Review of zoonotic parasites in medical and veterinary fields in the Republic of Korea

Metabarcoding of pathogenic parasites based on copro-DNA analysis of wild animals in South Korea

Four species of dominant wild animals, namely, Prionailurus bengalensis euptilurus, Nyctereutes procyonoides koreensis, Hydropotes inermis argyropus, and Sus scrofa coreanus, are hosts of potential infectious agents, including helminths and protozoa. Therefore, it is necessary to analyze the infectious agents present in these wild animals to monitor and control the spread of pathogens. In the present study, fecal samples from 51 wild animals were collected from the mountains of Yangpyeong, Hoengseong, and Cheongyang in South Korea and metabarcoding of the V9 region of the 18S rRNA gene was performed to identify various parasite species that infect these wild animals. Genes from nematodes, such as Metastrongylus sp., Strongyloides spp., Ancylostoma sp., and Toxocara sp., were detected in the fecal samples from wild animals. In addition, platyhelminthes, including Spirometra sp., Echinostomatidae gen. sp., Alaria sp., Neodiplostomum sp., and Clonorchis sp., and protozoa, including Entamoeba sp., Blastocystis sp., Isospora sp., Tritrichomonas sp., Pentatrichomonas sp., and Cryptosporidium sp., were detected. In the present study, various parasites infecting wild animals were successfully identified using metabarcoding. Our technique may play a crucial role in monitoring parasites within wild animals, especially those causing zoonoses.

Echinostomes and Other Intestinal Trematode Infections

Intestinal trematodes are among the most common types of parasitic worms. About 76 species belonging to 14 families have been recorded infecting humans. Infection commonly occurs when humans eat raw or undercooked foods that contain the infective metacercariae. These parasites are diverse in regard to their morphology, geographical distribution and life cycle, which make it difficult to study the parasitic diseases that they cause. Many of these intestinal trematodes have been considered as endemic parasites in the past. However, the geographical limits and the population at risk are currently expanding and changing in relation to factors such as growing international markets, improved transportation systems, new eating habits in developed countries and demographic changes. These factors make it necessary to better understand intestinal trematode infections. This chapter describes the main features of human intestinal trematodes in relation to their biology, epidemiology, host-parasite relationships, pathogenicity, clinical aspects, diagnosis, treatment and control.

Prevalence of gastrointestinal parasitic infections in wild mammals of a safari park and a zoo in Bangladesh

In safari parks and zoos, wild animals are kept mainly for recreational purposes. Animals in these enclosures are also crucial for the education, research, and conservation aspect. To ensure better management and good health of wild animals in captivity, it is essential to monitor the occurrence of gastrointestinal (GI) parasitic (helminths and protozoa) infections. The current investigation was undertaken to investigate the prevalence of GI parasitic infections in wild mammals at Bangabandhu Sheikh Mujib (BSM) safari park and Chattogram (CTG) zoo of Bangladesh. A total of 72 individual faecal samples were collected from 25 species of wild mammals. Routine qualitative (e.g. direct smear, sedimentation, and flotation) and quantitative (e.g. McMaster technique) tests were performed to identify the eggs or oocysts of helminths and protozoa. Results demonstrated that wild mammals of both BSM safari park and CTG zoo were infected with a total of 17 genera/species of helminths and protozoa. The overall prevalence of GI parasitic infections in wild mammals of both zoological parks was 65.3% (95% confidence interval [CI]: 53.14-76.12), whereas it was 72.4% (95% CI: 52.76-87.27) in the BSM safari park and 60.5% (95% CI: 44.41-75.02) in the CTG zoo. In both zoological parks, infection with nematodes was more frequent compared to other helminth into the wild mammals. The herbivores were more infected with GI parasites than carnivores and omnivores of both BSM safari park and CTG zoo. The mean eggs/oocysts per gram of faeces was the highest in the carnivores compared to herbivores and omnivores of both enclosures. The findings of the current study demonstrated that wild mammals of both BSM safari park and CTG zoo suffered from various GI parasitic infections. Regular monitoring along with proper therapeutic measures may reduce the severe consequences of GI parasitic infections in captive wild animals.

