Parasitic contamination of vegetables marketed in Arba Minch town, southern Ethiopia

Fresh Leafy Vegetables and Parasitic Contamination: Practical Solutions

This study aimed at investigating the parasitic contamination of fresh leafy vegetables in Tehran, Iran, during 2020-2021. A cross-sectional study was conducted and 180 fresh leafy vegetables (including leek, watercress, mint, spring onion, radish, basil, parsley, lettuce, and spinach) were collected randomly in the five regions of Tehran, Iran. Each 200-g sample was soaked with tap water containing detergent, and the obtained sediment was centrifuged and examined for parasitic stages using a light microscope. The overall rate of parasitic contamination was 19.4%, with Trichostrongylus and Toxocara eggs being the most prevalent parasites (3.9%) and the highest rate of parasitic contamination was observed in spinach (40%), whereas no contamination was found in spring onions. Except for radish, other vegetable samples had multiple parasitic infections. Due to the contamination of vegetables, it is necessary to have a suitable method to reduce the parasites. Consequently, policymakers should safeguard public health by consistently monitoring contaminants in food and prioritizing education and research on methods to mitigate their presence in the food chain.

Parasitic contamination of fresh vegetables and fruits sold in open-air markets in peri-urban areas of Jimma City, Oromia, Ethiopia: A community-based cross-sectional study

BACKGROUND

Consuming contaminated raw vegetables and fruits is one of the primary means of parasite transmission to humans. Periodic monitoring of parasitic contamination in these food items is a crucial step in preventing the spread of parasitic disease in the community. This study was aimed at detecting intestinal parasitic contamination caused by consuming raw vegetables and fruits sold in three open-air markets and its associated factors in peri-urban areas of Jimma City, Oromia, Ethiopia.

METHODS

A cross-sectional study was conducted on fruits and vegetables collected from three peri-urban open-aired markets (namely; Hora Gibe, Bore and Jiren markets) in peri-urban areas of Jimma City between July and September 2021. A total of 187 fresh vegetable samples and 188 fruits were collected and examined for intestinal parasite contamination. About 200g of fruit and vegetable samples were processed and examined microscopically for parasite contamination, utilizing direct wet mount and modified Zeihl-Neelson staining methods in accordance with standard protocols. A structured questionnaire was used to collect data on the socio-demographic characteristics of vendors and risk factors for fruit and vegetable contamination. All data were analyzed using SPSS version 20.0.

RESULT

Of the 187 fresh vegetable samples and 188 fresh vegetable samples, 105 (56.1%) and 68/188 (36.2%) of vegetables and fruit samples, respectively, were found contaminated with one or more intestinal parasites. Remarkably, high level of contamination in fresh vegetable samples was recorded both in Carrot (Daucus carota) 63.8% (30/46) and Lettuce (Lactuca sativa) 63.1% (29/46) while Green pepper (Capsicum spp.) is the least contaminated. In fruit samples, Avokado (Persea americana) 42.6% (20/47) and Banana (Musa acuminata) 14.9% (7/47) were the most and the least commonly contaminated items respectively. The identified helminthes and protozoans were Ascaris lumbricoides, Strongyloides stercoralis, Hymenolepis nana, Entamoeba histolytica/dispar, Giardia lamblia, Cryptosporidium spp., Toxocara spp. And Fasciola spp. The most predominant parasite encountered was A. lumbricoides 46(12.3%) whereas both Toxocara spp. 12(6.9) and Fasciola spp. 2(0.5) were the least detected parasites. It is worth-mentioned that the rate of contamination in Bore market (38.15%) was higher compared with Jiren market (34.7%) and Hora Gibe market (27%). However, the rate of contamination in vegetables and fruit obtained from the three district was non-significant (p = 0.19). Contamination was more common in vegetables than fruits (AOR = 5.78, p<0.001). It was also observed that decreased parasitic contamination was significantly associated with washing the products before displaying it for selling (p < 0.001).

CONCLUSION

The study has identified a high rate of raw vegetables and fruits contaminated with intestinal helminthes and protozoan. Contaminated fresh vegetables and fruits in open-aired peri-urban markets of Jimma city, Ethiopia may play a significant role in transmission of intestinal parasitic infections to humans, particularly A. lumbricoides infection. Therefore, it is urgently needed for health authorities to educate the public on the proper handling of vegetables and fruits prior to consumption.

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.

Prevalence of intestinal parasitic infections and associated risk factors among patients attending Debarq Primary Hospital, northwest Ethiopia

Intestinal parasitic infections (IPIs) are major public health problems in developing countries. This study was conducted to determine the prevalence and associated risk factors of IPIs at Debarq Primary Hospital in northwest Ethiopia. A health facility-based cross-sectional study was conducted from March 2022 to June 2022. The study participants were recruited from patients who visited Debarq Primary Hospital during the study period. Stool samples were collected from each participant and examined for intestinal parasites using direct wet-mount and formal-ether concentration techniques. Socio-demographic data were collected using a structured questionnaire. Out of 422 individuals examined, 33.64% were infected with at least one intestinal parasite species. Entamoeba histolytica/dispar, Giardia intestinalis, Ascaris lumbricoides, and hookworm were found in 12.79%, 8.53%, 7.10%, and 1.65% of the participants, respectively. Double and triple parasite infections were found in 2.37% and 0.23% of the participants, respectively. A habit of eating unwashed vegetables (Adjusted odds ratio (AOR) = 9.98, 95% confidence interval (CI) = 2.68-37.14) and low income (AOR = 6.66, 95% CI = 1.87-23.70) were associated with increased odds of IPIs. Participants with a habit of hand washing after using the toilet had 0.05 (95% CI = 0.13-0.22) lower odds of IPIs than those who did not. In conclusion, IPIs are common among Debarq Primary Hospital patients and are associated with factors such as low income, not washing hands after using the toilet, and eating unwashed vegetation, necessitating control and prevention efforts in the study area that include health education and the provision and use of sanitary facilities.

