OBJECTIVE:Reflux within the superficial microvenous network may play a critical role in the development of skin changes associated with chronic venous insufficiency. This study aimed to extend previous ex vivo observations to determine the in vivo utility of near infrared fluorescence (NIRF) imaging to assess superficial venous reflux in the leg. METHODS:A total of 28 limbs were examined in 17 participants. These included limbs with (CEAP C2, n = 6; C3, n = 1; and C4, n = 15) and without (CEAP C0, n = 6) venous disease. Indocyanine green (5 mL at 0.1 mg/mL) was infused via an (antegrade) cannula in the distal great saphenous vein and the medial leg imaged using NIRF. Venous reflux was assessed using the Valsalva maneuver, with or without superficial outflow obstruction (thigh cuff inflated to 50 mmHg). RESULTS:Consistent with our previous ex vivo study, NIRF imaging visualized a wide range of different microvenous reflux patterns in vivo. These included focal and diffuse regions of fluorescence within the skin, the extent of which appeared to be associated with venous disease (CEAP C classification) severity. The observed reflux patterns also appeared to be functional correlates of perforator vein or saphenofemoral junctional incompetence. CONCLUSIONS:This preliminary in vivo study provides proof-of-principle observations suggesting a potential novel method for investigating microvenous reflux in superficial venous disease. CLINICAL RELEVANCE:This study reports the first in vivo use of near-infrared fluorescence (NIRF) imaging with indocyanine green to assess superficial microvenous reflux within intact limbs. This preliminary data suggests that the extent and distribution of skin fluorescence may be associated with venous disease severity (CEAP Clinical classification). It also provides potential mechanistic insight, identifying reflux patterns that appear to be functional correlates of venous incompetence. This study suggests that NIRF imaging could provide a novel tool for investigating microvenous contributions to chronic venous disease and its skin manifestations.

Exercise provides a therapeutic pathways to mitigate cognitive decrements through benefits to cerebrovascular and neurological function. Intranasal delivery of insulin also offers a therapeutic pathway, possibly via enhancing cerebral metabolism. We assessed cerebral oxygen and glucose metabolism (CMRO2 and CMRglc, respectively) via cross-brain blood sampling and ultrasound measurement of cerebral blood flow (CBF), following two successive intranasal insulin (INI) administrations (52 IU); once at rest, and again at rest but following 1 h of prolonged cycling exercise. Measurement timepoints following both INI administration were 5, 10, 15, 20, 30, 45, and 60 min post. Eleven healthy young adults (5 female, 22.4 ± 1.7 kg/m2) completed this protocol, and, between INI bouts, completed cycling exercise, consisting of 2-3 one-minute bouts at 80%-100% of work rate max followed by 90 min at 90% of lactate threshold (~2 h total). At rest, INI had no effect on CMRO2 (p = 0.141) while CMRglc may have been elevated (p = 0.086). Comparing the effects of INI pre- and post-exercise, CMRO2 was not different (condition, p = 0.333). Collapsing both conditions (pre- and post-exercise) CMRO2 was increased from baseline at 30 min (time, p = 0.007). CMRglc was also not different between conditions (condition, p = 0.498), but was increased (time, p < 0.001) from baseline (0.34 ± 0.02 mmol/min) to 45 min (0.40 ± 0.02 mmol/min) by 20% ± 28% (p = 0.017) across both conditions. Whole brain cerebral metabolism sensitivity to intranasal insulin is minimal at rest, but seems to be increased following exercise, likely due to exercise induced hypoglycaemia driving a supercompensatory response. These findings provide mechanistic support for the cognitive benefits of exercise, and potentially intranasal insulin, through enhanced cerebral metabolism.