Seropositivity Rates of Strongyloides stercoralis Antibody in the Southeastern Region of Republic of Korea: A Single-Center Retrospective Study

Strongyloides stercoralis infection is not endemic in the Republic of Korea (Korea) with a positivity rate of <1% in stool examination. However, there is a risk of hyperinfection in immunosuppressed individuals. It is necessary to determine the seropositivity of S. stercoralis antibodies in Korea. This study investigated the seropositivity of S. stercoralis antibodies in the southeastern area of Korea. From January 2019 to June 2021, serum samples were collected from participants who visited the study center in the southeastern region of Korea for routine health check-ups. We determined serum levels of specific anti-Strongyloides IgG antibodies in 834 samples by enzyme-linked immunosorbent assay. We observed that 92 samples (11.0%) tested showed a positive response. The age of the participants was 51±10.7 years, and 43.4% of them were men. The antibody positivity rate based on the location of the participants' residence were 12.3% (Gyoungsangnam-do), 10.2% (Busan), and 10.1% (Ulsan), respectively. Total eosinophil count was associated with positive test results (154.8±152.0 per mm3 versus 202.1±178.9 per mm3, P=0.006). Logistic regression analysis revealed that blood eosinophil count, age above 50 years, and residence in Sacheon were factors associated with the positive status of S. stercoralis antibody. Our finding suggests that it is necessary to test for S. stercoralis in actual clinical settings in Korea.

Effect of urbanization on zoonotic gastrointestinal parasite prevalence in endemic toque macaque (Macaca sinica) from different climatic zones in Sri Lanka

Understanding variations in host-parasite relationships with urbanization is vital for both, public health management and conservation of endemic animals with high anthropogenic interactions. Toque macaques (Macaca sinica) are such endemic old-world monkeys in Sri Lanka. Three macaque sub species inhabit the main climatic zones of the island; M . s. sinica , M . s. aurifrons and M . s. opisthomelas inhabit the dry zone, wet zone, and montane regions of the island, respectively. This study aimed to examine parasite prevalence in this host in association with urbanization. A total of 180 fecal samples were collected from the three sub species of toque macaques inhabiting the main climatic zones (dry, wet, and montane) in Sri Lanka; 20 samples each were collected from urban, suburban, and wild populations representing each climatic zone. Twenty gastrointestinal (GI) parasite genera types i.e. five types of protozoan cysts, two types of trematode ova, four types of cestode ova, eight types of nematode ova, and a single type of acanthocephalan ova were identified. The overall prevalence of parasites was 62% (112/180) with the highest prevalence of Strongyloides infection. In all three sub species, toque macaque populations with proximity to human settlements, including urban and suburban populations, manifested a greater GI parasitic prevalence, mean ova/cyst counts and species richness, compared to their wild counterparts. Importantly, records of five parasite types in toques in Sri Lanka are reported for the first time, while Moniliformis type was reported as a first record in free ranging macaques, globally. This study clearly demonstrated that human contact and habitat modification may influence patterns of parasitic infections in macaques. As most of the parasite types identified manifest zoonotic potential, with public health implications, close associations of macaques may cause a threat to human well-being.

Perceptions, attitudes and practices regarding canine zoonotic helminthiases among dog owners in Nyagatare district, Rwanda

Background

Despite their importance to society, dogs are susceptible to various helminths. This study aimed to understand perceptions, attitudes and practices (PAP) regarding canine zoonotic helminthiases (CZH) among dog owners in Rwanda.

Methods

A cross‐sectional study was carried out in Nyagatare district of Rwanda, where 203 dog owners were randomly selected and interviewed. To analyse this study's data, we used frequency distributions, chi‐square test of association and binary logistic regression model.