Prevalence and Determinants of Geohelminthiasis among School-Age Children in Jimma City, Ethiopia

School-age children (SAC) are at a higher risk of geohelminth or soil-transmitted helminth (STH) infections due to their practice of walking and playing barefoot, lack of adequate sanitary facilities, and poor personal hygiene. In Ethiopia, periodic deworming has been implemented since 2013 with the aim of interrupting the transmission of STH in children by 2025. To evaluate the likely success of such a control program, it is crucial to monitor the transmission of STH, especially in peri-urban settings where environmental sanitation is modest. The aim of this study was to determine the prevalence and determinants of STH infections among SAC in peri-urban areas of Jimma City, Southwestern Ethiopia. A community-based cross-sectional study was conducted in five peri-urban Kebeles of Jimma City from July to September, 2021. Systematic random sampling was used to select 522 households with at least one child, and 478 children (5-15 years old) were recruited randomly from the households. Data on sociodemographic and potential risk factors were collected using a structured questionnaire. Stool samples from each study participant were collected and examined microscopically using the Kato-Katz technique. Multivariate logistic regression model was used to identify risk factors associated with STH infections. The prevalence of any STH among SAC was 23.4%, with Ascaris lumbricoides being the predominant STH species (15.7%), followed by Trichuris trichiura (9%) and hookworm (2.1%). Most (86.6%) of the STH-positive SAC had a single infection and a light infection intensity (88.2%), with a mean intensity of 367.4 eggs per gram. Location of Kebele (AOR = 2.73; 95% CI: 1.21-6.16, p=0.016), lack of hand washing after defecation (AOR = 6.39; 95% CI: 3.16-12.95, p < 0.001), untrimmed fingernails (AOR = 2.65; 95% CI: 1.56-4.51, p < 0.001), and lack of previous deworming (AOR = 2.90; 95% CI: 1.47-5.74, p=0.002) were significant predictors for STH infections among SAC. In conclusion, the study revealed that STH infections are significant health problem in the peri-urban areas of Jimma City. Strengthening periodic deworming and improving children's hygiene through health education are required to reduce the transmission.

Assessment of Intestinal Parasites and Its Associated Factors among Fruits and Vegetables Collected from Local Markets of Bule Hora Town, Southeast Ethiopia

Background

Vegetable and fruit consumptions are important for health as they are good sources of carbohydrates, vitamins, minerals, and fiber. However, contamination of vegetables and fruits is indicated as the main contributing factor to parasitic contamination.

Objective

This study aims to assess the prevalence and associated factors of intestinal parasites among fruits and vegetables collected from local markets in Bule Hora Town, Southeast Ethiopia.

Methods

A cross-sectional assessment was carried out on 391 raw fruits and vegetables from the market in Bule Hora Town from July 29 to August 17, 2022. After being soaked in physiological saline and vigorously shaken for 15 minutes with the help of a mechanical shaker, a total of 391 samples taken from various fruits and vegetables were evaluated using the sedimentation concentration technique. Software SPSS version 25 was used to analyze the data after it had been entered using EpiData version 3.1. To assess various associated factors, binary and multivariable logistic regression was employed.

Results

142 (36.3%) of the 391 samples analyzed had at least one species of parasite. The parasite Ascaris lumbricoides (40.1%) was found the most frequently, whereas Strongyloides spp. was found the least frequently. Variables such as fingernail trimming (AOR = 1.99; 95% CI: 1.274-3.108), hand washing habit with soap after using toilet (AOR = 2.912; CI: 1.896-4.47), and eating raw vegetables or fruits (AOR = 0.604; CI: 0.394-0.925) were associated with parasitic contamination.

Conclusions

The results of this study show that eating vegetables that are raw in the study area carries a potentially significant risk of contracting parasitic illnesses. Therefore, the appropriate bodies should make an effort to lower the rate of product contamination with intestinal parasites by educating vendors and the general public.

Prevalence of Soil-Transmitted Helminths and Schistosoma mansoni among Schoolchildren across Altitudinal Gradients in Amhara National Regional State, Ethiopia

Soil-transmitted helminths (STHs) and Schistosoma mansoni infections are common parasitic infections in sub-Saharan Africa. Their distributions vary across altitudes in Ethiopia. Hence, ongoing updates of infection risk factors and prevalence data are necessary for successful intervention. A school-based, cross-sectional study was conducted from October to December 2019 involving 530 schoolchildren who were recruited by systematic random sampling from Amhara Regional State. A structured questionnaire was used to collect data on sociodemographic, geographical and environmental factors. Stool samples were collected and processed by Ritchie's and Kato Katz techniques. Data were entered into EpiData and analyzed using SPSS. Descriptive statistics were used to compute prevalence, and logistic regression was used to assess factors associated with STHs and S. mansoni infections. Variables with P < 0.05 were considered statistically significant. Among 530 schoolchildren, 169 (31.9%) and 78 (14.7%) were infected with STHs and S. mansoni, respectively. The prevalence of STHs (40.2%) in the semi-highlands and S. mansoni (30.4%) in the lowlands was high. Infrequent shoes wearing, exposure to soil, not washing vegetables before eating, and living outside in lowland areas were significantly associated with STHs infections (P < 0.05). Schoolchildren who fetched water to irrigate fields, swam in rivers, and lived in lowland areas were significantly associated with S. mansoni infection (P < 0.05). In conclusion, prevalence rates of STHs and S. mansoni infections differed across altitudes in Amhara Regional State. Therefore, current control strategies including deworming and provision of clean water and education on sanitation and hygiene should be intensified and adapted to the local context.

Exploring genetic variability of Giardia duodenalis and Enterocytozoon bieneusi in raw vegetables and fruits: implications for food safety and public health in Mozambique

Giardia duodenalis and Enterocytozoon bieneusi are etiological agents of enteric diseases characterized by diarrhea that can progress to chronicity in humans, especially in children and in immunocompromised patients. This study aims to assess the genetic pattern of G. duodenalis and E. bieneusi detected in vegetables and fruits commercialized in Maputo markets, Mozambique and determine their public health importance. Eight study points were sampled: a farmer zone, a wholesale, four retail markets, and two supermarkets in Maputo city, where eight types of horticultural products were purchased. Using nested-PCR methods, 2.8% (9/321) and 1.3% (4/321) of samples monitored were positive for G. duodenalis and E. bieneusi, respectively. Based on the analysis of the β-giardin and ITS rRNA sequences of G. duodenalis and E. bieneusi detected, respectively, four different sequences of G. duodenalis (three novel sequences: BgMZ1, BgMZ2, and BgMZ3, and one known sequence) all from assemblage B and three genotypes of E. bieneusi (two novel sequences: EbMZ4 and EbMZ5, and one known sequence: KIN-1) from group 1. These microorganisms were found and characterized for the first time in horticultural products in Maputo markets. All identified G. duodenalis and E. bieneusi display high genetic similarity within their β-giardin and ITS rRNA sequences, respectively, having been clustered into assemblages and genotypes with high zoonotic transmission potential. Our study may represent a relevant step in the understanding of these intestinal pathogens in association with fresh vegetables and fruits for human consumption, for a better and broader "One Health" approach.

