall affects E. coli levels and whether disadvantaged communities experience disproportionate impacts from extreme rainfall on E. coli contamination. Leveraging 21 years of E. coli data along with climate data and watershed characteristics, this study employed Multiscale Geographically Weighted Regression (MGWR) models to quantify the seasonal and spatial impacts of extreme rainfall on E. coli concentrations in Texas. Our results indicate that during dry seasons, regions in northern and eastern Texas exhibit significantly higher impacts of extreme rainfall on E. coli concentrations, which is associated with high proportions of pastures, wetlands, and silt. However, during wet seasons, western and southern regions experience slightly higher extreme rainfall induced E. coli contamination risks likely due to significantly increased runoff from the rainfall together with higher slopes and clay-rich soil. In addition, we found census tracts with higher proportions of Black and Latino populations experience greater extreme rainfall impacts on E. coli levels in different months. Furthermore, an analysis of historical trends in extreme rainfall intensity indicates that climate variability could further amplify the existing inequalities in exposure to E. coli contamination. Our findings highlight the disproportionate impacts of extreme rainfall induced E. coli contamination on disadvantaged communities and emphasize the critical need for targeted intervention strategies to mitigate these risks effectively and equitably in Texas.

Cryptosporidium Infection During Pregnancy and Effects on Pregnancy Outcomes in Israel

Cryptosporidium is a parasite that typically causes self-limited gastroenteritis. Little is known about the course of infection and its impact during pregnancy. This retrospective cohort study conducted in Israel assessed the effects of Cryptosporidium infection on pregnancy and obstetrical outcomes. The study population included pregnant women with a positive PCR stool test for Cryptosporidium and a control group of pregnant women with negative tests, matched at a 3:1 ratio based on age, gestational week, and sector. Their medical records were retrieved for symptoms, treatments, pregnancy termination, gestational age, birth weight, Apgar score, and head circumference. Fisher's exact or chi-squared tests were used to determine significance. Between January 2020 and December 2023, 2512 pregnant women underwent PCR stool testing. Of these, 93 were positive for Cryptosporidium, mostly in 2022. Their median age was 31 (range: 23-42 years), and 77.4% were from medium-high socioeconomic status. The most common symptom was diarrhea (90/93, 96.7%). The infection was self-limiting in all cases, with none requiring specific treatment. No significant differences were found in miscarriage rate, delivery week, birth weight, Apgar score, or head circumference compared to the controls. This study illuminates the clinical course of Cryptosporidium infection in pregnant women, emphasizing a generally favorable outcome without the necessity for therapeutic intervention.

The United European Gastroenterology green paper-climate change and gastroenterology

Climate change, described by the World Health Organization (WHO) in 2021 as 'the single biggest health threat facing humanity', causes extreme weather, disrupts food supplies, and increases the prevalence of diseases, thereby affecting human health, medical practice, and healthcare stability. Greener Gastroenterology is an important movement that has the potential to make a real difference in reducing the impact of the delivery of healthcare, on the environment. The WHO defines an environmentally sustainable health system as one which would improve, maintain or restore health while minimizing negative environmental impacts. Gastroenterologists encounter the impacts of climate change in daily patient care. Alterations in the gut microbiome and dietary habits, air pollution, heat waves, and the distribution of infectious diseases result in changed disease patterns affecting gastrointestinal and hepatic health, with particularly severe impacts on vulnerable groups such as children, adolescents, and the elderly. Additionally, women are disproportionally affected, since climate change can exacerbate gender inequalities. Paradoxically, while healthcare aims to improve health, the sector is responsible for 4.4% of global carbon emissions. Endoscopy is a significant waste producer in healthcare, being the third highest generator with 3.09 kg of waste per day per bed, contributing to the carbon footprint of the GI sector. Solutions to the climate crisis can offer significant health co-benefits. Steps to reduce our carbon footprint include fostering a Planetary Health Diet and implementing measures for greener healthcare, such as telemedicine, digitalization, education, and research on sustainable healthcare practices. Adhering to the principles of 'reduce, reuse, recycle' is crucial. Reducing unnecessary procedures, which constitute a significant portion of endoscopies, can significantly decrease the carbon footprint and enhance sustainability. This position paper by the United European Gastroenterology aims to raise awareness and outline key principles that the GI workforce can adopt to tackle the climate crisis together.

Aetiology of diarrhoea in children aged zero to nine years in low- and middle-income countries: A systematic review

Background

While diarrhoeal disease remains a leading cause of death in children aged <5 years in low- and middle-income countries (LMICs), it also poses significant health risks for older children, underscoring the importance of our study focusing on children aged <10 years. In this systematic review, we assessed common diarrhoea aetiologies in children aged <10 years in LMICs.

