Waterborne Parasitic Diseases Research Articles

Cercarial dermatitis: Clinical course and prevention

IntroductionCercarial dermatitis (swimmer's itch) is a water-borne parasitic skin disease caused by larvae (cercariae) of a nonhuman species of schistosome. The prevailing symptoms are nodulopapular skin lesions accompanied by pruritus. The condition occurs virtually worldwide and is considered to be an emerging public health problem in Europe. In most cases, the symptoms are associated with cercariae of avian schistosomes of the genus <i>Trichobilharzia</i> spp.AimThe aim of this review article is to present the most important information on the course of the disease, its diagnostics, treatment and epidemiology. Additionally, it offers an account of preventive measures targeted at reducing the risk of infection.Material and methodsA literature search was conducted using electronic databases such as PubMed, Google Scholar and Willey Online Library. Altogether, 40 articles were subject to analysis.Results and discussionThe data obtained from the literature survey process were systematised and presented in 5 sections. Clinically, effective control of swimmer’s itch should comprise measures from the fields of diagnostics, treatment, epidemiology and prevention.ConclusionsSwimmer’s itch poses diagnostic difficulties, primarily due to the low specificity of its symptoms. Owing to a lack of conclusive data on the fate of cercariae penetrating human skin and a growing number of documented cases of cercarial dermatitis worldwide, further intensive research into the matter is warranted.

PREVALENCE OF SCHISTOSOMA HAEMATOBIUM INFECTION AMONG PRIMARY SCHOOL CHILDREN IN FASKARI AND FUNTUA LOCAL GOVERNMENT AREAS OF KATSINA STATE, NIGERIA

Schistosomiasis is a water-borne parasitic disease caused by Schistosoma; the digeic trematode found in the blood vessels of a man and livestock. This study was conducted to determine the prevalence of schistosoma haematobium infection among the Primary Schools pupils in Faskari and Funtua Local Government Areas of Katsina State. A total of 496 of urine samples were collected from children of 8 Primary Schools in the study areas; 4 from each local government. A questionnaire was used to collect socio-demographic and other exposure information to explore Schistosoma infection for urine, and urine sedimentation microscopic technique was used for sample analysis. Data were expressed in prevalence (%) and subjected to Chi-square analysis at p < 0.05. Out of the 496 children assessed, 160 (32.2%) were positive for urinary schistosomiasis. The prevalence is significantly (p<0.05) higher in Faskari Model Primary School with (48.3%). It was found from the result that, there was no significant relationship (P=6.608) between source of water and Schistosoma haematobium infection among the pupils in the study areas. There was also no statistical association (P= 1.570) between the source of water for bathing and the infection of urinary schistosomiasis among the students in the study areas. Therefore, schistosomiasis is prevalent in the study areas with Faskari local government having higher prevalence of the infection.

Aligning antimicrobial resistance surveillance with schistosomiasis research: an interlinked One Health approach.

One Health surveillance involves the analysis of human, animal and environmental samples, recognising their interconnectedness in health systems. Such considerations are crucial to investigate the transmission of many pathogens, including drug-resistant bacteria and parasites. The highest rates of antimicrobial resistance (AMR)-associated deaths are observed in sub-Saharan Africa, where concurrently the waterborne parasitic disease schistosomiasis can be highly endemic in both humans and animals. Although there is growing acknowledgment of significant interactions between bacteria and parasites, knowledge of relationships between schistosomes, microbes and AMR remains inadequate. In addition, newly emergent research has revealed the previously underappreciated roles of animals and the environment in both AMR and schistosomiasis transmission. We consider shared environmental drivers and colonisation linkage in this narrative review, with a focus on extended-spectrum beta-lactamase-mediated resistance among bacteria from the Enterobacteriaceae family, which is exceedingly prevalent and responsible for a high burden of AMR-associated deaths. Then we examine novel findings from Malawi, where the landscapes of AMR and schistosomiasis are rapidly evolving, and make comparisons to other geographic areas with similar co-infection epidemiology. We identify several knowledge gaps that could be addressed in future research, including the need to characterise the impact of intestinal schistosomiasis and freshwater contact on intestinal AMR colonisation, before proposing a rationale for connecting AMR surveillance and schistosomiasis research within a One Health framework.

