Waterborne transmission of protozoan parasites: a review of worldwide outbreaks - an update 2017-2022

Global prevalence of Giardia infection in nonhuman mammalian hosts: A systematic review and meta-analysis of five million animals

BACKGROUND

Members of the Giardia genus are zoonotic protozoan parasites that cause giardiasis, a diarrheal disease of public and veterinary health concern, in a wide range of mammal hosts, including humans.

METHODOLOGY

We conducted a systematic review and meta-analysis to provide evidence-based data on the worldwide prevalence of Giardia infection in nonhuman mammals that can be used as scientific foundation for further studies. We searched public databases using specific keywords to identify relevant publications from 1980 to 2023. We computed the pooled prevalence estimates utilizing a random-effects meta-analysis model. Animals were stratified according to their taxonomic hierarchy, as well as ecological and biological factors. We investigated the influence of predetermined variables on prevalence estimates and heterogeneity through subgroup and meta-regression analyses. We conducted phylogenetic analysis to examine the evolutionary relationships among different assemblages of G. duodenalis.

PRINCIPAL FINDINGS

The study included 861 studies (1,632 datasets) involving 4,917,663 animals from 327 species, 203 genera, 67 families, and 14 orders from 89 countries. The global pooled prevalence of Giardia infection in nonhuman mammals was estimated at 13.6% (95% CI: 13.4-13.8), with the highest rates observed in Rodentia (28.0%) and Artiodactyla (17.0%). Herbivorous (17.0%), semiaquatic (29.0%), and wild (19.0%) animals showed higher prevalence rates. A decreasing prevalence trend was observed over time (β = -0.1036477, 95% CI -0.1557359 to -0.0515595, p < 0.000). Among 16,479 G. duodenalis isolates, 15,999 mono-infections belonging to eight (A-H) assemblages were identified. Assemblage E was the predominant genotype (53.7%), followed by assemblages A (18.1%), B (14.1%), D (6.4%), C (5.6%), F (1.4%), G (0.6%), and H (0.1%). The highest G. duodenalis genetic diversity was found in cattle (n = 7,651, where six assemblages including A (13.6%), B (3.1%), C (0.2%), D (0.1%), E (81.7%), and mixed infections (1.2%) were identified.

CONCLUSIONS/SIGNIFICANCE

Domestic mammals are significant contributors to the environmental contamination with Giardia cysts, emphasizing the importance of implementing good management practices and appropriate control measures. The widespread presence of Giardia in wildlife suggests that free-living animals can potentially act as sources of the infection to livestock and even humans through overlapping of sylvatic and domestic transmission cycles of the parasite.

High parasite prevalence driven by the human-animal-environment interface: a One Health study in an urban area in southern of Chile

Parasitic infections remain a global health concern, affecting human populations worldwide. However, comprehensive studies evaluating human, animal, and environmental interactions driven transmission of parasites are limited. We conducted a One Health study in an urban area of Valdivia, Chile. Human participants provided fecal and blood samples for parasitological and serological analysis. Environmental soil samples were collected from public parks, and fecal samples from owned and stray dogs were analyzed. Detection of intestinal parasites employed microscopy and molecular techniques, including next-generation sequencing (NGS), while anti-Toxocara canis antibodies in humans were assessed using ELISA. Socioeconomic surveys explored risk factors associated with parasitism. Parasite prevalence was 28% in humans, 26% in owned dogs, and 44% in environmental dog feces. Anti-T. canis IgG antibodies were present in 33% of humans. Soil contamination was identified in up to 30.5% of park samples, harboring zoonotic parasites such as Toxocara sp. and Trichuris vulpis, the same species identified in environmental dog feces. Zoonotic subtypes of Giardia duodenalis and Blastocystis sp. were detected in humans. Our findings highlight significant zoonotic and environmental transmission contributing to human parasitic infections in urban settings, underscoring the need for integrated public health interventions. This study demonstrates the importance of adopting an OneHealth approach in the study of parasitology. The complex ecology of parasites requires an integrated perspective to fully understand their transmission pathways and develop effective control strategies. By emphasizing the interconnectedness of human, animal, and environmental health, we aim to contribute to the management and mitigation of this persistent public health issue.

Evaluating the role of synanthropic filth flies in the transmission of zoonotic parasites: field and laboratory evidence from different animal rearing sites in upper Egypt with focus on Cryptosporidium spp

BACKGROUND

Synanthropic filth flies thrive in human and animal habitats, posing health risks through the transmission of infectious agents. They breed on organic waste, including animal feces, making them carriers of various pathogens. In Egypt, where livestock farming is common and poor sanitation, these flies may contribute to zoonotic disease transmission. The current study investigates parasitic infections in filth flies from three livestock farms in Assiut Governorate, Upper Egypt, highlighting their role as vectors for zoonotic infections, particularly Cryptosporidium, via morphological and molecular tools.

METHODS

A total of 12,749 flies were collected from the study sites via sweep nets. After taxonomic identification, the flies were examined microscopically for parasites using various concentration and staining techniques. Positive samples were further confirmed for infections, particularly for Cryptosporidium parasites, via nested PCR and sequence analysis targeting the COWP and SSU rRNA genes.

RESULTS

This study revealed the presence of several fly species from seven dipteran families, particularly the family Muscidae, primarily Musca domestica, which presented a high parasite infestation rate of 96.6%. This study revealed a high prevalence of various protozoans and helminths in the collected flies. Cryptosporidium was the most prevalent parasite (64.4-100%), infecting all fly species. Entamoeba and Balantidium were also significant, especially in M. domestica (22.6-90.1%, 8.9-100%), Fannia canicularis (10.5-74.4%, 44.2-88.2%), and Borborillus vitripennis (11.1-50%, 37.2-91.4%). Giardia, Trichuris, and Trichostrongylidae had low to moderate prevalence in multiple fly species. Mites are commonly detected on fly exoskeletons, with high infestation rates observed in Musca domestica (77-100%) and Physiphora alceae (66.7-100%). The present study also reported sporadic infections with Trichomonas, Toxocara vitulorum, and pseudoscorpions, along with notable midge larval infestations (52.1%), mainly at site B. Parasitic infections were highest in autumn and spring, with the lowest rates in winter. Molecular identification confirmed the presence of the zoonotic species Cryptosporidium parvum and Cladotanytarsus gedanicus.

CONCLUSION

This study revealed that zoonotic parasites exist in flies and pose potential risks when they are found near humans. Cryptosporidium parvum is the prevalent parasite causing diarrhea outbreaks in animals. This is the first genetic evidence of Cladotanytarsus gedanicus midge from Upper Egypt.

