Seasonal change in the number of Cryptosporidium parvum oocysts in water samples from the rivers in Hokkaido, Japan, detected by the ferric sulfate flocculation method

Comprehensive molecular epidemiology of Cryptosporidium species in Japan

Cryptosporidium species, causing diarrheal illnesses in humans and animals worldwide, are under investigation for their molecular epidemiology in Japan. The study focuses on detecting Cryptosporidium species in humans, animals, water, and the environment, revealing three species in people: C. parvum, C. meleagridis, and C. hominis. Subtype IIa of the C. parvum gp60 gene is prevalent, indicating potential zoonotic transmission. Animal studies identified sixteen species, mainly cattle and pets, with C. parvum (subtype IIa) common in cattle and C. canis and C. felis prevalent in pets. Additionally, C. bovis and C. ryanae were found in cattle and sika deer. Knowledge gaps exist, particularly in water and environmental source typing, with limited research revealing five species and five genotypes, suggesting a significant role of water in transmission. Further research is needed to understand the molecular diversity and transmission dynamics across humans, animals, water, and the environment in Japan.

Cryptosporidium species and cryptosporidiosis in Japan: a literature review and insights into the role played by animals in its transmission

Cryptosporidium species infect domestic animals, livestock, and humans. These protozoan parasites are frequently reported as major environmental contaminants in many countries despite their differing climatic, socioeconomic, and demographic factors. This review focuses on the research findings that relate to Cryptosporidium epidemiology, genetic diversity, and associated risk factors relating to animals, contaminated water sources, and humans in Japan. Adequate knowledge of these factors is essential for understanding the economic and public health importance of cryptosporidiosis in Japan so that effective control strategies against it are implemented. Cryptosporidium infections are highly prevalent in animals in Japan. Among the different animal species, cattle infections stand out because of their economic importance and zoonotic potential. Living circumstances in Japan restrain Cryptosporidium transmission between humans, but there is evidence to suggest that animals, especially those in close contact with humans, can be potential sources of human infections. Water sampling studies have provided clues about how environmental contamination with Cryptosporidium oocysts can cause infections in livestock and wild animals. There is some evidence of person-to-person transmission of cryptosporidiosis, but only occasionally and under certain circumstances. By identifying the major role played by animals in Cryptosporidium transmission to people in Japan, we highlight the urgent need for disease control against this pathogen.

Waterborne protozoan pathogens in environmental aquatic biofilms: Implications for water quality assessment strategies

Biofilms containing pathogenic organisms from the water supply are a potential source of protozoan parasite outbreaks and a significant public health concern. The aim of the present study was to demonstrate the simultaneous and multi-spatial occurrence of waterborne protozoan pathogens (WBPP) in substrate-associated biofilms (SAB) and compare it to surface water (SW) and sediments with bottom water (BW) counterparts using manual filtration and elution from low-volume samples. For scenario purposes, simulated environmental biofilm contamination was created from in-situ grown one-month-old SAB (OM-SAB) that were spiked with Cryptosporidium parvum oocysts. Samples were collected from the largest freshwater reservoirs in Luzon, Philippines and a University Lake in Thailand. A total of 69 samples (23 SAB, 23 SW, and 23 BW) were evaluated using traditional staining techniques for Cryptosporidium, and Immunofluorescence staining for the simultaneous detection of Cryptosporidium and Giardia. WBPP were found in 43% SAB, 39% SW, and 39% BW of the samples tested in the present study with SAB results reflecting SW and BW results. Further highlights were demonstrated in the potential of using low-volume samples for the detection of parasites in source water. Scanning electron microscopy of OM-SAB samples revealed a naturally-associated testate amoeba shell, while Cryptosporidium oocysts spiked samples provided a visual profile of what can be expected from naturally contaminated biofilms. This study provides the first evidence for the simultaneous and multi-spatial occurrence of waterborne protozoan pathogens in low-volume aquatic matrices and further warrants SAB testing along with SW and BW matrices for improved water quality assessment strategies (iWQAS).