Schistosoma mansoni infection in residents of a riverside community in Eastern Amazon.

Schistosoma mansoni worms cause a waterborne parasitic disease called schistosomiasis. It commonly affects individuals in lack of sanitation structure. In Brazil, Pará state has Belém as one of the worst sanitation-ranking places in 2023, where schistosomiasis transmission was already documented. This study reports the occurrence of schistosomiasis in residents of Ilha das Onças, an island next to Belém. Stool samples were obtained from participants over 2 years old, all residents from Furo do Rio Grande, one of the rivers on the island. The Kato-Katz technique was performed for parasite investigation in the stool samples. Each participant responded to a sociodemographic and clinical questionnaire. The residences were georeferenced for map designing. Three out of 263 participants were S. mansoni positive, all men, ages ranging from 19 to 41 years old, with low parasitic load. Malacological surveys were carried out, but no Biomphalaria snails were found. Risk factors for schistosomiasis establishment are present on the island, and the lack of sanitation makes it a potential risk area. Malacological surveys are highly encouraged as preventive measures, as well as health surveillance for riverside populations, generating data that will help health authorities in the management and planning of preventive control actions.

Multi-locus sequence analysis reveals phylogenetically segregated Entamoeba histolytica population.

Amoebiasis, caused by the enteric parasite, Entamoeba histolytica, is one of the major food- and water-borne parasitic diseases in developing countries with improper sanitation and poor hygiene. Infection with E. histolytica has diverse disease outcomes, which are determined by the genetic diversity of the infecting strains. Comparative genetic analysis of infecting E. histolytica strains associated with differential disease outcomes from different geographical regions of the world is important to identify the specific genetic patterns of the pathogen that trigger certain disease outcomes of Amoebiasis. The strategy is able to elucidate the genealogical relation and population structure of infecting E. histolytica strains from different geographical regions. In the present study, we have performed a comparative genetic analysis of circulating E. histolytica strains identified from different parts of the world, including our study region, based on five tRNA-linked short tandem repeat (STR) loci (i.e., D-A, NK2, R-R, STGA-D and A-L) and evaluated their potential associations with differential disease outcomes of Amoebiasis. A number of regional-specific, emerging haplotypes of E. histolytica, significantly associated with specific disease outcomes have been identified. Haplotypes, which have a significant positive association with asymptomatic and amoebic liver abscess outcomes, showed a significant negative association with diarrheal outcome, or vice versa. Comparative multi-locus analysis revealed that E. histolytica isolates from our study region are phylogenetically segregated from the isolates of other geographical regions. This study provides a crucial overview of the population structure and emerging pattern of the enteric parasite, E. histolytica.

Accurate Diagnosis of Schistosoma mansoni and S. haematobium from Filtered Urine Samples Collected in Tanzania, Africa.

Schistosomiasis is a bloodborne, and waterborne parasitic disease caused by the human Schistosoma species, namely Schistosoma mansoni and S. haematobium. The parasite requires an intermediate snail host, where they grow and develop, along with a human host (definitive). Schistosoma egg detection in feces (S. mansoni) and urine (S. haematobium) are the WHO-recommended confirmatory diagnostic tests. The goal of our research was to determine the efficacy of detecting single or dual Schistosome species from filtered human urine samples collected in Tanzania by amplifying species-specific cell-free repeat DNA fragments via polymerase chain reaction (PCR) and gel electrophoresis. In total, 104 filtered human urine samples were evaluated and collected from individuals residing in the village of Kayenze, Tanzania. All samples were detected with 100% accuracy and no cross-amplification was present. For a single infection of S. mansoni, 22 (21%) of the samples were positive, while 15 (14%) of the samples were negative via PCR. Moreover, for a single infection of S. haematobium, 7 (7%) of the samples were positive, while 15 (14%) of the samples were negative. Dual infections were found in a higher percentage, with 60 (58%) of the samples being positive. Thus, we have justified that PCR is more sensitive and specific by amplifying species-specific cell-free repeat DNA fragments from the same urine sample than WHO-recommended methods of processing stool and urine.

Associations of water contact frequency, duration, and activities with schistosome infection risk: A systematic review and meta-analysis.