Retrospective case-case study investigation of a significant increase in Cryptosporidium spp. in England and Wales, August to September 2023

BackgroundLaboratory surveillance detected an unprecedented increase in Cryptosporidium spp. (predominantly Cryptosporidium hominis) in England and Wales in August 2023. Cases are not routinely followed up in all of England and Wales, and initial investigations identified no common exposures.AimTo perform a retrospective case-case study investigation of the increase in Cryptosporidium spp. in England and Wales.MethodsWe conducted an unmatched case-case study with 203 cases of laboratory-confirmed C. hominis and 614 comparator cases of laboratory-confirmed Campylobacter spp. reported between 14 August and 30 September 2023. We fitted a multilevel logistic regression model, with random intercepts for geographical region, to estimate adjusted odds ratios (aOR) for exposures. We present the final model as aOR and 95% confidence intervals (CI).ResultsMultivariable analysis identified associations with swimming pool use (aOR: 5.3, 95% CI: 2.3-9.3), travel to Spain (aOR: 6.5, 95% CI: 3.5-12.3) and young age, with children 0-4 years having the strongest association of being a case (aOR: 3.6, 95% CI: 1.5-8.6). We also identified associations with swimming in a river, and travel to France or Türkiye, but there was low frequency of exposure among cases and comparator cases.ConclusionsFollowing the largest recorded increase of Cryptosporidium spp. and in particular C. hominis cases in England and Wales, we identified several exposures, suggesting that causation was likely to be multifactorial. We recommend development of a standardised questionnaire to enable rapid investigation of future case increases, which will improve existing surveillance and inform public health actions.

Impact of the SARS-CoV-2 Pandemic on the Prevalence and Incidence of Enteric Protozoa in a Spanish Tertiary-Care Hospital and a Referral Center for Tropical Diseases, 2019-2023

OBJETIVE

The aim of this study was to describe the impact of non-pharmaceutical interventions (NPIs) against SARS-CoV-2 in patients with symptoms of enteric protozoa (EP), including Blastocystis spp., Dientamoeba fragilis, Giardia lamblia, Cryptosporidium spp., Entamoeba histolytica, and Cyclospora cayetanensis, in the overall population and in patients who were consulted at a National Referral Center for Imported Tropical Diseases (NRCITD patients) from a healthcare area in Madrid (Spain).

METHOD

Data on patients with positive RT-PCR results for EP were collected. The periods analyzed were prepandemic (P0, 1 April 2019-31 March 2020), and the first (P1, 1 April 2020-31 March 2021), second (P2, 1 April 2021-31 March 2022), and third (P3, 1 April 2022-31 March 2023) pandemic years. We compared the prevalence, median age, absolute incidence (EP per 100,000 population of each period), and patient profile (NRCITD vs. non-NRCITD) during the study periods using Fisher's test (p < 0.05) and the T-test (p < 0.001).

RESULTS

During P0, 24.8%, [95% CI: 23.9-25.6] of patients tested for EP RT-PCR were positive, 22.6% [95% CI: 21.5-23.7] were positive in P1, 20.4%, [95% CI: 19.5-21.3] were positive during P2, and 20% [95% CI: 19.2-20.9] of patients tested during P3 were positive. During the study, there was no difference in the median ages. The prevalence and absolute incidence of EP showed a decreasing trend during the pandemic for the NRCITD and non-NRCITD patients (p < 0.05).

CONCLUSION

Blastocystis spp. and D. fragilis showed a lower decrease in prevalence during P1 (p > 0.05) due to the higher detection of colonized patients during the SARS-CoV-2 pandemic. However, G. lamblia and Cryptosporidium spp. showed the highest decrease in prevalence and absolute incidence during P2 (p < 0.05) because of the NPIs implemented during the SARS-CoV-2 pandemic. The NTRCID patients showed a higher prevalence of Blastocystis spp. than the non-NTRCID patients during every period studied (p < 0.001). E. histolytica and C. cayetanensis showed a homogeneous trend.

Update on transmission of zoonotic Giardia in cattle

Giardia is the most common protozoan cause of diarrhoeal illness in humans worldwide. Despite this, our understanding of the zoonotic transmission of Giardia, and in particular the role of cattle as a zoonotic reservoir, is not well understood, due to the limitations of current typing systems and a recent taxonomic revision of the genus. Newly improved multilocus sequencing typing tools are not yet widely used and are not applicable to all species. However, data generated to date suggest that zoonotic transmission of Giardia of bovine origin is limited. Carefully designed epidemiological investigations using improved typing tools are essential to understand the extent of zoonotic transmission from cattle. Improved on-farm biosecurity measures are also needed to control the transmission of zoonotic Giardia in cattle.

Detection and molecular characterization of Blastocystis sp., Enterocytozoon bieneusi and Giardia duodenalis in asymptomatic animals in southeastern Iran

Domestic animals can harbor a variety of enteric unicellular eukaryotic parasites (EUEP) with zoonotic potential that pose risks to human health. The aim of this study was to evaluate the occurrence and genetic diversity of EUEP of zoonotic relevance in domestic animals in Iran. Faecal samples were collected from cattle, sheep, camels, goats, donkeys, horse, and dogs. A real-time PCR was performed to detect the parasites, followed by sequence-based genotyping analyses on isolates that tested positive for Enterocytozoon bieneusi, Giardia duodenalis, and Blastocystis sp.. Overall, 53 out of 200 faecal samples (26.5%, 95% CI 20.5-33.2) were positive for one or more EUEP. Enterocytozoon bieneusi was found in 23.8%, 12.0%, 26.1%, and 13.3% of cattle, sheep, goats, and camels, respectively. Giardia duodenalis was identified in 19.3% of cattle and 6.7% of camels. Blastocystis sp. was detected in 5.7% of cattle and 16.7% of camels. Enterocytozoon bieneusi genotypes macaque1, J, BEB6, and CHG3 were identified in 3.7% (1/27), 3.7% (1/27), 44.4% (12/27), and 48.2% (13/27) of the isolates, respectively. Giardia duodenalis assemblage B and Blastocystis subtype 10 were identified in one cattle and one camel isolate, respectively. These findings suggest that domestic animals could serve as potential reservoirs for EUEP of zoonotic relevance and might play a significant role in transmitting these parasites to humans and other animals.

Prevalence and Genetic Diversity of Parasites in Humans and Pet Dogs in Rural Areas of Los Ríos Region, Southern Chile

Parasitic infections pose a significant global health burden, affecting millions of people worldwide. Despite their importance, studies integrating human and animal parasitology to understand transmission pathways are scarce. This study, conducted between August 2022 and April 2023, aimed to investigate the prevalence of parasites in humans and domestic dogs in the Los Rios Region, southern Chile, and explore the risk factors associated with parasitism. A total of 291 human participants provided fecal and blood samples for parasitological and serological analyses, while 92 fecal samples from owned dogs were analyzed. The detection of intestinal parasites employed microscopy and molecular techniques, including next-generation sequencing (NGS). Anti-Toxocara canis and anti-Echinococcus granulosus antibodies in humans were assessed using ELISA. Socioeconomic surveys explored the risk factors associated with parasitism. The results showed a parasite prevalence of 39% in humans and 40% in dogs. Anti-Toxocara canis IgG antibodies were detected in 28.2% of humans. Zoonotic subtypes of Giardia duodenalis and Blastocystis sp. were identified. Thus, the results of our study indicate a high prevalence of intestinal and extraintestinal parasites in the human population of our region. Furthermore, our findings underscore the significant risk of zoonotic transmission of parasites from companion animals. This study contributes to the understanding of parasite transmission dynamics in southern Chile and has implications for public health policy and practice. The results emphasize the importance of considering the connection between human, animal, and environmental health to develop effective control strategies and mitigate the impact of parasitic infections.

