MEDICAL-SURGICAL MANAGEMENT OF INTESTINAL INFECTION BY PROSTHENORCHIS ELEGANS IN NONHUMAN PRIMATES FROM COSTA RICA.

Parasitism is one of the most important diseases in nonhuman primates (NHP). Parasitism by Prosthenorchis elegans can be a threat to health and conservation of NHP in Costa Rica. Surgical management of intestinal acanthocephalan infection in two squirrel monkeys (Saimiri oerstedii) and one white-faced monkey (Cebus imitator) is described as an alternative to the lack of pharmacologic control options when there is a high burden of parasites present. A complete physical evaluation, including medical ultrasound techniques, allow for diagnosis of the parasite and its lesions. When animals present with a high burden of parasites, surgical management has shown to promote good health outcomes and increase the probability of survival.

Infection with Blastocystis spp. and its association with enteric infections and environmental enteric dysfunction among slum-dwelling malnourished adults in Bangladesh.

BACKGROUND: Blastocystis spp. (Blastocystis) is a widely distributed gastrointestinal protist frequently reported in countries with tropical and sub-tropical climate. We sought to determine the factors associated with Blastocystis infection and investigate its role on biomarkers of intestinal health among slum-dwelling malnourished adults in Bangladesh. METHODOLOGY: Total 524 malnourished adults with a body mass index ≤18.5 kg/m2 were included in this analysis. Presence of Blastocystis in feces was evaluated by TaqMan Array Card assays. PRINCIPAL FINDINGS: Blastocystis was tested positive in 78.6% of the participants. Prevalence of infection with atypical strains of enteropathogenic Escherichia coli (aEPEC) (56% vs. 38%, p<0.001), and Trichuris trichiura (28% vs. 15%, p-value = 0.02) was significantly greater in adults with Blastocystis, while Giardia intestinalis was significantly lower (8% vs. 14%, p-value = 0.04) in Blastocystis positive adults. Malnourished adults who were living in households with high crowding index (aOR = 2.18; 95% CI = 1.11, 4.65; p-value = 0.03), and infected with aEPEC (aOR = 2.14; 95% CI = 1.35, 3.44; p-value = 0.001) and Trichuris trichiura (aOR = 1.97; 95% CI = 1.08, 3.77; p = 0.03) were more likely to be infected with Blastocystis. A significant negative relationship was observed between Blastocystis and fecal concentrations of alpha-1 antitrypsin (ß = -0.1; 95% CI = -1.7, -0.1; p-value<0.001) and Reg1B (ß = -3.6; 95% CI = -6.9, -3.0; p-value = 0.03). CONCLUSIONS: The study findings suggest that the presence of Blastocystis in human intestine influences gut health and may have potential pathogenic role in presence of other pathogens.

Intestinal Histopathology due to an Acanthocephalan in Two Corvid Species from Northern Italy.

Carnivorous birds maintain parasites in the sylvatic cycle and have a role in their diffusion. The histopathology and ultrastructure of the intestine of 29 Hooded Crows (Corvus corone cornix) and 51 Eurasian Magpies (Pica pica), from the Province of Ferrara (Northern Italy), naturally infected with Sphaerirostris picae (Acanthocephala), were investigated. In both bird species, the prevalence of infection was around 10%, and the intensity of the infection in the Hooded Crows ranged from two to 12 acanthocephalans per host, whereas in the Eurasian Magpies it ranged from one to nine worms per bird. Previous records on the histopathology of acanthocephalans in birds do not provide information on the type of cells involved in the host's reaction. We aimed to gain information on the effects of acanthocephalans on the structural integrity of the birds' intestine and to describe the type of immune cells in the hosts against the parasite. Our results showed that S. picae disrupted the intestinal wall at the site of attachment by means of its neck and proboscis, and three main types of bird intestinal reactions were noticed. The most severe response of the hosts was against the proboscis because of the action of its hooks with recruitment of macrophages, giant cells, eosinophils, and heterophils. Sphaerirostris picae perforated the birds' entire intestinal wall, reaching the peritoneal visceral serosa, but it did not provoke a diffuse peritonitis.

The association between the lack of safe drinking water and sanitation facilities with intestinal Entamoeba spp infection risk: A systematic review and meta-analysis.