We report a case of a traumatic arteriovenous fistula (AVF) between the superficial femoral artery and femoral vein that went undetected for 27 years following an ice axe injury during a climbing accident in 1997. An AVF is an abnormal connection between an artery and a vein, where blood flows directly from the high-flow arterial system to the low-flow venous system, bypassing the capillaries. A 74-year-old male presented with a 2-year history of extensive left leg swelling. He had visible posterior thigh and calf varicose veins and a small scar to the left medial upper thigh. He was otherwise fit and hiking regularly. He also had mild left ventricular and severe bi-atrial dilation, with high output cardiac failure and cardiac remodelling. With ultrasound, a traumatic AVF between the superficial femoral artery and femoral vein was identified. We also assessed the arterial vasodilatory function in both femoral arteries for a within-subject comparison of the chronic effects of high shear stress - the result of high flows through the AVF. This case study discusses the imaging and physiological test findings, along with further details of the climbing accident which were revealed by the patient. Traumatic AVFs are uncommon, and to our knowledge, this is the first documented case of an AVF resulting from an ice axe injury. Almost three decades later, the moment on the mountain left its mark; this case illustrates the complications associated with an untreated AVF.

OBJECTIVE:Low preoperative cardiorespiratory fitness is associated with poorer functional and subjective recovery following hip or knee arthroplasty. The objective of this study was to evaluate the ability of simple, indirect assessment tools (the Duke Activity Status Index, daily step count, and timed up and go test) to estimate directly measured cardiorespiratory fitness and identify patients with low preoperative fitness (<15 mL/kg/min) among those with severe hip or knee osteoarthritis. METHODS:Ninety-one patients with severe hip or knee osteoarthritis who were scheduled for total joint arthroplasty were recruited. Within 1 week before surgery, participants performed symptom-limited maximal cardiopulmonary exercise testing, the Duke Activity Status Index questionnaire, accelerometry to determine daily step count, and the timed up and go test. RESULTS:All three indirect tools provided strong estimates of peak oxygen consumption ( V ̇ O2) (r2 ≥ 0.61). The Duke Activity Status Index slightly underestimated peak V ̇ O2 by 0.9 mL/kg/min. All three metrics performed strongly in their ability to accurately identify patients without a peak V ̇ O2 < 15 mL/kg/min; however, their accuracy to positively predict peak V ̇ O2 > 15 mL/kg/min was only fair. CONCLUSION:These simple, practical, cost-effective tools have utility for estimating preoperative fitness to rule out low fitness. These tools could be used by perioperative clinicians for identifying patients who may not require preoperative cardiopulmonary exercise testing, thereby optimizing resource allocation.

Brain-derived neurotrophic factor (BDNF) is implicated in neuronal differentiation, maturation, survival, and synaptic plasticity. Circulating BDNF is often quantified to represent brain neuronal plasticity following acute exercise. However, BDNF in the fluid compartment surrounding the brain has not been quantified in healthy humans following exercise. We measured total and free BDNF in arterial and internal jugular venous (IJV) blood to assess cross-brain BDNF release, and in cerebrospinal fluid (CSF) via lumbar puncture, before and following ∼2 h of cycling exercise. We hypothesized that exercise would elevate both systemic circulating BDNF and CSF BDNF concentrations. Herein, in humans, we demonstrate that BDNF in the CSF is elevated following exercise. We also report a net release of BDNF from the brain into circulation despite being several orders of magnitude less concentrated in the CSF.NEW & NOTEWORTHY Across species, acute exercise increases brain-derived neurotrophic factor in circulation and so is considered a therapeutic strategy to improve brain health. We coupled arterial and jugular venous cannulation with concurrent cerebrospinal fluid measurement via lumbar puncture, to measure the cerebral exchange of brain-derived neurotrophic factor, before and after participants cycled for ∼2 h. The current data demonstrate that brain-derived neurotrophic factor in the cerebrospinal fluid is elevated following exercise.

