Waterborne Parasites Research Articles

The genetic variation of different developmental stages of Schistosoma japonicum: do the distribution in snails and pairing preference benefit the transmission?

BackgroundSchistosoma japonicum is a waterborne parasite that causes schistosomiasis in humans and in more than 40 animal species. Schistosoma japonicum shows distinct genetic differentiation among geographical populations and multiple hosts, but the genetic diversity of different developmental stages of S. japonicum from is less studied. Such studies could elucidate ecological mechanisms in disease transmission by analysing feedbacks in individual physiology and population state.MethodsAfter infection using cercariae from a pool of snails shedding together (Method I) and infection using mixed equal numbers of cercariae from individually shed snails (Method II), different developmental stages of S. japonicum were genotyped with microsatellite loci, including 346 cercariae, 701 adult worms and 393 miracidia. Genetic diversity and molecular variation were calculated at different population levels. Kinships (I′) among cercariae at intra-snail and inter-snail levels were evaluated. Genetic distance (Dsw) was compared between paired and unpaired worms, and partner changing was investigated through paternity identification for miracidia.ResultsThe cercaria clones in individual snails varied from 1 to 8 and the kinship of cercariae within individual snails was significant higher (P < 0.001) than that among different snails after deleting near-identical multi-locus genotypes (niMLGs). The allelic diversity of worms in Method I was lower (P < 0.001) than that in Method II, and allele frequency among mice in Method I was also less consistent. The parents of some miracidia were worms that were not paired when collected. The Dsw between each female of paired and unpaired males was much larger (P < 0.001) than that between the female and male in each pair.ConclusionsMost of the infected snails contained multiple miracidia clones. The aggregation of genetically similar S. japonicum miracidia in individual snails and the unbalanced distribution of miracidia among snails suggests a non-uniform genetic distribution of cercariae among snails in the field. This further influenced the genetic structure of adult worms from infections with different cercariae sampling methods. Schistosoma japonicum in mice can change paired partner, preferring to mate with genetically similar worms. These characteristics provide implications for understanding the balance in genetic diversity of S. japonicum related to the transmission of schistosomiasis.

Isolation of N. philippinensis and N. americana strains from irrigation waters of farmland soils in Iran.

Free-living amoebae (FLA) including Acanthamoeba spp., Naegleria fowleri, and Balamuthia mandrillaris are among the many waterborne parasites. There is not much known about the possible FLA contamination of the irrigation resources watering crops and agricultural lands in this country. Forty-five water samples were collected from water canals used for irrigation of farmlands and tested for the presence of pathogenic FLA using morphological and molecular-based methodology. The ITS region of Naegleria species was sequenced and a phylogenetic tree was generated to confirm the genetic associations and taxonomic status of the identified Naegleria spp. A total of seven (15.5%) samples were positive for FLA. Molecular analyses identified two strains as N. philippinensis (isolates: PW1 and PW2) isolated from irrigation treated water. One strain showed high homology with N. americana (isolate: PW3). To the best of our knowledge, the present study is the first study to isolate the two strains of N. philippinensis and N. americana from agricultural waters in Iran. The presence of the FLA in irrigation waters should be considered a potential health threat for exposed farmers and other people.

A Systematic Review of Water and Gender Interlinkages: Assessing the Intersection With Health