Intestinal protozoa infections are responsible for considerable morbidity and mortality, especially where the exposed population suffers from a lack of drinking water and sanitation facilities. In this study, the association between the lack of safe drinking water and sanitation (toilet) facilities with intestinal Entamoeba spp infection in the children (5-11 years), adult (18-55 years), and all age (5-55 years) were assessed. For this purpose, some of the international databases such as Scopus, PubMed, Web of Science, and Embase were screened to up to 7 June 2019 in order to retrieve the related citations. Also, the pooled odds ratios (ORs) following 95% confidence intervals (CIs) were calculated using a random-effects model. Twenty-nine articles with 36 studies were included while the OR extracted or calculated by using 2 × 2 contingency tables. However, the ingestion of contaminated water insignificantly can increase the odds ratio (OR) of Entamoeba spp infection (OR 1.01, (95% confidence interval [CI] 0.58 to 1.43), no access to sanitation (toilet) facilities significantly can increase odds of Entamoeba spp infection (OR 1.18, 95% CI 1.05 to 1.32). The meta-regression analysis showed that over time, odds of intestinal Entamoeba spp infection increased in both lack of safe drinking water (Coefficient: 3.24, P-value < 0.01) and sanitation (toilet) facilities (Coefficient: 2.36, P-value < 0.05) subgroups. Considering the findings, lack of safe drinking water resulted in a further increase in intestinal Entamoeba spp infection among adult (OR: 2.76), children (OR = 0.57) and all age groups (OR: 1.50), and also lack of sanitation (toilet) facilities resulted in further increase intestinal Entamoeba spp infection in children (OR: 1.06), adult (OR: 1.26) and all age (OR: 1.16). In this context, the lack of safe drinking water and sanitation facilities (toilet) was associated with a high risk of intestinal Entamoeba spp infection. Further attempts to providing public health facilities can control the prevalence of intestinal Entamoeba spp.

Primary hydatid cyst of the small intestine masquerading as intestinal duplication in a child.

Hydatid disease or hydatidosis is a worldwide zoonosis disease caused by the tapeworm of Echinococcus granulosus and still widely endemic in Tunisia especially in rural areas where the sheep-dog cycle is dominant. It is an important public health problem in the pediatric age group causing significant morbidity and mortality. We report a case of primary hydatid cyst of the small intestine in a child and we want to highlight the difficulty that we meet in the diagnosis despite the contribution of imaging.

Soil fungi enable the control of gastrointestinal nematodes in wild bovidae captive in a zoological park: a 4-year trial.

The control of gastrointestinal nematodes among ruminants maintained in zoological parks remains difficult due to infective stages develop in the soil. For the purpose to improve the possibilities of the control of gastrointestinal nematodes (genera Trichostrongylus, Nematodirus, Chabertia and Haemonchus) affecting wild captive bovidae ruminants belonging to the subfamilies Antilopinae, Caprinae, Bovinae and Reduncinae, commercial pelleted feed enriched with a blend of 104-105 spores of both filamentous fungi Mucor circinelloides + Duddingtonia flagrans per kg meal was provided for a period of 3.5 years. All animals were dewormed at the beginning of the trial and also when exceeding a cut-off point of 300 eggs per gram of feces (EPG). The anthelmintic efficacy ranged between 96 and 100%. The need for repeating the administration of parasiticide treatment disappeared at the 24th month of study in the Antilopinae individuals, and at the 8th month in the Caprinae, Bovinae and Reduncinae. No side-effects were observed on the skin or in the digestive, respiratory or reproductive system. It was concluded that this strategy provides a sustainable tool for preventing the contamination of paddocks where captive ruminants are maintained, decreasing the risk of infection by gastrointestinal nematodes and consequently the need of frequent deworming.

Pathogenesis and post-infectious complications in giardiasis.

Giardia is an important cause of diarrhoea, and results in post-infectious and extra-intestinal complications. This chapter presents a state-of-the art of our understanding of how this parasite may cause such abnormalities, which appear to develop at least in part in Assemblage-dependent manner. Findings from prospective longitudinal cohort studies indicate that Giardia is one of the four most prevalent enteropathogens in early life, and represents a risk factor for stunting at 2 years of age. This may occur independently of diarrheal disease, in strong support of the pathophysiological significance of the intestinal abnormalities induced by this parasite. These include epithelial malabsorption and maldigestion, increased transit, mucus depletion, and disruptions of the commensal microbiota. Giardia increases epithelial permeability and facilitates the invasion of gut bacteria. Loss of intestinal barrier function is at the core of the acute and post-infectious complications associated with this infection. Recent findings demonstrate that the majority of the pathophysiological responses triggered by this parasite can be recapitulated by the effects of its membrane-bound and secreted cysteine proteases.

