Contribution of socio-demographic factors in prevalence of soil-transmitted helminth infections among newly arrived laborers in Jeddah, Saudi Arabia.

Background: Soil-transmitted diseases are caused by intestinal worms transmitted via various routes into the human body resulting in various clinical manifestations. This study aimed to investigate the socio-demographic factors contributing mainly to the prevalence of soil-transmitted helminths (STHs) among newly arrived laborers in Jeddah, Saudi Arabia. Methods: A total of 188 stool specimens were collected and examined macroscopically and microscopically using different techniques. In addition, real-time PCR was used as a molecular tool to detect several STHs. The descriptive analysis was used to evaluate demographic data and categorical variables in association with STHs infection. Results: Of all participants, the mean age was 26.08 ± 2.67 years, including 103 females and 85 males. A total of 86 (45.70%) were illiterate, followed by 60 (31.90%) of participants belonging to elementary level. STHs and other intestinal parasites were detected among 35 newly arrived laborers (18.61%). Nineteen cases (10.11%) were infected with STHs, including 15 cases with one STHs (four A. lumbricoides, four N. americanus, four T. trichiura, two S. stercoralis, one A. duodenale) and four cases with two STHs (two T. trichiura and N. americanus; one S. stercoralis and A. duodenale; one T. trichiura and S. stercoralis). High rates of STHs infection were detected among drivers (11.70%) followed by housemaids (11.20%), but with no significant association to occupation. Higher rates of STHs infection were detected among those used to walk on soil barefoot in their home countries before arriving in Jeddah. Conclusion: This study found that none of the newly arrived expatriate laborers in Jeddah was aware of STHs. About 10% of them had infection with one or two STHs, mainly among newly arrived laborers from Asian countries. There is a need for awareness programs and regular screening for STHs and other intestinal parasites among newly arrived expatriate laborers.

Unveiling the Transmission Potential of Opisthorchis viverrini and Intestinal Helminths Along the Thailand-Laos Border in Thailand.

AIMS: In pursuit of enhancing prevention efforts for the notably high endemic Opisthorchis viverrini infection in lower Mekong sub-region countries, particularly Thailand and Laos, this cross-sectional study investigated the transmission potential of O. viverrini and other intestinal helminths along the Thailand-Laos border in seven Thai villages. METHODS AND RESULTS: Human and pet faecal samples, Bithynia snails and cyprinid fish were analysed for helminth infections. Additionally, a questionnaire survey assessed relevant risk factors among the human population. Two groups of helminth infections were detected in humans: foodborne infections (FBIs) including O. viverrini, minute intestinal flukes (MIFs), and Taenia spp., and soil-transmitted infections (STIs) including hookworm and Strongyloides stercoralis, with prevalence rates of 7.4%, 0.5%, 2.5%, 0.5%, 2.5% and 3%, respectively. Smoking was identified as a risk factor for O. viverrini infection [adjusted odds ratios (ORa) = 3.12, 95% confidence intervals (CI): 1.33-7.30, p = 0.009] and FBIs (ORa = 2.47, 95% CI: 1.14-5.33, p = 0.022), while male was a risk factor for FBIs (ORa = 2.62, 95% CI: 1.16-5.94, p = 0.021). In dogs, hookworm, Toxocara spp., Spirometra mansoni, Trichuris vulpis and Hymenolepis diminuta were identified with prevalence rates of 35.6%, 8.1%, 8.1%, 1.2% and 1.2%, respectively. In cats, hookworm, Toxocara spp., S. mansoni, Strongyloides spp., Platynosomum fastosum, MIFs and H. diminuta were identified with prevalence rates of 50%, 17.9%, 10.7%, 7.1%, 3.6%, 3.6% and 3.6%, respectively. Bithynia snails showed 2% virgulate and 0.7% unknown cercariae infections, while among 19 cyprinid fish species, only unknown metacercariae were found. CONCLUSIONS: Our findings underscore the necessity of an integrated approach following the One Health concept to effectively combat these parasitic diseases while addressing human, animal and environmental health.

Soil-Transmitted Helminth Infections in Shanghai, China: Surveillance from 2014 to 2023.