Discovering the anti-parasitic activity of melatonin loaded lecithin/chitosan nanoparticles against giardiasis and cryptosporidiosis in Balb/c infected mice

Background

Giardia duodenalis and Cryptosporidium parvum are the primary causes of diarrhea with global attention due to the severe pathophysiological changes leading to mortality. During this study, we explored the biological protozoal contaminants (Giardia and Cryptosporidium spp.) in some areas of the Nile River. Then, we evaluated effectiveness of melatonin (Mel) and melatonin loaded lecithin/chitosan nanoparticles (Mel-LCNPs) against giardiasis and cryptosporidiosis in mice models using parasitological and inflammatory response examination.

Results

The number of positive samples for Cryptosporidium was higher than that for Giardia with percentage of 46.67% and 40.0%, respectively. Prior to treatment, the physical characterization (hydrodynamic size and zeta potential) and in vitro characterization of Mel-LCNPs were carried. Mel-LCNPs revealed a hydrodynamic size of 78.8 nm and a zeta potential of − 27.2 mV. Furthermore, they have powerful antioxidant and anti-inflammatory properties, while displaying minimal anticoagulant and cytotoxic effects during in vivo evaluation. Mel was consistently discharged from nanoparticles in a regulated and enduring manner for 36 h. Moreover, Mel in NPs has an entrapment efficiency (EE) of 33.6% and a drug loading capacity (DLC) of 7.2% and significant reduction (100% and 99.4%, respectively) in the shedding of Giardia cysts and Cryptosporidium oocysts. This reduction was higher than that observed with Mel alone or LCNPs alone on the 14th day post-infection. Moreover, mice of group V, which received Mel-LCNP treatment, exhibited significantly normal levels of interleukin-4 (IL-4) and interferon-gamma (IFN-γ) as well as healthy control mice group (group I).

Conclusion

Mel-LCNPs were highly effective preparations against giardiasis and cryptosporidiosis in Balb/c mice experimentally infected with proved antioxidant, anti-inflammatory, and immunological modulatory characteristics.

Anti-protozoal potential of electrospun polymeric nanofiber composite membranes for treatment of contaminated drinking water

The effectiveness of conventional techniques for removal of water contaminants remains doubtful on micropollutants, including waterborne protozoa. To the best of knowledge, this study is the first highlighting the use of electrospun polymeric nanofiber composite membranes coated with metal nanoparticles against Cyclospora cayetanensis and Giardia lamblia in vitro. Plain and hybrid nanofiber membranes loaded with zinc oxide, copper oxide and silver nanoparticles were prepared, characterized, and used for filtration of contaminated drinking water. Comparison between membranes was achieved through water examination microscopically and molecularly, counting and viability assessment of trapped protozoa on the membranes after filtration. Moreover, the membranes were examined by scanning electron microscopy (SEM) for detection of the trapped Cyclospora oocysts and Giardia cysts ultrastructural changes. Results showed that following water filtration, no protozoa were detected microscopically and melting curves were not plotted. A statistically significant reduction in the number of viable Cyclospora oocysts and Giardia cysts incubated for 4 days was reported. By SEM, dramatic distortions were observed in the trapped protozoa on hybrid membranes with superiority of silver nanoparticles. We concluded that the electrospun polymeric nanofibers composite membranes can be considered a promising alternative to standard water filtration methods.

Genetic diversity and prevalence of Blastocystis subtypes in Alborz Province, Iran: A molecular epidemiological study

The primary objective of this study was to evaluate the genetic diversity of Blastocystis. Additionally, it aimed to explore, for the first time in Iran, the potential association between Blastocystis infection and ABO blood groups. Another focus was to examine the relationship between Blastocystis subtypes and blood groups, an often overlooked risk factor, within the population of Alborz Province, Iran. 450 stool samples were collected from diagnostic facilities across Alborz Province between June 2022 and April 2024. The presence of Blastocystis was confirmed in 64 out of 450 samples (14.22 %) using the Nested PCR-RFLP technique. Among the 64 positive samples, nine (2 %) were classified as indeterminate. Two distinct Blastocystis subtypes were identified in 55 isolates, accounting for 12.22 % of the total samples. ST1 was detected in 44 isolates (9.77 %), rendering it the most prevalent subtype, while ST3 was identified in 11 isolates (2.44 %). Phylogenetic trees were constructed using sequencing data and compared against genotypes available in GenBank. Significant differences between infected and non-infected individuals were observed regarding educational attainment, marital status, and blood type (p < 0.05). A significant association was found between ABO blood groups and the prevalence of Blastocystis infection (p = 0.019). However, when examining the correlation between Blastocystis subtypes (ST1 and ST3) and ABO blood groups, no significant overall association was observed. Nonetheless, specific associations were found for blood groups O+ and B-, with subtype ST1 being more prevalent in these groups.

Long-term symptoms in children after a Cryptosporidium hominis outbreak in Sweden: a 10-year follow-up

In 2010, a Cryptosporidium hominis outbreak resulted in 27,000 clinical cryptosporidiosis cases (45% of the population) in Östersund, Sweden. Long-term abdominal and joint symptoms are common following cryptosporidiosis in adults, and it can affect the development of children in low-income countries. We investigated the potential consequences for children in a high-income setting. In 2011, we prospectively surveyed 600 randomly selected children aged 0-5 years from Östersund. Cases were defined as respondents reporting new episodes of diarrhoea during the outbreak. After 10 years, respondents received a follow-up questionnaire about long-term symptoms (n = 423). We used X2 and Mann-Whitney U tests to assess between-group differences in demographics and the mean number of symptoms. Logistic regressions adjusted for sex, age, and prior issues with loose stools were used to examine associations between case status and symptoms reported at follow-up. We retrieved data on healthcare visits from patient records. In total, 121 cases and 174 non-cases responded to the follow-up questionnaire (69.7%). Cases reported 1.74 (median 1.00, range 0-14) symptoms and non-cases 1.37 (median 0.00, range 0-11) symptoms (p = 0.029). Cases were more likely to report joint symptoms (aOR 4.0, CI 1.3-12.0) and fatigue (aOR 1.9, CI 1.1-3.4), but numbers were generally low. We found no between-group differences in abdominal symptoms, healthcare utilization, or disease diagnoses. Children aged 0-5 years from high-income countries may experience long-term symptoms after cryptosporidiosis, but may not be affected to the same extent as adults or their peers living in low-income countries.

Norditerpene natural products from subterranean fungi with anti-parasitic activity

Cryptosporidium is a common, waterborne gastrointestinal parasite that causes diarrheal disease worldwide. Currently there are no effective therapeutics to treat cryptosporidiosis in at-risk populations. Since natural products are a known source of anti-parasitic compounds, we screened a library of extracts and pure natural product compounds isolated from bacteria and fungi collected from subterranean environments for activity against Cryptosporidium parvum. Eight structurally related norditerpene lactones isolated from the fungus Oidiodendron truncatum collected from the Soudan Iron mine in Minnesota showed potent activity and were further tested to identify the most active compounds. The availability of a diverse suite of natural structural analogs with varying activities allowed us to determine some structure activity relationships for both anti-parasitic activity as well as cytotoxicity. The two most potent compounds, oidiolactones A and B, had EC50s against intracellular Cryptosporidium parvum of 530 and 240 nM respectively without cytotoxicity to confluent HCT-8 host cells. Both compounds also inhibited the related parasite Toxoplasma gondii. Oidiolactone A was active against asexual, but not sexual, stages of C. parvum, and killed 80% of the parasites within 8 hours of treatment. This compound reduced C. parvum infection by 70% in IFNγ-/- mice, with no signs of toxicity. The high potency, low cytotoxicity, and in vivo activity combined with high production, easy isolation from fungi, and synthetic accessibility make oidiolactones A and B attractive scaffolds for the development of new anti-Cryptosporidium therapeutics.