DETECTION OF WATER-BORNE PARASITES IN DRINKING WATER OF BAGHDAD, IRAQ

Background:

Within the past few decades, there has been an increase in the number of water-borne disease outbreaks and emergence of newly recognized waterborne parasites. Several factors which contribute to the spread of these diseases include: water, heavy rains and agricultural residues which transfer the parasites to water surface from the soil. The aim of this study was to detect the presence of parasites in the river and drinking water of Al-Wahdaa and Al-Rasheed Drinking Project and household water tanks from some regions of Baghdad.

Method:

Forty samples were collected from river and drinking water of Drinking Project. Fifty four samples of household water tanks were collected from some regions of Baghdad.

Results:

Cryptosporidium oocyst, which was founded in river water samples are more than those in drinking water. Furthermore, it was existed in Diyala Bridge &Taha Mosque from April – August and oocyst was diagnosed by using of Zheil-Neelson. Wet mount slide method was applied to detect cysts of free-living amoeba Acanthomoeba, Naegleria. The number of cysts in July and August were higher than other months for Drinking Project and the water tanks for all regions.

Conclusion:

These results emphasize the importance screening of the water to prevent possible of the spread of parasitic protozoan and that the cracks occurrence in drinking water pipes between the stations and houses led to contamination of water with the infective stage of parasites, especially in the areas that are near agricultural fields which polluted with the cows’ waste.

Water-borne protozoa parasites: The Latin American perspective

Health systems, sanitation and water access have certain limitations in nations of Latin America (LA): typical matters of developing countries. Water is often contaminated and therefore unhealthy for the consumers and users. Information on prevalence and detection of waterborne parasitic protozoa are limited or not available in LA. Only few reports have documented in this field during the last forty years and Brazil leads the list, including countries in South America and Mexico within Central America region and Caribbean islands. From 1979 to 2015, 16 outbreaks of waterborne-protozoa, were reported in Latin American countries. T. gondii and C. cayetanensis were the protozoa, which caused more outbreaks and Giardia spp. and Cryptosporidium spp. were the most frequently found protozoa in water samples. On the other hand, Latin America countries have not got a coherent methodology for detection of protozoa in water samples despite whole LA is highly vulnerable to extreme weather events related to waterborne-infections; although Brazil and Colombia have some implemented laws in their surveillance systems. It would be important to coordinate all surveillance systems in between all countries for early detection and measures against waterborne-protozoan and to establish effective and suitable diagnosis tools according to the country's economic strength and particular needs.

Serological detection and epidemiology of Neospora caninum and Cryptosporidium parvum antibodies in cattle in southern Egypt

Neospora caninum and Cryptosporidium parvum are intracellular protozoan parasites that are distributed worldwide and of major economical concern in cattle industry. N. caninum can cause abortion storms and high culling rates, whereas C. parvum has zoonotic implications and can cause diarrhea in calves. There are currently no data on the prevalence of neosporosis and cryptosporidiosis in humans or animals in southern Egypt. Prevalence of these two infections was determined in a sample of cattle from two different areas in southern Egypt, Sohag and Qena, using enzyme-linked immunosorbent assay. A total 301 cattle were sampled, of which 18.9% were positive for N. caninum, 35.9% were positive for C. parvum and 10.0% were positive for both. Geographical location and breeding system were considered as potential risk factors for C. parvum infection. A higher prevalence of infection was identified on small scale farms, compared with larger, intensive systems, with a prevalence of 50.2% compared with 37.8%, respectively. Animals in Sohag had a significantly higher prevalence compared with Qena, with a seroprevalence of 46.1% compared with 31.6%, respectively. In brief, marked seroprevalence recorded in this study indicates a high incidence of N. caninum and C. parvum infections in cattle, and this necessitates the application of more effective strategies for combating these types of infections on farms in Egypt.

