Diarrheal disease and enteric infections in LMIC communities: how big is the problem?

The impact of temperature on non-typhoidal Salmonella and Campylobacter infections: an updated systematic review and meta-analysis of epidemiological evidence

BACKGROUND

As temperatures rise, the transmission and incidence of enteric infections such as those caused by Salmonella and Campylobacter increase. This study aimed to review and synthesise the available evidence on the effects of exposure to ambient temperatures on non-typhoidal Salmonella and Campylobacter infections.

METHODS

A systematic search was conducted for peer-reviewed epidemiological studies published between January 1990 and March 2024, in PubMed, Scopus, Embase, and Web of Science databases. Original observational studies using ecological time-series, case-crossover or case-series study designs reporting the association between ambient temperature and non-typhoidal Salmonella and Campylobacter infections in the general population were included. A random-effects meta-analysis was performed to pool the relative risks (RRs) per 1 °C temperature increase, and further meta regression, and subgroup analyses by climate zone, temperature metrics, temporal resolution, lag period, and continent were conducted. The Navigation Guide systematic review methodology framework was used to assess the quality and strength of evidence. The study protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO).

FINDINGS

Out of 3472 results, 44 studies were included in this systematic review encompassing over one million cases each of Salmonella and Campylobacter infections. Geographically, the 44 studies covered 27 countries across five continents and most of the studies were from high income countries. The meta-analysis incorporated 23 Salmonella studies (65 effect estimates) and 15 Campylobacter studies (24 effect estimates). For each 1 °C rise in temperature, the risk of non-typhoidal Salmonella and Campylobacter infections increased by 5% (RR: 1.05, 95% CI: 1.04-1.06), and 5% (RR: 1.05, 95% CI: 1.04-1.07%), respectively, with varying risks across different climate zones. The overall evidence was evaluated as being of "high" quality, and the strength of the evidence was determined to be "sufficient" for both infections.

INTERPRETATION

These findings emphasise the relationship between temperature and the incidence of Salmonella and Campylobacter infections. It is crucial to exercise caution when generalising these findings, given the limited number of studies conducted in low and middle-income countries. Nevertheless, the results demonstrate the importance of implementing focused interventions and adaptive measures, such as the establishment of localised early warning systems and preventive strategies that account for climatic fluctuations. Furthermore, our research emphasises the ongoing need for surveillance and research efforts to monitor and understand the changing dynamics of temperature-related enteric infections in the context of climate change.

FUNDING

Australian Research Council Discovery Projects grant (ARC DP200102571) Program.

Magnitude of enteric pathogens associated with diarrhea and antibiotic resistance of enteric bacterial pathogens isolated among children under 5 years of age in Bule Hora town, West Guji, Ethiopia

Background

Diarrhea is the second leading cause of morbidity and mortality worldwide among all ages, and one of the leading causes of poor health and premature death in the developing world. Microorganisms, such as viruses, bacteria, and parasites, are responsible for enteric infections among children. Excessive and inappropriate use of antimicrobial drugs and poor infection control practices have transformed antimicrobial resistance into a serious threat to public health worldwide. Therefore, it is essential to investigate the prevalence of enteric pathogens and the antimicrobial susceptibility patterns of bacterial pathogens.

Objective

Assess the prevalence of enteric pathogens associated with diarrhea in children under 5 years at the Bule Hora Health Facility in 2021.

Methods

An institution-based cross-sectional study was conducted from May 2021 to July 2021 in a Bule Hora Health Centre and Hospital. A total of 422 children with diarrhea were included in the study in the outpatient department. Sociodemographic and associated factors were evaluated using a pre-tested questionnaire. A sufficient amount of stool specimens was collected following standard microbiological procedures. An antigen detection kit was used to diagnose rotaviruses, parasites were examined using microscopy, and bacterial identification was carried out by culture and biochemical tests. The antibiotic susceptibility test of the bacterial isolates was performed using the Kirby-Bauer disc diffusion method. The data were analyzed using SPSS version 20. The p-value less than 0.05 was declared statistically significant.