Results

Overall, 75.9% and 30% of the respondents were aware of canine and human helminthiases, respectively. Around 74.4% knew that dogs source helminthiases from eating raw infected meat. Also, 74.4% knew vomiting, diarrhoea and swelling of the belly as clinical signs of the helminthiases. Around 58.6% washed hands with soap and water after handling a dog. Only 17.2% and 15.5% dewormed the dogs and treated them against ectoparasites using conventional anthelmintics and acaricides manufactured for dogs, respectively. Of all respondents, 33% held genuine perceptions, while 78.3% and 25.1% adopted positive attitudes and appropriate practices about CZH, respectively. The respondents’ educational level and length of dog ownership correlated with their perceptions and practices about CZH, respectively, while sources of information on CZH influenced their PAP of such infections. The adjusted odds ratio (OR) of having genuine perceptions and positive attitudes were more than 82% lower among those who sourced the information from neighbours & colleagues compared to those who gathered it through reading. Again, the length of dog ownership (OR = 0.37, 95% CI: 0.15–0.90) correlated with the respondent's practices about CZH.

Conclusions

Only 33% and 25.1% of the respondents held genuine perceptions and adopted positive attitudes regarding CZH, respectively. The findings indicate increased zoonotic helminths in dogs, possible spillover in humans and anthelmintic resistance. Therefore, awareness campaigns are needed to upgrade dog owners’ knowledge of the zoonotic helminthiases in dogs in Nyagatare district.

Parasites Circulating in Wild Synanthropic Capybaras (Hydrochoerus hydrochaeris): A One Health Approach

Capybaras (Hydrochoerus hydrochaeris) are affected by a wide range of protozoan and metazoan-derived parasitic diseases. Among parasites of free-ranging capybaras are soil-, water-, food- and gastropod-borne parasitosis, today considered as opportunistic infections in semiaquatic ecosystems. The overlapping of the capybara’s natural ecological habitats with human and domestic animal activities has unfortunately increased in recent decades, thereby enhancing possible cross- or spillover events of zoonotic parasites. Due to this, three synanthropic wild capybara populations in the Orinoco Basin were studied for the occurrence of gastrointestinal parasite infections. A total of forty-six fecal samples were collected from free-ranging capybaras in close proximity to livestock farms. Macroscopical analyses, standard copromicroscopical techniques, coproELISA, PCR, and phylogenetic analysis revealed thirteen parasite taxa. In detail, the study indicates stages of five protozoans, four nematodes, one cestode, and three trematodes. Two zoonotic parasites were identified (i.e., Plagorchis muris, and Neobalantidium coli). The trematode P. muris represents the first report within South America. In addition, this report expands the geographical distribution range of echinocoelosis (Echinocoleus hydrochoeri). Overall, parasitological findings include two new host records (i.e., P. muris, and Entamoeba). The present findings collectively constitute baseline data for future monitoring of wildlife-derived anthropozoonotic parasites and call for future research on the health and the ecological impact of this largest semiaquatic rodent closely linked to humans, domestic and wild animals.

Evaluation of zoonotic platyhelminthe infections identified in slaughtered livestock in Iran, 2015-2019

Background

Platyhelminth infections of livestock can result in considerable economic losses. This study aims to evaluate the spatial frequency of cystic echinococcosis (CE), dicrocoeliasis, and fascioliasis in livestock slaughtered in Iran during the years 2015–2019 and estimate direct costs associated with organ condemnation due to these parasites.

Methods

Abattoir data from 413 abattoirs representing all 31 Iranian provinces were collected from the Iran Veterinary Organization. Infection prevalence was calculated per year at the province level. The Local Moran’s I statistic was performed to evaluate spatial autocorrelation of animals positive at slaughter for the years 2015–2019. Direct costs associated with condemned livers were calculated for each parasitic condition, with costs associated with condemned lungs also included for CE.

Results

Overall prevalence values for the study timeframe were as follows: sheep and goat fascioliasis 1.56% (95% CI: 1.56–1.56%), cattle fascioliasis 3.86% (95% CI: 3.85–3.88%), sheep and goat dicrocoeliasis 4.63% (95% CI: 4.62–4.63%), cattle dicrocoeliasis 3.08% (95% CI: 3.07–3.09%), sheep and goat CE 5.32% (95% CI: 5.32–5.33%), and cattle CE 7.26% (95% CI: 7.24–7.28%). Northwest Iran had the highest prevalence of CE and fascioliasis. High infection areas for Dicrocoelium spp. included the provinces of Zanjan, Gilan, Qazvin, and Tehran, which are located in northern Iran. Direct economic losses for sheep and goat fascioliasis, dicrocoeliasis, and CE for the study period were US$13,842,759, US$41,771,377, and US$22,801,054, respectively. Direct economic losses for cattle fascioliasis, dicrocoeliasis, and CE for the study period were US$1,989,200, US$1,668,986, and US$2,656,568, respectively.

