Melioidosis masquerading as malignancy in tropical Australia; lessons for clinicians and implications for clinical management.

Melioidosis is a life-threatening, emerging infectious disease caused by the environmental bacterium Burkholderia pseudomallei. Melioidosis is hyperendemic in tropical Australia and southeast Asia, however the disease is increasingly encountered beyond these regions. Early diagnosis is essential as the infection has a case-fatality rate of up to 50 %. Melioidosis most commonly involves the lungs, although almost any organ can be affected. Most patients present acutely but an insidious presentation over weeks to months is also well described. We present a case series of 7 patients from tropical Australia whom local clinicians initially believed to have cancer ‒ most commonly lung cancer ‒ only for further investigation to establish a diagnosis of melioidosis. All 7 patients had comorbidities that predisposed them to developing melioidosis and all survived, but their delayed diagnosis resulted in 3 receiving anti-cancer therapies that resulted in significant morbidity. The study emphasises the importance of thorough diagnostic evaluation and repeated collection of microbiological samples. It is hoped that our experience will encourage other clinicians ‒ in the appropriate clinical context ‒ to consider melioidosis as a potential explanation for a patient's presentation, expediting its diagnosis and the initiation of potentially life-saving therapy.

Enterococcus contamination of infant foods and implications for exposure to foodborne pathogens in peri-urban neighbourhoods of Kisumu, Kenya.

We collected infant food samples from 714 households in Kisumu, Kenya, and estimated the prevalence and concentration of Enterococcus, an indicator of food hygiene conditions. In a subset of 212 households, we quantified the change in concentration in stored food between a morning and afternoon feeding time. In addition, household socioeconomic characteristics and hygiene practices of the caregivers were documented. The prevalence of Enterococcus in infant foods was 50% (95% confidence interval: 46.1 - 53.4), and the mean log10 colony-forming units (CFUs) was 1.1 (SD + 1.4). No risk factors were significantly associated with the prevalence and concentration of Enterococcus in infant foods. The mean log10 CFU of Enterococcus concentration was 0.47 in the morning and 0.73 in the afternoon foods with a 0.64 log10 mean increase in matched samples during storage. Although no factors were statistically associated with the prevalence and the concentration of Enterococcus in infant foods, household flooring type was significantly associated with an increase in concentration during storage, with finished floors leading to 1.5 times higher odds of concentration increase compared to unfinished floors. Our study revealed high prevalence but low concentration of Enterococcus in infant food in low-income Kisumu households, although concentrations increased during storage implying potential increases in risk of exposure to foodborne pathogens over a day. Further studies aiming at investigating contamination of infant foods with pathogenic organisms and identifying effective mitigation measures are required to ensure infant food safety.

Melioidosis of the Female Genitourinary Tract.

Prostatic abscess is a common manifestation of melioidosis in men, but the characteristics of female genitourinary melioidosis are incompletely defined. There were 453 cases of melioidosis in Far North Queensland, tropical Australia, between January 1998 and April 2023; genitourinary involvement was less common in women than in men (13/140 [9%] versus 76/313 [24%], odds ratio [95% confidence interval]: 0.32 [0.17-0.60], P = 0.0004). In 11 of these 13 (85%) women, other organs were also affected. The two women with disease involving only the genitourinary tract had underlying anatomical abnormalities: one had an ovarian malignancy, the only case to involve the female reproductive system in the cohort, while the other had a urethral diverticulum. In 3 of 13 (23%) women, genitourinary involvement was identified only with computed tomography, emphasizing the importance of early imaging of patients with melioidosis to identify unexpected foci of disease and to inform the optimal duration of antibiotic therapy.

Protocol for the PATHOME study: a cohort study on urban societal development and the ecology of enteric disease transmission among infants, domestic animals and the environment.