Schistosomiasis is a water-borne parasitic disease which affects over 230 million people globally. The relationship between contact with open freshwater bodies and the likelihood of schistosome infection remains poorly quantified despite its importance for understanding transmission and parametrising transmission models. We conducted a systematic review to estimate the average effect of water contact duration, frequency, and activities on schistosome infection likelihood. We searched Embase, MEDLINE (including PubMed), Global Health, Global Index Medicus, Web of Science, and the Cochrane Central Register of Controlled Trials from inception until May 13, 2022. Observational and interventional studies reporting odds ratios (OR), hazard ratios (HR), or sufficient information to reconstruct effect sizes on individual-level associations between water contact and infection with any Schistosoma species were eligible for inclusion. Random-effects meta-analysis with inverse variance weighting was used to calculate pooled ORs and 95% confidence intervals (CIs). We screened 1,411 studies and included 101 studies which represented 192,691 participants across Africa, Asia, and South America. Included studies mostly reported on water contact activities (69%; 70/101) and having any water contact (33%; 33/101). Ninety-six percent of studies (97/101) used surveys to measure exposure. A meta-analysis of 33 studies showed that individuals with water contact were 3.14 times more likely to be infected (OR 3.14; 95% CI: 2.08-4.75) when compared to individuals with no water contact. Subgroup analyses showed that the positive association of water contact with infection was significantly weaker in children compared to studies which included adults and children (OR 1.67; 95% CI: 1.04-2.69 vs. OR 4.24; 95% CI: 2.59-6.97). An association of water contact with infection was only found in communities with ≥10% schistosome prevalence. Overall heterogeneity was substantial (I2 = 93%) and remained high across all subgroups, except in direct observation studies (I2 range = 44%-98%). We did not find that occupational water contact such as fishing and agriculture (OR 2.57; 95% CI: 1.89-3.51) conferred a significantly higher risk of schistosome infection compared to recreational water contact (OR 2.13; 95% CI: 1.75-2.60) or domestic water contact (OR 1.91; 95% CI: 1.47-2.48). Higher duration or frequency of water contact did not significantly modify infection likelihood. Study quality across analyses was largely moderate or poor. Any current water contact was robustly associated with schistosome infection status, and this relationship held across adults and children, and schistosomiasis-endemic areas with prevalence greater than 10%. Substantial gaps remain in published studies for understanding interactions of water contact with age and gender, and the influence of these interactions for infection likelihood. As such, more empirical studies are needed to accurately parametrise exposure in transmission models. Our results imply the need for population-wide treatment and prevention strategies in endemic settings as exposure within these communities was not confined to currently prioritised high-risk groups such as fishing populations.

Urogenital schistosomiasis (UGS) and female genital schistosomiasis (FGS) in Cameroon: an observational assessment of key reproductive health determinants of girls and women in the Matta Health Area

Objectives and settingAcross sub-Saharan Africa, urogenital schistosomiasis (UGS), in particular female genital schistosomiasis (FGS), is a significant waterborne parasitic disease, with its direct burden on the sexual and reproductive health...

Schistosoma mansoni larvae in vitro cultures using Biomphalaria glabrata extracts

Schistosomiasis is one of the most prevalent waterborne parasitic diseases affecting humans. In natural conditions, snails are necessary for maintenance of its lifecycle and also required as intermediate hosts to maintain the lifecycle in laboratory settings. In the present study, the location of S. mansoni larvae in Biomphalaria glabrata snails after infection (inoculation of miracidia) was investigated. Larvae were found located in the head-foot (HF) area of B. glabrata snails at 10 days post-infection (DPI), then their location was predominantly changed to the hepatopancreas and ovotestis (HPOT) area by 56 DPI. Next, the effects of extracts from various organs of B. glabrata snails including HF and HPOT for in vitro culturing of S. mansoni larvae were investigated. The HF extract enabled prolonged culturing of S. mansoni larvae. Furthermore, sequential use of that followed by the HPOT extract supported larval development or reproduction of daughter sporocysts. These results may provide important information for identifying essential factors and molecules for culturing Schistosoma larvae in vitro.

From the One Health Perspective: Schistosomiasis Japonica and Flooding.