Soil-transmitted helminthiasis remains a notable health problem in developing countries. In 1990 in Shanghai, a city in eastern China, 47% of the population was affected. Due to a series of comprehensive approaches, the prevalence decreased to 0.5% in 2009. We collected 10-year surveillance data to assess the epidemic situation of soil-transmitted helminth (STH) infections in Shanghai. Stool samples and questionnaires from participants were collected. The Kato-Katz technique was used to detect infections with Ascaris lumbricoides, hookworm (Ancylostoma duodenale and Necator americanus), and Trichuris trichiura. From 2014 to 2023, a total of 77,685 participants were screened for parasitic infections, and the overall prevalence of STH infections decreased from 0.1% to 0% in Shanghai. Of 77,685 participants, 25 (0.03%) were positive for intestinal helminths, with the most common parasite being A. lumbricoides (72.0%). Generally, elderly participants from rural areas with lower education levels were more likely to be infected with STHs. A total of 2,914 questionnaires were collected, and most respondents (72.6%) had good knowledge about the transmission routes of STHs. However, 12.3% of participants did not know the damage to health caused by STHs, and 19.3% had no idea of how to prevent infection. These data demonstrate the current state of STH infections in Shanghai. The results suggest that various comprehensive measures should be encouraged, continuously implemented, and strengthened accordingly so that STH elimination can be integrated into the Healthy China initiative by 2030.

Molecular detection of intestinal parasites in a rural community of Colombia: A one health approach to explore potential environmental-zoonotic transmission.

AIMS: Protozoan and helminth parasitic infections pose significant public health challenges, especially in developing countries with rural populations marked by suboptimal hygiene practices and socio-economic constraints. The parasites are the etiological agents of these infections and have a notably elevated global prevalence. Therefore, this study focuses on estimating the frequency and transmission dynamics of several parasitic species, including Blastocystis, Giardia, Cryptosporidium spp., Entamoeba histolytica, Ascaris lumbricoides, Trichuris trichiura, Taenia spp. and hookworms, within a rural community in southwest Colombia with a particular emphasis on the One Health framework, considering environmental and zoonotic transmission potentials. METHODS AND RESULTS: This study involved the analysis of 125 samples, encompassing human participants (n = 99), their domestic pets (dogs) (n = 24) and water sources (n = 2). Parasite detection was carried out utilizing a combination of microscopy and molecular techniques. Furthermore, the characterization of Blastocystis subtypes (STs) was achieved through Oxford Nanopore sequencing of the rRNA-18S gene. The investigation also entailed the examination of potential associations between intestinal parasitism and various sociodemographic factors. Results revealed a high frequency of parasitic infections when employing molecular methods, with Blastocystis (n = 109/87%), Giardia (n = 20/16%), Ancylostoma duodenale (n = 28/22%), Ancylostoma ceylanicum (n = 7/5.6%), E. histolytica (n = 6/4.8%), Cryptosporidium spp. (n = 12/9.6%) and even Taenia (n = 1/0.8%) detected. Cryptosporidium spp. was also identified in water samples. Coinfections were prevalent, with 57% (n = 70) of samples exhibiting single-parasite infections and 43% (n = 53) showing various degrees of polyparasitism, emphasizing the complexity of transmission dynamics. Blastocystis subtyping, conducted via Oxford Nanopore sequencing, revealed a diversity of subtypes and coexistence patterns, with ST2 being the most prevalent. CONCLUSIONS: This research underscores the importance of using molecular techniques for frequency estimation, particularly emphasizing the relevance of zoonotic transmission in parasitic infections. It highlights the significance of the One Health approach in comprehending the circulation of parasites among animals, humans and environmental sources, thereby directly impacting public health and epidemiological surveillance.

Host feces, olfactory beacon guiding aggregation of intestinal parasites Gasterophilus pecorum (Diptera: Gasterophilidae).