Parasitic Contamination of Fresh Leafy Green Vegetables Sold in Northern Lebanon

Contaminated, raw or undercooked vegetables can transmit parasitic infections. Here, we investigated parasitic contamination of leafy green vegetables sold in local markets in the Tripoli district, Lebanon, during two consecutive autumn seasons (2020-2021). The study involved the microscopic examination of 300 samples of five different types of vegetables (60 samples per type) and used standardized qualitative parasitological techniques for some protozoa and helminths. The results showed that 16.7% (95% interval for p: 12.6%, 21.4%) (50/300) of the vegetable samples were contaminated with at least one parasite. The most frequently detected parasite was Blastocystis spp. (8.7%; 26/300); this was followed in frequency by Ascaris spp. (3.7%; 11/300). Among the different vegetable types, lettuce (23.3%; 14/60) was the most contaminated, while arugula was the least contaminated (11.7%; 7/60). The statistical analysis did not reveal any significant association between the prevalence of parasitic contamination and the investigated risk factors, which included collection date, vegetable type, market storage status, and wetness of vegetables at the time of purchase (p > 0.05). The high prevalence of parasitic contamination also suggested the potential presence of other microbial pathogens. These findings are important because leafy green vegetables are preferentially and heavily consumed raw in Lebanon. Thus, implementing effective measures that target the farm-to-fork continuum is recommended in order to reduce the spread of intestinal pathogens.

Individual and Community-Level Risk Factors for Giardiasis in Children under Five Years of Age in Pakistan: A Prospective Multi-Regional Study

OBJECTIVES

This study aimed to estimate the prevalence of Giardia lamblia infection and identify associated risk factors at both individual and community levels in a pediatric population in different agroecological zones of Khyber Pakhtunkhwa, Pakistan.

METHODS

A community-based cross-sectional study was conducted from March to December 2022. Using stratified sampling, 1026 households were recruited from nine agroecological zones. Stool samples were collected from 1026 children up to the age of five years and processed for detection of Giardia using a commercial ELISA kit. Data on potential risk factors were collected using a pre-structured questionnaire. A multivariable logistic regression model was used to identify risk factors associated with giardiasis.

RESULTS

The study found that the prevalence of giardiasis in the study area was 3.31%. Children aged 13-24 months were found to be at higher risk for giardiasis. Illiterate mothers and fathers attending daycare institutions/kindergartens, mothers not practicing hand washing during critical times, households with companion animals, and homes where stray dogs/cats enter were identified as predictors of giardiasis at the individual level. Children living in sub-mountain valleys use un-piped water, inadequate domestic water storage vessels, drink un-boiled or unfiltered water, live near rubbish heaps or un-paved streets/pathways, and have unimproved latrine facilities were identified as risk factors of giardiasis at the community level.

CONCLUSIONS

The study highlights the need for integrated intervention approaches at both individual and community levels to reduce the incidence of giardiasis in Khyber Pakhtunkhwa, Pakistan. Interventions aimed at promoting behavioral change and providing safe and adequate water sources, combined with individual-level interventions such as hand washing and awareness of giardiasis prevention methods, would be critical to addressing this health concern. Inter-sectoral collaboration between the health sector and other sectors would also be necessary to achieve meaningful progress in reducing the incidence of giardiasis in resource-limited areas.

Prevalence of helminths in fresh vegetables: a narrative literature review

The consumption of fresh vegetables is related to healthy lifestyle habits present in culinary preparations in different regions. The presence of pathogenic parasites in these foods can cause gastrointestinal disorders. Thus, the objective of the present study was to carry out a narrative review of the literature on the prevalence of helminths in fresh vegetable samples. The analysis of the studies published from 2016 to 2022 showed that hookworms and Ascaris lumbricoides are the most common pathogenic helminths in fresh vegetable samples, with a prevalence of up to 73.8% and 55.1%, respectively. In addition, studies have shown associations between the presence of helminths and pathogenic protozoa. The results obtained in this review indicate the urgent need to implement actions at all stages of the vegetable production chain, from the water used in planting irrigation to cleaning before sale to the final consumer. © 2022 Society of Chemical Industry.

Blastocystis subtypes in raw vegetables from street markets in northern Thailand

Blastocystis is a stramenopile protist of controversial pathogenicity. The organism colonizes a broad range of vertebrate and invertebrate hosts. Blastocystis has also been found in the environment both in water and soil. Several routes of transmission have been proposed including human to human, animal to human, and via contaminated food and water. In recent years, the presence of Blastocystis in vegetables has started to be explored. However, most studies have focused on microscopic detection. Moreover, works of this type from Asia are barely available. Hence, the aim of this preliminary study was to examine the occurrence of Blastocystis in raw vegetables sold in markets in northern Thailand. Fresh produce (n = 20) commonly used in Thai cuisine (Lanna) was purchased from two street markets and screened for Blastocystis using qPCR. Blastocystis was detected in 45% of the samples with the dominant subtype being ST3. Produce growing underground, such as galangal, carrot, and beetroot, were positive for the organism suggesting soil or inadequately composted manure as the source of contamination. To our knowledge, our study is the first to perform subtyping of Blastocystis in vegetables. Our results hint toward fresh produce being a, as yet, not widely explored, transmission route of Blastocystis in the studied community. Looking forward, large-scale investigations on the prevalence of this and other organisms under the One Health umbrella should be undertaken.

Molecular investigation of ready-to-eat salads for Giardia duodenalis and Cryptosporidium spp. in Portugal

Foodborne outbreaks are often associated with the consumption of salads. However, published studies on the detection of foodborne pathogens in ready-to-eat salads are scarce. The aim of this study was to detect Giardia duodenalis and Cryptosporidium DNA in ready-to-eat salads, by applying techniques of molecular biology to study the frequency of contamination in salads. A total of 100 packages of ready-to-eat salads containing assorted leafy green vegetables were randomly purchased from hypermarkets located in central regions of Portugal (Coimbra and Viseu). Nested-PCR and qPCR methods were used to detect G. duodenalis and Cryptosporidium DNA. Species and assemblages of the parasites were identified by sequence analysis and PCR. Eighteen of the 100 samples (18%) were positive for G. duodenalis and twelve were sequenced and identified as assemblage A. Cryptosporidium spp. were not detected in any salads. Overall, pre-harvest and post-harvest preventive measures may be need for G. duodenalis control throughout the food production industry, from the field to consumers.