Results

The overall prevalence of enteropathogens in children under 5 years of age was 17%, with no mixed infections detected. Of this, 7.8% of the children's stool samples contained bacterial pathogens, 5% tested positive for rotavirus, and 4.2% contained intestinal parasites. Unprotected drinking water sources, poor carrier hand washing practices, and poor cleaning of utensils for child feeding were factors significantly associated with the prevalence of enteropathogens. Bacterial isolates have shown a high prevalence of resistance to amoxicillin.

Conclusion

Therefore, it is important to take steps to reduce the spread of enteric pathogens among children under 5 years practicing good hygiene, ensuring sanitation, and providing clean drinking water. We recommend performing antimicrobial susceptibility tests before prescribing treatment to children with diarrhea.

Prevalence and Influencing Factor Analysis of Typhoid/Paratyphoid Fever - China, 2011-2020

Introduction

Over the last 12 years, there has been a consistent decline in the cases of typhoid/paratyphoid fever in China. Studying the epidemiological patterns of these diseases in various provincial-level administrative divisions (PLADs) and examining potential influencing factors can provide crucial information for implementing successful control strategies.

Methods

In this study, we analyzed the cases and incidence rates of typhoid/paratyphoid fever reported in various PLADs of China from 2011 to 2022, along with exploring potential influencing factors. We initially studied spatial shifts in the incidence rates through centroid shift analysis. Seasonal variations in typhoid/paratyphoid fever onset were examined using heatmaps. Spatial autocorrelation analysis was utilized to understand the spatial correlations among different PLADs. To assess potential factors, we utilized a generalized estimating equations model that integrated spatial lag effects and sequence comparison analysis.

Results

The study identified significant geographical clustering of typhoid/paratyphoid fever cases in southwestern China. A decrease in incidence rates in the west resulted in a movement of the disease center towards the east. Higher incidence occurred during warmer seasons, highlighting the seasonal pattern of the diseases. Factors such as meteorological conditions and socioeconomic status were probable influencers of typhoid/paratyphoid fever.

Conclusions

The geographical and temporal spread of typhoid/paratyphoid fever can be impacted by meteorological and socioeconomic factors. Enhancing economic conditions, particularly in regions with high disease prevalence, could aid in the prevention and management of these fevers.

Network analysis of patterns and relevance of enteric pathogen co-infections among infants in a diarrhea-endemic setting

Despite significant progress in recent decades toward ameliorating the excess burden of diarrheal disease globally, childhood diarrhea remains a leading cause of morbidity and mortality in low-and-middle-income countries (LMICs). Recent large-scale studies of diarrhea etiology in these populations have revealed widespread co-infection with multiple enteric pathogens, in both acute and asymptomatic stool specimens. We applied methods from network science and ecology to better understand the underlying structure of enteric co-infection among infants in two large longitudinal birth cohorts in Bangladesh. We used a configuration model to establish distributions of expected random co-occurrence, based on individual pathogen prevalence alone, for every pathogen pair among 30 enteropathogens detected by qRT-PCR in both diarrheal and asymptomatic stool specimens. We found two pairs, Enterotoxigenic E. coli (ETEC) with Enteropathogenic E. coli (EPEC), and ETEC with Campylobacter spp., co-infected significantly more than expected at random (both pairs co-occurring almost 4 standard deviations above what one could expect due to chance alone). Furthermore, we found a general pattern that bacteria-bacteria pairs appear together more frequently than expected at random, while virus-bacteria pairs tend to appear less frequently than expected based on model predictions. Finally, infants co-infected with leading bacteria-bacteria pairs had more days of diarrhea in the first year of life compared to infants without co-infection (p-value <0.0001). Our methods and results help us understand the structure of enteric co-infection which can guide further work to identify and eliminate common sources of infection or determine biologic mechanisms that promote co-infection.