The aim of this study was to identify the aggregation sites and transmission characteristics of Gasterophilus pecorum, the dominant pathogen of endangered equines in desert steppe. Therefore, we tested with a four-arm olfactometer the olfactory response of the G. pecorum adults to the odors that have a great impact on their life cycle, and also investigated the occurrence sites of the adults in the area where the Przewalski's horse (Equus przewalskii) roam frequently during the peak period of G. pecorum infection. The results of four-directional olfactory test showed that the fresh horse feces had a stronger attraction rate on both male (50.4%) and female flies (38.2%). Stipa caucasica, the only oviposition plant where G. pecorum lay eggs, had a better attraction effect on females than that on males. And the attraction rates of S. caucasica to G. pecorum females in the early growth stage (Stipa I) and mid-growth stage (Stipa II) were 32.8% and 36.8%, respectively. In addition, the two-directional olfactory test showed that the attraction rate of males to fresh horse feces (68.90%) was higher than that to Stipa II (31.10%), and females also showed similar olfactory responses. Moreover, in our field investigation, 68.29% of G. pecorum adults were collected from around the horse feces. The results of laboratory test and field investigation implied that the location mechanism of G. pecorum aggregation for mating is related to the orientation of horse feces. The horse feces and the vicinity are the key contamination areas of G. pecorum, and it is also the areas where horses are seriously infected with G. pecorum. Those fresh feces, which gather abundant information about the host, naturally had the greatest chance of contacting with the host; G. pecorum adults create the opportunity to enter directly into the host's mouth and infect the host by laying eggs on S. caucasica, which is the most favorite plant of the host in this area. These characteristics are one of the main reasons why G. pecorum has become the dominant species under the condition of sparse vegetation in desert steppe.

Reproductive females and young mouflon (Ovis gmelini musimon × Ovis sp.) in poor body condition are the main spreaders of gastrointestinal parasites.

Several individual, environmental and parasitic factors can influence the impacts of parasites on host's fitness and on host's ability to transmit these parasites to new hosts. Identifying these factors and the individuals who play a greater role in parasite transmission is of main concern for the development of parasite control strategies. In the present study, we aimed to describe the diversity of gastrointestinal parasites and to identify the individual factors influencing the faecal spreading of parasites in a free-ranging population of Mediterranean mouflon. From the analysis of 433 faecal samples, we found Eimeria spp. and gastrointestinal strongyles (GIS) were the most common parasites (>94%). The faecal oocyst counts of Eimeria spp. were the highest during the first years of life. It was 1.6 times higher in females than in males and 2.5 times higher in individuals in poor than in good body condition. Similarly, the faecal egg count of GIS was higher in females and decreased with age, but only in males. Finally, reproductive females had GIS faecal egg count values 2.6 times higher than non-reproductive females. Management strategies of parasites should thus primarily focus on reproductive females and young individuals in poor body condition as they represent the main contamination source of the environment.

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.

Environmental Contamination by Dog Feces in Touristic Areas of Italy: Parasitological Aspects and Zoonotic Hazards.

Public spaces are common sites of fecal contamination which is concerning considering the prevalence rates of gastrointestinal pathogens carried by pets. Multiple pet-bound parasite species capable of infecting humans have previously been reported in fecal samples collected from urban areas around the globe, including Italy. In addition, the presence of gastrointestinal parasites has recently been shown in pets from the island of Sardinia, a well-known touristic destination. For these reasons, this study aims to evaluate the level of fecal contamination of two of the most important cities on Sardinia. Furthermore, the presence of endoparasites in fecal samples collected was also investigated to assess the parasitological risks associated with such contamination. A grid approach using a geographical information system was applied, followed by transect counting and sampling. A total of 956 and 220 dog feces with an average feces count of 4.7 and 2.6 per 100 linear meters were found for Sassari and Alghero, respectively. In Sassari 15.6% (52/333) and in Alghero 6.8% (6/88) of the samples tested positive for parasitic elements. Hookworms, Strongyloides stercoralis, Toxocara sp., and Trichuris vulpis were among the parasites most identified. This study showed significant urban contamination of both Sassari and Alghero with dog feces and the parasites within them, including potentially zoonotic species. The general public as well as tourists visiting the island should be aware of the risks associated with this and appropriate measures taken.

Prevalence and Associated Factors of Soil-Transmitted Helminth Infections among Children Living with and without Open Defecation Practices in Northwest Ethiopia: A Comparative Cross-Sectional Study.