Background: Significant developmental challenges in low-resource settings limit access to sustainable water, sanitation, and hygiene (WASH). However, in addition to reducing human agency and dignity, gendered WASH inequities can also increase disease burden among women and girls. In this systematic review, a range of challenges experienced by women relating to inadequate WASH resources are described and their intersection with health are explored. We further assess the effectiveness of interventions in alleviating inequalities related to the Sustainable Development Goals (SDGs) three (health), five (gender), and six (water). Methods: We searched the MEDLINE database to identify research articles related to water (i.e., WASH), gender, and sustainability. An analysis of both observational and interventional studies was undertaken. For each study, content analysis was performed to identify the relevant WASH, gender, and health related outcomes, and the main conclusions of the study. Results: Key themes from our search included that women and girls face barriers toward accessing basic sanitation and hygiene resources, including a lack of secure and private sanitation and of Menstrual Hygiene Management (MHM) resources. In total, 71% of identified studies reported a health outcome, suggesting an intersection of water and gender with health. Half of the research studies that included a health component reflected on the relationship between WASH, gender, and infantile diseases, including under-5 mortality, waterborne parasites, and stunting. In addition, we found that women and girls, as a result of their role as water purveyors, were at risk of exposure to contaminated water and of sustaining musculoskeletal trauma. A limited number of studies directly compared gender differences in accessing WASH resources, and an even smaller fraction (N = 5, 8.5%) reported sex-disaggregated outcomes. Educational, infrastructural, and programmatic interventions showed promise in reducing WASH and health outcomes. Indeed, infrastructural WASH interventions can be successful if long-term maintenance is ensured. Conclusions: Significant WASH inequities in women and girls further manifest as health burdens, providing strong evidence that the water-gender-nexus intersects with health. Thus, addressing gender and water inequities holds the potential to alleviate disease burden and have a significant impact on achieving the SDGs, including SDG three, five, and six.

Acceptability and feasibility of genital self-sampling for the diagnosis of female genital schistosomiasis: a cross-sectional study in Zambia

Background: Female genital schistosomiasis (FGS) is a neglected and disabling gynaecological disorder that is difficult to diagnose and is part of the wider spectrum of urogenital disease caused by the waterborne parasite Schistosoma haematobium. Over 90% of human schistosomiasis cases are found in sub-Saharan Africa with 3.8 million people infected with schistosomes in Zambia. Reported FGS prevalence ranges from 33-75% of those with urinary schistosomiasis in endemic areas, suggesting a potentially high FGS burden in Zambia alone. The Bilharzia and HIV (BILHIV) study evaluated home self-sampling genital collection methods for the diagnosis of FGS. Methods: Eligible participants included non-pregnant, sexually active women aged 18-31 who were previously recruited for the HPTN 071 (PopART) trial in Livingstone, Zambia. Household demographic and symptom questionnaires were administered by community workers. Participants were offered vaginal and cervical self-swabs and a urine cup. Cervicovaginal lavage (CVL) was performed in clinic by midwives. Information was collected from participants on the acceptability and feasibility of genital self-sampling. Results: From January-August 2018, 603 women were enrolled, and 87.3% (527/603) completed clinic follow up. A high proportion of participants indicated that self-collection of specimens was “easy” or “very easy” on a 5-point Likert scale. A high proportion of women would be willing to self-collect all three specimens again in future: vaginal swab 96.7% (583/603), cervical swab 96.5% (582/603), and urine 96.2% (580/603). Home-based self-sampling was preferred over provider-based sampling in the clinic due to greater privacy 58.5% (353/603), convenience 46.3% (279/603) and need for transportation 15.9% (96/603). Conclusions: Home based genital self-sampling for FGS diagnosis is highly acceptable. This scalable method may inform future efforts for community-based diagnosis of FGS.

TREATMENT POTENTIAL OF ALOE VERA GEL IN GAIRDIA INTESTINALIS INFECTED ALBINO RATS

Aloe vera has been used as a traditional medicine in many cultures, especially Egypt, and known for its therapeutical effects with dermatitis, ulcer and burns. It has many beneficial properties as it is a powerful antioxidant, anti-inflammatory and antimicrobial agent. G. intestinalis is a waterborne parasite that causes human giardiasis. In Egypt, outbreaks commonly occur in areas where water treatment is insufficient leading to infection rates of 50% of the total population. The current treatment against G. intestinalis involves metronidazole, known as flagyl, which can induce many side effects as headache, vertigo, nausea, and a metallic taste in the mouth. Previous studies showed that high doses of metronidazole, over long periods, have mutagenic and carcinogenic effects in experimental animals. The study aims to evaluate the effect of Aloe vera in treatment of G. intestinalis in male albino rats in comparison to metronidazole. Our results showed that Aloe vera cleared the infection and reduced inflammatory cytokines in treated groups. Thus it can be used instead of metronidazole in treatment of G. intestinalis due to its anti-inflammatory properties and to avoid the undesired side effect of the metronidazole.