Local accessory gene sharing among Egyptian Campylobacter potentially promotes the spread of antimicrobial resistance

Campylobacter is the most common cause of bacterial gastroenteritis worldwide, and diarrhoeal disease is a major cause of child morbidity, growth faltering and mortality in low- and middle-income countries. Despite evidence of high incidence and differences in disease epidemiology, there is limited genomic data from studies in developing countries. In this study, we aimed to quantify the extent of gene sharing in local and global populations. We characterized the genetic diversity and accessory-genome content of a collection of Campylobacter isolates from the Cairo metropolitan area, Egypt. In total, 112 Campylobacter isolates were collected from broiler carcasses (n=31), milk and dairy products (n=24), and patients suffering from gastroenteritis (n=57). Among the most common sequence types (STs), we identified the globally disseminated host generalist ST-21 clonal complex (CC21) and the poultry specialists CC206, CC464 and CC48. Notably, CC45 and the cattle-specialist CC42 were under-represented, with a total absence of CC61. Core- and accessory-genome sharing was compared among isolates from Egypt and a comparable collection from the UK (Oxford). Lineage-specific accessory-genome sharing was significantly higher among isolates from the same country, particularly CC21, which demonstrated greater local geographical clustering. In contrast, no geographical clustering was noted in either the core or accessory genome of CC828, suggesting a highly admixed population. A greater proportion of Campylobacter coli isolates were multidrug resistant compared to Campylobacter jejuni. Our results suggest that there is more horizontal transfer of accessory genes between strains in Egypt. This has strong implications for controlling the spread of antimicrobial resistance among this important pathogen.

Determinants of multimorbidity of infectious diseases among under-five children in Bangladesh: role of community context

Background

The presence of more than one morbid condition among children has become a global public health concern. Studies carried out in Bangladesh have primarily focused on diarrhoea and acute respiratory tract infections independently without considering their co-occurrence effect. The present study examines the multimorbid conditions of infectious diseases in under-five Bangladeshi children. It explores multimorbidity determinants and the role of community context, which are often overlooked in previous literature.

Methods

Utilizing the most recent Demographic and Health Survey of Bangladesh (2017–18), we used mixed-effects random-intercept Poisson regression models to understand the determinants of multimorbidity of infectious diseases in under-five Bangladeshi children considering the community-level characteristics.

Results

The present study found that 28% of the children experienced multimorbidity two weeks prior to the survey. Community-level variability across all the statistical models was statistically significant at the 5% level. On average, the incidence rate of multimorbidity was 1.34 times higher among children from high-risk communities than children from low-risk communities. Moreover, children residing in rural areas and other urban areas involved 1.29 [CI: 1.11, 1.51] and 1.28 [CI: 1.11, 1.47] times greater risk of multimorbidity respectively compared to children from city corporations. Additionally, the multimorbidity incidence was 1.16 times [CI: 1.03, 1.30] higher among children from high-altitude communities than children living in low-altitude communities.

Conclusion

The significant effect of public handwashing places suggests community-based interventions among individuals to learn hygiene habits among themselves, thus, the severity of coexistence nature of infectious diseases. A higher incidence of coexistence of such infectious diseases in the poor and semi-urban populace further recommends a targeted awareness of a clean environment and primary healthcare programmes.

Cost-effectiveness of a weaning food safety and hygiene programme in rural Gambia

OBJECTIVE

The main objective of the economic evaluation was to determine the cost-effectiveness of a weaning food safety and hygiene programme in reducing rates of diarrhoea compared with the control in rural Gambia.

METHODS

The public health intervention, using critical control points and motivational drivers, was evaluated in a cluster randomised controlled trial at 6- and 32-month follow-up. An economic evaluation was undertaken alongside the RCT with data collected prospectively from a societal perspective. Decision-analytic modelling was used to explore cost-effectiveness over a longer time period (4 years).