Soil-transmitted helminth (STH) infections cause devastating effect in human health. School-age children (SAC) account for the highest prevalence of STH infections in sub-Sahara. Open defecation practicing might be the major contributing factor, and creating an open defecation-free (ODF) declared community is also a big challenge. This study aimed to assess the prevalence of STH infections and associated factors among SAC in ODF declared and open defecation-practicing kebeles. A comparative cross-sectional study was conducted among 806 SAC from January 2019 to April 2019. Questionnaire-based data were collected using a structured questionnaire. Stool samples were collected and processed via the Kato-Katz technique. Prevalence and associated factors were computed with descriptive statistics and regression, respectively. Variables with a P-value < 0.05 were considered as significantly associated. This study revealed that the prevalence of STH infections in open defecation-practicing and ODF declared kebeles were 39.0% and 30.0%, respectively. Wearing open shoes, wearing shoes sometimes, and playing with soil were significantly associated (P < 0.01) with STH infections in ODF declared kebeles. Similarly, wearing shoes sometimes, not using latrine, and playing with soil were also significantly associated (P < 0.01) with STH infections in open defection-practicing kebeles. In conclusion, lower prevalence of STH infections was recorded in ODF declared than in open defection-practicing kebeles. Wearing shoes sometimes, playing with soil, and not using latrine were associated with STH infections. Therefore, creating an ODF environment and community awareness should be strengthened.

Zoonotic transmission of intestinal helminths in southeast Asia: Implications for control and elimination.

Intestinal helminths are extremely widespread and highly prevalent infections of humans, particularly in rural and poor urban areas of low and middle-income countries. These parasites have chronic and often insidious effects on human health and child development including abdominal problems, anaemia, stunting and wasting. Certain animals play a fundamental role in the transmission of many intestinal helminths to humans. However, the contribution of zoonotic transmission to the overall burden of human intestinal helminth infection and the relative importance of different animal reservoirs remains incomplete. Moreover, control programmes and transmission models for intestinal helminths often do not consider the role of zoonotic reservoirs of infection. Such reservoirs will become increasingly important as control is scaled up and there is a move towards interruption and even elimination of parasite transmission. With a focus on southeast Asia, and the Philippines in particular, this review summarises the major zoonotic intestinal helminths, risk factors for infection and highlights knowledge gaps related to their epidemiology and transmission. Various methodologies are discussed, including parasite genomics, mathematical modelling and socio-economic analysis, that could be employed to improve understanding of intestinal helminth spread, reservoir attribution and the burden associated with infection, as well as assess effectiveness of interventions. For sustainable control and ultimately elimination of intestinal helminths, there is a need to move beyond scheduled mass deworming and to consider animal and environmental reservoirs. A One Health approach to control of intestinal helminths is proposed, integrating interventions targeting humans, animals and the environment, including improved access to water, hygiene and sanitation. This will require coordination and collaboration across different sectors to achieve best health outcomes for all.

Detection of enteric parasite DNA in household and bed dust samples: potential for infection transmission.

BACKGROUND: Enteric parasites are transmitted in households but few studies have sampled inside households for parasites and none have used sensitive molecular methods. METHODS: We collected bed and living room dust samples from households of children participating in a clinical trial of anthelmintic treatment in rural coastal Ecuador. Dust was examined for presence of DNA specific for 11 enteric parasites (Ascaris lumbricoides, Trichuris trichiura, Ancylostoma duodenale, Necator americanus, Strongyloides stercoralis, Toxocara canis and T. cati, Giardia lamblia, Blastocystis hominis, Cryptosporidium spp., and Entamoeba histolytica) by quantitative PCR (qPCR). RESULTS: Of the 38 households sampled, 37 had positive dust for at least one parasite and up to 8 parasites were detected in single samples. Positivity was greatest for B. hominis (79% of household samples) indicating a high level of environmental fecal contamination. Dust positivity rates for individual pathogens were: S. stercoralis (52%), A. lumbricoides (39%), G. lamblia (39%), Toxocara spp. (42%), hookworm (18%) and T. trichiura (8%). DNA for Cryptosporidium spp. and E. histolytica was not detected. Bed dust was more frequently positive than floor samples for all parasites detected. Positivity for A. lumbricoides DNA in bed (adjusted OR: 10.0, 95% CI: 2.0-50.1) but not floor dust (adjusted OR: 3.6, 95% CI: 0.3-37.9) was significantly associated with active infections in children. CONCLUSIONS: To our knowledge, this is the first use of qPCR on environmental samples to detect a wide range of enteric pathogen DNA. Our results indicate widespread contamination of households with parasite DNA and raise the possibility that beds, under conditions of overcrowding in a humid tropical setting, may be a source of transmission.