Conclusion

Our findings provide valuable data for future monitoring of these important parasitic diseases in Iranian livestock. Disease control strategies are required to reduce the economic and public health impact of these platyhelminths.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-021-02888-9.

Helminth Parasites among Rodents in the Middle East Countries: A Systematic Review and Meta-Analysis

Rodents can be a source of zoonotic helminths in the Middle East and also in other parts of the world. The current systematic review aimed to provide baseline data on rodent helminths to recognize the threats of helminth parasites on public health in the Middle East region. Following a systematic search on PubMed, Scopus, and Web of Science, a total of 65 research studies on rodent cestodes, nematodes, and trematodes, which were conducted in the countries of the Middle East, were analyzed. The study identified 44 rodent species from which Mus musculus, Rattus norvegicus, and Rattus rattus were most common (63%) and recognized as the primary rodent hosts for helminth infestation in this region. Cestodes were the most frequently reported (n = 50), followed by nematodes (49), and trematodes (14). The random effect meta-analysis showed that the pooled prevalence of cestode (57.66%, 95%CI: 34.63-80.70, l2% = 85.6, p < 0.001) was higher in Saudi Arabia, followed by nematode (56.24%, 95%CI: 11.40-101.1, l2% = 96.7, p < 0.001) in Turkey, and trematode (15.83%, 95%CI: 6.25-25.1, l2% = 98.5, p < 0.001) in Egypt. According to the overall prevalence estimates of individual studies, nematodes were higher (32.71%, 95%CI: 24.89-40.54, l2% = 98.6, p < 0.001) followed by cestodes (24.88%, 95%CI: 19.99-29.77, l2% = 94.9, p < 0.001) and trematodes (10.17%, 95%CI: 6.7-13.65, l2% = 98.3, p < 0.001) in the rodents of the Middle East countries. The review detected 22 species of helminths, which have zoonotic importance. The most frequent helminths were Capillaria hepatica, Hymenolepis diminuta, Hymenolepis nana, and Cysticercus fasciolaris. There was no report of rodent-helminths from Bahrain, Jordan, Lebanon, Oman, United Arab Emirates, and Yemen. Furthermore, there is an information gap on rodent helminths at the humans-animal interface level in Middle East countries. Through the One Health approach and countrywide detailed studies on rodent-related helminths along with their impact on public health, the rodent control program should be conducted in this region.

Gastrointestinal parasites in the opossum Didelphis aurita: Are they a potential threat to human health?

Currently, a great proportion of the emerging infectious human diseases are zoonotic, with most of the pathogens originated from wildlife. In this sense, synanthropic animals such as marsupials play important role in the dissemination of pathogens due to their proximity to human dwellings. These hosts are affected by many gastrointestinal parasites, including species with zoonotic potential. The aim of this study was to assess the diversity of gastrointestinal parasites infecting the black-eared opossum D. aurita captured in urban areas of Southeastern, Brazil. In addition, the potential risk for the human population based on the One Health perspective has been discussed. Forty-nine marsupial specimens were captured with Tomahawk live traps and fecal samples were collected. The samples were evaluated by parasitological procedures. Eggs and oocysts were analyzed at different magnifications (400 × and 1000 ×), and their identification, together with adult nematodes, was established on morphological and morphometric data. Forty-three hosts (87.76%) scored positive for at least one gastrointestinal parasite, being 83.67% (41/49) for helminths, and 65.30% (32/49) for protozoa. For Cryptosporidium sp., only 13 samples were evaluated due to insufficient amount of feces obtained of some animals. A prevalence of 23.08% (3/13) was reported for this parasite. PCR analysis revealed Ancylostomatidae eggs to belong to the genus Ancylostoma. Our results demonstrated that multiparasitism is frequently found in these animals and a high percentage of potentially zoonotic parasites are observed, implying that D. aurita may be involved in zoonotic cycles in urban environments.