Microbiological water quality assessment of swimming pools and jacuzzis in Northern Greece: a retrospective study

Swimming pools and jacuzzis can pose significant public health risks as potential sources of infections. The present study aimed to evaluate the prevalence and concentration of microbiological indicators in recreational water facilities in Thessaloniki, Northern Greece, focusing on their hygiene status before and after the COVID-19 pandemic. Between January 2018 and December 2022, 1114 water samples were analyzed by the regional Water Hygiene Laboratory at Aristotle University of Thessaloniki, using standardized ISO methods. Jacuzzis exhibited the highest microbial contamination, particularly for Pseudomonas aeruginosa (19.7%), while indoor adult pools showed the lowest. Overall, P. aeruginosa was found in 12.4% of samples, with the highest concentrations in jacuzzis (median: 30 CFU/100 ml). Significant seasonal variations were identified in the prevalence of total microbial flora (p < 0.001) and total coliforms (p = 0.03), as well as in the concentration of residual chlorine (p = 0.023). During the COVID-19 pandemic, microbial prevalence decreased across facilities. We concluded a strong compliance with Greek and international microbiological standards. The decline in microbial prevalence overtime likely reflects the impact of the strict hygiene measures implemented during the pandemic. These findings highlight the importance of maintaining rigorous hygiene practices to protect public health.

Environmental surveillance of Cryptosporidium and Giardia in surface supply water and treated sewage intended for reuse from an urban area in Brazil

Environmental monitoring of protozoa, with the potential to trigger diseases, is essential for decision-making by managing authorities and for the control of water surveillance. This study aimed to detect and quantify Cryptosporidium oocysts and Giardia cysts in surface water for drinking water supply and treated sewage for reuse in the city of São Paulo. Samples collected bimonthly for one year were concentrated using the USEPA 1623.1 and 1693 methods for surface water and treated effluents, respectively. Immunofluorescence and nucleic acid amplification techniques were used to detect and quantify (oo)cysts. The cloning technique followed by sequencing and phylogenetic analyses were performed to characterize species and genotypes. The immunofluorescence detected Cryptosporidium spp. and Giardia spp. in 69.2% (9/13) and 100% (13/13) of the surface water samples (0.1-41 oocysts/L and 7.2-354 cysts/L, respectively). In the reuse samples, 85.7% (12/14) were positive for both protozoa and the concentrations varied from 0.4 to 100.6 oocysts/L and 1.2 and 93.5 cysts/L. qPCR assays showed that 100% of surface water (0.1-14.6 oocysts/L and 0.3-639.8 cysts/L) and reused samples (0.1-26.6 oocysts/L and 0.3-92.5 cysts/L) were positive for both protozoa. Species C. parvum, C. hominis, and C. muris were identified using the 18S rRNA gene, demonstrating anthroponotic and zoonotic species in the samples. Multilocus SSU rRNAanalyses of the SSU rRNA, tpi, and gdh genes from Giardia intestinalis identified the AII, BII, and BIV assemblages, revealing that contamination in the different matrices comes from human isolates. The study showed the circulation of these protozoa in the São Paulo city area and the impairment of surface water supply in metropolitan regions impacted by the discharge of untreated or inadequately treated sewage regarding the removal of protozoa, emphasizing the need to implement policies for water safety, to prevent the spread of these protozoa in the population.

Molecular characterization and risk analysis of Giardia duodenalis assemblages in corticosteroid-treated and non-treated patients in Ismailia, Arab Republic of Egypt

BACKGROUND

Giardia duodenalis (G. duodenalis) is an intestinal protozoan parasite of human and animal hosts. The present study investigated and compared the assemblages of G. duodenalis-infected faecal samples in patients on corticosteroid therapy (POCT) and control patients-not on corticosteroid therapy (CONT) and differentiated its assemblages and/or sub-assemblages' relationship with associated risk factors.

METHODS

Utilizing multi-locus sequence typing (MLST) with three loci targeted-triosephosphate isomerase (tpi), ꞵ-giardin (bg), and glutamate dehydrogenase (gdh)-G. duodenalis isolated from POCT and CONT were analyzed. Risk factors linked with Giardia infection and its assemblages were investigated.

RESULTS

In total, 52 G. duodenalis-infected patients were enrolled: 21 POCT and 31 CONT. The mean age was 12.3 years, the majority were male (59.6%), and 73.1% lived in rural areas. The POCT group was 36 times more likely than the CONT group to have a concurrent parasitic infection. About 73% (38/52) of Giardia samples were genotyped and/or sub-genotyped in at least one of the three loci. MLST identified sixteen isolates (42.0%) as assemblage B, ten isolates (26.3%) as assemblage A, and twelve isolates (31.6%) as a mixed infection of A + B and B + E. Most individuals of the POCT group were infected with G. duodenalis assemblage A while most of the CONT group were infected with assemblage B. Sub-assemblage AII was identified by phylogenetic analysis in the isolates of both groups under investigation.

CONCLUSION

This research advances giardiasis epidemiology in Arab Republic of Egypt (ARE) and reflects how corticosteroid-treated patients differ from those non-treated in Giardia assemblage pattern and their susceptibility to concomitant infection. Overall, Giardia assemblage patterns in this research populations reflect anthroponotic and zoonotic transmission, emphasizing the importance of public health policy and giardiasis prevention of illness transmission, particularly among those on corticosteroid therapy in ARE.

Prevalence of intestinal protozoan parasites among Asian schoolchildren: a systematic review and meta-analysis

PURPOSE

Intestinal protozoan parasites among Asian schoolchildren are a subject of concern due to their prevalence and potential health impact. Understanding and addressing this issue is crucial for public health in the region.

METHODS

We conducted a comprehensive search for articles published up to December 2023 across four databases, including Scopus, PubMed, ProQuest, and Web of Science. To estimate the combined prevalence, a random-effects model with a 95% confidence interval (CI) was applied, and the statistical analysis was performed using meta-analysis packages in R version (3.6.1). This study is registered with PROSPERO (CRD42023481146).

RESULTS

Among 131 eligible articles, the prevalence of intestinal protozoan parasites was 0.208 (95% CI = 0.180-0.238). Lebanon and Tajikistan had the highest country-level prevalence at 0.851 and 0.836, respectively, with Giardia duodenalis being the most prevalent species at 0.082.

CONCLUSION

In summary, our study highlights the urgent public health issue of protozoan parasites among Asian schoolchildren due to poor sanitation and water quality. Immediate interventions are essential, considering climate and socioeconomic factors, to combat these infections and improve overall health.

Establishment and preliminary application of PCR-RFLP genotyping method for Giardia duodenalis in goats

BACKGROUND

Giardia duodenalis (G. duodenalis) is a globally distributed zoonotic protozoan that parasitizes the small intestines of humans and various mammals, such as goats and sheep. The objective of this study was to establish a convenient, accurate, and specific method based on restriction fragment length polymorphism (RFLP) for genotyping assemblages A, B and E of G. duodenalis in goats. The β-giardin gene was amplified using primer pairs bgF1, bgR1, bgF2 and bgR2 by nested PCR. The PCR products were digested with the restriction enzymes Hinf I and Bgl I. The established PCR-RFLP method was used to detect and analyze the genetic subtypes of G. duodenalis in 130 fecal samples from goats and compared simultaneously with microscopic examination and nucleic acid sequencing for G. duodenalis.