INTRODUCTION: Global morbidity from enteric infections and diarrhoea remains high in children in low-income and middle-income countries, despite significant investment over recent decades in health systems and water and sanitation infrastructure. Other types of societal development may be required to reduce disease burden. Ecological research on the influence of household and neighbourhood societal development on pathogen transmission dynamics between humans, animals and the environment could identify more effective strategies for preventing enteric infections. METHODS AND ANALYSIS: The 'enteric pathome'-that is, the communities of viral, bacterial and parasitic pathogens transmitted from human and animal faeces through the environment is taxonomically complex in high burden settings. This integrated cohort-exposure assessment study leverages natural socioeconomic spectrums of development to study how pathome complexity is influenced by household and neighbourhood infrastructure and hygiene conditions. We are enrolling under 12-month-old children in low-income and middle-income neighbourhoods of two Kenyan cities (Nairobi and Kisumu) into a 'short-cohort' study involving repeat testing of child faeces for enteric pathogens. A mid-study exposure assessment documenting infrastructural, behavioural, spatial, climate, environmental and zoonotic factors characterises pathogen exposure pathways in household and neighbourhood settings. These data will be used to inform and validate statistical and agent-based models (ABM) that identify individual or combined intervention strategies for reducing multipathogen transmission between humans, animals and environment in urban Kenya. ETHICS AND DISSEMINATION: The protocols for human subjects' research were approved by Institutional Review Boards at the University of Iowa (ID-202004606) and AMREF Health Africa (ID-ESRC P887/2020), and a national permit was obtained from the Kenya National Commission for Science Technology and Innovation (ID# P/21/8441). The study was registered on Clinicaltrials.gov (Identifier: NCT05322655) and is in pre-results stage. Protocols for research on animals were approved by the University of Iowa Animal Care and Use Committee (ID 0042302).

Chemokine binding to PSGL-1 is controlled by O-glycosylation and tyrosine sulfation.

Protein glycosylation influences cellular recognition and regulates protein interactions, but how glycosylation functions alongside other common posttranslational modifications (PTMs), like tyrosine sulfation (sTyr), is unclear. We produced a library of 53 chemoenzymatically synthesized glycosulfopeptides representing N-terminal domains of human and murine P-selectin glycoprotein ligand-1 (PSGL-1), varying in sTyr and O-glycosylation (structure and site). Using these, we identified key roles of PSGL-1 O-glycosylation and sTyr in controlling interactions with specific chemokines. Results demonstrate that sTyr positively affects CCL19 and CCL21 binding to PSGL-1 N terminus, whereas O-glycan branching and sialylation reduced binding. For murine PSGL-1, interference between PTMs is greater, attributed to proximity between the two PTMs. Using fluorescence polarization, we found sTyr is a positive determinant for some chemokines. We showed that synthetic sulfopeptides are potent in decreasing chemotaxis of human dendritic cells toward CCL19 and CCL21. Our results provide new research avenues into the interplay of PTMs regulating leukocyte/chemokine interactions.

Development of Shortened Enrichment Methods for Detection of Salmonella Typhimurium Spiked in Milk.

Rapid and accurate testing of pathogenic Salmonella enterica in dairy products could reduce the risk of exposure to the bacterial pathogens for consumers. This study aimed to reduce the assessment time needed for enteric bacteria recovery and quantification in food using the natural growth properties of Salmonella enterica Typhimurium (S. Typhimurium) in cow's milk and efficiently using rapid PCR methods. Over 5 h of 37 °C enrichment, culture and PCR methods measured increases in the non-heat-treated S. Typhimurium concentration at similar rates, with an average increase of 2.7 log10 CFU/mL between the start of enrichment and 5 h. In contrast, no bacteria were recovered by culture after S. Typhimurium in milk received heat treatment, and the number of gene copies of heat-treated Salmonella detected by PCR did not increase with the enrichment time. Thus, comparing culture and PCR data over just 5 h of enrichment time can detect and differentiate between replicating bacteria and dead bacteria.

Heparan sulfate glycomimetics via iterative assembly of "clickable" disaccharides.

