Food and Waterborne Parasitology最新文献

Irrigation water contaminated by human fecal material may elevate the risk of produce contamination with the enteric parasite Cyclospora cayetanensis. Oocysts of C. cayetanensis are resistant to commonly used disinfectants and a method of removing C. cayetanensis from irrigation water would mitigate this risk. We evaluated zero valent iron (ZVI) sand filtration as one such method. We sought to determine if sand filters containing ZVI outperformed those without ZVI. We first evaluated the abundant poultry parasites Eimeria maxima, E. tenella and E. acervulina as surrogates for C. cayetanensis. We determined if a miniaturized gravity fed ZVI-sand filter, scaled to evaluate scarce supplies of C. cayetanensis oocysts, provided useful information about the performance of larger filtration systems. Filters were inoculated with oocysts, rinsed, and the resulting filtrate examined microscopically for oocysts. We performed experiments to measure the effect of varying ZVI concentrations, repeated filter use, simulated agricultural water, and oocyst size and condition. We then compared the performance of mini filters to that of larger, gravity-fed pool filters and found that ZVI-sand filtration was far more effective at removing Eimeria spp. from water when compared to sand filtration, at both scales. Sand mini filters retained 13–54 % of E. acervulina oocysts, and pool filters retained 82 %, but when combined with 50 % (mini filter) or 35 % (pool filter) v/v ZVI, mini filters retained 89–99 % of oocysts and pool filters retained >99 %. The effectiveness of the mini filters increased with increasing ZVI concentration, and the addition of ZVI far outweighed the influence of any other measured variable. We then performed experiments including C. cayetanensis, which provided similar results to those utilizing Eimeria; 59 % of inoculated C. cayetanensis oocysts were retained in sand mini filters, and 97 % in mini filters composed of 35 % v/v ZVI. In sum, ZVI is highly effective in removing oocysts from water and Eimeria is a useful surrogate for C. cayetanensis to assess filtration. ZVI-sand filtration shows promise as a tool to mitigate the risk of C. cayetanensis contamination of irrigation water. Further studies should evaluate the performance of ZVI-sand in pressurized fast filtration systems under a range of field conditions.

Blastocystis spp. is a common intestinal parasite found in humans and various animals, including marine species like fish, bivalves, and sponges. While traditionally considered non-pathogenic, emerging evidence suggests potential foodborne concerns, especially for vulnerable populations. The present systematic review and meta-analysis reviewed four electronic databases (PubMed, Scopus, Google Scholar, and Web of Science) until June 13, 2024, for studies reporting the prevalence and subtypes (STs) distribution of Blastocystis spp. in marine animals, including fish, bivalves, and sponges, to assess foodborne concern and zoonotic importance. In the analysis of 11 studies involving 1329 marine animals from nine countries, five studies/datasets (742 samples) focused on fish, five studies/datasets (567 samples) on bivalves, and one (20 samples) on sponges. This review found that 12.4 % (95 % CI: 4.3–31 %) of marine animals globally were infected by Blastocystis spp., with bivalves showing the highest infection rate at 32 % (95 % CI: 13–59.7 %), exceeding sponges with a single study at 10 % (95 % CI: 2.5–32.4 %), and fish at 4.4 % (95 % CI: 2–9.3 %). Sensitivity analysis assessed changes in weighted prevalence after excluding certain studies. A subgroup analysis of Blastocystis spp. prevalence was conducted based on publication years, countries, continents, WHO regions, and sample sizes. The data collected indicated that marine animals serve as suitable reservoirs for various Blastocystis spp. STs (ST1-ST4, ST7, ST8, ST10, ST14, ST23, ST26, and ST44), with most (except for ST26 and ST44) having the potential for zoonotic transmission. Overall, the findings emphasize the potential for foodborne risk posed by Blastocystis spp. in marine animals and highlight the need for improved monitoring and control measures to ensure food safety.