RESULTS

Genetic sequencing confirmed that the PCR-RFLP method accurately distinguished G. duodenalis assemblages A, B and E, as well as different combinations of mixed infections of these three assemblages. Among the 130 samples tested by PCR-RFLP, a total of 26 samples (20.00%) tested positive for G. duodenalis, a higher sensitivity than microscopic examination at 13.85% (18/130). Sequence alignment analysis revealed that among the 26 PCR-positive samples, two were identified as assemblage AI, while the remaining 24 were identified as assemblage E or E12.

CONCLUSIONS

This study established an accurate, efficient and rapid PCR-RFLP genotyping method using the bg sequence of G. duodenalis, enabling accurate identification and effective differentiation of goat-derived G. duodenalis assemblages without requiring sequencing.

High genetic diversity of Enterocytozoon bieneusi in minks and raccoon dogs in northern China

Enterocytozoon bieneusi, a zoonotic pathogen prevalent in both humans and animals, is the most frequently diagnosed microsporidian species in humans and presents significant public health risks. However, data on the prevalence and genotypes of E. bieneusi in farmed minks (Neovison vison) and raccoon dogs (Nyctereutes procyonoides) in China are limited. Therefore, 275 minks (89 from Hebei Province, 57 from Heilongjiang Province, 109 from Liaoning Province, 20 from Shandong Province) and 235 raccoon dogs (114 from Hebei Province, 27 from Heilongjiang Province, 61 from Liaoning Province, 33 from Jilin Province) were examined for the prevalence and genotypes of E. bieneusi through sequence analysis of the internal transcribed spacer (ITS) region of the rRNA gene. The overall prevalence of E. bieneusi was 18.6% (95/510), with 10.5% (29/275) in farmed minks and 28.1% (66/235) in raccoon dogs. Ten genotypes (CHN-F1, genotype D, Type IV, EbpC, NCF2, NCF5, NCF6, Peru8, Henan V, and MJ5) were identified in minks and raccoon dogs. This study is the first to detect the CHN-F1, NCF2, NCF6, Peru8, and Henan V genotypes in minks and the NCF5, NCF6, and MJ5 genotypes in raccoon dogs. Additionally, the D, Type IV, and Peru8 genotypes, previously identified in humans, were also found in minks and raccoon dogs, suggesting that these animals could be potential sources of human microsporidiosis. These findings expand the understanding of E. bieneusi's host distribution in China and contribute to the prevention of zoonotic E. bieneusi infections among farmed animals.

Molecular prevalence and genotype identification of Enterocytozoon bieneusi in cattle and goats from Zhejiang Province, China

Introduction

Enterocytozoon bieneusi (E. bieneusi) is a widespread intracellular fungi that poses a significant zoonotic threat due to its infectivity toward both humans and animals.

Methods

To evaluate the zoonotic transmission potential of this fungi, a molecular investigation was undertaken on E. bieneusi in cattle and goats reared across multiple cities in Zhejiang Province, China. A total of 651 fresh samples were collected, consisting of 265 cattle and 386 goats. The presence of E. bieneusi was determined by PCR amplification and sequencing analysis of the internal transcribed spacer (ITS) region of the small subunit ribosomal RNA (SSU rRNA) gene in all collected samples.

Results

The results revealed that 17.1% (111/859) of the animals were afflicted with E. bieneusi, cattle having a prevalence of 14.0% (37/265) and goats displaying a higher rate of 19.2% (74/386). Seventeen E. bieneusi genotypes were identified, including 10 known, CHG5 (n = 30), CHG3 (n = 21), I (n = 14), J (n = 12), CHG2 (n = 11), COS-II (n = 8), D (n = 4), CHG19 (n = 2), ETMK5 (n = 1), and Henan III (n = 1), and seven novel, ZJG-I to ZJG-VI and ZJN-I (one each) genotypes.

Discussion

These findings indicate widespread infection of E. bieneusi among the surveyed animals, thereby raising concerns about zoonotic genotypes that could pose potential threats to public health. Furthermore, the identification of novel genotypes of E. bieneusi offers valuable insights into the genetic diversity of this pathogen.

Food and Waterborne Cryptosporidiosis from a One Health Perspective: A Comprehensive Review

A sharp rise in the global population and improved lifestyles has led to questions about the quality of both food and water. Among protozoan parasites, Cryptosporidium is of great importance in this regard. Hence, Cryptosporidium's associated risk factors, its unique characteristics compared to other protozoan parasites, its zoonotic transmission, and associated economic losses in the public health and livestock sectors need to be focused on from a One Health perspective, including collaboration by experts from all three sectors. Cryptosporidium, being the fifth largest food threat, and the second largest cause of mortality in children under five years of age, is of great significance. The contamination of vegetables, fresh fruits, juices, unpasteurized raw milk, uncooked meat, and fish by Cryptosporidium oocysts occurs through infected food handlers, sewage-based contamination, agricultural effluents, infected animal manure being used as biofertilizer, etc., leading to severe foodborne outbreaks. The only Food and Drug Administration (FDA)-approved drug, Nitazoxanide (NTZ), provides inconsistent results in all groups of patients, and currently, there is no vaccine against it. The prime concerns of this review are to provide a deep insight into the Cryptosporidium's global burden, associated water- and foodborne outbreaks, and some future perspectives in an attempt to effectively manage this protozoal disease. A thorough literature search was performed to organize the most relevant, latest, and quantified data, justifying the title. The estimation of its true burden, strategies to break the transmission pathways and life cycle of Cryptosporidium, and the search for vaccine targets through genome editing technology represent some future research perspectives.

Molecular characterization of Giardia duodenalis, Cryptosporidium spp., and Entamoeba spp. infecting domestic and feral/stray cats in Jordan

This study aimed to carry out a molecular screening for the presence of Giardia, Cryptosporidium, and/or Entamoeba in the feces of pet and stray/feral cats in Jordan. G. duodenalis was found in 27.9% (95% CI, 23.2-32.9) of the 348 sampled cats overall; E. histolytica was found in only 0.6% (95% CI, 0.1-2.1) of the cats, while none of the sampled cats had Cryptosporidium infections. The infection rate of G. duodenalis among indoor cats (32.3%) did not differ significantly from that among outdoor cats (24.1%). There were significantly more infections (p = 0.0004) geographically in the cold semiarid areas (67%) than in the cold desert areas (24%). Multilocus sequence typing analysis of amplicons based on the bg, tpi, and gdh genes revealed that the majority of G. duodenalis infections were zoonotic assemblage B (65.9%; 64 of 97 positive samples); followed by feline-specific assemblage F (18.5%, 18/97); cattle-specific assemblage E (5.2%, 5/97); and then assemblage C that was shared with canids (1.0%; 1/97). Within Giardia isolates, a substitution mutation (A/G) was found at position 297 of the complete protein coding sequence (cds) of tpi-assemblage B, which may represent a new spreading mutation within this gene among the cat population in Jordan. The results of the present study suggest that close human-cat interactions could play a role in zoonotic transmission of Giardia, but further research is needed to determine the possible contribution of cats to the transmission of other protozoa to humans.