Arthrobotrys cladodes and Pochonia chlamydosporia in the biological control of nematodiosis in extensive bovine production system.

Cattle production in extensive systems favours the occurrence of gastrointestinal nematodes, and the use of nematophagous fungi complements the control strategies for these nematodes. The aim of this study was to evaluate the effectiveness of the fungi Arthrobotrys cladodes and Pochonia chlamydosporia in the biological control of gastrointestinal parasitic nematodes in grazing cattle. Twenty-four calves were randomly divided into four groups and allocated to independent paddocks from February 2018 to January 2019. In the first group, the animals received pellets containing P. chlamydosporia. In the second group, the animals received pellets containing A. cladodes. In the third group, the animals received pellets containing a combination of the fungi A. cladodes and P. chlamydosporia. In the control group, the animals received pellets without fungus. The combined use of A. cladodes and P. chlamydosporia showed greater efficacy in the biological control of bovine gastrointestinal parasitic nematodes than the same fungi used separately. The parasite load was lower and weight gain was greater (P ⩽ 0.05) in the groups of cattle treated with nematophagous fungi. Therefore, the use of A. cladodes and P. chlamydosporia is promising in the biological control of nematodiosis in cattle.

The Contribution of Eimeria Coinfection and Intestinal Inflammation to Cecal Colonization and Systemic Spread of Salmonella Typhimurium Deficient in Tetrathionate Reductase or Type III Secretion Systems Salmonella Pathogenicity Island 1 or 2.

Intestinal inflammation may provide a growth advantage for Salmonella and enhance its systemic spread in chickens. Salmonella triggers intestinal inflammation in the host by using type III secretion systems (T3SS) and produces the inflammatory end product tetrathionate. In mice, tetrathionate respiration confers a growth advantage for Salmonella Typhimurium over the competitive microbiome in the inflamed intestine. Coccidia also promote intestinal inflammation and enhance Salmonella intestinal growth and systemic spread in chickens. The objective of this study was to evaluate the contribution of inflammation, induced by Eimeria spp. or Salmonella Typhimurium, to Salmonella colonization and dissemination in chickens. In addition, the fitness costs associated with defects in tetrathionate reductase and T3SS associated with Salmonella Pathogenicity Island 1 or 2 (SPI-1 or SPI-2) were evaluated in in vivo competition experiments with wild-type Salmonella strain, with or without Eimeria coinfection. One-day-old specific-pathogen-free chickens were orally inoculated with a sham inoculum or with 4 × 102Eimeria oocysts cocktail of Eimeria tenella, Eimeria acervulina, Eimeria maxima, and Eimeria mitis. At 6 days of age, birds were orally administered a 1:1 ratio of Salmonella Typhimurium wild-type and mutant deficient in tetrathionate reductase, SPI-1, or SPI-2 (108 colony forming units/bird). Ceca, livers, and drumsticks were collected at 3, 7, 14, and 42 days after Salmonella infection, for bacteriology. Intestinal inflammation was scored by histology. Significantly higher intestinal inflammation was observed in challenge groups compared with the control. However, there were no significant differences in intestinal inflammation scores between groups coinfected with both Eimeria spp. and Salmonella Typhimurium and birds infected with Salmonella alone, and Eimeria coinfection did not increase Salmonella prevalence or abundance. Contrary to mouse studies, tetrathionate reductase did not enhance Salmonella Typhimurium cecal colonization or systemic spread in chickens. SPI-1 and SPI-2 played a significant role in Salmonella dissemination and cecal colonization in chickens, respectively.