Anaerobic digestion of agricultural manure and biomass - Critical indicators of risk and knowledge gaps

Anaerobic digestion (AD) has been identified as a potential green technology to treat food and municipal waste, agricultural residues, including farmyard manure and slurry (FYM&S), to produce biogas. FYM&S and digestate can act as soil conditioners and provide valuable nutrients to plants; however, it may also contain harmful pathogens. This study looks at the critical indicators in determining the microbial inactivation potential of AD and the possible implications for human and environmental health of spreading the resulting digestate on agricultural land. In addition, available strategies for risk assessment in the context of EU and Irish legislation are assessed. Storage time and process parameters (including temperature, pH, organic loading rate, hydraulic retention time), feedstock recipe (carbon-nitrogen ratio) to the AD plant (both mesophilic and thermophilic) were all assessed to significantly influence pathogen inactivation. However, complete inactivation of all pathogens is unlikely. There are limited studies evaluating risks from FYM&S as a feedstock in AD and the spreading of resulting digestate. The lack of process standardisation and varying feedstocks between AD farms means risk must be evaluated on a case by case basis and calls for a more unified risk assessment methodology. In addition, there is a need for the enhancement of AD farm-based modelling techniques and datasets to help in advancing knowledge in this area.

IDENTIFICATION AND PREVALENCE OF GASTROINTESTINAL PARASITES IN BEEF CATTLE IN SIAK SRI INDRAPURA, RIAU, INDONESIA

Gastrointestinal (GI) parasites infection are one of the major constraints cattle farm in tropical countries including Indonesia and some of GI parasites in cattle have the potential to transmit to humans. This study was aimed to identify and determine the level of prevalence of gastrointestinal (GI) parasites in beef cattle in Siak Sri Indrapura District, Riau Province, Indonesia. This research was conducted on 100 beef cattle consisted of, respectively, 32, 34 and 34 cattles from Bungaraya, Sabak Auh, and Dayun sub-district. The characteristic of sample such as age and sex cattle, cage management, feed and drinking water were recorded. Native, sedimentation and sucrose flotation methods were used to find protozoa and eggs worm. We assessed GI parasites based on finding eggs worm, protozoan cyst and coccidial oocysts in stool samples and identification of GI parasite was based on the morphology and size of the eggs worm and cysts or oocysts of protozoan. The result showed that all of 100 feces samples that examined 100% positive infection for parasites. There were eleven types of gastrointestinal parasites that have been identified, 6 genera of protozoan and 5 genera of worms. The prevalence of gastrointestinal parasites in beef cattles in Siak Sri Indrapura District were Blastocystis sp. (100%), Entamoeba sp. (90%), Eimeria sp. (53%), Giardia sp. (7%), Balantidium coli (4%), Cryptosporidium sp. (2%) Oesophagustomum sp. (45%), Toxocara vitulorum (20%), Moniezia expansa (9%), Trichuris sp. (5%), and Fasciola sp. (4%). In conclusion, Siak Sri Indrapura Riau is an endemic GI parasite and this can threaten the health of livestock and potentially as a zoonotic transmission.

Detection of Chilomastix mesnili in Common Marmoset (Callithrix jacchus) and Treatment with Metronidazole

BACKGROUND

Recently, the use of common marmoset (Callithrix jacchus) has increased in biomedical research as an animal model. This study aimed to test fecal samples to monitor bacterial and parasite infections in common marmoset at the Laboratory Animal Center of Osong Medical Innovation Foundation in Korea.

METHODS

To monitor bacteria and parasites in common marmoset, we tested 43 fecal samples of 43 common marmosets by culture and parasitological test in 2014. Infection by Chilomastix mesnili was determined by PCR method.

RESULTS

We identified nonpathogenic bacteria such as Proteus mirabilis and Escherichia coli in feces of normal common marmosets. Interestingly, C. mesnili was isolated from a healthy common marmoset by fecal centrifugation concentration and PCR. The monkey infected with C. mesnili was treated with metronidazole. After the treatment, C. mesnili were not found in feces using fecal centrifugation concentration and PCR.