Pet chinchillas (Chinchilla lanigera): Source of zoonotic Giardia intestinalis, Cryptosporidium ubiquitum and microsporidia of the genera Encephalitozoon and Enterocytozoon

The domestic chinchilla (Chinchilla lanigera) is kept as a pet and previous studies suggest that it may play an important role as a source of zoonotic parasites, including Giardia intestinalis, Cryptosporidium spp. and microsporidia. In this study, we examined the occurrence and genetic diversity of above mentioned parasites in pet chinchillas in the Czech Republic by PCR/sequencing of the 18S rRNA, TPI, and ITS genes. Of 149 chinchillas from 24 breeders, 91.3 % were positive for G. intestinalis, 8.1 % for Cryptosporidium spp., 2.0 % for Encephalitozoon spp., and 5.4 % for E. bieneusi. Molecular analyses revealed presence of G. intestinalis assemblage B, C. ubiquitum (XIIa family), E. bieneusi genotypes D, SCF2, and, CHN-F1, and E. intestinalis. The infection intensity of G. intestinalis determined by qRT-PCR reached up to 53,978 CPG, C. ubiquitum up to 1409 OPG, E. intestinalis up to 1124 SPG, and E. bieneusi up to 1373 SPG. Only two chinchillas with C. ubiquitum and five with G. intestinalis had diarrhoea at the time of the screening. Three chinchillas in the long-term study were consistently positive for G. intestinalis, with intermittent excretion of C. ubiquitum, E. intestinalis, and E. bieneusi over 25 weeks. The findings indicate that chinchillas are frequently infected with zoonotic parasitic protists, but that these infections rarely show clinical signs. The lack of visible signs could reduce the vigilance of pet owners when handling their chinchillas, increasing the risk of transmission within breeding groups and possibly to humans.

A Multiplex PCR Assay for Simultaneous Detection of Giardia duodenalis, Cryptosporidium parvum, Blastocystis spp. and Enterocytozoon bieneusi in Goats

Giardia duodenalis, Cryptosporidium parvum, Blastocystis spp. and Enterocytozoon bieneusi are four common zoonotic parasites associated with severe diarrhea and enteric diseases. In this study, we developed a multiplex PCR assay for the simultaneous detection of these four zoonotic protozoans in goat stool samples and assessed its detection efficiency. Specific primers were designed from conserved gene sequences retrieved from GenBank, and the PCR conditions were optimized. Genomic DNA from 130 samples was subjected to both single-target PCR and multiplex PCR. The multiplex PCR assay successfully amplified specific gene fragments (G. duodenalis, 1400 bp; C. parvum, 755 bp; Blastocystis spp., 573 bp; E. bieneusi, 314 bp). The assay sensitivity was ≥102 copies of pathogenic DNA clones with high specificity confirmed by negative results for other intestinal parasites. The detection rates were 23.08% (30/130) for G. duodenalis, 24.62% (32/130) for C. parvum, 41.54% (54/130) for Blastocystis spp., and 12.31% (16/130) for E. bieneusi, matching the single-target PCR results. The sensitivity and predictive values were 100.00%. This multiplex PCR provided a rapid, sensitive, specific, and cost-effective approach for detecting these four parasites. It also provided essential technical support for the rapid detection and epidemiological investigation of G. duodenalis, C. parvum, Blastocystis spp., and E. bieneusi infections in goat fecal samples.

Waterborne Cryptosporidium species and Giardia duodenalis in resources of MENA: A systematic review and meta-analysis

This review explores our understanding of Cryptosporidium species and Giardia duodenalis distribution in Middle East and North African (MENA) water resources. Results emphasize that Cryptosporidium species (sp.) and G. duodenalis (oo)cysts are present in distinct categories of water in ten MENA countries. Cryptosporidium sp. proportional prevalence in the MENA region was 24.5% (95% CI 16.3-33.8), while G. duodenalis prevalence was 37.7% (95% CI 21.9-55.1). Raw wastewater and surface water were the water categories most significantly impacted. Both parasites were reported in the various types of MENA drinking waters. The most frequent species/genotypes reported were C. hominis, C. parvum, and G. duodenalis assemblage A. Despite the high prevalence of (oo)cysts reported, we should consider the absence of waterborne outbreaks. This indicates significant underestimation and underreporting of both parasites in MENA. Stakeholders should apply water contamination legislation to eradicate Cryptosporidium sp. and G. duodenalis (oo)cysts from water resources/categories.

Brown rats (Rattus norvegicus) as potential reservoirs of Enterocytozoon bieneusi in Heilongjiang Province, China: high prevalence, genetic heterogeneity, and potential risk for zoonotic transmission

Introduction

Enterocytozoon bieneusi, an obligatory intracellular fungus, is prevalent among animals and humans. Due to their close interaction with humans and their extensive regional distribution, brown rats (Rattus norvegicus) are important pathogen reservoirs. To assess the zoonotic transmission potential of E. bieneusi, a molecular investigation was conducted on 817 R. norvegicus from four cities in Heilongjiang Province, China.

Methods

A total of 817 R. norvegicus were collected from four cities in Heilongjiang Province, China. The genotyping of E. bieneusi was conducted through PCR amplification of the small subunit ribosomal RNA (SSU rRNA)'s internal transcribed spacer (ITS) segments. Phylogenetic and similarity analyses were used to examine zoonotic potential and genetic characteristics of the E. bieneusi-positive specimens.

Results

Among the 817 R. norvegicus, the total infection rate was 33.3% (272/817). Seventy-five genotypes were identified, including 14 known genotypes D (n = 167), A (n = 15), HLJ-CP1 (n = 12), WR8 (n = 6), EbpC (n = 2), BEB6 (n = 1), CS-4 (n = 1), CHPM1 (n = 1), Henan-II (n = 1), HNH-22 (n = 1), HNH-25 (n = 1), I (n = 1), JLD-XI (n = 1), SDD5 (n = 1), and 61 novel genotypes designated as SHWR1 (n = 10), SYSWR1 (n = 2), and SHWR2 to SHWR17, SYSWR2 to SYSWR36 and QTHWR1 to QTHWR8 (n = 1, each). Moreover, 10 samples exhibited mixed genotype infections, including D + A (n = 3), D + EbpC (n = 1), D + HLJ-CP1 (n = 1), D + SHWR1 (n = 1), D + SHWR16 (n = 1), D + SHWR17 (n = 1), SDD5 + WR8 (n = 1), and CS-4 + SYSWR36 (n = 1). Phylogenetic analysis grouped the genotypes into three main groups: group 1 (n = 67), group 2 (n = 5), and group 9 (n = 3).

Discussion

The high prevalence and genetic diversity of E. bieneusi in Heilongjiang Province's R. norvegicus imply that these animals spread the pathogen. The R. norvegicus that E. bieneusi carries can spread zoonotic disease, making it a serious hazard to the local human population. Therefore, it is imperative to raise awareness about the dangers posed by R. norvegicus and implement measures to reduce their population to prevent environmental contamination.