RESULTS

Direct out-of-pocket healthcare expenditure for households due to diarrhoea was large. The intervention significantly reduced reported childhood diarrhoeal episodes after 6 months (incident risk ratio = 0.40, 95% CI 0.33, 0.49) and 2 years after the intervention (incident risk ratio = 0.68, 95% CI 0.46, 1.02). The within-trial analysis found that the intervention led to total savings of 8064 dalasi 6 months after the intervention and 4224 dalasi 2 years after the intervention. Based on the model results, if the intervention is successful in maintaining the reduction in the risk of diarrhoea, the ICER is US$ 814 per DALY avoided over 4 years. This is cost-effective.

CONCLUSIONS

This study suggests that there are substantial household costs associated with diarrhoeal episodes in children. The within-trial analysis and model results suggest that the community-based approach to improving weaning food hygiene and safety is likely to be cost-effective compared with control.

Exploring behavioural factors affecting nutritional supplement use among children in Honduras

OBJECTIVE

This study explored social and behavioural factors associated with a home fortification of complementary foods program among families of undernourished children in 14 rural communities in Honduras.

DESIGN

We collected and analysed survey data from a convenience sample of 196 households participating in a nutritional program using home fortification of complementary foods in 2017. The program supplied families with a soy-based atole powder fortified with micronutrients. A research team completed a face-to-face survey exploring social and behavioural factors associated with nutritional supplement use. Anthropometric measurements for participating children were abstracted from health clinic records of previous quarterly appointments.

SETTING

The study took place in San Jose del Negrito, Honduras.

PARTICIPANTS

Participants were parents or guardians of children enrolled in the nutrition program.

RESULTS

Nearly half of participant families shared the nutritional supplement with other family members besides the index child, while 10 % reported using the supplement as a meal replacement for the child. Low education level of mothers was associated with improper use of the supplement (P = 0·005). Poorer families were more likely to share the supplement (P = 0·013).

CONCLUSIONS

These results highlight the challenges of programs using home fortification of complementary foods in the context of food scarcity. Findings highlight the importance of increasing rural children's overall caloric intake, perhaps by increasing access to locally available protein sources. Results also suggest transitioning nutritional programs to family-based interventions to increase overall intended compliance to nutrition programming.

Growth faltering regardless of chronic diarrhea is associated with mucosal immune dysfunction and microbial dysbiosis in the gut lumen

Despite the impact of childhood diarrhea on morbidity and mortality, our understanding of its sequelae has been significantly hampered by the lack of studies that examine samples across the entire intestinal tract. Infant rhesus macaques are naturally susceptible to human enteric pathogens and recapitulate the hallmarks of diarrheal disease such as intestinal inflammation and growth faltering. Here, we examined intestinal biopsies, lamina propria leukocytes, luminal contents, and fecal samples from healthy infants and those experiencing growth faltering with distant acute or chronic active diarrhea. We show that growth faltering in the presence or absence of active diarrhea is associated with a heightened systemic and mucosal pro-inflammatory state centered in the colon. Moreover, polyclonal stimulation of colonic lamina propria leukocytes resulted in a dampened cytokine response, indicative of immune exhaustion. We also detected a functional and taxonomic shift in the luminal microbiome across multiple gut sites including the migration of Streptococcus and Prevotella species between the small and large intestine, suggesting a decompartmentalization of gut microbial communities. Our studies provide valuable insight into the outcomes of diarrheal diseases and growth faltering not attainable in humans and lays the groundwork to test interventions in a controlled and reproducible setting.

High-throughput sequencing reveals genetic determinants associated with antibiotic resistance in Campylobacter spp. from farm-to-fork