A Crosstalk Between Glucosylceramide Synthase and Long‐Chain Fatty Acid Elongase is Critical for Regulating Cyst Production in an Intestinal Protozoan, Giardia lamblia

The waterborne parasite, Giardia lamblia, is a major cause of intestinal illness (giardiasis) worldwide. Giardia is classified as a model organism to study evolution because of its compact genome, reduced metabolic pathways, and lack of emblematic eukaryotic organelles. The infection by Giardia is transmitted by osmotically‐resistant cysts in contaminated food, water, and feces. It has been shown that giardial glucosylceramidesynthase (gGlcT1), an important enzyme of the sphingolipid metabolic pathway, plays a critical role in inducing encystation and cyst production. Modulation of gGlcT1 expression by overexpression interferes with cyst production and cyst viability in culture. In addition, our laboratory has reported that gGlcT1 is a dual‐substrate enzyme, with separate catalytic domains that facilitate the synthesis of both glucosylceramide and galactosylceramide, and its overexpression increases the uptake of membrane lipids and cholesterol significantly. Interestingly, although this parasite has a limited lipid synthesis ability, it expresses a long chain fatty acid elongase (gFAELO) gene, which is mostly expressed in cysts. Because FAELO enzymes are involved in remodeling of fatty acyl chain of membrane lipids and gGlcT1 overexpression increases lipid uptake by Giardia, we investigated whether the interplay between gGlcT1 and gFAELO is important for maintaining the lipid homeostasis in this parasite and whether that drives the process of cyst production. Five clones were developed to track gGlcT1 and/or gFAELO expression. Under different promoters, it was found that the enzyme expression of both enzymes and the enzymatic activity of gGlcT1 was modulated depending on life stage and co‐expression with gFAELO. The production and morphology of cysts was also affected as evaluated by encystation and confocal microscopy. These results suggest that the coordinated temporal expression of gGlcT1 and gFAELO alters lipid homeostasis in Giardia, which could be critical for infective cyst production.Support or Funding InformationThis work was supported by grant R01AI095667 from the NIH (NIAID). Vanessa was supported by the NIH RISE Grant 5R25GM069621 from NIGMS. The biochemical, molecular, and confocal microscopy experiments were carried out at the Genomic Analysis, Cytometry, Screening, and Imaging Core Facilities at the Border Biomedical Research Center (UTEP), supported by grant G12MD007592 from NIMHD (NIH).

TREATMENT POTENTIAL OF ALOE VERA GEL IN GAIRDIA INTESTINALIS INFECTED ALBINO RATS

Aloe vera has been used as a traditional medicine in many cultures, especially Egypt, and known for its therapeutical effects with dermatitis, ulcer and burns. It has many beneficial properties as it is a powerful antioxidant, anti-inflammatory and antimicrobial agent. G. intestinalis is a waterborne parasite that causes human giardiasis. In Egypt, outbreaks commonly occur in areas where water treatment is insufficient leading to infection rates of 50% of the total population. The current treatment against G. intestinalis involves metronidazole, known as flagyl, which can induce many side effects as headache, vertigo, nausea, and a metallic taste in the mouth. Previous studies showed that high doses of metronidazole, over long periods, have mutagenic and carcinogenic effects in experimental animals. The study aims to evaluate the effect of Aloe vera in treatment of G. intestinalis in male albino rats in comparison to metronidazole. Our results showed that Aloe vera cleared the infection and reduced inflammatory cytokines in treated groups. Thus it can be used instead of metronidazole in treatment of G. intestinalis due to its anti-inflammatory properties and to avoid the undesired side effect of the metronidazole.