Heparan sulfate (HS) glycosaminoglycans are widely expressed on the mammalian cell surfaces and extracellular matrices and play important roles in a variety of cell functions. Studies on the structure-activity relationships of HS have long been hampered by the challenges in obtaining chemically defined HS structures with unique sulfation patterns. Here, we report a new approach to HS glycomimetics based on iterative assembly of clickable disaccharide building blocks that mimic the disaccharide repeating units of native HS. Variably sulfated clickable disaccharides were facilely assembled into a library of mass spec-sequenceable HS-mimetic oligomers with defined sulfation patterns by solution-phase iterative syntheses. Microarray and surface plasmon resonance (SPR) binding assays corroborated molecular dynamics (MD) simulations and confirmed that these HS-mimetic oligomers bind protein fibroblast growth factor 2 (FGF2) in a sulfation-dependent manner consistent with that of the native HS. This work established a general approach to HS glycomimetics that can potentially serve as alternatives to native HS in both fundamental research and disease models.

A Mixed Methods Process Evaluation of a Food Hygiene Intervention in Low-Income Informal Neighbourhoods of Kisumu, Kenya.

OBJECTIVES: Diarrhoea is a leading cause of infant mortality with the main transmission pathways being unsafe water and contaminated food, surfaces and hands. The 'Safe Start' trial evaluated a food hygiene intervention implemented in a peri-urban settlement of Kisumu, Kenya, with the aim of reducing diarrhoeagenic enteric infections among infants. Four food hygiene behaviours were targeted: handwashing with soap before preparation and feeding, boiling infant food before feeding, storing infant food in sealed containers, and exclusive use of designated utensils during feeding. METHODS: A process evaluation of the intervention was guided by a theory of change describing the hypothesised implementation and receipt of the intervention, mechanisms of change, and the context. These were assessed by qualitative and quantitative data that included debriefing sessions with the delivery teams and Community Health Volunteers (CHVs), and structured observations during food preparation. RESULTS: The intervention achieved high coverage and fidelity with over 90% of 814 eligible caregivers participating in the intervention. Caregivers in the intervention arm demonstrated an understanding of the intervention messages, and had 1.38 (95% CI: 1.02-1.87) times the odds of washing hands before food preparation and 3.5 (95% CI: 1.91-6.56) times the odds of using a feeding utensil compared to caregivers in the control group. Contextual factors, especially the movement of caregivers within and outside the study area and time constraints faced by caregivers influenced uptake of some intervention behaviours. CONCLUSION: Future interventions should seek to explicitly target contextual factors such as secondary caregivers and promote food hygiene interventions as independent of each other.

Assessing the relationship between domestic work experience and musculoskeletal health among rural Nigerian women.

BACKGROUND: Women performing strenuous domestic tasks (especially those in developing countries) are at risk of experiencing musculoskeletal pain (MSP). Physical, psychosocial, and social conditions of work in rural environments contribute to women's domestic work experiences (DWEs) and the risk of MSP. The impact of DWEs on women's health is especially severe in water-insecure countries like Nigeria. This study examines the relationship between a recently developed measure of DWEs and self-reported pain in the lower back (LBP), neck/shoulder (NSP), and elbow/hand/wrist regions (EHWP) among rural Nigerian women. METHODS: Interviewer-administered survey data were collected from 356 women in four rural communities of Ibadan, Nigeria. Binary and ordinal logistic regression models were used to examine the relationship between DWE factor scores, sociodemographic characteristics, and musculoskeletal pain symptoms and severity after controlling for sociodemographic covariates. Effect estimates of association were presented using the odds ratio (OR), and the corresponding 95% confidence interval (CI) at p-value of 0.05. FINDINGS: Among 356 participants, the 2-month prevalence of LBP was 58%, NSP was 30%, and EWHP 30%. High DWE scores were significantly associated with higher odds of experiencing and having more severe LBP, NSP, and EHWP. Specifically, the odds of LBP [(OR = 2.88; 95% CI = 1.64-5.11), NSP (OR = 4.58; 95% CI = 2.29-9.40) and EHWP (OR = 1.88; 95% CI = 1.26-3.77)] were significantly higher among women who perceived their domestic work responsibilities as very stressful (i.e., 'high stress appraisal') compared to those with lower stress appraisal scores. Those who were time-pressured and had less autonomy over familial duties (i.e., 'high demand/low control') had significantly higher odds of LBP [(OR = 2.58; 95% CI = 1.64-4.09) and NSP (OR = 1.49; 95% CI = 1.24-2.58)]. Frequently fetching and carrying water over long distances and time (i.e., 'high water sourcing and carriage') was also associated with higher odds of LBP [(OR = 1.31; 95% CI = 1.09-1.79) and NSP (OR = 1.20; 95% CI = 1.08-1.76). CONCLUSION: Strenuous and stressful DWEs were associated with MSP among rural Nigerian women. This study provides new evidence on how the physical, social, and psychosocial factors of domestic work can increase women's risk of MSP.