Molecular identification of the Cryptosporidium deer genotype in the Hokkaido sika deer (Cervus nippon yesoensis) in Hokkaido, Japan

The protozoan Cryptosporidium occurs in a wide range of animal species including many Cervidae species. Fecal samples collected from the Hokkaido sika deer (Cervus nippon yesoensis), a native deer of Hokkaido, in the central, western, and eastern areas of Hokkaido were examined by polymerase chain reaction (PCR) to detect infections with Cryptosporidium and for sequence analyses to reveal the molecular characteristics of the amplified DNA. DNA was extracted from 319 fecal samples and examined with PCR using primers for small-subunit ribosomal RNA (SSU-rRNA), actin, and 70-kDa heat shock protein (HSP70) gene loci. PCR-amplified fragments were sequenced and phylogenetic trees were created. In 319 fecal samples, 25 samples (7.8 %) were positive with SSU-rRNA PCR that were identified as the Cryptosporidium deer genotype. Among Cryptosporidium-positive samples, fawns showed higher prevalence (16.1 %) than yearlings (6.4 %) and adults (4.7 %). The result of Fisher's exact test showed a statistical significance in the prevalence of the Cryptosporidium deer genotype between fawn and other age groups. Sequence analyses with actin and HSP70 gene fragments confirmed the SSU-rRNA result, and there were no sequence diversities observed. The Cryptosporidium deer genotype appears to be the prevalent Cryptosporidium species in the wild sika deer in Hokkaido, Japan.

Prevalence and genotyping of Cryptosporidium spp. in farm animals in Egypt

In this study, we examined the prevalence and molecular characteristics of Cryptosporidium in buffalo, dairy cattle and sheep in different farms at Kafr El Sheikh Province, Egypt. Rectal fecal samples, including 466 samples from buffalo, 1697 from cattle and 120 from sheep, were collected from different ages and screened by modified Ziehl-Neelsen acid-fast microscopy for detection of Cryptosporidium oocysts. All studied farms were positives with an overall prevalence of 1.29% in buffalo (4.17% in claves versus 0.48% in adults), 7.07% in cattle (6.90% in calves versus 10.20% and 6.10% in heifers and adults, respectively) and 2.50% in sheep (4.40% in lambs versus 1.30% in adults). PCR-RFLP analyses of small-subunit rRNA genes from positive specimens revealed the occurrence of C. parvum and C. ryanae in buffalo; C. parvum, C. ryanae, C. bovis and C. andersoni in cattle and only C. xiaoi in sheep. Genotypes distribution showed that C. ryanae was the dominant species (60.0%) followed by C. parvum (40.0%) in buffalo calves. Meanwhile, in cattle calves, C. parvum was the commonest species (74.23%) followed by C. ryanae (16.10%) and C. bovis (9.70%). Subtyping of C. parvum based on sequence analysis of the polymorphic 60 kDa glycoprotein gene locus showed the presence of subtypes IIdA20G1 and IIaA15G1R1 in both buffalo and cattle calves, addressing the potential role of calves in zoonotic cryptosporidiosis in Egypt.

Seasonal patterns of gastrointestinal illness and streamflow along the Ohio River

Waterborne gastrointestinal (GI) illnesses demonstrate seasonal increases associated with water quality and meteorological characteristics. However, few studies have been conducted on the association of hydrological parameters, such as streamflow, and seasonality of GI illnesses. Streamflow is correlated with biological contamination and can be used as proxy for drinking water contamination. We compare seasonal patterns of GI illnesses in the elderly (65 years and older) along the Ohio River for a 14-year period (1991-2004) to seasonal patterns of streamflow. Focusing on six counties in close proximity to the river, we compiled weekly time series of hospitalizations for GI illnesses and streamflow data. Seasonal patterns were explored using Poisson annual harmonic regression with and without adjustment for streamflow. GI illnesses demonstrated significant seasonal patterns with peak timing preceding peak timing of streamflow for all six counties. Seasonal patterns of illness remain consistent after adjusting for streamflow. This study found that the time of peak GI illness precedes the peak of streamflow, suggesting either an indirect relationship or a more direct path whereby pathogens enter water supplies prior to the peak in streamflow. Such findings call for interdisciplinary research to better understand associations among streamflow, pathogen loading, and rates of gastrointestinal illnesses.