Methods

We identified relevant articles in PubMed, Embase, and Web of Science using pre-defined search criteria. We included case series and case-control studies of children aged <10 years with non-bloody, bloody, acute, persistent, and chronic diarrhoea. Articles that evaluated two or more diarrhoea pathogens in LMICs conducted between 1 January 1990 and 31 July 2020 were eligible for inclusion. We stratified combined data from case series and case-control studies by age and World Health Organization (WHO) regions.

Results

76 studies published between 1990-2020 were eligible for inclusion. Among these, eight were case-control studies. 56 papers focused only on children aged <5 years, while 20 also included children aged ≥5 years. The most common viral pathogens among <5 years old children were rotavirus, norovirus, adenovirus, and astrovirus. Bacterial pathogens included Escherichia coli, Salmonella enterica, Shigella species, and Campylobacter species, while parasitic pathogens included Cryptosporidium, Giardia, and Entamoeba species. Rotavirus was the most common viral pathogen among children across all age groups and every WHO region. Escherichia coli was prevalent in all age groups and was responsible for most diarrhoea cases in the African Region. Among parasitic pathogens, Entamoeba species and Giardia were prevalent in children aged three to five years, with the former a major cause of diarrhoea in the Eastern Mediterranean Region. Similarly, in children aged six to 10 years, bacterial pathogens, including Escherichia coli, Salmonella, and Shigella, suggest a continued significance of these pathogens beyond the age of five. Common viral pathogens for this group were rotavirus, norovirus, and sapovirus, although the number of studies for this age group is limited.

Conclusions

Escherichia coli, rotavirus, and Entamoeba species were the most common pathogens responsible for diarrhoea in children aged <5 years in LMICs. Future research should focus on characterising the pathogens responsible for causing diarrhoea in children aged six to 10 years stratified by geographic area of residence, i.e. WHO region and urban vs rural. Case-control or cohort studies covering a full 12-month period to account for seasonality are needed for a more accurate picture of diarrhoea aetiology among children.

Registration

PROSPERO (CRD42020204005).

Identification of new targets for the diagnosis of cysts (four) and trophozoites (one) of the eye pathogen Acanthamoeba

Acanthamoebae , which are free-living amoebae, cause corneal inflammation (keratitis) and blindness, if not diagnosed and effectively treated. While trophozoites adhere to and damage the cornea, Acanthamoeba cysts, the walls of which contain cellulose and have two layers connected by conical ostioles, are the diagnostic form by microscopy of the eye or of corneal scrapings. We recently used structural and experimental methods to characterize cellulose-binding domains of Luke and Leo lectins, which are abundant in the inner layer and ostioles. However, no antibodies have been made to these lectins or to a Jonah lectin and a laccase, which are abundant in the outer layer. Here we used confocal microscopy to show that rabbit antibodies to recombinant Luke, Leo, Jonah, and laccase generally support localizations of GFP-tagged proteins in walls of transfected Acanthamoebae. Rabbit antibodies to all four wall proteins efficiently detected calcofluor white-labeled cysts of 10 of 11 Acanthamoeba isolates obtained from the ATCC, including five T4 genotypes that cause most cases of keratitis. Laccase shed into the medium during encystation was detected by an enzyme-linked immunoassay. We also used structural and experimental methods to characterize the mannose-binding domain of an Acanthamoeba mannose-binding protein and showed that rabbit antibodies to the mannose-binding domain efficiently detected trophozoites of all 11 Acanthamoeba isolates. We conclude that four wall proteins are all excellent targets for diagnosing Acanthamoeba cysts in the eye or corneal scrapings, while the mannose-binding domain is an excellent target for identifying trophozoites in cultures of corneal scrapings.

Importance

Free-living amoeba in the soil or water cause Acanthamoeba keratitis, which is diagnosed by identification of cysts by microscopy of the eye or of corneal scrapings, using calcofluor-white that unfortunately cross-reacts with fungi and plants. Alternatively, Acanthamoeba infections are diagnosed by identification of trophozoites in cultures of scrapings. Here we showed that rabbit antibodies to four abundant cyst wall proteins (Jonah, Luke, Leo, and laccase) each efficiently detect calcofluor-white-labeled cysts of 10 of 11 Acanthamoeba isolates obtained from the ATCC. Further, laccase released into the medium by encysting Acanthamoebae was detected by an enzyme-linked immunoassay. We also showed that rabbit antibodies to the mannose-binding domain of the Acanthamoeba mannose-binding protein, which mediates adherence of trophozoites to keratinocytes, efficiently identifies trophozoites of all 11 ATCC isolates. In summary, four wall proteins and the ManBD appear to be excellent targets for diagnosis of Acanthamoeba cysts and trophozoites, respectively.