Contribución de la coinfección por Eimeria y de la inflamación intestinal a la colonización cecal y a la propagación sistémica de Salmonella Typhimurium deficiente en tetrationato reductasa o de sistemas de secreción de tipo III de islas de patogenicidad 1 o 2 de Salmonella. La inflamación intestinal puede proporcionar una ventaja para el crecimiento de Salmonella y aumentar su propagación sistémica en pollos. Salmonella desencadena la inflamación intestinal en el huésped mediante el uso de sistemas de secreción tipo III (T3SS) y produce el producto final inflamatorio, tetrationato. En ratones, la respiración con tetrationato confiere una ventaja de crecimiento para Salmonella Typhimurium sobre el microbioma competitivo en el intestino inflamado. Coccidia también promueve la inflamación intestinal y mejora el crecimiento intestinal de Salmonella y la propagación sistémica en pollos. El objetivo de este estudio fue evaluar la contribución de la inflamación, inducida por Eimeria spp. o Salmonella Typhimurium, en la colonización y diseminación de Salmonella en pollos. Además, se evaluaron los costos de aptitud asociados con defectos en la tetrationato reductasa y T3SS asociados con las islas de patogenicidad 1 o 2 de Salmonella (SPI-1 o SPI-2) mediante experimentos de competencia in vivo con cepas de Salmonella de tipo silvestre, con o sin coinfección con Eimeria. Pollos libres de patógenos específicos de un día de edad se inocularon por vía oral con un inóculo falso o con 4 × 102 de un coctel de ooquistes de Eimeria que incluyó Eimeria tenella, Eimeria acervulina, Eimeria maxima y Eimeria mitis. A los seis días de edad, se les administró a las aves administró por vía oral una proporción 1: 1 de Salmonella Typhimurium de tipo silvestre o tipo mutante que es deficiente de tetrationato reductasa, SPI-1 o SPI-2 (108 unidades formadoras de colonias/ave). Se recolectaron ciegos, hígados y pernas a los tres, siete, catorce y 42 días después de la infección por Salmonella, para bacteriología. La inflamación intestinal se calificó por histología. Se observó inflamación intestinal significativamente mayor en los grupos de desafío en comparación con el control. Sin embargo, no hubo diferencias significativas en las puntuaciones de inflamación intestinal entre los grupos coinfectados con Eimeria spp. y Salmonella Typhimurium y las aves infectadas con Salmonella por si sola y la coinfección con Eimeria no aumentó la prevalencia o abundancia de Salmonella. A diferencia de los estudios en ratones, la tetrationato reductasa no mejoró la colonización cecal de Salmonella Typhimurium o la diseminación sistémica en pollos. Las islas de patogenicidad SPI-1 y SPI-2 jugaron un papel importante en la diseminación de Salmonella y en la colonización cecal en pollos, respectivamente.

Associations between soil-transmitted helminthiasis and viral, bacterial, and protozoal enteroinfections: a cross-sectional study in rural Laos.

BACKGROUND: Humans are susceptible to over 1400 pathogens. Co-infection by multiple pathogens is common, and can result in a range of neutral, facilitative, or antagonistic interactions within the host. Soil-transmitted helminths (STH) are powerful immunomodulators, but evidence of the effect of STH infection on the direction and magnitude of concurrent enteric microparasite infections is mixed. METHODS: We collected fecal samples from 891 randomly selected children and adults in rural Laos. Samples were analyzed for 5 STH species, 6 viruses, 9 bacteria, and 5 protozoa using a quantitative reverse transcription polymerase chain reaction (qRT-PCR) assay. We utilized logistic regression, controlling for demographics and household water, sanitation, and hygiene access, to examine the effect of STH infection on concurrent viral, bacterial, and protozoal infection. RESULTS: We found that STH infection was associated with lower odds of concurrent viral infection [odds ratio (OR): 0.48, 95% confidence interval (CI): 0.28-0.83], but higher odds of concurrent bacterial infections (OR: 1.81, 95% CI: 1.06-3.07) and concurrent protozoal infections (OR: 1.50, 95% CI: 0.95-2.37). Trends were consistent across STH species. CONCLUSIONS: The impact of STH on odds of concurrent microparasite co-infection may differ by microparasite taxa, whereby STH infection was negatively associated with viral infections but positively associated with bacterial and protozoal infections. Results suggest that efforts to reduce STH through preventive chemotherapy could have a spillover effect on microparasite infections, though the extent of this impact requires additional study. The associations between STH and concurrent microparasite infection may reflect a reverse effect due to the cross-sectional study design. Additional research is needed to elucidate the exact mechanism of the immunomodulatory effects of STH on concurrent enteric microparasite infection.

Intestinal injury caused by Eimeria spp. impairs the phosphotransfer network and gain weight in experimentally infected chicken chicks.