Campylobacter species are one of the most common causative agents of gastroenteritis worldwide. Resistance against quinolone and macrolide antimicrobials, the most commonly used therapeutic options, poses a serious risk for campylobacteriosis treatment. Owing to whole genome sequencing advancements for rapid detection of antimicrobial resistance mechanisms, phenotypic and genotypic resistance trends along the "farm-to-fork" continuum can be determined. Here, we examined the resistance trends in 111 Campylobacter isolates (90 C. jejuni and 21 C. coli) recovered from clinical samples, commercial broiler carcasses and dairy products in Cairo, Egypt. Multidrug resistance (MDR) was observed in 10% of the isolates, mostly from C. coli. The prevalence of MDR was the highest in isolates collected from broiler carcasses (13.3%), followed by clinical isolates (10.5%), and finally isolates from dairy products (4%). The highest proportion of antimicrobial resistance in both species was against quinolones (ciprofloxacin and/or nalidixic acid) (68.4%), followed by tetracycline (51.3%), then erythromycin (12.6%) and aminoglycosides (streptomycin and/or gentamicin) (5.4%). Similar resistance rates were observed for quinolones, tetracycline, and erythromycin among isolates recovered from broiler carcasses and clinical samples highlighting the contribution of food of animal sources to human illness. Significant associations between phenotypic resistance and putative gene mutations was observed, with a high prevalence of the gyrA T86I substitution among quinolone resistant isolates, tet(O), tet(W), and tet(32) among tetracycline resistant isolates, and 23S rRNA A2075G and A2074T mutations among erythromycin resistant isolates. Emergence of resistance was attributed to the dissemination of resistance genes among various lineages, with the dominance of distinctive clones. For example, sub-lineages of CC828 in C. coli and CC21 in C. jejuni and the genetically related clonal complexes 'CC206 and CC48' and 'CC464, CC353, CC354, CC574', respectively, propagated across different niches sharing semi-homogenous resistance patterns.

Diarrhea as a Potential Cause and Consequence of Reduced Gut Microbial Diversity Among Undernourished Children in Peru

Background

Detrimental effects of diarrhea on child growth and survival are well documented, but details of the underlying mechanisms remain poorly understood. Recent evidence demonstrates that perturbations to normal development of the gut microbiota in early life may contribute to growth faltering and susceptibility to related childhood diseases. We assessed associations between diarrhea, gut microbiota configuration, and childhood growth in the Peruvian Amazon.

Methods

Growth, diarrhea incidence, illness, pathogen infection, and antibiotic exposure were assessed monthly in a birth cohort of 271 children aged 0–24 months. Gut bacterial diversity and abundances of specific bacterial taxa were quantified by sequencing 16S rRNA genes in fecal samples collected at 6, 12, 18, and 24 months. Linear and generalized linear models were used to determine whether diarrhea was associated with altered microbiota and, in turn, if features of the microbiota were associated with the subsequent risk of diarrhea.

Results

Diarrheal frequency, duration, and severity were negatively associated with bacterial diversity and richness (P < .05). Children born stunted (length-for-age z-score [LAZ] ≤ −2) who were also severely stunted (LAZ ≤ −3) at the time of sampling exhibited the greatest degree of diarrhea-associated reductions in bacterial diversity and the slowest recovery of bacterial diversity after episodes of diarrhea. Increased bacterial diversity was predictive of reduced subsequent diarrhea from age 6 to 18 months.

Conclusions

Persistent, severe growth faltering may reduce the gut microbiota's resistance and resilience to diarrhea, leading to greater losses of diversity and longer recovery times. This phenotype, in turn, denotes an increased risk of future diarrheal disease and growth faltering.