Genetic diversity of Blastocystis in kindergarten children in southern Xinjiang, China.

BACKGROUND: Blastocystis is one of the most common intestinal parasites in humans and various animals worldwide. Few studies are available regarding the genetic characterization of Blastocystis infections in humans in China. METHODS: In the present study, 609 fecal samples were collected from two- to six-year-old kindergarten children in southern Xinjiang and were examined by polymerase chain reaction (PCR). RESULTS: The infection rate of Blastocystis was 14.3% (87/609); no significant difference was observed among counties and between sexes. Blastocystis subtypes ST1 (n = 38), ST2 (n = 8), and ST3 (n = 41) were identified by sequence analysis of the small subunit ribosomal RNA gene. Genetic polymorphisms were observed at the intra-subtype level, including seven variations for ST1 (ST1A to ST1G), four for ST2 (ST2A to ST2D), and two for ST3 (ST3A and ST3B); with ST1F and ST2B being new variations. CONCLUSIONS: ST1 and ST3 are the two common Blastocystis subtypes in the study area. More extensive studies in both humans and animals in different regions are needed to better characterize the transmission of Blastocystis.

Parasitic Infections in Children with Disability in Resource Poor Settings: The Research Gaps.

The burden of parasitic infections among children with disability in resource-poor settings has not been summarised through a focused review. Here, we have summarised the key studies reporting the burden of parasitic infections among children without and with a disability. In most instances, among children without disability, Giardia or soil-transmitted helminths dominate the epidemiology, while among disabled individuals, enteric protozoa are the predominant parasites to be reported in both resource-rich and resource-poor countries. Cryptosporidium is generally the leading protozoan to be detected among these populations but all other parasites have been detected in varying frequencies. There is a paucity of data on the precise epidemiology of parasitic infections in children with disability. A large-scale epidemiological study, using modern genomic methodology, is a research priority.

Sexual Transmission of Intestinal Parasites and Other Enteric Pathogens among Men Who Have Sex with Men Presenting Gastrointestinal Symptoms in an STI Unit in Barcelona, Spain: A Cross-Sectional Study.

Sexually transmitted infections (STIs) are a major problem worldwide. In addition, the spectrum of STIs is now expanding, including parasitic, bacterial, and viral infections. The study retrospectively describes the presence of enteric pathogens among 73 patients with gastrointestinal symptoms of enteritis and proctocolitis attending to an STI unit in Barcelona, Spain, between 2015 and 2016. Only patients investigated for intestinal parasitic infections were included in the study. Different diagnostic procedures were established for the detection of parasites, bacterial enteropathogens, and other STI agents. Entamoeba histolytica was the most prevalent pathogen in our cohort (20.5%), especially among individuals with proctocolitis. Contrarily, Giardia intestinalis was detected in 11.0% of patients, only associated with enteritis cases. Polymicrobial infections were common in our study (45.2%). Of note, 55.6% of shigellosis cases were coinfected with E. histolytica. The investigation highlights the importance of including parasites as differential gastrointestinal diagnosis, disregarding travel history, particularly among risk populations.

The importance of considering the neglected intestinal protozoan parasite Dientamoeba fragilis.