Environmental and behavioural exposure pathways associated with diarrhoea and enteric pathogen detection in 5-month-old, periurban Kenyan infants: a cross-sectional study.

OBJECTIVES: The aim of this study was to test whether household environmental hygiene and behavioural conditions moderated associations between diarrhoea and enteric pathogen detection in infants 5 months of age in Kenya and pathogen sources, including latrine access, domestic animal co-habitation and public food sources. DESIGN: Cross-sectional study utilising enrolment survey data of households participating in the Safe Start cluster-randomised controlled trial . SETTING: Kisumu, Kenya. PARTICIPANTS: A total of 898 caregivers with 5-month (22 week ± 1 week) aged infants were enrolled in the study and completed the enrolment survey. PRIMARY AND SECONDARY OUTCOME MEASURES: Outcomes were (1) caregiver-reported 7-day diarrhoea prevalence and (2) count of types of enteric viruses, bacteria and parasites in infant stool. Exposures and effect modifiers included water access and treatment, cohabitation with domestic animals, sanitation access, handwashing practices, supplemental feeding, access to refrigeration and flooring. RESULTS: Reported handwashing after handling animals (adjusted odds ratio (aOR)=0.20; 95% CI=0.06 to 0.50) and before eating (aOR=0.44; 95% CI=0.26 to 0.73) were strongly associated with lower risk of caregiver-reported diarrhoea, while cohabitation with animals (aOR=1.54; 95% CI=1.01 to 2.34) living in a household with vinyl-covered dirt floors (aOR=0.60; 95% CI=0.45 to 0.87) were strongly associated with pathogen codetection in infants. Caregiver handwashing after child (p=0.02) or self-defecation (p=0.03) moderated the relationship between shared sanitation access and infant exposure to pathogens, specifically private latrine access was protective against pathogen exposure of infants in households, where caregivers washed hands after defecation. In the absence of handwashing, access to private sanitation posed no benefits over shared latrines for protecting infants from exposure. CONCLUSION: Our evidence highlights eliminating animal cohabitation and improving flooring, postdefecation and food-related handwashing, and safety and use of cow milk sources as interventions to prevent enteric pathogen exposure of young infants in Kenya. TRIAL REGISTRATION NUMBER: NCT03468114.

Days of Flooding Associated with Increased Risk of Influenza.

Influenza typically causes mild infection but can lead to severe outcomes for those with compromised lung health. Flooding, a seasonal problem in Iowa, can expose many Iowans to molds and allergens shown to alter lung inflammation, leading to asthma attacks and decreased viral clearance. Based on this, the hypothesis for this research was that there would be geographically specific positive associations in locations with flooding with influenza diagnosis. An ecological study was performed using influenza diagnoses and positive influenza polymerase chain reaction tests from a de-identified large private insurance database and Iowa State Hygienic Lab. After adjustment for multiple confounding factors, Poisson regression analysis resulted in a consistent 1% associated increase in influenza diagnoses per day above flood stage (95% confidence interval: 1.00-1.04). This relationship remained after removal of the 2009-2010 influenza pandemic year. There was no associated risk between flooding and influenza-like illness as a nonspecific diagnosis. Associated risks between flooding and increased influenza diagnoses were geographically specific, with the greatest risk in the most densely populated areas. This study indicates that populations who live, work, or volunteer in flooded environments should consider preventative measures to avoid environmental exposures to mitigate illness from influenza in the following year.