The effect of slow deep breathing (SDB) on the dynamic transduction of sympathetic nerve activity to the superficial femoral artery (SFA), femoral vein (FV), and blood pressure was determined. In 12 healthy volunteers (five women, 25 ± 7 yr, means ± SD), simultaneous imaging of the SFA and FV, along with contemporary measures of muscle sympathetic nerve activity (MSNA), was obtained and signal-averaging techniques were used to quantify sympathetic neurovascular transduction at rest (baseline) and during 5 min SDB at 6 breaths/min. At baseline, MSNA bursts were followed by transient increases in mean arterial pressure (MAP; peak +3.0 ± 1.2 mmHg), decreases in SFA flow (nadir -6.3 ± 4.5 mL/min), and small, inconsistent increases in FV flow (peak +4.3 ± 6.7 mL/min). SDB decreased MSNA burst frequency and burst incidence by ∼30%, whereas MAP was unchanged. During SDB, MSNA bursts were followed by greater increases in MAP (peak +6.0 ± 2.4 mmHg, P < 0.001 vs. baseline), greater decreases in SFA flow (nadir -9.8 ± 4.0 mL/min, P = 0.002 vs. baseline), and a tendency for a greater increase in FV flow (peak +20.6 ± 21.0 mL/min, P = 0.051). Therefore, although SDB reduces MSNA, the augmented MSNA transduction to blood pressure may help to preserve MAP. SDB evoked greater reductions in SFA flow and increases in FV flow following an MSNA burst, which may work synergistically with the respiratory muscle pump to facilitate venous return. Collectively, these findings highlight the important role played by MSNA in the dynamic regulation of peripheral blood flow, venous return, and blood pressure.NEW & NOTEWORTHY Sympathetic neurovascular transduction to mean arterial pressure (MAP), superficial femoral artery (SFA), and femoral vein (FV) flow were quantified at baseline and during slow deep breathing (SDB). MAP was unchanged during SDB, whereas MSNA was decreased, and sympathetic transduction to MAP, SFA flow, and FV flow (tendency) were increased. Respiratory-coupled oscillations in MSNA, SFA flow, and FV flow appear to work synergistically with the respiratory muscle pump to facilitate venous return during SDB.

A footbath may be an accessible form of passive heat therapy (PHT) to improve cardiovascular health. As a localized PHT stimulus, it is unclear whether longer durations are superior for promoting adaptive hemodynamic and vascular adjustments. Fourteen older adults (7 females; means ± SD; age: 68 ± 6 yr) performed 30-, 45-, and 60-min lower-leg hot-water (42°C) immersions and a 60-min thermoneutral (36°C) sham immersion on 4 separate days. Superficial femoral artery blood flow and flow-mediated dilation (FMD) were assessed pre- and postimmersion, and the time course of recovery was characterized over the 60 min following immersion. Twenty-four-hour ambulatory blood pressure was monitored over each experimental day. Femoral artery blood flow increased following immersion in all PHT conditions (mean of all PHT conditions: +345 ± 211%; P < 0.001) but was unchanged in sham. The 30- and 45-min PHT conditions sustained a higher leg blood flow than sham for the full hour following immersion (all post hoc comparisons: P < 0.01), whereas the 60-min condition was not different from sham by 30 min into recovery. FMD was greater following 45-min PHT than sham over the hour of recovery (mean of recovery time points: 2.5 ± 0.9% FMD vs. 1.7 ± 1.0%; P = 0.002). Twenty-four hour mean arterial pressure was lower with 45-min and 60-min PHT compared with sham (both -4 ± 4 mmHg; P < 0.05). A 45-min footbath results in comparable hemodynamic adjustments as 60 min of immersion and leads to the largest acute improvement in vascular function. As such, a 45-min footbath may be the preferred dose of PHT to use in future interventions seeking to improve vascular health and blood pressure.NEW & NOTEWORTHY A longer duration footbath may not be better for cardiovascular benefits in older adults. Leg blood flow increases, and ambulatory blood pressure is reduced similarly with 30, 45, and 60 min of lower-leg hot-water immersion. However, only a 45-min footbath improves endothelial function compared with a thermoneutral sham immersion. Forty-five minutes is the most favorable acute dose of lower-leg hot-water immersion and may be the most suitable for chronic interventions seeking to improve cardiovascular health.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