CONCLUSION

This is the first case report of C. mesnili infection in common marmoset. Treatment with metronidazole is found to be highly effective in eradicating C. mesnili infection in common marmoset.

Comparative proteomics analysis of Trichinella spiralis muscle larvae exposed to albendazole sulfoxide stress

The drug albendazole (ABZ) has a positive effect against Trichinella spiralis infection and has been used for the treatment and prevention of trichinellosis in humans and animals. However, the molecular mechanism ofthe effects of ABZ on T. spiralis remains unknown. Albendazole sulfoxide (ABZSO) is the main intermediary metabolic product of ABZ, and it is often used as a substitute for ABZ in metabolism and bioavailability research. Herein, isobaric tagging reagents for relative and absolute quantification (iTRAQ)-based LC-MS/MS analysis was used to identify the effect of ABZSO on the proteome of T. spiralis muscle larvae in vitro. 3795 proteins were quantified from 22974 unique peptides. Comparative proteomics analysis displayed that 417 proteins were remarkably differentially expressed in ABZSO-treated larvae, of which 213 proteins were up-regulated and 204 proteins were down-regulated. Quantitative real-time PCR of ten randomly-selected genes verified the proteomic data. Gene ontology annotation and KEGG pathway analysis showed that most of the differentially expressed proteins were involved in cell apoptosis, signal pathway, amino acid metabolism, protein synthesis/assembly/degradation and other biological processes. This study firstly provided the comprehensive proteomics data of T. spiralis in response to ABZSO, and would help us to deeply understand the molecular mechanism of ABZSO effects on T. spiralis.

Zoonotic intestinal parasites of carnivores: A systematic review in Iran

AIM

Parasitic infections, especially of the zoonotic-parasitic type, are the most important health, economic, and social problems in developing countries, including Iran. The aim of this study was to review systematically the available data on gastrointestinal parasites of carnivores in Iran and their ability to infect humans.

MATERIALS AND METHODS

Studies reporting intestinal parasites of carnivores were systematically collected from nine electronic English and Persian databases and Proceedings of Iranian parasitology and veterinary congresses published between 1997 and 2015. A total of 26 studies issued from 1997 to 2015 met the eligibility criteria.

RESULTS

The pooled proportion of intestinal parasites of carnivores was estimated as 80.4% (95% confidence interval=70.2-88.8%). The overall prevalence of gastrointestinal parasites in dogs, cats, foxes, and jackals were 57.89%, 90.62%, 89.17%, and 97.32%, respectively. Dipylidium caninum (20.45%), Toxocara spp. (18.81%), Taenia hydatigena (15.28%), Mesocestoides lineatus (11.83%), Echinococcus granulosus (10%), and Toxascaris leonina (8.69%) were the most frequently observed parasites.

CONCLUSION

High prevalence rates of zoonotic intestinal parasites of carnivores particularly Echinococcus spp. and Toxocara spp. increase the risk of acquiring zoonotic infections such as cystic hydatid, alveolar cysts, and visceral or ocular larva migrants in Iranian people. Therefore, it is essential for public health centers to develop more effective control strategies to decrease infections rates in carnivores' populations.

Where are we after 60 years of paragonimiasis research? A bibliometric assessment

Paragonimiasis is highly prevalent endemic food-borne disease in Southeast Asia and Latin America, and constitutes a major public health concern. A bibliometric analysis was performed about the worldwide scientific production of paragonimiasis. We browsed in the Science Citation Index-Expanded (SCI-E) (1957-2015), Scopus (1976-2015), Medline/PubMed/GoPubMed® (1970-2015), ScIELO (1981-2014) and LILACS (1985-2011). All types of articles were included and categorized by year of publication, number, type of scientific article, city and institution of origin, international cooperation, scientific journal, impact factor, language of publication, authors and H index. In SCI-E, 1,028 manuscripts were recovered, while Japan (21.9%) and the USA (17.7%) were the countries with highest scientific production. In this database, Asian region studies received 5,454 citations (H index=32). In Scopus 2161 items were recovered, corresponding to 45.8% of Asian countries. Japan (18.2%) was the first with the University of Miyazaki (11.7% of the country); South Korea (9.5%) was second with the Seoul National University (11.2% of the country). In SciELO 29 items were found, with no contributions from the Asian region. In LILACS 1487 articles were found (22.9% covering Asia). Among the databases, the Journal of Parasitology (Impact factor=1.227) showed the highest number of manuscripts and "Agatsuma T", from Japan, was the author with most records. Japan and South Korea lead global scientific production on paragonimiasis. By contrast, in Latin America, production has been extremely low especially in the last five years.