Schistosomiasis is a water-borne parasitic disease distributed worldwide, while schistosomiasis japonica localizes in the People’s Republic of China, the Philippines, and a few regions of Indonesia. Although significant achievements have been obtained in these endemic countries, great challenges still exist to reach the elimination of schistosomiasis japonica, as the occurrence of flooding can lead to several adverse consequences on the prevalence of schistosomiasis. This review summarizes the influence of flooding on the transmission of schistosomiasis japonica and interventions responding to the adverse impacts from the One Health perspective in human beings, animals, and the environment. For human and animals, behavioral changes and the damage of water conservancy and sanitary facilities will increase the intensity of water contact. For the environment, the density of Oncomelania snails significantly increases from the third year after flooding, and the snail habitats can be enlarged due to active and passive diffusion. With more water contact of human and other reservoir hosts, and larger snail habitats with higher density of living snails, the transmission risk of schistosomiasis increases under the influence of flooding. With the agenda set for global schistosomiasis elimination, interventions from the One Health perspective are put forward to respond to the impacts of increased flooding. For human beings, conducting health education to increase the consciousness of self-protection, preventive chemotherapy for high-risk populations, supply of safe water, early case finding, timely reporting, and treating cases will protect people from infection and prevent the outbreak of schistosomiasis. For animals, culling susceptible domestic animals, herding livestock in snail-free areas, treating livestock with infection or at high risk of infection, harmless treatment of animal feces to avoid water contamination, and monitoring the infection status of wild animals in flooding areas are important to cut off the transmission chain from the resources. For the environment, early warning of flooding, setting up warning signs and killing cercaria in risk areas during and post flooding, reconstructing damaged water conservancy facilities, developing hygiene and sanitary facilities, conducting snail surveys, using molluscicide, and predicting areas with high risk of schistosomiasis transmission after flooding all contribute to reducing the transmission risk of schistosomiasis. These strategies need the cooperation of the ministry of health, meteorological administration, water resources, agriculture, and forestry to achieve the goal of minimizing the impact of flooding on the transmission of schistosomiasis. In conclusion, flooding is one of the important factors affecting the transmission of schistosomiasis japonica. Multi-sectoral cooperation is needed to effectively prevent and control the adverse impacts of flooding on human beings, animals, and the environment.

A large outbreak of giardiasis in a municipality of the Bologna province, north-eastern Italy, November 2018 to April 2019.

Giardiasis, the disease caused by the flagellate Giardia duodenalis (syn. G.lamblia, G. intestinalis), is the most commonly reported among the five food- and waterborne parasitic diseases under mandatory surveillance in 24 EU countries. From November 2018 to April 2019, an outbreak of giardiasis occurred in a municipality of the Bologna province, in north-eastern Italy. Microscopy and immunochromatography identified cysts and antigens, respectively, of the parasite in stool samples of 228 individuals. Molecular typing of 136 stool samples revealed a vast predominance (95%) of G. duodenalis assemblage B. Investigations into potential sources indicated tap water as the most likely vehicle of infection, although cysts were not detected in water samples. Control measures mostly aimed at preventing secondary transmission by informing citizens about the outbreak, and by treatment of patients with anti-parasitic drugs. This is the first documented human outbreak of giardiasis in Italy; its investigation has highlighted the difficulties in the timely detection and management of this parasite, which is often overlooked as a cause of human gastroenteritis. The long and variable incubation time, absence of specific symptoms and a general lack of awareness about this pathogen contributed to delay in diagnosis.

Ecoepidemiology of Schistosomiasis mansoni in a rural area of Sergipe, Brazil

Schistosomiasis mansoni is a severe water-borne parasitic disease which etiological agent is Schistosoma mansoni. Among the municipalities of Sergipe, Malhador, has one of the highest prevalence. The present research intends to describe the echoepidemiology of schistosomiasis mansoni in a rural community. A cross-sectional epidemiological study was carried out based on primary data resulting from malacological (light exposure technique) and coproscopic (Kato-Katz method) surveys A questionnaire was applied to evaluate the epidemiological variables of interest. In the descriptive data analysis, the software BioEstat (version 5.0) was used. The spatial analysis of the infection distribution in the studied locality was done through TerraView 4.2.0, using the kernel intensity estimator. The statistical analysis was performed through the Chi-Square Test and Multiple Logistic Regression. 95 people participated of the census survey. The prevalence was 45%. As for the parasite load, the mild infection prevailed (53.49%), followed by moderate (37.1%) and high (9.30%). Regarding the dichotomous epidemiological variables analyzed, the time of residence (OR = 11.5114), degree of contact with water (OR = 3.9383), knowledge about the disease (OR = 2.0148) and gender (OR = 1.5141) were highlighted. Nine breeding sites were detected and georeferenced. This study provided information that allows health services and public managers to plan, implement and evaluate the impact of measures to be taken to control the transmission of the disease.