Marked increase in cryptosporidiosis cases, Spain, 2023

BackgroundBy mid-September 2023, several event notifications related to cryptosporidiosis had been identified from different regions in Spain. Therefore, a request for urgent notification of cryptosporidiosis cases to the National Surveillance Network was launched.AimWe aimed at assessing the extent of the increase in cases, the epidemiological characteristics and the transmission modes and compared to previous years.MethodsWe analysed data on case notifications, outbreak reports and genotypes focusing on June-October 2023 and compared the results to 2016-2022.ResultsIn 2023, 4,061 cryptosporidiosis cases were notified in Spain, which is an increase compared to 2016-2022. The cumulative incidence was 8.3 cases per 100,000 inhabitants in 2023, sixfold higher than the median of 1.4 cases per 100,000 inhabitants 2016-2022. Almost 80% of the cases were notified between June and October. The largest outbreaks were related to contaminated drinking water or swimming pools. Cryptosporidium hominis was the most common species in the characterised samples (115/122), and the C. hominis IfA12G1R5 subtype, previously unusual in Spain, was detected from 76 (62.3%) of the 122 characterised samples.ConclusionsA substantial increase in cryptosporidiosis cases was observed in 2023. Strengthening surveillance of Cryptosporidium is essential for prevention of cases, to better understand trends and subtypes circulating and the impact of adverse meteorological events.

Molecular detection and genetic variability of Cryptosporidium spp. in wild Asian house shrews (Suncus murinus) from southern Zhejiang province, China

Shrews play a crucial role as repositories for diverse pathogens linked to zoonotic infectious diseases. However, the genetic information regarding Cryptosporidium in Chinese shrews remains unexplored. The objectives of this study were twofold: to determine the occurrence rate of Cryptosporidium spp. in wild shrews residing in the southern part of Zhejiang Province, China, and to investigate their genetic characteristics. A total of 282 wild shrews were captured between April and October of 2023. The detection of Cryptosporidium in fecal samples, collected from each animal's rectum, was performed using PCR and sequencing of the partial small subunit of ribosomal RNA (SSU rRNA) gene. The 60-kDa glycoprotein (gp60) gene was utilized to further subtype the positive samples of C. viatorum and C. parvum. All animals were identified as Suncus murinus, and a positive result for Cryptosporidium was obtained in 14.2 % (40/282) of the samples. The following species and genotypes were identified: C. ratti (n = 19), C. parvum (n = 2), C. viatorum (n = 1), Cryptosporidium rat genotype IV (n = 13), and Cryptosporidium skunk genotype (n = 5). Furthermore, the subtypes IIdA15G1 and XVdA3 were detected within C. parvum and C. viatorum, respectively. Molecular evidence indicates that S. murinus is concurrently infected with rodent-adapted and zoonotic species/genotypes, actively contributing to the dissemination of cryptosporidiosis.

Food and Drinking Water as Sources of Pathogenic Protozoans: An Update

This narrative review was aimed at collecting updated knowledge on the risk factors, illnesses caused, and measures for the prevention of protozoan infections transmitted by food and drinking water. Reports screened dated from 2019 to the present and regarded global prevalence in food handlers, occurrence in food and drinking water, impact on human health, and recently reported outbreaks and cases of severe infections attributable to the dietary route. Cryptosporidium spp., Cyclospora cayetanensis, Entamoeba histolytica, and Cystoisospora belli were the protozoans most frequently involved in recently reported waterborne and foodborne outbreaks and cases. Blastocystis hominis was reported to be the most widespread intestinal protozoan in humans, and two case reports indicated its pathogenic potential. Dientamoeba fragilis, Endolimax nana, and Pentatrichomonas hominis are also frequent but still require further investigation on their ability to cause illness. A progressive improvement in surveillance of protozoan infections and infection sources took place in developed countries where the implementation of reporting systems and the application of molecular diagnostic methods led to an enhanced capacity to identify epidemiological links and improve the prevention of foodborne and waterborne protozoan infections.

Host specificity and zoonotic Enterocytozoon bieneusi genotypes in wild rodents from the Inner Mongolian Autonomous Region and Liaoning Province of China

Introduction

Wild rodents can serve as reservoirs or carriers of E. bieneusi, thereby enabling parasite transmission to domestic animals and humans. This study aimed to investigate the prevalence of E. bieneusi in wild rodents from the Inner Mongolian Autonomous Region and Liaoning Province of China. Moreover, to evaluate the potential for zoonotic transmission at the genotype level, a genetic analysis of the isolates was performed.

Methods

A total of 486 wild rodents were captured from two provinces in China. Polymerase chain reaction (PCR) was performed to amplify the vertebrate cytochrome b (cytb) gene in the fecal DNA of the rodents to detect their species. The genotype of E. bieneusi was determined via PCR amplification of the internal transcribed spacer (ITS) region of rDNA. The examination of genetic characteristics and zoonotic potential requires the application of similarity and phylogenetic analysis.

Results

The infection rates of E. bieneusi in the four identified rodent species were 5.2% for Apodemus agrarius (n = 89), 4.5% for Cricetulus barabensis (n = 96), 11.3% for Mus musculus (n = 106), and 38.5% for Rattus norvegicus (n = 195). Infection was detected at an average rate of 17.4% among 486 rodents. Of the 11 identified genotypes, nine were known: SHR1 (detected in 32 samples), D (30 samples), EbpA (9 samples), PigEbITS7 (8 samples), HNR-IV (6 samples), Type IV (5 samples), HNR-VII (2 samples), HNH7 (1 sample), and HNPL-V (1 sample). Two novel genotypes were also discovered, NMR-I and NMR-II, each comprising one sample. The genotypes were classified into group 1 and group 13 via phylogenetic analysis.

Discussion

Based on the initial report, E. bieneusi is highly prevalent and genetically diverse in wild rodents residing in the respective province and region. This indicates that these animals are crucial for the dissemination of E. bieneusi. Zoonotic E. bieneusi-carrying animals present a significant hazard to local inhabitants. Therefore, it is necessary to increase awareness regarding the dangers presented by these rodents and reduce their population to prevent environmental contamination.

Molecular characterization of Cryptosporidium in wild rodents from the Inner Mongolian Autonomous Region and Liaoning Province, China: assessing host specificity and the potential for zoonotic transmission

Introduction

Wild rodents are key hosts for Cryptosporidium transmission, yet there is a dearth of information regarding their infection status in the Inner Mongolian Autonomous Region and Liaoning Province of China. Therefore, the present study was conducted to determine the prevalence and genetic characteristics of Cryptosporidium among wild rodents residing in these two provinces.

Methods

A total of 486 rodents were captured, and fresh feces were collected from each rodent's intestine for DNA extraction. Species identification of rodents was performed through PCR amplification of the vertebrate cytochrome b (cytb) gene. To detect the presence of Cryptosporidium in all fecal samples, PCR analysis and sequencing of the partial small subunit of the ribosomal RNA (rRNA) gene were performed.

Results

Four species of rodents were identified: Rattus norvegicus, Mus musculus, Apodemus agrarius, and Cricetulus barabensis. Positive results for Cryptosporidium were obtained for 9.2% (18/195), 6.6% (7/106), 5.6% (5/89), and 6.3% (6/96) of these rodents, respectively, with an average infection rate of 7.4% (36/486). The identification revealed the presence of five Cryptosporidium species, C. ubiquitum (n = 8), C. occultus (n = 5), C. muris (n = 2), C. viatorum (n = 1), and C. ratti (n = 1), along with two Cryptosporidium genotypes: Rat genotype III (n = 10) and Rat genotype IV (n = 9).