Globally, intestinal protozoa E. histolytica/dispar and Giardia lamblia are the cause of amoebiasis and giardiasis, respectively. Despite their important medical importance and common occurrence in Ethiopia, they are minimally addressed in terms of their prevalence, sensitive diagnostic methods, and associated risk factors. Infections with E. histolytica/dispar and G. lamblia are often misdiagnosed and underreported in impoverished countries. Thus, the purpose of this study was to ascertain the prevalence of Giardia lamblia and E. histolytica/dispar infections as well as related variables among schoolchildren in the Amhara region. A cross-sectional study was conducted among 844 schoolchildren in the Amhara region from April to December 2019. A stool sample was collected from each study participant and processed via the formol ether concentration technique (FECT) and spontaneous tube sedimentation techniques (STST). Data were entered in EpiData and analysed by SPSS statistical software. The prevalence of E. histolytica and G. lamblia infections using each diagnostic method and composite reference was determined by descriptive statistics. The association of risk factors with E. histolytica/dispar and G. lamblia infections was analysed by logistic regression and variables with p < 0.05 were considered to have statistical significance. From the total, 243 (28.8%) schoolchildren were found to be infected by at least one of E. histolytica/dispar or G. lamblia. The prevalence of E. histolytica/dispar and G. lamblia infections was 201 (23.8%) and 62 (7.3%), respectively. The co-infection prevalence with both E. histolytica/dispar and G. lamblia was 22 (2.6%). The sensitivity (78.6%) and negative predictive value of STST (19.6%) were higher than FECT sensitivity (65.4%) and negative predictive value (13.1%). Children in 10–14 years of age (AOR = 1.66;95%CI: 1.16–2.38), lived in the rural (AOR = 1.97;95%CI: 1.12–3.49), used latrine improperly (AOR = 1.49;95%CI: 1.04–2.13), did not wash hands before meal (AOR = 2.10; 95%CI:1.08–4.10), and after latrine (AOR = 1.51;95%CI: 1.05–2.19), ate unwashed raw vegetables (AOR = 1.85;95%CI:1.26–2.70), and played with soil (AOR = 1.48;95%CI:1.06–2.06) were associated with E. histolytica/dispar and G. lamblia infection. These findings revealed high prevalence of E. histolytica/dispar and G. lamblia infections was high in the Amhara region. Therefore, proper implementation of water, sanitation and hygiene should be advocated at the community and school levels to mitigate the disease burden.

Humans may become accidental dead-end hosts for a series of zoonotic foodborne parasites, of which Toxoplasma gondii, Echinococcus spp., Toxocara spp., and Trichinella spiralis are of major public health interest, due to their potential pathological implications. The aims of the study were to evaluate the exposure to these pathogens in north-western Romania, and to investigate their potential association to risk factors. From June 2022 to January 2024, 554 patients admitted to a tertiary hospital in north-western Romania were screened for the presence of IgG antibodies against T. gondii, Echinococcus spp., Toxocara canis, and T. spiralis by ELISA, and potential risks were assessed using a questionnaire. Overall, 225 samples (40.6%) were positive for at least one pathogen. The highest seroprevalence for IgG was found for T. gondii (33.9%), followed by Echinococcus spp. (9.1%), T. spiralis (2.9%), and T. canis (1.1%). For T. spiralis, raw meat consumption was associated with positivity. For T. gondii, increased age, rural environment, contact with cats, consumption of unwashed fruits/vegetables and drinking water from unverified sources were significantly associated to seropositivity. The present study provides new insights into the epidemiological status of zoonotic foodborne parasite in Romania, underlining the need to increase awareness on the importance of water, sanitation and food habits in relation with this neglected pathology.

Trichinellosis, caused by 13 species/subspecies/genotypes in the nematode genus Trichinella, is a worldwide zoonosis. In the United States, trichinellosis was of historical and economic significance because of European restrictions on the import of U.S. pork. Before the advent of effective protective measures, most cases of trichinellosis were derived from consumption of undercooked or inadequately processed, infected pork. Research conducted at the United States Department of Agriculture (USDA) since 1891, and policies established by USDA regulatory agencies, have helped to reduce Trichinella infections in commercially raised domestic pigs to negligible levels. Here, we review the history of this scientific progress, placing special emphasis on research conducted at the USDA's Beltsville Agricultural Research Center.

Digenean (Heterophyidae) trematodes include several zoonotic species such as the genus Metagonimus (Katsurada, 1912). Metagonimus romanicus (Ciurea, 1915) is a species widely distributed in Europe, whose metacercariae can be found on cyprinoids from the River Danube in Hungary. The aim of the study was to measure the viability of Metagonimus romanicus metacercariae by physical (freezing, heating, desiccation) and chemical (acetic acid and NaCl solutions) treatments. The methods were chosen as a model for procedures commonly used in traditional food preservation (such as freezing, salting, pickling and smoking) to measure the survival rate of metacercariae under different conditions. Most physical treatments (freezing of metacercariae at −20 °C, keeping them at 40 °C and 60 °C and desiccation) and chemical treatments (2.5%, 5%, 10% acetic acid solution and 5% and 10% NaCl solution) killed the metacercariae in a relatively short time (from 30 min to 6 days depending on the treatment) so their effects eliminated the risk of zoonotic infection. On the other hand, the metacercariae survived at room temperature and at 4 °C up to one month. Therefore, storing unprepared fish in domestic refrigerators cannot prevent infection with metacercariae in humans.