Status and control of common food-borne parasitic diseases in China: a review

Food-borne parasitic diseases include meat-borne, fish-borne, plant-borne, water-borne, mollusk-borne and freshwater crustacean-borne parasitic diseases. The review summarizes the current status and control of 6 major food-borne parasitic diseases in China, including clonorchiasus, paragonimiasis, Taenia solium taeniasis, toxoplasmosis, trichinellosis and angiostrongyliasis, aiming to increase the understanding of food-borne parasitic diseases and provide insights into the development of the control strategy for food-borne parasitic diseases. The transmission of food-borne parasitic diseases are predominantly associated with diet, and neither eating raw nor semi-cooked food is the most effective measure to prevent the development of food-borne parasitic diseases.

Prevalence and pattern of waterborne parasitic infections in eastern Africa: A systematic scoping review

Waterborne parasitic diseases form one of common and important public health and economic problems in low- and middle-income countries, though little is known on the burden and patterns of these diseases in most regions. This systematic scoping review informs on the prevalence and pattern of waterborne parasitic infections in eastern Africa from 1st of January 1941 to 31st of December 2019. The review found limited number of published studies on waterborne parasitic diseases, though 13 of the 15 studied countries in eastern Africa provided one or more published report(s) totalling 47 reports. Focus of studies was mainly on schistosomiasis where 44.8% of the 47 retrieved studies reported it. Other frequently reported diseases were giardiasis (23.4% of reports), soil-transmitted helminths (23.4%) and amoebiasis (21.3%). Rarely reported diseases were malaria, cryptosporidiosis, isosporiasis, dracunculiasis and trichomoniasis. Based on parasitological examinations, schistosomiasis prevalence ranged from 17 to 33% in Burundi, 1.9 to 73.9% in Ethiopia, 2.1 to 18% in Kenya, 7.2 to 88.6% in Uganda, 22.9 to 86.3% in Tanzania, 27.2 to 65.8% in Somalia, 15 to >50% in Mauritius, 2.4% in Eritrea and 5.0 to 93.7% in Madagascar. Amoebiasis prevalence was 4.6–15,3% (Ethiopia), 5.9–58.3% (Kenya), 54.5% (Rwanda), 0.7–2.7% (Sudan), 19.93% (Uganda) and 4.5–5.0% (Seychelles). Giardiasis prevalence was 0.6–55.0% (Ethiopia), 16.6% (Kenya), 3.6% (Rwanda), 21.1% (Sudan), 40.7% (Uganda), 45.0% (Eritrea) and 3.3–6.0% (Seychelles). Soil-transmitted helminths prevalence was 41.7–52.4% (Ethiopia), 32.4–40.7% (Kenya), 9997 cases (Rwanda), 85.0% (Somalia), 4.7% (Madagascar) and 1.1–84% (Seychelles), Ascaris lumbricoides, Trichuris trichiura and hookworms were the most common helminths detected. Malaria prevalence was 2.9–4.31% (Ethiopia), an annual episode of 9 million people (Sudan), 13.0% (Tanzania), 146 hospital cases (Madagascar), 1.4–2.0% (Seychelles) and <5.0% in Djibouti. It is also observed that >50% of the populations in eastern Africa region lack improved drinking water sources or sanitation facilities. This may account for the observed high prevalence of the diseases. The author also suggests likely underestimation of the prevalence as most waterborne parasitic diseases are neglected and cases likely only recorded and left unpublished in health facilities. Thus for a thorough mapping of burdens of these diseases, grey literature, including hospital records must be reviewed while interventions focusing on improved water and sanitation are likely to reduce the burden considerably.