BACKGROUND:A periurban outbreak of Rift Valley fever virus (RVFV) among dairy cattle from May through August 2018 in northern Tanzania was detected through testing samples from prospective livestock abortion surveillance. We sought to identify concurrent human infections, their phylogeny, and epidemiologic characteristics in a cohort of febrile patients enrolled from 2016 to 2019 at hospitals serving the epizootic area. METHODS:From September 2016 through May 2019, we conducted a prospective cohort study that enrolled febrile patients hospitalized at 2 hospitals in Moshi, Tanzania. Archived serum, plasma, or whole blood samples were retrospectively tested for RVFV by PCR. Human samples positive for RVFV were sequenced and compared to RVFV sequences obtained from cattle through a prospective livestock abortion study. Phylogenetic analysis was performed on complete RVFV genomes. RESULTS:Among 656 human participants, we detected RVFV RNA in 4 (0.6%), including 1 death with hepatic necrosis and other end-organ damage at autopsy. Humans infected with RVFV were enrolled from June through August 2018, and all resided in or near urban areas. Phylogenetic analysis of human and cattle RVFV sequences demonstrated that most clustered to lineage B, a lineage previously described in East Africa. A lineage E strain clustering with lineages in Angola was also identified in cattle. CONCLUSIONS:We provide evidence that an apparently small RVFV outbreak among dairy cattle in northern Tanzania was associated with concurrent severe and fatal infections among humans. Our findings highlight the unidentified scale and diversity of interepizootic RVFV transmission, including near and within an urban area.

Spontaneously occurring bursts of sympathetic nerve activity contribute to the moment-to-moment control of blood pressure by evoking an alpha-adrenergic mediated arterial vasoconstriction. However, the venous system also receives a rich sympathetic innervation, contains alpha-adrenergic receptors, and venoconstriction has been elicited by sympatho-excitatory stimuli (e.g., hypoxia, exercise) in some studies. Herein we tested the hypothesis that spontaneously occurring bursts of sympathetic activity evoke dynamic changes in venous tone and consequently, flow. In nine healthy volunteers (4 women, 26±7 years, 24±4 kg·m 2 ; mean±SD) simultaneous 10-minute recordings of femoral artery and vein blood flow (duplex ultrasound), muscle sympathetic nerve activity (MSNA, microneurography), and blood pressure (finger photoplethysmography) were made. Sympathetic transduction was quantified as the change in mean arterial pressure (MAP), femoral artery flow, and femoral vein flow, following spontaneous bursts of MSNA using signal-averaging techniques. As expected, sympathetic bursts were accompanied by a transient increase in MAP (peak +3.2±1.2 mmHg), while MAP fell following cardiac cycles not associated with a sympathetic burst (nadir -1.1±0.6 mmHg). Similarly, sympathetic bursts were followed by a transient decrease in femoral artery blood flow (nadir -9.2±4.6 ml/min), whereas increases were exhibited following cardiac cycles not associated with a sympathetic burst (peak +2.5±2.6 ml/min). In contrast, sympathetic bursts evoked comparatively smaller, less consistent and directionally opposite changes in femoral vein flow (average over 15 cardiac cycles +2.1±6.0 ml/min), while small decreases were observed following cardiac cycles not associated with a sympathetic burst (-0.8±1.7 ml/min). Collectively, these findings indicate that spontaneously occurring bursts of sympathetic nerve activity exert a minimal contribution to the moment-to-moment control of femoral venous flow in young healthy humans. Further studies examining sympathetic venous transduction during physiological stressors (e.g., exercise), and in other venous beds (e.g., mesenteric) and populations (e.g., hypertension) are warranted. JPF is supported by a Health Research Council Programme grant (19/687). This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.