A review study of waterborne parasites in Iraq

Waterborne parasites are primary parasites that are ubiquitous and affect humans, pets, and wildlife throughout the world. According to the World Health Organization, more than 80 human diseases transmitted by water in developing countries, 60% of the population do not have access to clean drinking water .Waterborne diseases occur worldwide, and outbreaks caused by the contamination of community water systems have the potential to cause disease in large number of consumers. This study dealt with the database of studies of waterborne parasites in Iraq. Which includes the following classes of parasites: Nematodes as Ascaris lumbericoides, Trichuris sp., Strongyloides stericorailis and Enterobius vermicularis. Cestodes as Taenia sp. and Hymenolips nana. Trematodes as Fasciola sp. and Schistosoma haematobium. Protozoa as Entamoeba histolytica, Trichomonus vaginalis, Chilomastix sp., Iodamoeba butschlii, Naegleriae sp., Coccidia sp., Acanthamoeba sp., Cryptosporidium parvum, Cryptosporidium muris, Giardia lamblia, Blantidium sp., and Entamoeba coli.

A review study of waterborne parasites in Iraq

A review study of waterborne parasites in Iraq

Reduced expression of a rhomboid protease, EhROM1, correlates with changes in the submembrane distribution and size of the Gal/GalNAc lectin subunits in the human protozoan parasite, Entamoeba histolytica.

Entamoeba histolytica is a food- and waterborne parasite that causes amebic dysentery and amoebic liver abscesses. Adhesion is one of the most important virulence functions as it facilitates motility, colonization of host, destruction of host tissue, and uptake of nutrients by the parasite. The parasite cell surface adhesin, the Gal/GalNAc lectin, facilitates parasite-host interaction by binding to galactose or N-acetylgalactosamine residues on host components. It is composed of heavy (Hgl), intermediate (Igl), and light (Lgl) subunits. Igl is constitutively localized to lipid rafts (cholesterol-rich membrane domains), whereas Hgl and Lgl transiently associate with rafts. When all three subunits are localized to rafts, galactose-sensitive adhesion is enhanced. Thus, submembrane location may regulate the function of this adhesion. Rhomboid proteases are a conserved family of intramembrane proteases that also participate in the regulation of parasite-host interactions. In E. histolytica, one rhomboid protease, EhROM1, cleaves Hgl as a substrate, and knockdown of its expression inhibits parasite-host interactions. Since rhomboid proteases are found within membranes, it is not surprising that lipid composition regulates their activity and enzyme-substrate binding. Given the importance of the lipid environment for both rhomboid proteases and the Gal/GalNAc lectin, we sought to gain insight into the relationship between rhomboid proteases and submembrane location of the lectin in E. histolytica. We demonstrated that EhROM1, itself, is enriched in highly buoyant triton-insoluble membranes reminiscent of rafts. Reducing rhomboid protease activity, either pharmacologically or genetically, correlated with an enrichment of Hgl and Lgl in rafts. In a mutant cell line with reduced EhROM1 expression, there was also a significant augmentation of the level of all three Gal/GalNAc subunits on the cell surface and an increase in the molecular weight of Hgl and Lgl. Overall, the study provides insight into the molecular mechanisms governing parasite-host adhesion for this pathogen.

Anti-Schistosoma mansoni effects of essential oils and their components.

Schistosoma mansoni is endemic in 55 countries around the world. S. mansoni is a water-borne parasite of humans belonging to the group of blood flukes. Generally, schistosomiasis is treated with praziquantel, which results in frequent treatment failures and reinfections. Essential oils have diverse biological effects, including antimicrobial, antiprotozoal and antiparasitic. This review aimed at summarizing available in vitro, in vivo and clinical trials showing evidence and mechanisms of actions of essential oils and their derivatives acting against S. mansoni. The findings suggest that a number of essential oils and/or their components act against S. mansoni. Essential oils and/or their derivatives may be one of the potential sources of antischistosomal drugs.

Update on Giardia: Highlights from the seventh International Giardia and Cryptosporidium Conference.

