A Systematic Review of Zoonotic Enteric Parasites Carried by Flies, Cockroaches, and Dung Beetles

Filth flies, cockroaches, and dung beetles have been close neighbors with humans and animals throughout our joint histories. However, these insects can also serve as vectors for many zoonotic enteric parasites (ZEPs). Zoonoses by ZEPs remain a paramount public health threat due to our close contact with animals, combined with poor water, sanitation, and hygiene access, services, and behaviors in many global regions. Our objective in this systematic review was to determine which ZEPs have been documented in these vectors, to identify risk factors associated with their transmission, and to provide effectual One Health recommendations for curbing their spread. Using PRISMA guidelines, a total of 85 articles published from 1926 to 2021 were reviewed and included in this study. Qualitative analysis revealed that the most common parasites associated with these insects included, but were not limited to: Ascaris spp., Trichuris spp., Entamoeba spp., and Cryptosporidium spp. Additionally, prominent risk factors discovered in the review, such as poor household and community WASH services, unsafe food handling, and exposure to domestic animals and wildlife, significantly increase parasitic transmission and zoonoses. The risk of insect vector transmission in our shared environments makes it critically important to implement a One Health approach in reducing ZEP transmission.

Prevalence of Intestinal Parasite Infections in Stray Dogs in Taif Region, KSA

Background: The study of intestinal parasites that occur in stray dogs in the Taif region, KSA, is most important since there is little data available on this subject. Methods: Dog fecal samples were collected from 129 dogs in three different areas. Fecal samples were processed and analyzed by different mount techniques including, parasitological examination, wet-mount preparation and modified Kinyoun’s acid-fast technique. Result: The total prevalence of enteric parasites was 115 positive cases; for helminths was (62.7%) and for protozoa (26.3%). Mixed infection was higher than single infection in three areas. The total prevalence of helminths eggs by different mount preparation recovered from fecal sample examination from single or mixed form E. granulosus, T. canis and T. vulpis was of high infection rate (15.5%), (10.07%), (10.07%), followed by A. lumbercoides (7.7 %). Finally, T. leonine (6.9%), both A. caninum and A. braziliense are of the same percentage (6.2%). Concerning single and mixed protozoa infection, Giardia was of a high prevalence (16.2%), followed by Cryptosporidium (8.5%) and finally E. histolytica (1.5%) in fecal samples of doges. These data revealed that infection levels of parasites in stray dogs in the studied areas were high, knowing that this is the first study for mixed infections between dogs and humans in KSA.

Zoonotic enteric parasites in Mongolian people, animals, and the environment: Using One Health to address shared pathogens

Background Cryptosporidium spp. and Giardia duodenalis are important zoonotic enteric pathogens of One Health concern for humans, animals, and the environment. For this study, we investigated parasite prevalence and risk factors among rural, peri-urban, and urban households and environments of Mongolia. Methods This cross-sectional study implemented a household risk factor survey at 250 home sites along with sample collection from humans, animals, flies, and drinking water. Multiplex real-time PCR analysis was conducted to look for Cryptosporidium spp. and/or Giardia duodenalis within household samples. Results Lab analysis found one or both zoonotic parasites at 20% of the participating households (51/250). Human samples had a parasite prevalence of 6.4% (27/419), domestic animals at 3.3% (19/570), pooled filth flies at 14.8% (17/115), and drinking water samples at 2% (5/250). Parasite presence at the household was significantly associated with a household’s use of an improved drinking water source (OR 0.27; CI 0.12–0.61; p = < 0.01), having an indoor handwashing site (OR 0.41; CI 0.19–0.92; p = 0.03), domestic animal ownership (OR 2.40; CI 1.02–5.65; p = 0.05), and rural location (OR 0.50; CI 0.25–0.98; p = 0.04). Household use of an improved drinking water source remained significant in the multivariate model (OR 0.16; CI 0.04–0.68; p = 0.01). Conclusion In Mongolia, public and veterinary health are intertwined, particularly for rural herding households. Increased access to safe water, sanitation and hygiene infrastructure could help prevent further transmission of zoonotic enteric parasites. Public health interventions, policy and messaging should utilize a One Health framework employing joint leadership from local human and animal health sectors.

Enteric parasites and socio-epidemiological variables in an academic community

Studies linking human health to environmental conditions are essential since parasitic diseases are connected to environmental and sanitary aspects. This study identified the prevalence of enteric parasites in an academic community in the municipality of Santo Antônio de Jesus, Bahia, Brazil. The purpose was to determine the existence, or not, of links between infections and socio-epidemiological variables, such as personal hygiene habits, the presence of sewage systems and the environment. Participants answered a questionnaire and received universal collectors for fecal samples. Spontaneous sedimentation methods and Rugai were used for diagnosis. One hundred twenty-one samples were analyzed, in which a 38.8% parasite prevalence was detected as well as a 61.7% rate of monoparasitism, as well as a predominance of protozoa Endolimax nana (78.7%) and Giardia duodenalis (21.3%). Among parasitized individuals, 97.9% lived in the Recôncavo Baiano region. The following statistical significance stands out in the findings, with p<0.05: individuals who had already bathed in the local river were more likely to be parasitized than those who had not (p = 0.034) and individuals who washed their hands more frequently before meals proved to be less prone to intestinal parasitic infections (p = 0.018). Results evidenced the presence of enteric parasites in a number of participants in spite of their being university students. The socio-epidemiological variables analyzed brought to light characteristics that favor the establishment of the epidemiological infection triad, such as improper packaging of household waste on disposal and no records of regular domestic water tank cleaning. KEY WORDS: Enteric parasites; environment; diagnosis; health education.