Serological and Molecular Detection of Toxoplasma gondii and Babesia microti in the Blood of Rescued Wild Animals in Gangwon-do (Province), Korea

Infections of Toxoplasma gondii and Babesia microti are reported in many wild animals worldwide, but information on their incidence and molecular detection in Korean wild fields is limited. In this study, the prevalence of T. gondii and B. microti infection in blood samples of 5 animal species (37 Chinese water deer, 23 raccoon dogs, 6 roe deer, 1 wild boar, and 3 Eurasian badgers) was examined during 2008–2009 in Gangwon-do (Province), the Republic of Korea (=Korea) by using serological and molecular tests. The overall seropositivity of T. gondii was 8.6% (6/70); 10.8% in Chinese water deer, 4.3% in raccoon dogs, and 16.7% in roe deer. PCR revealed only 1 case of T. gondii infection in Chinese water deer, and phylogenic analysis showed that the positive isolate was practically identical to the highly pathogenetic strain type I. In B. microti PCR, the positive rate was 5.7% (4/70), including 2 Chinese water deer and 2 Eurasian badgers. Phylogenetic analysis results of 18S rRNA and the β-tubulin gene showed that all positive isolates were US-type B. microti. To our knowledge, this is the first report of B. microti detected in Chinese water deer and Eurasian badger from Korea. These results indicate a potentially high prevalence of T. gondii and B. microti in wild animals of Gangwon-do, Korea. Furthermore, Chinese water deer might act as a reservoir for parasite infections of domestic animals.

Microbiological survey of mice (Mus musculus) purchased from commercial pet shops in Kanagawa and Tokyo, Japan

Information regarding the prevalence of infectious agents in mice in pet shops in Japan is scarce. This information is particularly useful for minimizing the risk of potential transmission of infections to laboratory mice. Therefore, we surveyed infectious agents in mice from pet shops in Kanagawa and Tokyo, Japan. The survey was conducted in 28 mice from 5 pet shops to screen for 47 items (17 viruses, 22 bacteria and fungi, 10 parasites) using culture tests, serology, PCR, and microscopy. The most common viral agent detected was murine norovirus (17 mice; 60.7%), followed by Theiler’s murine encephalomyelitis virus (13 mice; 46.4%), and mouse hepatitis virus (12 mice; 42.8%). The most common agent amongst the bacteria and fungi was Pasteurella pneumotropica (10 mice; 35.7%), followed by Helicobacter ganmani and Pneumocystis murina (8 mice; 28.5%, for both). Tritrichomonas muris was the most common parasite (19 mice; 67.8%), followed by Spironucleus muris (13 mice; 46.4%), Aspiculuris tetraptera, and Syphacia obvelata (8 mice each; 28.5%). Remarkably, a zoonotic agent, Hymenolepis nana, was found in 7 mice (25%). Given these results, we suggest that the workers in laboratory animal facilities should recognize again the potential risks of mice outside of the laboratory animal facilities as an infectious source, and avoid keeping mice as pets or as feed for carnivorous reptiles as much as possible for risk management.

Intestinal parasites among wild rodents in Northern Gangwon-do, Korea

To determine geographical patterns of natural parasite infections among wild rodents, a total of 46 wild rodents from 3 different localities in northern Gangwon-do (Province), Korea were examined for intestinal parasite infections. Along with nematodes such as hookworms and Syphacia spp., Plagiorchis muris (2 specimens) (Trematoda) were collected from striped field mice, Apodemus agrarius. In a Korean wood mouse, Apodemus peninsulae, the overall nematode infections were similar to A. agrarius, but an adult worm of Echinostoma hortense (Trematoda) was collected. In addition, 2 species of cestodes, i.e., Hymenolepis nana and Hymenolepis diminuta, were collected from A. agrarius. Through this survey, A. agrarius and A. peninsule were confirmed as the natural definite hosts for zoonotic intestinal helminths, i.e., P. muris, E. hortense, H. nana, and H. diminuta, in northern Gangwon-do, Korea. Considering increased leisure activities around these areas, seasonal and further comprehensive surveys on wild rodents seem to be needed to prevent zoonotic parasite infections.