Although Giardia duodenalis is recognized as one of the leading causes of parasitic human diarrhea in the world, knowledge of the mechanisms of infection is limited, as the pathophysiological consequences of infection remain incompletely elucidated. Similarly, the reason for and consequences of the very specific genome-organization in this parasite with 2 active nuclei is only partially known. Consistent with its tradition, the 7th International Giardia and Cryptosporidium Conference (IGCC 2019) was held from June 23 to 26, 2019, at the Faculty of Medicine and Pharmacy of the University of Rouen-Normandie, France, to discuss current research perspectives in the field. This renowned event brought together an international delegation of researchers to present and debate recent advances and identify the main research themes and knowledge gaps. The program for this interdisciplinary conference included all aspects of host-parasite relationships, from basic research to applications in human and veterinary medicine, as well as the environmental issues raised by water-borne parasites and their epidemiological consequences. With regard to Giardia and giardiasis, the main areas of research for which new findings and the most impressive communications were presented and discussed included: parasite ecology and epidemiology of giardiasis, Giardia-host interactions, and cell biology of Giardia, genomes and genomic evolution. The high-quality presentations discussed at the Conference noted breakthroughs and identified new opportunities that will inspire researchers and funding agencies to stimulate future research in a “one health” approach to improve basic knowledge and clinical and public health management of zoonotic giardiasis.

Parasitic Contamination of Drinking Water and Egyptian Standards for Parasites in Drinking Water

Water is life and access to clean drinking water is a fundamental human right. For human health, drinking water standards and guidelines have been developed to ensure their quality. Waterborne parasites are a great challenge and cause many diseases for humans. Thus, continuous monitoring of drinking water from the competent authorities in search of pollutants is required. The safety of drinking water for the growing population can be ensured by the correct use of water treatment technologies. Cryptosporidium is the first parasite to cause concern to health officials in the world. Also, Naegleria fowleri causes fatal cerebral infection, Acanthamoeba species that cause both cerebral and corneal disease; and Giardia which has heightened world concerns because of its severity. This study is based on highlighting on drinking water quality guidelines and standards published by the World Health Organization and some countries, especially Egypt. A growing concern globally after the scientists revealed the effects of polluted drinking water. So, a large number of the population is at risk of water pollution for the purpose of human access to clean drinking water and other uses.

Update on Cryptosporidium spp.: highlights from the Seventh International Giardia and Cryptosporidium Conference.

While cryptosporidiosis is recognized as being among the most common causes of human parasitic diarrhea in the world, there is currently limited knowledge on Cryptosporidium infection mechanisms, incomplete codification of diagnostic methods, and a need for additional therapeutic options. In response, the Seventh International Giardia and Cryptosporidium Conference (IGCC 2019) was hosted from 23 to 26 June 2019, at the Rouen Normandy University, France. This trusted event brought together an international delegation of researchers to synthesize recent advances and identify key research questions and knowledge gaps. The program of the interdisciplinary conference included all aspects of host-parasite relationships from basic research to applications to human and veterinary medicine, and environmental issues associated with waterborne parasites and their epidemiological consequences. In relation to Cryptosporidium and cryptosporidiosis, the primary research areas for which novel findings and the most impressive communications were presented and discussed included: Cryptosporidium in environmental waters, seafood, and fresh produce; Animal epidemiology; Human cryptosporidiosis and epidemiology; Genomes and genomic evolution encompassing: Comparative genomics of Cryptosporidium spp., Genomic insights into biology, Acquiring and utilizing genome sequences, Genetic manipulation; Host-parasite interaction (immunology, microbiome); and Diagnosis and treatment. High quality presentations discussed at the conference reflected decisive progress and identified new opportunities that will engage investigators and funding agencies to spur future research in a “one health” approach to improve basic knowledge and the clinical and public health management of zoonotic cryptosporidiosis.