Discussion

Based on the molecular evidence presented, the wild rodents investigated were concurrently infected with zoonotic (C. muris, C. occultus, C. ubiquitum and C. viatorum) as well as rodent-adapted (C. ratti and Rat genotype III and IV) species/genotypes, actively participating in the transmission of cryptosporidiosis.

Cryptosporidium spp. and Eimeria spp. (Apicomplexa: Eimeriorina) of freshwater Cyprinid fish species in the Kura River basin in Azerbaijan territory

This study aims to determine the prevalence of Cryptosporidium and Eimeria spp. oocysts in fish specimens in the river Kura. It was conducted during the 2021-2022 at two sites: Mingachevir reservoir in central Azerbaijan and in Neftchala district where the river finally enters the Caspian Sea through a delta of the Kura River estuary. The diagnosis of oocysts was performed microscopically. Fine smears from the intestine epithelial layers stained by Ziehl-Neelsen for Cryptosporidium oocysts. To identify Eimeria oocysts, each fish's faecal material and intestinal scrapings were examined directly under a light microscope in wet samples on glass slides with a coverslip. Results revealed a prevalence of Cryptosporidium and Eimeria species infections in fish hosts from both territories Rutilus caspicus, Alburnus filippi, Abramis brama orientalis and Carassius gibelio. Of 170 investigated fish specimens, 8.8% (15/170) were infected with Cryptosporidium species oocysts. Eimeria species oocysts were identified in 20.6% (35/170). The presence of Cryptosporidium and Eimeria infections in fish specimens are natural infections. However, their presence in fish species may be attributed to the age of the fish species and water pollution. This is the first report regarding the prevalence of Cryptosporidium oocysts in fish species in Azerbaijan.

Cryptosporidium and agriculture: A review

Cryptosporidiosis is a significant contributor to global foodborne and waterborne disease burden. It is a widespread cause of diarrheal diseases that affect humans and animals worldwide. Agricultural environments can become a source of contamination with Cryptosporidium species through faecal material derived from humans and animals. This review aims to report the main findings of scientific research on Cryptosporidium species related to various agricultural sectors, and highlights the risks of cryptosporidiosis in agricultural production, the contamination sources, the importance of animal production in transmission, and the role of farmed animals as hosts of the parasites. Agricultural contamination sources can cause water pollution in groundwater and different surface waters used for drinking, recreational purposes, and irrigation. The application of contaminated manure, faecal sludge management, and irrigation with inadequately treated water are the main concerns associated with foodborne and waterborne cryptosporidiosis related to agricultural activities. The review emphasizes the public health implications of agriculture concerning the transmission risk of Cryptosporidium parasites and the urgent need for a new concept in the agriculture sector. Furthermore, the findings of this review provide valuable information for developing appropriate measures and monitoring strategies to minimize the risk of infection.

Molecular prevalence and subtype distribution of Blastocystis spp. among children who have diarrheia or are asymptomatic in Wenzhou, Zhejiang Province, China

Blastocystis sp., a significant zoonotic parasite with a global distribution, was the focus of this study, which aimed to investigate its prevalence and genetic diversity among diarrheic and asymptomatic children in Wenzhou, China. We collected 1,032 fecal samples from Yuying Children's Hospital, Wenzhou, China, comprising 684 from children with diarrhea and 348 from asymptomatic children. Genomic DNA extracted from these samples was used to detect Blastocystis spp. by PCR, targeting the small subunit ribosomal RNA gene. Subsequently, a phylogenetic tree was constructed, applying the maximum likelihood method. Blastocystis spp. were detected in 67 (6.5%) of the fecal samples. The prevalence rate of Blastocystis spp. in diarrheic children (8.8%; 60/684) was significantly higher than that in asymptomatic children (2.0%; 7/348) (χ 2 = 17.3, p < 0.001). Sequence analysis of the SSU rRNA gene identified five known Blastocystis spp. subtypes, ST1 (n = 12), ST2 (n = 5), ST3 (n = 35), ST4 (n = 12), and ST7 (n = 3). ST1 and ST3 were present in both diarrheic and asymptomatic children, while ST2, ST4, and ST7 were exclusive to diarrheic children. Intra-subtype genetic polymorphisms were identified, comprising four variations in ST1 (ST1-1 to ST1-4), five in ST3 (ST3-1 to ST3-5), two in ST4 (ST4-1 and ST4-2), and two in ST7 (ST7-1 and ST7-2). Notably, ST1-2 to ST1-4, ST3-3 to ST3-5, and ST7-1 and ST7-2 represent newly identified variations. The composition and genetic characteristics of subtypes among children in this region suggest various sources of infection, including human-to-human and animal-to-human transmission.

Outbreak of Diarrhea Caused by a Novel Cryptosporidium hominis Subtype During British Military Training in Kenya

Background

We report clinical, epidemiological, and laboratory features of a large diarrhea outbreak caused by a novel Cryptosporidium hominis subtype during British military training in Kenya between February and April 2022.

Methods

Data were collated from diarrhea cases, and fecal samples were analyzed on site using the multiplex polymerase chain reaction (PCR) BioFire FilmArray. Water was tested using Colilert kits (IDEXX, UK). DNA was extracted from feces for molecular characterization of Cryptosporidium A135, Lib13, ssu rRNA, and gp60 genes.

Results

One hundred seventy-two of 1200 (14.3%) personnel at risk developed diarrhea over 69 days. One hundred six primary fecal samples were tested, and 63/106 (59.4%; 95% CI, 0.49%-0.69%) were positive for Cryptosporidium spp. Thirty-eight had Cryptosporidium spp. alone, and 25 had Cryptosporidium spp. with ≥1 other pathogen. A further 27/106 (25.5%; 95% CI, 0.18%-0.35%) had non-Cryptosporidium pathogens only, and 16/106 (15.1%; 95% CI, 0.09%-0.23%) were negative. C. hominis was detected in 58/63 (92.1%) Cryptosporidium spp.-positive primary samples, but the others were not genotypable. Twenty-seven C. hominis specimens were subtypable; 1 was gp60 subtype IeA11G3T3, and 26 were an unusual subtype, ImA13G1 (GenBank accession OP699729), supporting epidemiological evidence suggesting a point source outbreak from contaminated swimming water. Diarrhea persisted for a mean (SD) of 7.6 (4.6) days in Cryptosporidium spp. cases compared with 2.3 (0.9) days in non-Cryptosporidium cases (P = .001).

Conclusions

Real-time multiplex PCR fecal testing was vital in managing this large cryptosporidiosis outbreak. The etiology of a rare C. hominis gp60 subtype emphasizes the need for more genotypic surveillance to identify widening host and geographic ranges of novel C. hominis subtypes.

Increased number of cryptosporidiosis cases with travel history to Croatia might be related to swimming pools, Germany, 2023

In August and September 2023, an unusually high number of cryptosporidiosis cases identified by routine German surveillance had travelled to Croatia (n = 23). Nine cases had stayed in the same camping resort and seven further cases had stayed at other camping sites within 15 km. Based on our standardised questionnaires, the most likely source of infection was swimming pools (93%). Further environmental investigations on site might reveal potential common sources of contamination that could be targeted by control measures.