Foodborne disease hazards and burden in Ethiopia: A systematic literature review, 1990–2019

Background

Foodborne disease (FBD) affects millions of people each year, posing a health burden similar to malaria, tuberculosis or HIV. A recent World Bank study estimated the productivity losses alone attributed to unsafe food within Africa at $20 billion in 2016, and the cost of treating these illnesses at an additional $3.5 billion. Ethiopia faces multiple food safety challenges due to lack of infrastructure and basic pre-requisites for food safety such as clean water and environment, washing facilities, compounded by limited implementation of food safety regulations, and a lack of incentives for producers to improve food safety. A consolidation of our understanding and evidence of the source, nature and scale of FBD in Ethiopia is needed to inform policy and future research. We performed a Systematic Literature Review (SLR) of publications on FBD occurrence in Ethiopia including hazard presence and impact.

Method

The SLR followed Cochrane and PRISMA guidelines. We searched PubMed and CAB-Direct for relevant publications between 1990 and 2019 (inclusive). Observational studies and reviews were included. Two reviewers screened titles and abstracts, and retained publications were reviewed in full for quality and data extraction.

Result

In total 128 articles met the inclusion criteria. Most articles focused on the identification of biological hazards in food. High levels of microbial contamination in different food value chains were often found in the small, ad hoc, observational studies that dominated the literature. Raw milk (22/128, 17.0%) and raw beef (21/128, 16.4%) were the most studied food products. Foodborne (FB) parasites were often found at higher rates in food than bacterial and viral pathogens, possibly due to differences in ease of identification. High levels of bacterial contamination on the hands of food handlers were widely reported. There were no reports on the incidence of human FBDs or resulting health and economic impacts.

Conclusion

Our findings reflect existing concerns around food safety in Ethiopia. A lack of substantial, coordinated studies with robust methodologies means fundamental gaps remain in our knowledge of FBD in Ethiopia, particularly regarding FBD burden and impact. Greater investment in food safety is needed, with enhanced and coordinated research and interventions.

Parasitic Contamination and Microbiological Quality of Commonly Consumed Fresh Vegetables Marketed in Debre Berhan Town, Ethiopia

Parasitic and microbial contamination and the pattern of occurrence of the parasite species depends on weather conditions, socio-cultural conditions, sampling season, analyzed vegetable products, and other factors. Therefore, local assessment of vegetable contamination is crucial for targeted and effective interventions. A cross-sectional study was conducted from February to August 2022. A questionnaire was used to assess factors associated with parasite contamination of vegetables during the marketing period. The selected vegetables were purchased and processed for parasite and microbial analysis using standard methods. Finally, all data were summarized and analyzed using SPSS software version 25. A total of 180 vegetable samples were purchased from 180 vendors. This study identified a total of 129 parasites from 180 vegetable samples, with an overall contamination rate of (75; 41.7%). Both protozoa (41; 31.8%) and helminthes (88; 68.2%) were identified from vegetables. Contamination with more than one parasite species was (38; 21.1%). The kind of produce, finger nail status of vendors/sellers, the medium of the display, the type of market and not washed prior to display were significantly associated with parasite contamination. The results also showed that vegetable microbial load for total heterotrophic count, total coliform count, fecal coliform count, yeast count, and mold count was higher in the afternoon than in the morning. To decrease risks to public health, local health authorities and/or market inspectors should establish and implement strategies to reduce contamination such as encouraging specific display medium and washing of vegetables prior to display.

The Presence of Potentially Pathogenic Protozoa in Lettuce (Lactuca sativa) Sold in Markets in the Central Peruvian Andes

Peru is currently one of the world’s leading culinary destinations, whose world-renowned cuisine uses vegetables, mainly lettuce, as frequent ingredients. Vegetable consumption is promoted worldwide as a part of a healthy diet. However, vegetables, more frequently lettuce, have been implicated as a vehicle of infection for several foodborne parasites. This study aimed to determine the presence of potentially pathogenic parasites in lettuce marketed in the Central Andes of Peru. A total of 75 lettuce samples were collected from the two largest wholesale markets and the main open-air market in Jauja province, in the central Peruvian Andes. The province of provenance (coast vs. highlands), lettuce variety (“curly-leaf”, “iceberg”, and “butter”), and type of market were recorded. The samples were microscopically examined for detection of parasitic life forms using standard parasitological methods including direct slide smear, Lugol’s iodine staining, and Modified Ziehl−Neelsen staining. The overall positivity of parasitic contamination in lettuces was 45.3% (CI 95%: 34−56.6%). Cryptosporidium spp., Isospora belli, Giardia lamblia, Balantidium coli, and Entamoeba spp. were detected in twenty-six (34.7%), six (8%), four (5.3%), two (2.7%), and two (2.7%) lettuces, respectively. I. belli was found in a significantly (p < 0.01) lower proportion in the “butter” variety, and significantly (p < 0.05) higher contamination with G. lamblia was found in lettuce sold at the open-air market. B. coli, G. lamblia, and E. histolytica/E. dispar/E. moshkovskii were detected only in lettuce from the highlands (Tarma province). This study provides important data for health authorities to develop food safety programs. This information is also of interest to the international community because of the increased visibility that Peru has gained as a tourist destination.

Microbial and Parasitic Contamination of Vegetables in Developing Countries and Their Food Safety Guidelines

The safety of humans is of paramount importance in the vegetable production chain. Evidence of microbial and parasitic contamination of these products poses a great threat to consumers. This is an emerging issue the world is battling, and it is still in the process of unravelling. However, one of the contributing factors responsible for the rapid spread of these pathogens to millions of people among other factors is the distribution of food in our food systems. The purpose of this study was to draw the attention of producers, retailers, consumers, and various stakeholders to the occurrence and potential hazard of these organisms, their contamination origin, and food safety protocols. Among the food system, vegetables play a major role, and their consumption has increased as they form a larger portion of daily diets. This urge for healthy diets coupled with changing dietary habits and human population explosion has therefore accelerated their production. This has resulted in parasitic and microbial contamination gaining grounds in salad vegetables, and as such, a wide range of microbes such as Escherichia coli O157: H7, Listeria monocytogenes, Salmonella spp., Shigella, and Staphylococcus, and parasites such as Giardia lamblia, Entamoeba coli, Entamoeba histolytica, Cystoisospora belli, Toxoplasma gondii, Trichuris trichiura, and Ascaris lumbricoides have been isolated from them. Therefore, major routes for salad vegetable contamination and prevention methods have been pointed out in this review article. The topic of protective countermeasures will also be covered here in this review. Notwithstanding, several control measures have been reported to be effective and efficient in removing or eliminating pathogens, including treatment of irrigation water and fertilizers, use of disinfectants like vinegar and saltwater, irradiation, ozone, and bacteriophages. Though consumption of vegetables and salads is encouraged due to their nutritional advantage, appropriate systems should be put in place to ensure their safety.