Prevalence of Urinary and Intestinal Schistosomiasis Among Rice Framers in Asutsuare, Ghana

Schistosomiasis (urinary and intestinal) is a chronic, water-borne parasitic disease caused by blood flukes of the genus Schistosoma. The disease poses health problems in Ghana and is known to be associated with recreational and agricultural activities that involving frequent contact with freshwater. This study, therefore, determined the prevalence of urinary and intestinal Schistosomiasis among rice farmers in Asutsuare, a rural farming community in the Greater Accra Region of Ghana. A total of 150 study participants comprising of 88 farmhands (people hired to work on rice farm) and 62 rice farm owners of both sexes with ages between 15-68 years were involved. Urine and stool samples were collected from study participants. Urine samples were tested for haematuria, proteinuria and while stool samples were examined under the microscope for schistosome ova. A structured questionnaire was used to gather demographic data and other significant information from the study participants. The prevalence of urinary and intestinal schistosomiasis each among the study group was 19.3% and 2% respectively. The overall prevalence (prevalence of S. haematobium and S. mansoni put together) was (21.33%). The disease was mostly seen among farmhands with the prevalence of the two disease conditions being 21.6% and 3.4% for urinary and intestinal respectively. The prevalence of urinary schistosomiasis among the farm owners was 16.1%, but no intestinal schistosomiasis was detected. Both urinary and intestinal schistosomiasis are prevalent in the study area. The farm helps on rice farms are at a higher risk of contracting the disease than the farm/land owners.

Atypical Presentation of Urinary Schistosomiasis

Schistosomiasis or Bilharziasis is a water-borne parasitic disease which affects different organs depending on species involved. Urinary schistosomiasis is diagnosed mainly by the presence of urinary complaints, urinary excretion of parasite eggs and their presence in bladder as seen on histopathology along with changes on cystoscopy. We present a case of an asymptomatic adult Indian female with long standing history of passing adult worms in urine but lack of eggs. The worms were identified as Schistosoma and the patient was treated with Praziquantel. She came from an area which is not known to be endemic for Schistosoma. J Microbiol Infect Dis 2019; 9(2):95-99.

Prevalence and intensity of urinary schistosomiasis among school age children in Ikota, Southwestern Nigeria

Schistosomiasis is a water-borne parasitic disease second to malaria in terms of socio-economic importance. Epidemiological data upon which management control could be based is lacking in Ikota, Ondo State, Nigeria. The present study evaluated the prevalence and intensity of urinary schistosomiasis among School age children in Ikota, Ifedore Local Government Area (LGA) of Ondo State, Nigeria. Urine samples were first examined macroscopically for haematuria while reagent strip was used to detect proteinuria after which sedimentation method was used to analyse the samples for characteristic features of the Schistosoma haematobium. Data obtained from the study were analyzed using Pearson's Chi Square Test. A total of 150 subjects were examined, out of which 76 (50.7%) were male and 74 (49.3%) were female. Results obtained from this study revealed a total prevalence of 24% with mean intensity of 21.82 egg/10 mL of urine. The percentage distribution of the infection among the sexes showed that the male students had a lower prevalence of 21.1% of infection than their female counterparts who had 27.0% prevalence with no significant difference (P &gt; 0.05). It was also observed that age group 5-9 had the highest prevalence and mean intensity of 100% and 13.50 egg/10 mL of infection with no significant difference (P &gt; 0.05). In the same vein, sources of water vary significantly among the subjects (p &lt; 0.05). Those who depended on river water (75.0%) had the highest level of infection. Therefore, it is evident that S. haematobium infection is prevalent among the study subjects and appropriate management control strategies should be deployed to the study area.

Recurrence of Guinea Worm Disease in Chad after a 10-Year Absence: Risk Factors for Human Cases Identified in 2010-2011.