Parasitic infections caused by protozoan belonging to genus Eimeria are considered important for the poultry industry, due to their severe intestinal lesions and high mortality rates, causing significant economic losses. Although several mechanisms of coccidiosis pathogenesis are known, the effects of this infection on intestinal enzymes linked to adenosine triphosphate (ATP) metabolism, as creatine kinase (CK), adenylate kinase (AK), and pyruvate kinase (PK), remain unknown. Thus, the aim of this study was to evaluate whether coccidiosis impairs enzymes linked ATP metabolism in the intestine of chicken chicks. For this, 42 animals that were 2 days old were divided into two groups: uninfected (the negative control group) and experimentally infected on second day of life (the positive control group). On days 5, 10, and 15 post-infection (PI), fecal samples were collected for oocyst counts; intestinal tissue was collected in order to evaluate CK, AK, and PK activities, as well as parameters of the oxidative stress and histopathology. On days 10 and 15 PI, infected animals showed high counts of oocysts in fecal samples and intestinal lesions compared to the control group. Cytosolic CK activity was higher in infected animals on days 10 and 15 PI compared to the control group, while mitochondrial CK activity was lower on days 5, 10, and 15 PI. Also, AK activity was lower in infected animals on days 10 and 15 PI compared to control group, while no differences were observed between groups regarding PK activity. In relation to parameters of oxidative stress, intestinal lipid peroxidation and reactive oxygen species levels were higher in infected animals on days 10 and 15 PI compared to the control group, while non-protein thiol levels were lower on day 10 PI. On the 15th day, infected animals had lower body weight (P < 0.05). Based on this evidence, inhibition of mitochondrial CK activity causes an impairment of intestinal energetic homeostasis possibly through depletion on ATP levels, although the cytosolic CK activity acted as an attempt to restore the mitochondrial ATP levels through a feedback mechanism. Moreover, the impairment on energy metabolism appears to be mediated by excessive production of intestinal ROS, as well as oxidation of lipids and thiol groups.

Multiplex Nucleic Acid Amplification Testing to Diagnose Gut Infections: Challenges, Opportunities, and Result Interpretation.

Multiplex nucleic acid testing is increasingly used to diagnose childhood gastroenteritis. The advantages of this disruptive technology include rapidity, sensitivity, and ability to detect pathogenic viruses, bacteria, and parasites simultaneously. The drawbacks are its capacity to identify organisms of uncertain clinical significance in North American children, cost, and inability to provide viable bacteria for strain typing by public health authorities. However, this technology will certainly improve our knowledge of the causes of human gut infections. As data emerge, physicians should interpret results cautiously, and, most important, consider the context of the presentation before making clinical decisions based on the readouts.

Incidence of Intestinal Infectious Diseases due to Protozoa and Bacteria in Mexico: Analysis of National Surveillance Records from 2003 to 2012.

BACKGROUND: According to national epidemiological surveillance records, in Mexico six intestinal infectious diseases (IID) are among the top infectious communicable diseases. However, their incidence, relative importance, and spatial patterns have not been studied in detail. AIMS: We examine the epidemiology of IID due to bacteria and protozoa to identify which diseases are most important at two spatial scales, what is their integrated importance locally, and how their incidence correlates with Human Development Index (HDI). METHODS: We retrieved yearly number of new cases of eight IID from the national epidemiological morbidity report from 2003 to 2012 at the national level, by state, and to assess such information at a higher spatial resolution we included the municipalities for Mexico City. However, no comparisons were made to other municipalities due to unavailability of data. We compared incidence, obtained the disease-specific relative importance, and inspected spatial patterns for the integrated incidence. Finally, we tested whether HDI is correlated with incidence. RESULTS: We found that, except for two diseases, the relative importance of the other six IID contrasted not only between the national level and Mexico City, but also among states and municipalities in Mexico City. Besides, at both scales the distribution of the incidence showed disease-specific spatial patterns. Finally, there was a lack of consistent correlation between HDI and individual IID at both scales. CONCLUSION: Our results emphasize the need for local disease-focused selective models for control and prevention of IID. The maps displaying our analyses of epidemiological similarities may be used in orienting such effort.

Intestinal cryptosporidiosis in renal transplant recipients: Prevalence, species detection and comparative evaluation of SSU rRNA and Cryptosporidium oocyst wall protein genes.

Context: Cryptosporidiosis is intestinal opportunistic infection commonly occurring in immunocompromised patients including renal transplant (RT) recipients receiving continuous immunosuppressive therapy. Knowledge about species of Cryptosporidium-infecting RT recipients is necessary to know about mode of its transmission (anthroponotic or zoonotic). Various genes such as small subunit rRNA (SSU rRNA) and Cryptosporidium oocyst wall protein (COWP) genes may help in species identification though their sensitivity and specificity are highly variable. Subjects and Methods: A total of 993 and 575 stool samples were examined for Cryptosporidium by microscopy from 358 RT recipients and 200 healthy controls, respectively. Stool samples of RT recipients and healthy controls were subjected to polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP) for species identification. Results: Cryptosporidium was more commonly detected amongst RT recipients than healthy controls (30/358, 8.4% vs. 0/200, respectively; P < 0.001). The infection was more common amongst patients with diarrhoea than those without (26/162, 16.1% vs. 4/145, 2.8%; P < 0.001). Cryptosporidium parvum was identified in 10/30 (33.3%) and Cryptosporidium hominis in 20/30 (66.7%) samples. SSU gene PCR-RFLP proved to be more sensitive (100%) than COWP (90%); however, specificity of both was same (100%). Conclusions: Cryptosporidiosis is common amongst RT recipients, particularly those with diarrhoea. C. hominis is the most common species in the studied population. SSU rRNA PCR was more sensitive molecular method for the differentiation of Cryptosporidium species.