Foodborne Pathogens and Antimicrobial Resistance in Ethiopia: An Urgent Call for Action on "One Health"

Foodborne pathogens are the most common cause of foodborne disease worldwide. They contaminate food at all stages of the food chain, at the agricultural production level (soil and irrigation), from animal sources or at the time of preparation by food handlers. Therefore, food security is a critical issue that affects everyone in the world. Current studies indicate that the problem is more severe in low-income countries like Ethiopia. The majority of studies in Ethiopia have been conducted partially on human, animal or environmental samples with conventional culture-based diagnostic methods. Therefore, this review was conducted to gather information on the main foodborne pathogens and identify gaps in their traceability. Clinically important foodborne pathogens in Ethiopia include (A. lubmbricoids, Toxocara spp., H. nana. E. histolytica/dispar, G. intestinalis, H. diminuta and C. belli), bacteria (Salmonella spp, E. coli O157:H7, B. anthracis, Yersinia, C. perfringens, Klebsiella spp. M. paratuberculosis, and L. monocytogenes), and viruses like (rotaviruses, enteroviruses and astroviruses, hepatitis E virus). In Ethiopia, all isolated foodborne bacterial pathogens showed high rates of antimicrobial resistance (AMR). In particular, the most studied foodborne pathogens, Staphylococcus spp., Salmonella spp., and E. coli from specific sources, showing high levels of resistance to most of the antibiotics prescribed in Ethiopia. The occurrence and persistence of AMR in food is one of the main factors causing the spread of antimicrobial resistance in different compartments, humans, animals and the environment. Therefore, strategies of coordination and struggle from a One Health perspective is an urgent strategy to control antibiotic resistance in order to achieve better outcomes for human and animal health.

Protozoan Parasites and Leafy Greens in Marrakech: Study of Occurrence Using a Molecular Method

PURPOSE

The aim of this study was to assess the presence of T. gondii, Cryptosporidium spp. oocysts, and G. duodenalis cysts, in three leafy greens (coriander, lettuce, and parsley) commonly consumed raw. Despite the recognition of the association between the parasitic illnesses and the consumption of contaminated food, there is still a lack of studies investigating the occurrence of parasitic contamination in food matrices.

METHODS

A total of 152 leafy green samples were collected in Marrakech from April 2018 to October 2019. Parasites were eluted and concentrated before detection of their DNA by real-time qPCR.

RESULTS

The analysis revealed an overall rate of contamination of 32.2% (49/152), with 29.6% (45/152) positive for T. gondii and 2.6% (4/152) for G. duodenalis, while none was positive for Cryptosporidium spp.

CONCLUSION

The results showed that humans can be exposed to protozoan parasites through vegetables consumption. Further investigations can be performed to acquire new epidemiological data to assess the public health impact of these protozoan diseases in Morocco.

Cryptosporidium and Giardia in Biogas Wastewater: Management of Manure Livestock and Hygiene Aspects Using Influent, Effluent, Sewage Canal Samples, Vegetable, and Soil Samples

Cryptosporidium and Giardia are two water- and foodborne protozoan parasites that can cause diarrheal diseases. Poor microbial quality, sanitation conditions, and hygiene practices at exposure to biogas wastewater are important risk factors for human and animal infection. This study highlights the presence and level of both parasites in the environment in relation to biogas waste reuse in Vietnam. A total of 239 samples were collected from different types of samples in the studied districts in Bac Giang province in 2020 via direct immunofluorescent detection to study the occurrence of Cryptosporidium spp. and Giardia spp. (oo)cysts. Among the samples, Cryptosporidium was found in 19 (7.9%) with concentration from 1.10⁴ to 3.10⁵ oocysts/100 mL, while Giardia in 40 (16.7%) with concentration from 1.10⁴ to 2.10⁶ cysts/100 mL, respectively. In detail, the results show that the percentages of positive detection of Cryptosporidium spp. and Giardia spp. in influent, effluent, sewage canal, and vegetables were 13.1% (11/84), 6.0% (5/83), 15.4% (2/13) and 5.9% (1/17) and 26.2% (22/84), 7.2% (6/83), 7.7% (1/13) and 5.9% (1/17), respectively. The results show a trend of decreasing Cryptosporidium and Giardia densities, without statistical significance. Although these parasites decreased after biogas treatment, the remaining loads observed in biogas effluent can reach the watercourses and soil receiving it. Further investigations are needed to contribute to a general understanding of the risk of protozoan parasites, as well as strategies to control and reduce the contamination of environmental water sources and plants and reduce the burden of the pathogens in biogas wastewater in Vietnam.

Cyst detection and viability assessment of Balantioides coli in environmental samples: Current status and future needs

The ciliate Balantioides coli is a human enteric parasite that can cause life-threatening infections. It is a food- and waterborne parasite, with cysts being the infective stage. Despite its importance as a potential pathogen, few reports have investigated its presence in environmental samples, and some issues need attention including i) The accuracy of B. coli identification. In most cases, the protozoa is identified only by its morphological traits, which can be identical to those from other parasitic ciliates of animals. Genetic analysis of cysts recovered from environmental samples is necessary for species confirmation. In addition, genetic methods used with faecal samples need to be adequately validated with environmental matrices. ii) The methodology for searching this parasite in environmental samples. The protocols include an initial phase to isolate the cysts from the matrix followed by a second phase in which concentration procedures are usually applied. The methods may be valid but are not standardised and differences between studies could affect the results obtained. iii) The areas that needs further research. The development of genetic identification methods and standardised analytical protocols in environmental samples are required, as well as the assessment of viability and infectivity of B. coli cysts. The development of axenic culture systems will boost research on this parasite.

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Balantioides coli is mainly considered a foodborne parasite for humans.

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Detection methods in environmental samples are not standardised.

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Correct identification should be made by genetic analysis.

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Methods for B. coli cyst viability and infectivity assessment are to be developed.

Ocurrence of enteroparasites with zoonotic potential in animals of the rural area of San Andres, Chimborazo, Ecuador

OBJECTIVE

The aim of this research was the identification of the enteroparasites harbored by the animals of the San Andrés community, to evaluate their role as susceptible hosts and sources of infection for other animals, humans (zoonoses), as well as parasite forms spreaders to the environment in this rural area, located in the province of Chimborazo, Ecuadorian Andean region.