COVID-19 Crisis Creates Opportunity towards Global Monitoring & Surveillance

The spectrum of emerging new diseases as well as re-emerging old diseases is broadening as infectious agents evolve, adapt, and spread at enormous speeds in response to changing ecosystems. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a recent phenomenon and may take a while to understand its transmission routes from less traveled territories, ranging from fomite exposure routes to wastewater transmission. The critical challenge is how to negotiate with such catastrophic pandemics in high-income countries (HICs ~20% of the global population) and low-and middle-income countries (LMICs ~ 80% of the global population) with a total global population size of approximately eight billion, where practical mass testing and tracing is only a remote possibility, particularly in low-and middle-income countries (LMICs). Keeping in mind the population distribution disparities of high-income countries (HICs) and LMICs and urbanisation trends over recent years, traditional wastewater-based surveillance such as that used to combat polio may help in addressing this challenge. The COVID-19 era differs from any previous pandemics or global health challenges in the sense that there is a great deal of curiosity within the global community to find out everything about this virus, ranging from diagnostics, potential vaccines/therapeutics, and possible routes of transmission. In this regard, the fact that the gut is the common niche for both poliovirus and SARS-CoV-2, and due to the shedding of the virus through faecal material into sewerage systems, the need for long-term wastewater surveillance and developing early warning systems for better preparedness at local and global levels is increasingly apparent. This paper aims to provide an insight into the ongoing COVID-19 crisis, how it can be managed, and what measures are required to deal with a current global international public health concern. Additionally, it shed light on the importance of using wastewater surveillance strategy as an early warning practical tool suitable for massive passive screening, as well as the urgent need for microfluidic technology as a rapid and cost-effective approach tracking SARS-CoV-2 in wastewater.

Regulation of Enteric Infection and Immunity by Dietary Proanthocyanidins

The role of dietary components in immune function has acquired considerable attention in recent years. An important focus area is to unravel the role of bioactive dietary compounds in relation to enteric disease and their impact on gut mucosal immunity. Proanthocyanidins (PAC) are among the most common and most consumed dietary polyphenols, and are characterised by their variable molecular structures and diverse bioactivities. In particular, their anti-oxidative effects and ability to modulate gut microbiota have been widely described. However, there is limited evidence on the mechanism of action of PAC on the immune system, nor is it clearly established how PAC may influence susceptibility to enteric infections. Establishing the sites of action of PAC and their metabolites within the gut environment is fundamental to determine the applicability of PAC against enteric pathogens. Some mechanistic studies have shown that PAC have direct modulatory effects on immune cell signalling, isolated pathogens, and gut mucosal barrier integrity. Boosting the recruitment of immune cells and suppressing the amount of pro-inflammatory cytokines are modulating factors regulated by PAC, and can either be beneficial or detrimental in the course of re-establishing gut homeostasis. Herein, we review how PAC may alter distinct immune responses towards enteric bacterial, viral and parasitic infections, and how the modulation of gut microbiota may act as a mediating factor. Furthermore, we discuss how future studies could help unravel the role of PAC in preventing and/or alleviating intestinal inflammation and dysbiosis caused by enteric disease.

The Gut Microbiota: A Promising Target in the Relation between Complementary Feeding and Child Undernutrition

Child undernutrition is a major public health challenge that is persistent and disproportionately prevalent in low- and middle-income countries. Undernourished children face adverse health, economic, and social consequences that can be intergenerational. The first 1000 days of life, from conception until the child's second birthday, constitute the period of greatest vulnerability to undernutrition. The transition process from milk-based diets to solid, semi-solid, and soft food and liquids other than milk, referred to as complementary feeding (CF), occurs between the age of 6 mo and 2 y. CF practices that do not meet the WHO's guiding principles and are lacking in both quality and quantity increase susceptibility to undernutrition, restrict growth, and jeopardize child development and survival. The gut microbiota develops toward an adult-like configuration within the first 2-3 y of life. Recent studies suggest that significant changes in the gut microbial composition and functional capacity occur during the CF period, but these studies were conducted in high-income countries. Research in low- and middle-income countries, on the other hand, has implicated a disrupted gut microbiota in child undernutrition, and animal experiments reveal the potential for a causal relation. Given the growing body of evidence for a plausible role of the gut microbiota in the link between CF and undernutrition, microbiota-targeted complementary food may be a promising treatment modality for undernutrition management. The aims of this paper are to review the evidence for the relation between CF and undernutrition and to highlight the potential of the gut microbiota to be a promising target in this relation. Our summary of the current state of the knowledge in this area provides a foundation for future research and helps inform the design of interventions targeting the gut microbiota to combat child undernutrition and promote healthy growth.