Inclusion of environmentally themed search terms improves Elastic net regression nowcasts of regional Lyme disease rates.

Lyme disease is the most widely reported vector-borne disease in the United States. 95% of confirmed human cases are reported in the Northeast and upper Midwest (25,778 total confirmed cases from Northeast and upper Midwest / 27,203 total US confirmed cases). Human cases typically occur in the spring and summer months when an infected nymph Ixodid tick takes a blood meal. Current federal surveillance strategies report data on an annual basis, leading to nearly a year lag in national data reporting. These lags in reporting make it difficult for public health agencies to assess and plan for the current burden of Lyme disease. Implementation of a nowcasting model, using historical data to predict current trends, provides a means for public health agencies to evaluate current Lyme disease burden and make timely priority-based budgeting decisions. The objective of the study was to develop and compare the performance of nowcasting models using free data from Google Trends and Centers of Disease Control and Prevention surveillance reports. We developed two sets of elastic net models for five regions of the United States: 1. Using only monthly proportional hit data from the 21 disease symptoms and tick related terms, and 2. Using monthly proportional hit data from terms identified via Google correlate and the disease symptom and vector terms. Elastic net models using the full-term list were highly accurate (Root Mean Square Error: 0.74, Mean Absolute Error: 0.52, R2: 0.97) for four of the five regions of the United States and improved accuracy 1.33-fold while reducing error 0.5-fold compared to predictions from models using disease symptom and vector terms alone. Many of the terms included and found to be important for model performance were environmentally related. These models can be implemented to help local and state public health agencies accurately monitor Lyme disease burden during times of reporting lag from federal public health reporting agencies.

The exercise-induced inflammatory response in inflammatory bowel disease: A systematic review and meta-analysis.

BACKGROUND: This study investigated selected inflammatory responses to acute and chronic exercise in individuals with inflammatory bowel disease (IBD). METHODS: A systematic review and meta-analysis was conducted on all relevant exercise-based intervention publications with IBD participants. The study included articles that utilised a broad range of acute and chronic exercise interventions, with inflammatory biomarkers measured and symptoms documented, both pre- and post-exercise for those with IBD. The search was limited to studies published in English, the use of human participants, and primary studies, with no restrictions on date of publication or participant's age. Articles were retrieved through the electronic databases: PubMed, SPORTDiscus, and Scopus. This study adhered to Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. RESULTS: Six inflammatory markers were included in the meta-analysis which consisted of five studies. Exercise interventions resulted in no significant difference in IL-6 (SMD = -0.09; 95% CI = -0.49, 0.30; P = 0.64), TNF-α (SMD = 0.08; 95% CI = -0.31, 0.48; P = 0.68), CRP (SMD = -0.04; 95% CI = -0.58, 0.50; P = 0.89), IL-17 (SMD = 0.15; 95% CI = -0.45, 0.76; P = 0.62), leukocytes (SMD = 0.40; 95% CI = -0.53, 1.33; P = 0.40) or lymphocytes (SMD = 0.32; 95% CI = -0.33, 0.97; P = 0.33), thus, indicating exercise may have no effect on inflammatory markers in IBD. Bowel symptoms improved following regular moderate exercise that incorporated stress management. CONCLUSION: Heterogeneity among the identified literature may have led to exercise interventions being ineffective in reducing inflammation. Although the limited number of eligible studies may reduce the reliability of results, it emphasises the need for additional research in this domain. Importantly, no adverse symptomatic responses to exercise indicate that exercise is safe for IBD patients.

Understanding Rural Women's Domestic Work Experiences (DWE) in Ibadan, Nigeria: Development of a Measurement Tool Using Confirmatory Factor Analysis.