MATERIAL AND METHODS

The study was carried out combining 3 coproparasitological techniques: direct examination, Ritchie and Ziehl-Neelsen in 300 animal stool samples RESULTS: Blastocystis sp., Entamoeba spp., Giardia spp., Balantidium spp., Cryptosporidium spp., Ascaris spp., Toxocara spp., Ancylostoma spp., Strongylida, Hymenolepis nana and Echinococcus spp., were detected. Infection by protozoa (87.3%) was higher than helminths (31.0%). All cattle, sheep and guinea pigs were found parasitized, and the presence of Blastocystis sp., Entamoeba spp. and Cryptosporidium spp. by all groups of animals stands out. It is also remarkable the presence of Giardia spp. in swine (19.2%), big herbivores-livestock (11.5%), leporids (8.3%) and carnivores (5.9%); Balantidium spp. in swine (19.2%), big herbivores-livestock (5.8%) and carnivores (1.2%); Hymenolepis nana in guinea pigs (2.1%); and Toxocara spp. (15.7%), Echinococcus spp. (9.6%) and Ancylostoma spp. (6.0%) in dogs.

CONCLUSION

Animals from San Andrés have a wide spectrum of intestinal parasitic forms in their feces, being a source of infection to other animals and humans, and a source of contamination of the environment, posing a risk factor and reinforcing the idea of the need for more effective treatments and hygienic measures to improve livestock production and cutting its transmission.

The prevalence of foodborne parasites in raw vegetables in Iran: a comprehensive systematic review and meta-analysis

Foodborne parasites in raw vegetables could cause parasitic infections in humans. An effective approach to the reduction of pathogenic microorganisms in vegetables involves identifying the main sources of contamination and the ecology of the involved microorganisms. This review aimed to evaluate the prevalence of foodborne parasites in raw vegetables in Iran. According to the reviewed studies, the prevalence rate of Ascaris spp., Giardia spp., Toxocara spp., Fasciola, Trichuris, Cryptosporidium, Dicrocoeliasis, Taenia spp., and Entamoeba histolytica was 6 % (95 % CI: 5-8 %), 6 % (95 % CI: 5-7 %), 6 % (95 % CI: 4-7 %), 2 % (95 % CI: 1-2 %), 1 % (95 % CI: 1-2 %), 10 % (95 % CI: 6-15 %), 2 % (95 % CI: 1-3 %), 5 % (95 % CI: 4-6 %), and 3 % (95 % CI: 2-4 %), respectively. According to the standard deviation map, Ilam province was one of the high-risk areas in terms of food-borne parasites in raw vegetables (3 SD < prevalence < 4 SD). Given the key role of raw vegetables in human parasitic contamination, governments must implement more stringent programs for effective wastewater treatment, preventing domestic and wild animals from entering farms, not using human and animal manure on farms, using ready-to-eat packaged vegetables, food safety training for households, implementation of GMP and HACCP in the factory vegetable packaging are required in this regard, especially in the high-risk areas of Iran, such as Ilam province.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s40201-021-00714-w.

Occurrence of Intestinal Parasites of Public Health Significance in Fresh Horticultural Products Sold in Maputo Markets and Supermarkets, Mozambique

(1) Background: Giardia duodenalis and Cryptosporidium are important neglected parasites associated with diarrhea, such as the emerging Enterocytozoon bieneusi. All three are foodborne parasites raising concerns in public health. This study intended to understand the intestinal parasite occurrence with emphasis on G. duodenalis, Cryptosporidium, and E. bieneusi in fresh fruits/vegetables sold in the main municipal markets of Maputo city, Mozambique. (2) Methods: A total of 321 fresh horticultural products were purchased in the rainy and dry seasons (five markets/two supermarkets/one agricultural zone). Light microscopy (LM) and PCR analysis were performed. (3) Results: By LM and/or PCR, 29.3% of the samples presented at least one parasite (rainy season: 22.9%; dry season: 35.1%). The most contaminated horticultural products: collected in dry season, from Zimpeto and Fajardo markets, lettuce and pointed white cabbage. Overall, 3.7% of G. duodenalis, 1.3% of E. bieneusi, and other intestinal parasites (pathogenic and non-pathogenic) were identified. (4) Conclusions: Important pathogenic intestinal parasites were identified in fruits/vegetables commercially purchased in Maputo City. This fact must be taken into consideration when planning the management of these horticultural markets, in order to reduce the risk of contamination of fresh produce by intestinal parasites, and to prevent foodborne diseases.

Is Fresh Produce in Tigray, Ethiopia a Potential Transmission Vehicle for Cryptosporidium and Giardia?

In rural Ethiopia, where people often share their homes with their livestock, infections of humans and animals with Cryptosporidium and Giardia are relatively common. One possible transmission route is consumption of contaminated fresh produce; this study investigated the occurrence of Cryptosporidium and Giardia in fresh produce in four districts of rural Tigray in Ethiopia. Fresh produce samples (n = 55) were analysed using standard laboratory procedures. Overall, 15% (8/55) of samples were found to be contaminated. Although contamination levels were mostly low, a few samples had high numbers of Giardia cysts (up to around 70 cysts per 30 g sample). Molecular analyses were largely unsuccessful, but Giardia Assemblage A was identified in one sample. Contamination with these parasites was identified in two of the four districts, but, although a similar pattern has already been described for water contamination, this may be at least partially explained by sampling bias. Nevertheless, we speculate that access to clean water sources may be an important factor for reducing the occurrence of these pathogens. Given the public health and veterinary burden associated with both parasites, the factors which are of importance for their circulation in the communities and environments deserve further investigation.

Reactivation of latent infections in solid organ transplant recipients from sub-Saharan Africa: What should be remembered?

International migration from Sub-Saharan African countries to the European Union and the United States has significantly increased over the past decades. Although the vast majority of these immigrants are young and healthy people, a minority can be affected by chronic conditions eventually leading to solid organ transplantation (SOT). Importantly, these candidates can bear geographically restricted fungal and parasitic latent infections that can reactivate after the procedure. An appropriate evaluation before transplantation followed by treatment, whenever necessary, is essential to minimize such risk, as covered in the present review. In short, infection due to helminths (Schistosoma spp. and Strongyloides stercoralis) and intestinal protozoa (Entamoeba histolytica, Giardia lamblia or Cyclospora cayetanensis) can be diagnosed by multiple direct stool examination, serological assays and stool antigen testing. Leishmaniasis can be assessed by means of serology, followed by nucleic acid amplification testing (NAAT) if the former test is positive. Submicroscopic malaria should be ruled out by NAAT. Screening for Histoplasma spp. or Cryptococcus spp. is not routinely indicated. Consultation with an Infectious Diseases specialist is recommended in order to adjust preemptive treatment among Sub-Saharan African SOT candidates and recipients.