Moderate to Severe Diarrhea and Associated Factors Among Under-Five Children in Wonago District, South Ethiopia: A Cross-Sectional Study

Background

Diarrheal disease is the second leading cause of death in children under five years old and is responsible for killing around 525 000 children every year. Based on the world health organization estimates, diarrhea contributes to more than one in every ten (13%) child deaths in Ethiopia. Despite the emphasis given to improving child health, many children are still dying due to easily preventable and treatable diarrheal disease in Ethiopia.

Methods

A community cross-sectional study was conducted on randomly selected under-five children who live in Wonago district. Three hundred eighteen households were selected using a systematic sampling technique. Data were collected using a structured closed-ended questionnaire. Data were cleaned, coded, and entered into the statistical package for social sciences window version 20 statistical software analysis.

Results

The magnitude of moderate to severe diarrhea in the Wonago district was 30.9%. The number of family members (AOR: 2.7, 95% CI [1.277-5.716]), presence of animals in households (AOR: 2.591, 95% CI [1.188-5.650]), availability of latrine (AOR: 2.129, 95% CI [1.006-4.505]), and hand washing practice during a critical time (AOR: 2.683, 95% CI [1.139-6.319]) were strongly associated with moderate to severe diarrhea.

Conclusion

Childhood diarrhea remains an important health concern in the study area. This calls for a holistic and multimodal approach for the prevention, early identification, and intervention of diarrhea in children. More emphasis should also be given on personal, household, and environmental hygiene, as well as family planning.

S-Methylcysteine (SMC) Ameliorates Intestinal, Hepatic, and Splenic Damage Induced by Cryptosporidium parvum Infection Via Targeting Inflammatory Modulators and Oxidative Stress in Swiss Albino Mice

Cryptosporidiosis has been proposed to be one of the major causes of diarrhoeal disease in humans worldwide that possesses zoonotic concern. Thereby, this study investigated the potential effects of s-Methylcysteine (SMC) on the parasite in vivo followed by the measurement of cytokines, oxidative stress parameters, and an investigation of the major histopathological changes. Sixty male Swiss albino mice weighing 20-25 g were allocated equally into five groups and orally administered saline only (control), SMC only (SMC50) (50 mg/kg b.w.), and 10⁴Cryptosporidium parvum oocysts per mouse via an esophageal tube (C + ve untreated). The fourth and fifth groups (C + SMC25, C + SMC50) administrated 10⁴C. parvum oocysts combined with SMC25 (low dose) and 50 (high dose) mg/kg b.w., respectively. At days 7 and 14 post-infection (PI), the feces was collected from each group in order to count C. parvum oocysts. After two weeks of treatment, the animals were euthanized and the serum was collected for biochemical analysis. Next, the intestinal, spleen, and liver sections were dissected for histopathological examination. The results revealed lower oocyst numbers in the C + SMC25 and C + SMC50 groups compared to the infected untreated group. Moreover, higher doses of SMC treatment significantly reduced the enteritis induced by C. parvum in a dose-dependent manner. The hepatic lesions were also mitigated as demonstrated in C + SMC25 and C + SMC50 groups unlike the infected group via lowering the serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) enzymes and increasing albumin and globulin serum levels. SMC administration also reduced cytokines production (SAP, TNF-α, IL-6, and IFN-γ) mediated by Cryptosporidium infection in contrast to the infected untreated group. There were marked lymphoid depletion and amyloidosis observed in the infected untreated group, while the treated groups showed obvious increase in the lymphoid elements. Moreover, the scoring of intestinal parasites, hepatic, and splenic lesions in the SMC-treated groups exhibited significantly lower pathological lesions in different organs in a dose-dependent manner, compared to the infected untreated group. Our results also revealed a significant change in the malondialdehyde content with an elevation of glutathione and superoxide dismutase in the intestines collected from C + SMC25 and C + SMC50 mice relative to the untreated group. Taken together, our results indicated that SMC could be a promising effective compound for treating and declining C. parvum infestation via restoring structural alterations in different tissues, enhancing antioxidant enzymes, and suppressing the cytokines liberation.