A decade after reporting its last case of Guinea worm disease (GWD), a waterborne parasitic disease targeted for eradication, Chad reported 20 confirmed human cases from 17 villages-10 cases in 2010 and 10 cases in 2011. In 2012, the first GWD dog infections were diagnosed. We conducted a case-control study during April-May 2012 to identify human transmission risk factors and epidemiologic links. We recruited 19 cases and 45 controls matched by age, sex, time, and location of exposure based on the case patients' periods of infection 10-14 months earlier. Data were analyzed with simple conditional logistic regression models using Firth penalized likelihood methods. Unusually, GWD did not appear to be associated with household primary water sources. Instead, secondary water sources, used outside the village or other nonprimary sources used at home, were risk factors (matched odds ratio = 38.1, 95% confidence interval = 1.6-728.2). This study highlights the changing epidemiology of GWD in Chad-household primary water sources were not identified as risk factors and few epidemiologic links were identified between the handfuls of sporadic cases per year, a trend that continues. Since this investigation, annual dog infections have increased, far surpassing human cases. An aquatic paratenic host is a postulated mode of transmission for both dogs and humans, although fish could not be assessed in this case-control study due to their near-universal consumption. GWD's evolving nature in Chad underscores the continued need for interventions to prevent both waterborne and potential foodborne transmission until the true mechanism is established.

Zoonotic Cryptosporidium Species in Animals Inhabiting Sydney Water Catchments.

Cryptosporidium is one of the most common zoonotic waterborne parasitic diseases worldwide and represents a major public health concern of water utilities in developed nations. As animals in catchments can shed human-infectious Cryptosporidium oocysts, determining the potential role of animals in dissemination of zoonotic Cryptosporidium to drinking water sources is crucial. In the present study, a total of 952 animal faecal samples from four dominant species (kangaroos, rabbits, cattle and sheep) inhabiting Sydney’s drinking water catchments were screened for the presence of Cryptosporidium using a quantitative PCR (qPCR) and positives sequenced at multiple loci. Cryptosporidium species were detected in 3.6% (21/576) of kangaroos, 7.0% (10/142) of cattle, 2.3% (3/128) of sheep and 13.2% (14/106) of rabbit samples screened. Sequence analysis of a region of the 18S rRNA locus identified C. macropodum and C. hominis in 4 and 17 isolates from kangaroos respectively, C. hominis and C. parvum in 6 and 4 isolates respectively each from cattle, C. ubiquitum in 3 isolates from sheep and C. cuniculus in 14 isolates from rabbits. All the Cryptosporidium species identified were zoonotic species with the exception of C. macropodum. Subtyping using the 5’ half of gp60 identified C. hominis IbA10G2 (n = 12) and IdA15G1 (n = 2) in kangaroo faecal samples; C. hominis IbA10G2 (n = 4) and C. parvum IIaA18G3R1 (n = 4) in cattle faecal samples, C. ubiquitum subtype XIIa (n = 1) in sheep and C. cuniculus VbA23 (n = 9) in rabbits. Additional analysis of a subset of samples using primers targeting conserved regions of the MIC1 gene and the 3’ end of gp60 suggests that the C. hominis detected in these animals represent substantial variants that failed to amplify as expected. The significance of this finding requires further investigation but might be reflective of the ability of this C. hominis variant to infect animals. The finding of zoonotic Cryptosporidium species in these animals may have important implications for the management of drinking water catchments to minimize risk to public health.

Doenças infecciosas e parasitárias por veiculação hídrica e doenças respiratórias em área industrial, Norte do Brasil

Resumo A cidade de Barcarena, no Estado do Pará, é um importante polo industrial que, nos últimos anos, esteve sujeita a registros de incidentes ambientais. Neste estudo, foi apresentado o perfil de morbidade por doenças infecciosas e parasitárias (DIP) de veiculação hídrica e por doenças respiratórias (DR) em indivíduos residentes do município de Barcarena, no período de 2008 a 2012. A pesquisa foi realizada com dados secundários sobre mortalidade e internações, obtidos a partir do Departamento de Informática do Sistema Único de Saúde (DATASUS). O coeficiente médio de mortalidade para as DIP apresentou 0,37 óbito por 1.000 habitantes. A faixa etária mais afetada pelos casos de internações por DIP foi a de 0 a 5 anos, com coeficiente médio de incidência na ordem de 31,8 por 100 mil habitantes. Para as DR, as crianças com faixa etária de 0 a 14 anos foram, aparentemente, as mais expostas, com 62,85%, e os idosos acima de 60 anos, com 15,16% dos casos. As taxas de incidência e de mortalidade por DR ficaram na ordem de 39 por 100 mil habitantes. Os indicadores de saúde estudados nos alertam um risco para à saúde de populações em Barcarena e sugerem estudos quantitativos e qualitativos mais específicos de possíveis contaminações ambientais na região.