Assessment of Parasitic Contamination of Lettuce and Cabbages Sold in Selected Markets in Maputo City, Mozambique

Background

In Mozambique, vegetables are the main source of nutrients and they are consumed raw or cooked. Their consumption, especially in their raw form, might be a source of contamination, which may take place during production and/or transportation as well as in the markets. In this study we aimed to assess the profile and frequency of parasites in lettuces and cabbages sold in some selected markets in Maputo city, the capital of Mozambique.

Methods

A cross sectional study was conducted between February and March 2018, in 10 selected markets from Maputo City. A total of 100 combined samples of lettuces and cabbages were analyzed using a spontaneous sedimentation method. Data such as gender and age of the vendors and about handling of vegetables at the point of sale were also collected.

Results

Out of the samples, 84 (84%) were contaminated with parasites (86% of lettuces and 82% of cabbages). The analyses performed revealed the presence of E. coli (66%), S. stercoralis (40%), E. histolytica (20%), A. duodenalis (6%), S. haematobium (4%), A. lumbricoides (2%), S. mansoni (2%) and T. trichiura (1%). Two markets, Janete and Fajardo showed contamination in all samples. A Chi square analysis revealed a significant association between the contaminated cabbages and the market where they were obtained. The majority of vendors (57%) do not wash their hands before handling vegetables. Most of the vendors had tables to place vegetables (72%) and those tables are cleaned before display (86%). None of the differences observed in each risk factor studied were statistically significant.

Conclusion

The present study highlights that contamination of raw vegetables with pathogenic parasites in markets might represent a vector for transmission of intestinal and water- borne parasites to consumers. Future studies should investigate the extent of vegetable contamination at each stage of the supply chain from the farm to consumers, as well as its relationship to human parasitic infection and its consequences. Good hygienic practices of farmers, vendors and consumers should be enforced to break the contamination chain. Whenever possible, hydroponic cultivation should be encouraged to avoid the influence of highly contaminated soils.

Detection of Cyclospora cayetanensis on bagged pre-cut salad mixes within their shelf-life and after sell by date by the U.S. food and drug administration validated method

Recently, outbreaks of Cyclospora cayetanensis in the U.S. were linked to the consumption of a variety of salads containing romaine and/or iceberg lettuce, carrots and/or red cabbage. The Bacteriological Analytical Manual (BAM) Chapter 19b method was validated for the detection of C. cayetanensis in carrots, cabbage and romaine lettuce, but has not been previously evaluated in ready-to-eat (RTE) salad mixes. In addition, the only samples available for traceback investigations are sometimes leftovers in bad conditions. This study evaluated the validated BAM method for detection of C. cayetanensis in two different RTE mixed salads (mix 1: romaine and iceberg lettuces, carrots, and red cabbage and mix 2: romaine and iceberg lettuces, carrots, red cabbage, radish, and pea pods) in good condition and after their sell by date. Individual samples (25 g) were seeded with five and 200 C. cayetanensis oocysts. Unseeded produce was used as negative control. The method included washing of the produce, concentration and extraction of C. cayetanensis DNA and molecular detection of C. cayetanensis 18 S rRNA gene. As few as five oocysts were detected in both fresh and after sell by date mix salads. All unseeded samples were negative, and all samples of both salad types seeded with 200 oocysts were positive. In samples seeded with 200 oocysts, average 18 S rRNA C. cayetanensis C_T values were significantly higher in fresh salad mix 1 compared to fresh salad mix 2; C_T values were significantly higher in the after sell by date salads compared to their respective fresh mixes (p < 0.05). In conclusion, the BAM method was able to detect as few as five oocysts even in after sell by date RTE mix salads. However, the differences in detection observed, highlight the importance of evaluating the performance of the validated C. cayetanensis detection method in different food matrices and conditions, in advance for future outbreak investigations.

Prevalence of Cryptosporidium and Giardia in vegetables in Iran: a nineteen-years meta-analysis review

Cryptosporidium and Giardia are two major protozoa reported from vegetables and environment. The prevalence of these parasites supposes to be different regarding the climate zones. This review aimed to evaluate the prevalence of Cryptosporidium and Giardia in vegetables according to the major climate zones in Iran. The results showed pooled prevalence 7% (95% CI: 2%, 14%) and 4% (95% CI: 3%, 6%) for Cryptosporidium spp., and Giardia spp., respectively. The prevalence of Giardia spp. in mountain, desert and semi-desert, and Mediterranean regions was 4% (95% CI: 2%, 6%), 5% (95% CI: 3%, 8%) and 7% (95% CI: 1%, 18%), respectively. Cryptosporidium spp. was reported 8% (95% CI: 0%, 65%), 6% (95% CI: 0%, 18%) and 4% (95% CI: 0%, 77%) from mountain, desert and semi-desert, and Mediterranean climate zones, respectively. This review suggests the higher prevalence of Giardia and Cryptosporidium in Mediterranean and mountain regions, respectively.

Cryptosporidium spp., Giardia duodenalis and Toxoplasma gondii detection in fresh vegetables consumed in Marrakech, Morocco

BACKGROUND

Protozoan parasites such as Toxoplasma gondii, Giardia duodenalis, and Cryptosporidium spp., can be transmitted to humans via accidental consumption of contaminated water, fresh produce and foodstuffs. There is a lack of epidemiological data about these pathogens in Morocco. Hence the aim of this study, which is the determination of their prevalence in some leafy greens and root vegetables sold in Marrakech.

METHODS

A total of 132 vegetable samples including carrot, coriander, lettuce, parsley and radish were purchased monthly from three different markets in Marrakech from March 2017 to January 2018, pre-treated and subjected to microscopic and molecular analyses.

RESULTS

Of the 132 samples of vegetables analyzed by qPCR, the overall rate of protozoan was 21.21% (28/132); 22 samples were found to be contaminated with T. gondii, 6 with G. duodenalis, and none was positive for C. parvum/hominis. Whereas, modified Ziehl-Neelsen staining allowed the detection of Cryptosporidium spp. in 3% (4/132) of examined samples.