Positivity and intensity of Gnathostoma spinigerum infective larvae in farmed and wild-caught swamp eels in Thailand

From July 2008 to June 2009, livers of the swamp eels (Monopterus alba) were investigated for advanced third-stage larvae (AL3) of Gnathostoma spinigerum. Results revealed that 10.2% (106/1,037) and 20.4% (78/383) of farmed eels from Aranyaprathet District, Sa Kaeo Province and those of wild-caught eels obtained from a market in Min Buri District of Bangkok, Thailand were infected, respectively. The prevalence was high during the rainy and winter seasons. The infection rate abruptly decreased in the beginning of summer. The highest infection rate (13.7%) was observed in September and absence of infection (0%) in March-April in the farmed eels. Whereas, in the wild-caught eels, the highest rate (30.7%) was observed in November, and the rate decreased to the lowest at 6.3% in March. The average no. (mean±SE) of AL3 per investigated liver in farmed eels (1.1±0.2) was significantly lower (P=0.040) than those in the caught eels (0.2±0.03). In addition, the intensity of AL3 recovered from each infected liver varied from 1 to 18 (2.3±0.3) in the farmed eels and from 1 to 47 (6.3±1.2) in the caught eels, respectively. The AL3 intensity showed significant difference (P=0.011) between these 2 different sources of eels. This is the first observation that farmed eels showed positive findings of G. spinigerum infective larvae. This may affect the standard farming of the culture farm and also present a risk of consuming undercooked eels from the wild-caught and farmed eels.

Zoonotic enteric protozoa

A growing number of enteric protozoan species are considered to have zoonotic potential. Their clinical impact varies and in many cases is poorly defined. Similarly, the epidemiology of infections, particularly the role of non-human hosts, requires further study. In this review, new information on the life cycles and transmission of Giardia, Cryptosporidium, Entamoeba, Blastocystis and Balantidium are examined in the context of zoonotic potential, as well as polyparasitism and clinical significance.

An unusual case of hypereosinophilia and abdominal pain: an outbreak of Trichostrongylus imported from New Zealand

We report an outbreak of severe symptomatic Trichostrongylus spp. in travelers visiting a sheep farm in New Zealand. The unusual source of the outbreak was traced as the use of sheep manure as an organic fertilizer on a salad garden.

Pneumocystis: from a doubtful unique entity to a group of highly diversified fungal species

At the end of the 20th century the unique taxonomically enigmatic entity called Pneumocystis carinii was identified as a heterogeneous group of microscopic Fungi, constituted of multiple stenoxenic biological entities largely spread across ecosystems, closely adapted to, and coevolving in parallel with, mammal species. The discoveries and reasoning that led to the current conceptions about the taxonomy of Pneumocystis at the species level are examined here. The present review also focuses on the biological, morphological and phylogenetical features of Pneumocystis jirovecii, Pneumocystis oryctolagi, Pneumocystis murina, P. carinii and Pneumocystis wakefieldiae, the five Pneumocystis species described until now, mainly on the basis of the phylogenetic species concept. Interestingly, Pneumocystis organisms exhibit a successful adaptation enabling them to dwell and replicate in the lungs of both immunocompromised and healthy mammals, which can act as infection reservoirs. The role of healthy carriers in aerial disease transmission is nowadays recognized as a major contribution to Pneumocystis circulation, and Pneumocystis infection of nonimmunosuppressed hosts has emerged as a public health issue. More studies need to be undertaken both on the clinical consequences of the presence of Pneumocystis in healthy carriers and on the intricate Pneumocystis life cycle to better define its epidemiology, to adapt existing therapies to each clinical context and to discover new drug targets.