Non-monetary numeraires: Varying the payment vehicle in a choice experiment for health interventions in Uganda

Schistosomiasis is a serious health problem in many parts of Africa which is linked to poor water quality and limited sanitation resources. We administered a discrete choice experiment on water access and health education in rural Uganda, focussing on interventions designed to reduce cases of the disease. Unlike previous studies, we included a payment vehicle of both labour hours supplied per week and money paid per month within each choice set. We were thus able to elicit both willingness to pay and willingness to work for alternative interventions. Respondents exhibit high demand for new water sources. From the random parameter model, only households with knowledge about water-borne parasites are price sensitive and exhibit willingness to pay values. Through a latent class model specification, higher income respondents exhibit higher willingness to pay values for all programme attributes; however, lower income participants have higher willingness to work values for certain new water sources. We found a shadow wage rate of labour that is between 15 and 55% of the market wage rate.

Temperature and host diet jointly influence the outcome of infection in a Daphnia‐fungal parasite system

Abstract Climate change has the potential to shape the future of infectious diseases, both directly and indirectly. In aquatic systems, for example, elevated temperatures can modulate the infectivity of waterborne parasites and affect the immune response of zooplanktonic hosts. Moreover, lake warming causes shifts in the communities of primary producers towards cyanobacterial dominance, thus lowering the quality of zooplankton diet. This may further affect host fitness, resulting in suboptimal resources available for parasite growth. Previous experimental studies have demonstrated the respective effects of temperature and host diet on infection outcomes, using the zooplankter Daphnia and its microparasites as model systems. Although cyanobacteria blooms and heat waves are concurrent events in nature, few attempts have been made to combine both stressors in experimental settings. Here, we raised the zooplankter Daphnia (two genotypes) under a full factorial design with varying levels of temperature (the standard 19°C and elevated 23°C), food quality (Scenedesmus obliquus as high‐quality green algae, Microcystis aeruginosa and Planktothrix agardhii as low‐quality cyanobacteria) and exposed them to the parasitic yeast Metschnikowia bicuspidata. We recorded life history parameters of the host as well as parasite traits related to transmission. The combination of low‐quality cyanobacterial diets and elevated temperature resulted in additive detrimental effects on host fecundity. Low‐quality diets reduced parasite output, while temperature effects were context dependent. Overall, we argue that the combined effects of elevated water temperature and poor‐quality diets may decrease epidemics of a common fungal parasite under a climate change scenario.

Microfluidic diffraction phase microscopy and its application in parasites measurement

This paper proposes a method of using diffraction phase microscopy combined with microfluidic chip to quantitatively measure waterborne parasites. A diffraction phase microscopy system is built up by combining interferometry with optical microscope to achieve high sensitivity real-time measurement of parasites. Based on soft lithographic techniques, a double-layered microfluidic chip with U-shaped trapping structures is designed and fabricated for high throughput single parasites trapping. Ficoll solution with the same refractive index as polydimethylsiloxane (PDMS) is introduced into the microfluidic chamber to eliminate significant artifacts in phase imaging originating from diffraction at the edges of trapping structures. The accuracy of the system is verified using standard polystyrene microspheres of different diameters, and the error of maximum phase shift does not exceed 3%. 100 Giardia Lamblia (G. Lamblia) cysts and 100 Cryptosporidium Parvum (C. Parvum) oocysts are measured using this system. The phase maps of the parasites are obtained from the interferograms. The morphological parameters and quantitative optical volume difference distribution of the two kind of waterborne parasites are obtained by analyzing the quantitative phase maps. Quantitative data provides the basis for understanding their physiological characteristics. The microfluidic diffraction phase microscopy system has simple structure, good stability and high measurement accuracy, and has great potential for real-time monitoring and label-free quantitative studies of single microorganism.