Dientamoebiasis is globally distributed and detected in a large number of subjects with diarrhea, abdominal discomfort, flatulence, fatigue and loss of appetite. The life cycle and transmission of Dientamoeba fragilis are poorly understood. Microscopic examination of permanent stained smears is traditionally employed to diagnose the infection. However, this approach is time-consuming and the success in detecting D. fragilis depends on the microscopist's experience. Hence, only a few laboratories routinely carry out tests for D. fragilis. Consequently, the prevalence of D. fragilis infection is probably underestimated. Although novel, rapid and more sensitive diagnostic tests are becoming available for detecting intestinal parasites, they also possess some limitations. The aim of this study was to emphasize the importance of performing microscopic examination of permanent stained smears from at least one fresh stool specimen after sample arrival at the laboratory, as a mandatory practice for the diagnosis of dientamoebiasis, particulary where it is not possible to perform molecular assays.

Gastrointestinal, skin and blood parasites in Didelphis spp. from urban and sylvatic areas in São Paulo state, Brazil.

Didelphis (Marsupialia, Didelphimorphia) are synanthropic mammals, whose omnivorous diet predisposes them to infections caused by endoparasites. Their higher frequency in urban areas makes them potential carriers of zoonotic protozoans and helminths, enhancing potential transmission to humans. Our purpose was to study two common species, Didelphis albiventris (54 individuals) and D. aurita (2 individuals), which were screened for blood, skin and intestinal parasites in animals captured in urban areas and in riparian forest regions associated with the Capivari River Basin, in Monte Mor's municipality, São Paulo state (SP), Brazil. Blood and tissue samples were collected for DNA extraction and PCR. Fecal samples were collected and submitted to two sedimentation and two flotation methods. 77.6% of fecal samples were positive for nematode eggs, 34.5% for trematode eggs and 32.7% for protozoans. Two D. aurita specimens were naturally infected by Trypanosoma cruzi. Molecular analysis in a D. albiventris captured on a forested rural area was positive for Leishmania sp. DNA. Several parasites were found infecting Didelphis sp., demonstrating that this group of animals can harbor important zoonotic parasites, potentially playing a role as sylvatic reservoirs for human and domestic animal pathogens.

Polyparasitism and zoonotic parasites in dogs from a rural area of the Argentine Chaco.

Dogs play an important role as reservoirs and hosts of multiple pathogens shared with humans and wildlife, which contribute significantly to the global burden of disease. Here, we assessed the occurrence of a broad range of zoonotic and non-zoonotic parasites in dogs from a rural area in the humid Chaco; determined the occurrence of polyparasitism; and explored its association with selected risk factors. In total, 212 dogs were examined serologically to determine Trypanosoma cruzi infection and 152 of them also were examined for Ehrlichia canis, Borrelia bugderfori, Anaplasma phagocitophylum, Dirofilaria immitis and Toxoplasma gondii. Fecal samples from 85 dogs were examined for intestinal parasites. Seventeen parasite species were seen, 77% of which are zoonotic. The most prevalent parasites were Ancylostoma caninum (68.2%), T. gondii (55.3%, first report for dogs in Argentina), Giardia sp. (25.9%), Cryptosporidium sp. (20.0%), T. cruzi (16.5%), trematodes (15.3%) and Toxocara canis (14.1%). Polyparasitism was found in 96% of the dogs, with up to six parasite species in a single dog, and was significantly associated with age of dog but not with host body condition or sex. The most frequent pair of parasites found together were T. gondii-A. caninum (46%), A. caninum-T. cruzi (34%) and T. gondii-T. cruzi (27%). The prevalence of anemia and leukocytosis was significantly higher in dogs showing the worst body condition. Our findings likely reflect structural poverty, poor sanitation and lack of a safe water supply. Importantly, many of the prevalent parasites seen are threats to human health. 243 words.

Analysis of knowledge and attitudes related to parasitic infections among inhabitants of Ahvaz County, Khuzestan Province, Iran.