The objective of this study was to characterize the 24-h blood pressure response following an acute hot-water immersion exposure, specifically examining the effect of immersion duration and water temperature, in people with hypertension. Sixteen participants (11 females; 62 ± 7 y; 31.7 ± 7.5 kg.m-2) with hypertension (taking at least one anti-hypertensive medication) completed four randomized sessions: 1) 20-min and 2) 40-min hot-water immersion (40°C), 3) 40-min thermoneutral immersion (36.5°C), and 4) control (seated, no immersion). Blood pressure, heart rate, perceptual and affective responses were recorded throughout exposure. Immediately after exposure, participants were fitted with an ambulatory blood pressure monitor for the following 24 h. Twenty-four-hour SBP was 7 mm Hg lower (95% CI: -11, -2; p = 0.001) after the 40-min hot-water immersion and 6 mm Hg lower after both the 20-min hot-water immersion (-10, -1; p = 0.006) and 40-min thermoneutral immersion (-9, -3; p = 0.002) compared to control; these effects were similar across nighttime (i.e. 10 pm-6 am) and daytime periods. Twenty-four-hour DBP was not statistically different across any exposure (p = 0.093). The percentage of 24 h in target range for SBP (110-130 mm Hg) more than doubled (39% vs. 18%) following the 40-min hot-water immersion, compared to control. Clinically meaningful decreases in systolic blood pressure were evident with hot-water immersion in people with hypertension; these effects were present irrespective of immersion duration (i.e. 20 min vs. 40 min) or water temperature (36.5°C vs 40°C).

Hypertension affects over 30% of adults worldwide, significantly increasing the risk of cardiovascular, cerebrovascular, and renal diseases. Although regular physical activity is a well-established strategy for lowering blood pressure, additional therapeutic approaches may help individuals who struggle to achieve target blood pressure levels. Hot water immersion is garnering attention due to its potential cardiovascular benefits. Historically practiced for therapeutic and cultural purposes, hot water immersion induces physiological responses that share key similarities with physical activity. Accumulating evidence suggests that hot water immersion may contribute to blood pressure reduction. Although small-scale studies report promising acute and chronic blood-pressure-lowering effects, critical gaps remain in the literature. This review summarizes current evidence on the antihypertensive effects of hot water immersion, outlining key areas for future research. Hot water immersion may emerge as an accessible and culturally relevant adjunct therapy for hypertension management.

Immunometabolic processes maintain physiological homeostasis and are implicated in various chronic diseases. Fasting and exercise independently alter metabolic and immunological processes; their combination could provide insights into immunometabolic interactions. Using a randomized crossover design, 15 healthy adults (six females, nine males, 26.5 ± 4.3 years) fasted for 60 h with and without the addition of a 3 h cycling bout (65%-80% VO2 peak). Fasting alone (FAST) and with exercise (FEX) reduced plasma glucose, insulin, respiratory exchange ratio, and increased β-hydroxybutyrate (BHB; all p < 0.01). FEX elicited more rapid changes in glucose and BHB and higher BHB concentrations at 60 h (all p < 0.01). Both conditions decreased circulating TNF-⍺ concentrations and increased IL-10 (p < 0.01), although the increase in IL-10 appeared to be driven by the FEX condition (p = 0.03). IL-6 concentrations tended to increase in both conditions (p = 0.1). Total white blood cell count remained unchanged after 60 h in both conditions, with only modest changes in some leukocyte subpopulations. Collectively, the observed changes in circulating cytokine concentrations support an overall anti-inflammatory effect of prolonged fasting, while the maintenance of leukocyte concentrations suggests immune function is not compromised. Despite greater metabolic strain, the addition of prolonged exercise did not appear to augment changes in systemic cytokines and leukocytes.

Salmonella is among the causative agents for diarrhea worldwide, but its risk factors in Tanzanian children are poorly understood. A hospital-based cross-sectional study was conducted in Moshi, Kilimanjaro region, from July 2020 to November 2022 among children under five admitted with diarrhea. A questionnaire was administered to all parents/caretakers of the enrolled children. Logistic regression was utilized to analyze the risk factors, with significance at p < 0.05. A total of 306 children were enrolled in the study. The median age was 13.8 months (IQR 8.4–21.8). The majority (58.5%) were males, and 59.5% were from rural areas. Salmonella was identified in eight (2.6%) stool samples, with a higher prevalence in urban than rural areas (4.8% vs. 1.1%; p-value = 0.044). The significant risk factors associated with Salmonella infection among the children included consuming raw milk (adjusted OR = 30.19; 95% CI: 3.94–231.46), using infant formula (adjusted OR = 15.78; 95% CI: 2.98–83.56), undisclosed household income (adjusted OR = 9.98; 95% CI: 2.46–40.12), purchasing eggs direct from the farms (adjusted OR = 7.58; 95%CI: 1.31–43.96), and contact with chickens (adjusted OR = 6.49; 95%CI: 1.25–33.59). These findings highlight the need for targeted interventions to improve food safety, hygiene practices, and socioeconomic conditions.