Use of Oxford Nanopore MinION to generate full-length sequences of the Blastocystis small subunit (SSU) rRNA gene

Background Blastocystis sp. is one of the most common enteric parasites of humans and animals worldwide. It is well recognized that this ubiquitous protist displays a remarkable degree of genetic diversity in the SSU rRNA gene, which is currently the main gene used for defining Blastocystis subtypes. Yet, full-length reference sequences of this gene are available for only 16 subtypes of Blastocystis in part because of the technical difficulties associated with obtaining these sequences from complex samples. Methods We have developed a method using Oxford Nanopore MinION long-read sequencing and universal eukaryotic primers to produce full-length (> 1800 bp) SSU rRNA gene sequences for Blastocystis. Seven Blastocystis specimens representing five subtypes (ST1, ST4, ST10, ST11, and ST14) obtained both from cultures and feces were used for validation. Results We demonstrate that this method can be used to produce highly accurate full-length sequences from both cultured and fecal DNA isolates. Full-length sequences were successfully obtained from all five subtypes including ST11 for which no full-length reference sequence currently exists and for an isolate that contained mixed ST10/ST14. Conclusions The suitability of the use of MinION long-read sequencing technology to successfully generate full-length Blastocystis SSU rRNA gene sequences was demonstrated. The ability to produce full-length SSU rRNA gene sequences is key in understanding the role of genetic diversity in important aspects of Blastocystis biology such as transmission, host specificity, and pathogenicity.

Natural Infection with Giardia Is Associated with Altered Community Structure of the Human and Canine Gut Microbiome

ABSTRACT Enteric parasitic infections are among the most prevalent infections in lower- and middle-income countries (LMICs) and have a profound impact on global public health. While the microbiome is increasingly recognized as a key determinant of gut health and human development, the impact of naturally acquired parasite infections on microbial community structure in the gut, and the extent to which parasite-induced changes in the microbiome may contribute to gastrointestinal symptoms, is poorly understood. Enteric parasites are routinely identified in companion animals in the United States, presenting a unique opportunity to leverage this animal model to investigate the impact of naturally acquired parasite infections on the microbiome. Clinical, parasitological, and microbiome profiling of a cohort of 258 dogs revealed a significant correlation between parasite infection and composition of the bacterial community in the gut. Relative to other enteric parasites, Giardia was associated with a more pronounced perturbation of the microbiome. To compare our findings to large-scale epidemiological studies of enteric diseases in humans, a database mining approach was employed to integrate clinical and microbiome data. Substantial and consistent alterations to microbiome structure were observed in Giardia-infected children. Importantly, infection was associated with a reduction in the relative abundance of potential pathobionts, including Gammaproteobacteria, and an increase in Prevotella—a profile often associated with gut health. Taken together, these data show that widespread Giardia infection in young animals and humans is associated with significant remodeling of the gut microbiome and provide a possible explanation for the high prevalence of asymptomatic Giardia infections observed across host species. IMPORTANCE While enteric parasitic infections are among the most important infections in lower- and middle-income countries, their impact on gut microbiota is poorly understood. We reasoned that clinical symptoms associated with these infections may be influenced by alterations of the microbiome that occur during infection. To explore this notion, we took a two-pronged approach. First, we studied a cohort of dogs naturally infected with various enteric parasites and found a strong association between parasite infection and altered gut microbiota composition. Giardia, one of the most prevalent parasite infections globally, had a particularly large impact on the microbiome. Second, we took a database-driven strategy to integrate microbiome data with clinical data from large human field studies and found that Giardia infection is also associated with marked alteration of the gut microbiome of children, suggesting a possible explanation for why Giardia has been reported to be associated with protection from moderate to severe diarrhea.

Novel Antiparasitic Activity of the Antifungal Lead Occidiofungin

ABSTRACT Novel antiparasitic activity was observed for the antifungal occidiofungin. It efficaciously and irreversibly inhibited the zoonotic enteric parasite Cryptosporidium parvum in vitro with limited cytotoxicity (50% effective concentration [EC50] = 120 nM versus 50% cytotoxic concentration [TC50] = 988 nM), and its application disrupted the parasite morphology. This study expands the spectrum of activity of a glycolipopeptide named occidiofungin. Occidiofungin has poor gastrointestinal tract absorption properties, supporting future investigations into its potential activities on other enteric parasites.