Cellulose binding and the timing of expression influence protein targeting to the double-layered cyst wall of Acanthamoeba

The cyst wall of the eye pathogen Acanthamoeba castellanii contains cellulose and has ectocyst and endocyst layers connected by conical ostioles. Cyst walls contain families of lectins that localize to the ectocyst layer (Jonah) or the endocyst layer and ostioles (Luke and Leo). How lectins and an abundant laccase bind cellulose and why proteins go to locations in the wall are not known and are the focus of the studies here. Structural predictions identified β-jelly-roll folds (BJRFs) of Luke and sets of four disulfide knots (4DKs) of Leo, each of which contains linear arrays of aromatic amino acids, also present in carbohydrate-binding modules of bacterial and plant endocellulases. Ala mutations showed that these aromatics are necessary for cellulose binding and proper localization of Luke and Leo in the Acanthamoeba cyst wall. BJRFs of Luke, 4DKs of Leo, a single β-helical fold (BHF) of Jonah, and a copper oxidase domain of the laccase each bind to glycopolymers in both layers of deproteinated cyst walls. Promoter swaps showed that ectocyst localization does not just correlate with but is caused by early encystation-specific expression, while localization in the endocyst layer and ostioles is caused by later expression. Evolutionary studies showed distinct modes of assembly of duplicated domains in Luke, Leo, and Jonah lectins and suggested Jonah BHFs originated from bacteria, Luke BJRFs share common ancestry with slime molds, while 4DKs of Leo are unique to Acanthamoeba.IMPORTANCEAcanthamoebae is the only human parasite with cellulose in its cyst wall and conical ostioles that connect its inner and outer layers. Cyst walls are important virulence factors because they make Acanthamoebae resistant to surface disinfectants, hand sanitizers, contact lens sterilizers, and antibiotics applied to the eye. The goal here was to understand better how proteins are targeted to specific locations in the cyst wall. To this end, we identified three new proteins in the outer layer of the cyst wall, which may be targets for diagnostic antibodies in corneal scrapings. We used structural predictions and mutated proteins to show linear arrays of aromatic amino acids of two unrelated wall proteins are necessary for binding cellulose and proper wall localization. We showed early expression during encystation causes proteins to localize to the outer layer, while later expression causes proteins to localize to the inner layer and the ostioles.

From Investigating a Case of Cellulitis to Exploring Nosocomial Infection Control of ST1 Legionella pneumophila Using Genomic Approaches

Legionella pneumophila can cause a large panel of symptoms besides the classic pneumonia presentation. Here we present a case of fatal nosocomial cellulitis in an immunocompromised patient followed, a year later, by a second case of Legionnaires' disease in the same ward. While the first case was easily assumed as nosocomial based on the date of symptom onset, the second case required clear typing results to be assigned either as nosocomial and related to the same environmental source as the first case, or community acquired. To untangle this specific question, we applied core-genome multilocus typing (MLST), whole-genome single nucleotide polymorphism and whole-genome MLST methods to a collection of 36 Belgian and 41 international sequence-type 1 (ST1) isolates using both thresholds recommended in the literature and tailored threshold based on local epidemiological data. Based on the thresholds applied to cluster isolates together, the three methods gave different results and no firm conclusion about the nosocomial setting of the second case could been drawn. Our data highlight that despite promising results in the study of outbreaks and for large-scale epidemiological investigations, next-generation sequencing typing methods applied to ST1 outbreak investigation still need standardization regarding both wet-lab protocols and bioinformatics. A deeper evaluation of the L. pneumophila evolutionary clock is also required to increase our understanding of genomic differences between isolates sampled during a clinical infection and in the environment.

Climate change and human health: Last call to arms for us

Climate change, now the foremost global health hazard, poses multifaceted challenges to human health. This editorial elucidates the extensive impact of climate change on health, emphasising the increasing burden of diseases and the exacerbation of health disparities. It highlights the critical role of the healthcare sector, particularly anaesthesia, in both contributing to and mitigating climate change. It is a call to action for the medical community to recognise and respond to the health challenges posed by climate change.

Do medical devices contribute to sustainability? Environmental, societal and governance aspects

Sustainability of a product or device is currently primarily related to its environmental footprint. Here, a wider concept of sustainability is introduced for medical devices and their components in healthcare provision. Such devices sustain healthcare and patient wellbeing due to their quality specifications for material composition, product design and performance. The term quality must be intended in the most comprehensive term, including purity and biocompatibility of materials, device reliability, limited number of recalls and reduced risks as well as acceptability for patients. A close look on medical device specification shows, however, that additional parameters, such as societal, demographic and economic factors also determine medical device sustainability. The medical device life cycle, from design phase, production process to clinical application and the final disposal, also determines its impact. Recommendations for healthcare operators and managers will complete the hypothesis of this paper, that a thoroughly outlined device choice and operation together with a careful waste management of spent medical devices and their components positively affects medical device sustainability. As an example, the limited quantity of wastes and the reduced risks for adverse reaction have a positive impact on both the environmental pollution and on the costs sustained by the healthcare organisations and by the community. These factors determine both, the success of healthcare manoeuvres and the related environmental footprint.