Clinical characteristics and epidemiology of intestinal tapeworm infections over the last decade in Tokyo, Japan: A retrospective review.

BACKGROUND: Tapeworm (cestode) infections occur worldwide even in developed countries and globalization has further complicated the epidemiology of such infections. Nonetheless, recent epidemiological data on cestode infections are limited. Our objectives were to elucidate the clinical characteristics and epidemiology of diphyllobothriosis and taeniosis in Tokyo, Japan. METHODOLOGY/PRINCIPAL FINDINGS: We retrospectively reviewed 24 cases of human intestinal cestode infection from January 2006 to December 2015 at a tertiary referral hospital in Tokyo, Japan. The patients included were diagnosed with cestode infection based on morphological and/or molecular identification of expelled proglottids and/or eggs and treated in our hospital. Fifteen and 9 patients were diagnosed with diphyllobothriosis and taeniosis, respectively. The median patient age was 31 years (interquartile range [IQR]: 26-42 years), and 13 (54%) were male. Most of the patients (91.7%) were Japanese. All patients were successfully treated with praziquantel without recurrence. Diphyllobothriosis was caused by Diphyllobothrium nihonkaiense in all patients. Taeniosis was due to infection of Taenia saginata in 8 [88.9%] patients and T. asiatica in 1 [11.1%] patient. All patients with taeniosis were infected outside Japan, as opposed to those with diphyllobothriosis, which were domestic. The source locations of taeniosis were mostly in developing regions. The median duration of the stay of the patients with taeniosis at the respective source location was 1 month (IQR: 1-8). CONCLUSIONS/SIGNIFICANCE: The cestode infection, especially with D. nihonkaiense, has frequently occurred, even in Japanese cities, thereby implicating the probable increase in the prevalence of diphyllobothriosis among travelers, as the number of travelers is expected to increase owing to the Tokyo Olympics/Paralympics in 2020. In addition, medical practitioners should be aware of the importance of providing advice to travelers to endemic countries of taeniosis, including the potential risks of infection and preventive methods for these infections.

Household sanitation is associated with lower risk of bacterial and protozoal enteric infections, but not viral infections and diarrhoea, in a cohort study in a low-income urban neighbourhood in Vellore, India.

OBJECTIVE: This study examined associations between household sanitation and enteric infection - including diarrhoeal-specific outcomes - in children 0-2 years of age in a low-income, dense urban neighbourhood. METHODS: As part of the MAL-ED study, 230 children in a low-income, urban, Indian neighbourhood provided stool specimens at 14-17 scheduled time points and during diarrhoeal episodes in the first 2 years of life that were analysed for bacterial, parasitic (protozoa and helminths) and viral pathogens. From interviews with caregivers in 100 households, the relationship between the presence (and discharge) of household sanitation facilities and any, pathogen-specific, and diarrhoea-specific enteric infection was tested through mixed-effects Poisson regression models. RESULTS: Few study households (33%) reported having toilets, most of which (82%) discharged into open drains. Controlling for season and household socio-economic status, the presence of a household toilet was associated with lower risks of enteric infection (RR: 0.91, 95% CI: 0.79-1.06), bacterial infection (RR: 0.87, 95% CI: 0.75-1.02) and protozoal infection (RR: 0.64, 95% CI: 0.39-1.04), although not statistically significant, but had no association with diarrhoea (RR: 1.00, 95% CI: 0.68-1.45) or viral infections (RR: 1.12, 95% CI: 0.79-1.60). Models also suggested that the relationship between household toilets discharging to drains and enteric infection risk may vary by season. CONCLUSIONS: The presence of a household toilet was associated with lower risk of bacterial and protozoal enteric infections, but not diarrhoea or viral infections, suggesting the health effects of sanitation may be more accurately estimated using outcome measures that account for aetiologic agents.