Campylobacteriosis and antimicrobial resistance (AMR) are global public health concerns. Africa is estimated to have the world's highest incidence of campylobacteriosis and a relatively high prevalence of AMR in Campylobacter spp. from humans and animals. Few studies have compared Campylobacter spp. isolated from humans and poultry in Africa using whole-genome sequencing and antimicrobial susceptibility testing. We explored the population structure and AMR of 178 Campylobacter isolates from East Africa, 81 from patients with diarrhea in Kenya and 97 from 56 poultry samples in Tanzania, collected during 2006-2017. Sequence type diversity was high in both poultry and human isolates, with some sequence types in common. The estimated prevalence of multidrug resistance, defined as resistance to >3 antimicrobial classes, was higher in poultry isolates (40.9%, 95% credible interval 23.6%-59.4%) than in human isolates (2.5%, 95% credible interval 0.3%-6.8%), underlining the importance of antimicrobial stewardship in livestock systems.

Nonvisual opsins are transmembrane proteins expressed in the eyes and other tissues of many animals. When paired with a light-sensitive chromophore, nonvisual opsins form photopigments involved in various nonvisual, light-detection functions including circadian rhythm regulation, light-seeking behaviors, and seasonal responses. Here, we investigate the molecular evolution of nonvisual opsin genes in anuran amphibians (frogs and toads). We test several evolutionary hypotheses including the predicted loss of nonvisual opsins due to nocturnal ancestry and potential functional differences in nonvisual opsins resulting from environmental light variation across diverse anuran ecologies. Using whole-eye transcriptomes of 81 species, combined with genomes, multitissue transcriptomes, and independently annotated genes from an additional 21 species, we identify which nonvisual opsins are present in anuran genomes and those that are also expressed in the eyes, compare selective constraint among genes, and test for potential adaptive evolution by comparing selection between discrete ecological classes. At the genomic level, we recovered all 18 ancestral vertebrate nonvisual opsins, indicating that anurans demonstrate the lowest documented amount of opsin gene loss among ancestrally nocturnal tetrapods. We consistently found expression of 14 nonvisual opsins in anuran eyes and detected positive selection in a subset of these genes. We also found shifts in selective constraint acting on nonvisual opsins in frogs with differing activity periods, habitats, distributions, life histories, and pupil shapes, which may reflect functional adaptation. Although many nonvisual opsins remain poorly understood, these findings provide insight into the diversity and evolution of these genes across anurans, filling an important gap in our understanding of vertebrate opsins and setting the stage for future research on their functional evolution across taxa.

BACKGROUND:In northern Tanzania, Q fever, spotted fever group (SFG) rickettsioses, and typhus group (TG) rickettsioses are common causes of febrile illness. We sought to describe the prevalence and risk factors for these zoonoses in a pastoralist community. METHODS:Febrile patients ≥2 years old presenting to Endulen Hospital in the Ngorongoro Conservation Area were enrolled from August 2016 through October 2017. Acute and convalescent blood samples were collected, and a questionnaire was administered. Sera were tested by immunofluorescent antibody (IFA) IgG assays using Coxiella burnetii (Phase II), Rickettsia africae, and Rickettsia typhi antigens. Serologic evidence of exposure was defined by an IFA titre ≥1:64; probable cases by an acute IFA titre ≥1:128; and confirmed cases by a ≥4-fold rise in titre between samples. Risk factors for exposure and acute case status were evaluated. RESULTS:Of 228 participants, 99 (43.4%) were male and the median (interquartile range) age was 27 (16-41) years. Among these, 117 (51.3%) had C. burnetii exposure, 74 (32.5%) had probable Q fever, 176 (77.2%) had SFG Rickettsia exposure, 134 (58.8%) had probable SFG rickettsioses, 11 (4.8%) had TG Rickettsia exposure, and 4 (1.8%) had probable TG rickettsioses. Of 146 participants with paired sera, 1 (0.5%) had confirmed Q fever, 8 (5.5%) had confirmed SFG rickettsioses, and none had confirmed TG rickettsioses. Livestock slaughter was associated with acute Q fever (adjusted odds ratio [OR] 2.54, 95% confidence interval [CI] 1.38-4.76) and sheep slaughter with SFG rickettsioses case (OR 4.63, 95% CI 1.08-23.50). DISCUSSION:Acute Q fever and SFG rickettsioses were detected in participants with febrile illness. Exposures to C. burnetii and to SFG Rickettsia were highly prevalent, and interactions with livestock were associated with increased odds of illness with both pathogens. Further characterisation of the burden and risks for these diseases is warranted.