Gender norms prescribe domestic labor as primarily a female's responsibility in developing countries. Many domestic tasks depend on access to water, so the physical, emotional, and time demands of domestic labor may be exacerbated for women living in water-insecure environments. We developed a set of domestic work experience (DWE) measures tailored to work in rural areas in developing countries, assessed rural Nigerian women's DWE, and examined relationships among the measures. Interviewer-administered survey data were collected between August and September from 256 women in four rural Nigerian communities. Latent factors of DWE were identified by analyzing survey items using confirmatory factor analysis. Pearson's correlation was used to examine relationships among latent factor scores, and multivariate linear regression models were used to determine if factor scores significantly differed across socio-demographic characteristics. The DWE measures consisted of latent factors of the physical domain (frequency of common domestic tasks, water sourcing and carriage, experience of water scarcity), the psychosocial domain (stress appraisal and demand-control), and the social domain (social support). Significant correlations were observed among the latent factors within and across domains. Results revealed the importance of measuring rural Nigerian women's DWE using multiple and contextual approaches rather than relying solely on one exposure measure. Multiple inter-related factors contributed to women's DWE. Water insecurity exacerbated the physical and emotional demands of domestic labor DWE varied across age categories and pregnancy status among rural Nigerian women.

SARS-CoV-2 and other coronaviruses bind to phosphorylated glycans from the human lung.

SARS-CoV, MERS-CoV, and potentially SARS-CoV-2 emerged as novel human coronaviruses following cross-species transmission from animal hosts. Although the receptor binding characteristics of human coronaviruses are well documented, the role of carbohydrate binding in addition to recognition of proteinaceous receptors has not been fully explored. Using natural glycan microarray technology, we identified N-glycans in the human lung that are recognized by various human and animal coronaviruses. All viruses tested, including SARS-CoV-2, bound strongly to a range of phosphorylated, high mannose N-glycans and to a very specific set of sialylated structures. Examination of two linked strains, human CoV OC43 and bovine CoV Mebus, reveals shared binding to the sialic acid form Neu5Gc (not found in humans), supporting the evidence for cross-species transmission of the bovine strain. Our findings, revealing robust recognition of lung glycans, suggest that these receptors could play a role in the initial stages of coronavirus attachment and entry.

Differential recognition of oligomannose isomers by glycan-binding proteins involved in innate and adaptive immunity.

The recognition of oligomannose-type glycans in innate and adaptive immunity is elusive due to multiple closely related isomeric glycan structures. To explore the functions of oligomannoses, we developed a multifaceted approach combining mass spectrometry assignments of oligomannose substructures and the development of a comprehensive oligomannose microarray. This defined microarray encompasses both linear and branched glycans, varying in linkages, branching patterns, and phosphorylation status. With this resource, we identified unique recognition of oligomannose motifs by innate immune receptors, including DC-SIGN, L-SIGN, Dectin-2, and Langerin, broadly neutralizing antibodies against HIV gp120, N-acetylglucosamine-1-phosphotransferase, and the bacterial adhesin FimH. The results demonstrate that each protein exhibits a unique specificity to oligomannose motifs and suggest the potential to rationally design inhibitors to selectively block these protein-glycan interactions.

A meta-analysis of the association between physical demands of domestic labor and back pain among women.

BACKGROUND: Back pain (BP) is among the most common musculoskeletal problems globally and is a leading contributor to disability among adults. Millions of women especially those in low-income settings, engage in strenuous domestic activities that may increase their risk of BP. The purpose of this meta-analysis was to estimate the association between physically demanding domestic labor (PDDL) which is characterized as intensity, frequency, duration of work and biomechanical risk factors of work and BP among women. METHODS: Five databases were searched for records published from January 1991 to March 2020; and results from 11studies were included in the meta-analysis. A random effects model and the generic inverse-variance method was used to estimate the pooled odds ratio (OR), 95% confidence interval (CI), and the degree of heterogeneity among studies (I2). Stratified and sensitivity analyses were conducted to identify the influence of outliers and identify the sources of heterogeneity. RESULTS: Exposure to high PDDL was significantly associated with BP (OR = 1.63; 95% CI 1.30, 2.04; I2 = 70%). The odds of back pain were highest among the following groups: women performing domestic labor in non-neutral postures (OR = 2.30; 95% CI = 1.75-3.04; I2 = 0%; N = 4 studies) and among women from low- and middle-income countries (OR = 1.98; 95% CI = 1.58-2.49; I2 = 29%; N = 5 studies). We found no evidence of publication bias (Egger's test p-value = 0.15). CONCLUSIONS: PDDL may significantly increase a woman's risk of experiencing BP, but larger prospective studies are needed to further investigate the association. Presenting data on how domestic work affects the musculoskeletal health of women will be important in designing future interventions (behavioral, infrastructural, and ergonomic) that can reduce the burdens from domestic labor.