First description of Cryptosporidium bovis in Japan and diagnosis and genotyping of Cryptosporidium spp. in diarrheic pre-weaned calves in Hokkaido

Eighty fecal samples from pre-weaned calves with diarrhea were collected in the Tokachi area in Northern Japan to investigate the prevalence of Cryptosporidium species in such animals. Oocysts from fecal samples collected from each animal were concentrated using sucrose gradient centrifugation. Genomic DNA was extracted from each sample and processed by nested PCR to amplify the partial SSU rRNA gene of Cryptosporidium. Cryptosporidium infections were detected in 75% of the samples. Sequence analysis was performed on all positive samples. Phylogenetic analysis of 33 successfully sequenced isolates of the SSUrRNA PCR products revealed all but one were Cryptosporidium parvum infections. The remaining single case was Cryptosporidium bovis. These findings suggest that C. parvum is prevalent in diarrheic pre-weaned calves and can be a source of cryptosporidial infections for humans and animals in Hokkaido.

Cryptosporidium source tracking in the Potomac River watershed

To better characterize Cryptosporidium in the Potomac River watershed, a PCR-based genotyping tool was used to analyze 64 base flow and 28 storm flow samples from five sites in the watershed. These sites included two water treatment plant intakes, as well as three upstream sites, each associated with a different type of land use. The uses, including urban wastewater, agricultural (cattle) wastewater, and wildlife, posed different risks in terms of the potential contribution of Cryptosporidium oocysts to the source water. Cryptosporidium was detected in 27 base flow water samples and 23 storm flow water samples. The most frequently detected species was C. andersoni (detected in 41 samples), while 14 other species or genotypes, almost all wildlife associated, were occasionally detected. The two common human-pathogenic species, C. hominis and C. parvum, were not detected. Although C. andersoni was common at all four sites influenced by agriculture, it was largely absent at the urban wastewater site. There were very few positive samples as determined by Environmental Protection Agency method 1623 at any site; only 8 of 90 samples analyzed (9%) were positive for Cryptosporidium as determined by microscopy. The genotyping results suggest that many of the Cryptosporidium oocysts in the water treatment plant source waters were from old calves and adult cattle and might not pose a significant risk to human health.

Clams (Corbicula fluminea) as bioindicators of fecal contamination with Cryptosporidium and Giardia spp. in freshwater ecosystems in California

This study evaluated clams as bioindicators of fecal protozoan contamination using three approaches: (i) clam tissue spiking experiments to compare several detection techniques; (ii) clam tank exposure experiments to evaluate clams that had filtered Cryptosporidium oocysts from inoculated water under a range of simulated environmental conditions; (iii) sentinel clam outplanting to assess the distribution and magnitude of fecal contamination in three riverine systems in California. Our spiking and tank experiments showed that direct fluorescent antibody (DFA), immunomagnetic separation (IMS) in combination with DFA, and PCR techniques could be used to detect Cryptosporidium in clam tissues. The most analytically sensitive technique was IMS concentration with DFA detection of oocysts in clam digestive gland tissues, which detected 10 oocysts spiked into a clam digestive gland 83% of the time. In the tank experiment, oocyst dose and clam collection time were significant predictors for detecting Cryptosporidium parvum oocysts in clams. In the wild clam study, Cryptosporidium and Giardia were detected in clams from all three study regions by IMS-DFA analysis of clam digestive glands, with significant variation by sampling year and season. The presence of C. parvum DNA in clams from riverine ecosystems was confirmed with PCR and DNA sequence analysis.

Concentrating, purifying and detecting waterborne parasites

There has been recent emphasis on developing better methods for detecting diseases of zoonotic and veterinary importance. This has been prompted by an increase in human disease agents detectable in environmental samples, the potential for bioterrorism, and the lowering of international trade barriers and expansion of personal travel, which are bringing previously considered exotic diseases to new geographical localities. To appreciate the complexities of developing detection methods and working with environmental samples, it is appropriate to review technologies currently in use, as well as those in development and presently limited to research laboratories. Discussion of parasite detection would not be possible without including methods for parasite sampling, concentration, and purification because it is often necessary to process large sample volumes prior to analysis, and no reliable methods are available for significantly amplifying parasites in vitro. Reviewing proven methods currently in use will provide a baseline for generating, accepting and implementing the more sensitive and specific methods under development today.