Microfluidic diffraction phase microscopy for high-throughput, artifact-free quantitative phase imaging and identification of waterborne parasites

An artifact-free microfluidic diffraction phase microscopy (MFDPM) system to measure quantitative phase maps of individual Giardia lamblia (G. lamblia) cysts and Cryptosporidium parvum (C. parvum) oocysts is developed. The system includes a diffraction phase imaging unit aligned with a polydimethylsiloxane (PDMS) microfluidic chip. The microfluidic chip consists of arrays of U-shaped hydrodynamic trapping structures used to trap single cysts/oocysts, and a micromixer to precisely adjust the refractive index of immersion medium in the microfluidic chamber. When the refractive index of immersion medium is tuned to be equal to that of PDMS, the pronounced artifacts in quantitative phase imaging (QPI) originating from diffraction and scattering at the edges of trapping structures can be eliminated. The artifact-free quantitative phase maps of single microparticles are retrieved using Goldstein’s algorithm. Principal component analysis (PCA) is implemented to extract the distinctive features of the quantitative phase maps of G. lamblia cysts and C. parvum oocysts, and they can be identified with 100% accuracy using linear discriminant analysis (LDA) algorithm. The MFDPM is demonstrated to be a simple, accurate and high-throughput technique for artifact-free quantitative phase imaging of waterborne protozoa, and has great potential for label-free and rapid detection and identification of waterborne microorganisms.

Iron deficiency anemia, population health and frailty in a modern Portuguese skeletal sample.

IntroductionPortugal underwent significant political, demographic and epidemiological transitions during the 20th century resulting in migration to urban areas with subsequent overcrowding and issues with water sanitation. This study investigates population health during these transitions and interprets results within a framework of recent history and present-day public health information. We investigate skeletal evidence for anemia (cribra orbitalia and porotic hyperostosis) as indicators of stress and frailty–i.e., whether the lesions contribute to susceptibility for disease or increased risk of death.MethodsThe presence and severity of skeletal lesions were compared against known sex and cause of death data to investigate potential heterogeneity in frailty and the relationship between lesions and risk of dying over time. Additionally, we tested for the presence of selective mortality in our data (i.e., whether or not the sample is biased for individuals with higher frailty). Our sample derives from a large, documented, modern Portuguese collection from Lisbon and is the first study of its kind using a documented collection. The collection represents primarily middle-class individuals.Results and conclusionsAnalyses indicated that porotic hyperostosis became more common and severe over time, while cribra orbitalia severity increased over time. Neither process was linked to cause of death. However, there was a significant relationship to sex; males exhibited a higher prevalence and severity of lesions and increased mortality. A Gompertz function showed decreased survivorship in early life but increased survivorship over age 60. Using comorbidities of anemia, we were unable to detect selective mortality–i.e., in our sample, lesions do not represent a sign of poor health or increased frailty and are not significantly linked with a decreased mean age-at-death. However, lesion prevalence and severity do reflect the socioeconomic processes in urban Lisbon during the 1800s and 1900s and the possibility of water-borne parasites as the contributing factor for iron deficiency anemia.

Weather, environmental conditions, and waterborne Giardia and Cryptosporidium in Iqaluit, Nunavut.

Indigenous communities in the Arctic often face unique drinking water quality challenges related to inadequate infrastructure and environmental contamination; however, limited research exists on waterborne parasites in these communities. This study examined Giardia and Cryptosporidium in untreated surface water used for drinking in Iqaluit, Canada. Water samples (n = 55) were collected weekly from June to September 2016 and tested for the presence of Giardia and Cryptosporidium using microscopy and polymerase chain reaction (PCR). Exact logistic regressions were used to examine associations between parasite presence and environmental exposure variables. Using microscopy, 20.0% of samples tested positive for Giardia (n = 11) and 1.8% of samples tested positive for Cryptosporidium (n = 1). Low water temperatures (1.1 to 6.7 °C) and low air temperatures (-0.1 to 4.5 °C) were significantly associated with an increased odds of parasite presence (p = 0.047, p = 0.041, respectively). These results suggest that surface water contamination with Giardia and Cryptosporidium may be lower in Iqaluit than in other Canadian regions; however, further research should examine the molecular characterization of waterborne parasites to evaluate the potential human health implications in Northern Canada.