CONCLUSION

This survey on the presence of protozoan parasites in fresh vegetables revealed that vegetables sold in Marrakech are contaminated by these protozoan parasites, as it showed that leafy green vegetables were more susceptible for parasitic contamination than root ones.

A smartphone microscopic method for simultaneous detection of (oo)cysts of Cryptosporidium and Giardia

Background

Food and water-borne illness caused by ingestion of (oo)cysts of Cryptosporidium and Giardia is one of the major health problems globally. Several methods are available to detect Giardia cyst and Cryptosporidium oocyst in food and water. Most of the available methods require a good laboratory facility and well-trained manpower and are therefore costly. There is a need of affordable and reliable method that can be easily implemented in resource limited settings.

Methodology/Principle findings

We developed a smartphone based microscopic assay method to screen (oo)cysts of Cryptosporidium and Giardia contamination of vegetable and water samples. The method consisting of a ball lens of 1 mm diameter, white LED as illumination source and Lugols's iodine staining provided magnification and contrast capable of distinguishing (oo)cysts of Cryptosporidium and Giardia. The analytical performance of the method was tested by spike recovery experiments. The spike recovery experiments performed on cabbage, carrot, cucumber, radish, tomatoes, and water resulted in 26.8±10.3, 40.1±8.5, 44.4±7.3, 47.6±11.3, 49.2 ±10.9, and 30.2±7.9% recovery for Cryptosporidium, respectively and 10.2±4.0, 14.1±7.3, 24.2±12.1, 23.2±13.7, 17.1±13.9, and 37.6±2.4% recovery for Giardia, respectively. The spike recovery results are comparable with data obtained using commercial brightfield and fluorescence microscope methods. Finally, we tested the smartphone microscope system for detecting (oo)cysts on 7 types of vegetable (n = 196) and river water (n = 18) samples. Forty-two percent vegetable and thirty-nine percent water samples were found to be contaminated with Cryptosporidium oocyst. Similarly, thirty-one percent vegetable and thirty-three percent water samples were contaminated with Giardia cyst.

Conclusions

The newly developed smartphone microscopic method showed comparable performance to commercial microscopic methods. The new method can be a low-cost and easy to implement alternative method for simultaneous detection of (oo)cysts in vegetable and water samples in resource limited settings.

Food and water-borne illness arising from the consumption of contaminated food and water are serious health hazards globally. Cryptosporidium and Giardia are the major food and water‒borne parasites. The infection occurs mainly by (oo)cyst phase of the parasites. People in developing countries are more vulnerable to these parasites where infection is more likely underdiagnosed and underreported due to limited resources for detection. There is need of a method that is affordable and easy to implement. In this study, we developed and optimized a novel smartphone microscope method that can detect and quantify the (oo)cyst of the parasites in food and water samples. The developed method is easy to implement and affordable and provides similar performance to the other commercially available microscopic methods.

Detection of human intestinal protozoan parasites in vegetables and fruits: a review

Diarrheal diseases caused by intestinal protozoan parasites are a major food-borne public health problem across the world. Vegetables and fruits provide important nutrients and minerals, but are also common sources of some food-borne human pathogenic microorganisms. The contamination of raw vegetables and fruits with human pathogenic parasites are now a global public health threat, despite the health benefits of these foods in non-pharmacological prophylaxes against diseases. A large number of reports have documented the contamination of vegetables or fruits with human pathogenic microorganisms. In this paper, we reviewed the contamination and detection methods of human pathogenic intestinal protozoans that are frequently recovered from raw vegetables and fruits. The protozoan parasites include Cryptosporidium spp., Giardia duodenalis, Cyclospora cayetanensis, Entamoeba spp., Toxoplasma gondii, Balantioides coli, Blastocystis sp., Cystoisospora belli and Enterocytozoon bieneusi. The risk factors involved in the contamination of vegetables and fruits with parasites are also assessed.

Parasitic Contamination of Fruits and Vegetables Collected from Local Markets of Bahir Dar City, Northwest Ethiopia

Background

Fruits and vegetables, which are consumed raw, act as potential sources for the spread of various parasitic diseases. The rate of contamination and species of contaminant parasites varies based on climatic, ecological, and human factors. Therefore, local data about the contamination status and predisposing factors augments efforts for successful control of parasitic diseases.

Methods

A cross-sectional study was conducted on fruits and vegetables collected from local markets of Bahir Dar city from February to May 2019. A total of 384 samples were purchased from three randomly selected markets. Data on sociodemographic characteristics of vendors and factors associated with contamination of fruits and vegetables were collected using a structured questionnaire. About 200 g of fruit and vegetable samples were processed for parasites using direct wet mount and modified Zeihl–Neelson staining techniques following standard protocols. All data were analyzed using SPSS version 23.

Results

Among a total of 384 fruit and vegetable samples purchased from 112 vendors, 150 (39.1%) were contaminated with at least one species of parasite. Lettuce (56.4%) and mango (16.7%) were the most and the least commonly contaminated items respectively. Larva of Strongyloides species (13.5%) was the most frequently detected parasite followed by cysts of Entamoeba histolytica/E. dispar (12.8%). Contamination was more common in vegetables than fruits (AOR=2.968, p<0.001). Fruits and vegetables purchased from vendors with untrimmed fingernails (AOR=1.966, p=0.006), directly delivered from farmers (AOR=1.883, p=0.040), displayed in bucket with water (AOR=2.676, p=0.017) and those displayed without washing (AOR=5.511, p<0.001) were significantly associated with parasitic contamination.

Conclusion

The level of parasitic contamination of fruits and vegetables in Bahir Dar city is of public health importance. Hence, the public health sector should create public awareness in order to reduce parasitic transmission via fruits and vegetables.

Detection methods and prevalence of transmission stages of Toxoplasma gondii, Giardia duodenalis and Cryptosporidium spp. in fresh vegetables: a review

One of the ways of human parasitic infection is the accidental ingestion of vegetables contaminated with parasites, which represents a major human health hazard. This non-exhaustive review aims to evaluate studies carried out on five types of vegetables (lettuce, parsley, coriander, carrot and radish) since 2000, particularly the methods used for recovery, concentration, detection and identification of protozoan parasites such as Toxoplasma gondii, Giardia duodenalis and Cryptosporidium spp., and the results of each work. Various studies have determined the presence of pathogenic parasites in fresh vegetables with different rates; this variation in rate depends particularly on the detection method used which is related to each parasite and each vegetable type. The variation in parasitic prevalence in food could be due to different factors such as the geographical location, the size of analysed samples and the methods used for parasite detection.