Bacteroides Microbial Source Tracking Markers Perform Poorly in Predicting Enterobacteriaceae and Enteric Pathogen Contamination of Cow Milk Products and Milk-Containing Infant Food.

Consumption of microbiologically contaminated food is one of the leading causes of diarrheal diseases. Understanding the source of enteric pathogens in food is important to guide effective interventions. Enterobacteriaceae bacterial assays typically used to assess food safety do not shed light on the source. Source-specific Bacteroides microbial source tracking (MST) markers have been proposed as alternative indicators for water fecal contamination assessment but have not been evaluated as an alternative fecal indicator in animal-derived foods. This study tested various milk products collected from vendors in urban Kenyan communities and infant foods made with the milk (n = 394 pairs) using conventional culture methods and TaqMan qPCR for enteric pathogens and human and bovine-sourced MST markers. Detection profiles of various enteric pathogens and Bacteroides MST markers in milk products differed from that of milk-containing infant foods. MST markers were more frequently detected in infant food prepared by caregivers, indicating recent contamination events were more likely to occur during food preparation at home. However, Bacteroides MST markers had lower sensitivity in detecting enteric pathogens in food than traditional Enterobacteriaceae indicators. Bacteroides MST markers tested in this study were not associated with the detection of culturable Salmonella enterica and Shigella sonnei in milk products or milk-containing infant food. The findings show that while Bacteroides MST markers could provide valuable information about how foods become contaminated, they may not be suitable for predicting the origin of the enteric pathogen contamination sources.

Milk Product Safety and Household Food Hygiene Influence Bacterial Contamination of Infant Food in Peri-Urban Kenya.

BACKGROUND: Milk is a common infant food in peri-urban Kenya that can transmit diarrhea-causing enteric pathogens. Little is known about how contamination of milk at point of purchase and household handling of milk-based infant foods contribute to infant exposure to enteric pathogens. OBJECTIVE: To compare the prevalence and concentrations of bacterial indicator organisms and enteric pathogens in unpackaged, fresh pasteurized, and ultra-high temperature (UHT) treated milk at purchase and assess the influence of the type of milk used to prepare infant food on contamination of this food. METHODS: Paired samples of purchased milk and infant food prepared with this milk were obtained from 188 households in low-income neighborhoods in Kisumu, Kenya. Samples were cultured on selective media to isolate Salmonella enterica, Shigella spp., Klebsiella aerogenes, Proteus spp., and Escherichia coli, with pathogens validated by PCR. Probability of detection of these bacteria was compared by milk product treatment and packaging method, and between milk at point of purchase vs. food at point of infant consumption. RESULTS: Unpackaged milk was most contaminated at point of purchase, but bacterial contamination was also present in pasteurized and UHT milk at purchase. Presence of bacteria in UHT and fresh pasteurized milk at purchase predicted presence of the same bacteria type in infant food. Prevalence of bacterial contamination and concentration level for bacterial indicators generally increased between point of purchase and consumption in UHT and fresh pasteurized milk-based food but decreased in unpackaged milk-based food. Prevalence of the four fecal bacteria were similar in infant foods prepared with each type of milk. CONCLUSION: Both pre-market contamination and post-purchase handling influence the likelihood of infants ingesting foods contaminated by diarrheal pathogens.

Environmental and spatial determinants of enteric pathogen infection in rural Lao People's Democratic Republic: A cross-sectional study.

TRIAL REGISTRATION: clinicaltrials.gov (NCT02342860).