Parasitic diseases are among the major health problems of various societies, especially people in developing countries, causing high economic and mortality burdens. Many researchers have reported that awareness and knowledge of a disease are effective in preventing and controlling the disease. The aim of the present study was to assess the knowledge and attitudes on parasitic diseases of the population in Ahvaz County, southwestern Iran. This community-based cross-sectional study was carried out in 2017 on 3500 subjects above 15 years old of Ahvaz County. First, participants were provided the necessary information regarding the study, and then data were collected using a constructed questionnaire. Of the 3500 participants, 1732 (49.5%) were female and 1768 (50.5%) were male, 348 (9.9%) said that they had been infected with a parasitic disease at least once in their lifetime. Almost half of the participants (42.8%) knew malaria was a parasitic disease and 50.2%, 48.9%, and 41.5% were aware of the possible transmission of parasitic diseases through uncooked meat, dirty hands, and close contact with animals. Regarding clinical symptoms, 73.2% and 32.6% of the respondents knew diarrhea and abdominal pain respectively were clinical symptoms of intestinal parasitic diseases. However, only 31.3% were aware of the close contact with cats and the risk of human toxoplasmosis and possible abortion in pregnant women. The findings reveal that the attitude of most participants toward treatment was positive (93.9%), but only 47.5% of believed that disinfecting fruits and vegetables could prevent intestinal parasitic infections.

Long-Tailed Macaques (Macaca fascicularis) in Urban Landscapes: Gastrointestinal Parasitism and Barriers for Healthy Coexistence in Northeast Thailand.

Gastrointestinal parasites have diverse life cycles that can involve people, animals, and the environment (e.g., water and soil), demonstrating the utility of One Health frameworks in characterizing infection risk. Kosumpee Forest Park (Thailand) is home to a dense population of long-tailed macaques (Macaca fascicularis) that frequently interact with tourists and local residents. Our study investigated the presence of zoonotic parasites, and barriers to healthy coexistence by conducting stool analysis on macaques (N = 102) and people (N = 115), and by examining risk factors for infection with a household questionnaire (N = 95). Overall, 44% of macaques and 12% of people were infected with one or more gastrointestinal helminths, including Strongyloides spp., Ascaris spp., and Trichuris sp. An adults-only generalized linear mixed model identified three factors significantly associated with human infection: household size, occupational exposure, and contact with macaque feces at home. Participants identified both advantages and disadvantages to living in close contact with macaques, suggesting that interventions to improve human and animal health in Kosumpee Forest Park would be welcome.

Defining stopping criteria for ending randomized clinical trials that investigate the interruption of transmission of soil-transmitted helminths employing mass drug administration.

The current World Health Organization strategy to address soil-transmitted helminth (STH) infections in children is based on morbidity control through routine deworming of school and pre-school aged children. However, given that transmission continues to occur as a result of persistent reservoirs of infection in untreated individuals (including adults) and in the environment, in many settings such a strategy will need to be continued for very extended periods of time, or until social, economic and environmental conditions result in interruption of transmission. As a result, there is currently much discussion surrounding the possibility of accelerating the interruption of transmission using alternative strategies of mass drug administration (MDA). However, the feasibility of achieving transmission interruption using MDA remains uncertain due to challenges in sustaining high MDA coverage levels across entire communities. The DeWorm3 trial, designed to test the feasibility of interrupting STH transmission, is currently ongoing. In DeWorm3, three years of high treatment coverage-indicated by mathematical models as necessary for breaking transmission-will be followed by two years of surveillance. Given the fast reinfection (bounce-back) rates of STH, a two year no treatment period is regarded as adequate to assess whether bounce-back or transmission interruption have occurred in a given location. In this study, we investigate if criteria to determine whether transmission interruption is unlikely can be defined at earlier timepoints. A stochastic, individual-based simulation model is employed to simulate core aspects of the DeWorm3 community-based cluster-randomized trial. This trial compares a control arm (annual treatment of children alone with MDA) with an intervention arm (community-wide biannual treatment with MDA). Simulations were run for each scenario for both Ascaris lumbricoides and hookworm (Necator americanus). A range of threshold prevalences measured at six months after the last round of MDA and the impact of MDA coverage levels were evaluated to see if the likelihood of bounce-back or elimination could reliably be assessed at that point, rather than after two years of subsequent surveillance. The analyses suggest that all clusters should be assessed for transmission interruption after two years of surveillance, unless transmission interruption can be effectively ruled out through evidence of low treatment coverage. Models suggest a tight range of homogenous prevalence estimates following high coverage MDA across clusters which do not allow for discrimination between bounce back or transmission interruption within 24 months following cessation of MDA.