Salmonella is one of the most frequent causes of diarrhea globally. This study used a One Health approach to identify Salmonella species in children admitted with diarrhea and tested samples from the cases’ household environment to investigate their genetic similarity using whole genome sequencing. Surveillance of hospitalized diarrhea cases among children under 5 years was conducted in rural and urban Moshi Districts in the Kilimanjaro Region of Tanzania from July 2020 through November 2022. Household visits were conducted for every child case whose parent/caregiver provided consent. Stool samples, water, domestic animal feces, meat, and milk were collected and tested for Salmonella. Isolates were sequenced on the Illumina NextSeq platform. Multilocus Sequence Typing and phylogenetic analyses were performed to map the genetic relatedness of the isolates. Salmonella was isolated from 72 (6.0%) of 1,191 samples. The prevalence of Salmonella in children with diarrhea, domestic animal feces, food, and water was 2.6% (n = 8/306), 4.6% (n = 8/174), 4.2% (n = 16/382), and 17.3% (n = 39/225), respectively. Four (1.3%) of the 306 enrolled children had a Salmonella positive sample taken from their household. The common sequence types (STs) were ST1208, ST309, ST166, and ST473. Salmonella Newport was shared by a case and a raw milk sample taken from the same household. The study revealed a high diversity of Salmonella spp., however, we detected a Salmonella clone of ST1208 isolated at least from all types of samples. These findings contribute to understanding the epidemiology of Salmonella in the region and provide insight into potential control of foodborne diseases through a One Health approach.

In both the United States and Canada, the incidence of many reported infections caused by pathogens commonly transmitted through foods has been tracked for public health purposes, and used to estimate the actual number of illnesses, hospitalizations and deaths that occurred annually. Both the reporting requirements and the methods of estimating the overall human health burden have changed over time and will continue to do so. Though the health care systems and reporting requirements differ between the two countries, the results are broadly similar. For domestically acquired foodborne diseases, the estimated combined annual incidence in the United States among the 31 major pathogens assessed was 9.4 million cases of illness, or 3.1% of the 2010 population; of these, seven agents (norovirus, non-typhoidal Salmonella, Clostridium perfringens, Campylobacter, Toxoplasma gondii, Shiga toxin-producing E. coli O157, and Listeria monocytogenes) accounted for 90% of illnesses. Including an estimate for other unspecified agents, the estimated incidence was 47.8 million or 15.4% of the 2010 population. In Canada during a comparable period, the estimated combined annual incidence among the 30 pathogens assessed was 1.6 million or 4.8% of the 2010 population; the same seven pathogens similarly accounted for 91% of illnesses. Including unspecified agents as well, the incidence was 4.0 million or 11.9% of the 2010 population. For the major pathogens combined, the annual hospitalization rates were 18.1 per 100,000 for the US, and 11.7 per 100,000 for Canada; death rates were 0.44 per 100,000 for the US and 0.31 per 100,000 for Canada. In Canada, the estimates for campylobacteriosis exceed those for salmonellosis, while in the US the reverse is true. Differences in diagnostic practices and reporting may explain much of the observed differences between the two countries. For both countries, foodborne infections cause substantial health burdens, and need continued and expanded prevention efforts.