Identification of Enteropathogens by Multiplex PCR among Rural and Urban Guatemalan Children with Acute Diarrhea

Multiplex polymerase chain reaction (PCR) platforms have enhanced understanding of intestinal pathogens in low- and middle-income countries (LMICs). However, few such studies have been performed in Latin America, where poverty, poor sanitation, and undernutrition persist. Multiplex PCR (BioFire, Salt Lake City, UT) was used to identify viral, bacterial, and parasitic pathogens in stool collected on day 1 and 31 from children aged 6 to 35 months with acute, non-bloody diarrhea in two locations (rural and urban) in Guatemala. We analyzed correlation between pathogens and clinical, demographic, and socioeconomic variables; described patterns of pathogen acquisition, persistence, and clearance over the 30-day period; and calculated population attributable fractions (PAFs) for diarrheal causation for individual pathogens. We analyzed 316 subjects (144 urban; 172 rural) enrolled between March 2015 and January 2016. Rural subjects had significantly more malnutrition, animal exposure, and unimproved water/sanitation infrastructure. The majority of subjects had multiple pathogens/sample (4.8 rural and 2.7 urban). Few meaningful correlates were identified between individual pathogens and clinical, demographic, or environmental variables. Escherichia coli pathotypes, Shigella, Campylobacter, and Giardia had high rates of persistence between initial and 30-day follow-up. Statistically significant adjusted PAFs were identified for Campylobacter (14.9%, 95% CI: 3.2-23.1), norovirus (10.2%, 95% CI: 0.4-17.1), sapovirus (7.6%, 95% CI: 2.3-10.9), and adenovirus 40/41 (5.6%, 95% CI: 0.3-8.7). These observations further characterize the diversity and complexity of enteric pathogens in children in LMICs. Patterns of chronic symptomatic and asymptomatic infection among Latin American children are similar to those observed in other LMIC regions. Findings have direct implications for practitioners treating individuals with acute infectious diarrhea and should inform regional public health strategies.

Unorthodox ophthalmic preparations on the Ghanaian market: a potential risk for ocular and enteric infections

PURPOSE

Microbial contamination of orthodox ophthalmic preparations poses a serious threat to the user by causing ocular infections. There is no such information about unorthodox ophthalmic preparations in a medical pluralistic system such as Ghana. The aim of this study was to assess unorthodox ophthalmic medications on the Ghanaian market for possible microbial contaminations.

METHODS

Unorthodox ophthalmic preparations were collected across different herbal and homeopathic outlets in Ghana. A total of 27 samples were collected from the ten (10) regions in Ghana. The samples were inoculated in different culture media (Plate count Agar, Blood Agar, MacConkey Agar, Saboraud Dextrose Agar). The microorganisms isolated were identified using standard microbiological procedures and antimicrobial susceptibility was done to determine whether they were resistant or susceptible strains.

RESULTS

All the samples were contaminated with bacteria and the majority were contaminated with fungus. A total of forty-eight bacteria spp. was isolated thus seven different types namely: Staphylococcus aureus, Bacilli spp., Serrati spp., Escherichia coli, Pseudomonas spp., Klebsiella spp. and Shigella spp. with Staphylococcus aureus being the predominant bacteria. For fungi, a total of eleven fungi species thus four different types namely: Cephalosporium spp., Penicillium spp., Cercosporium spp. and Clasdosporium spp. with the predominant fungi being Penicillium spp. Per the class of preparations, 15 contaminants were isolated from ten (10) anti-inflammatory preparations. The fungi were all susceptible to both Ketoconazole and Fluconazole but the bacteria were resistant to all the conventional antibiotics except Ciprofloxacin and Gentamycin.

CONCLUSION

Unorthodox ophthalmic preparations found on the Ghanaian market are contaminated with bacteria and fungi of clinical importance.

Ashworth A, Ricke SC. A Historical Review on Antibiotic Resistance of Foodborne Campylobacter

Campylobacter is one of the most commonly reported foodborne human bacterial gastrointestinal pathogens. Campylobacter is the etiological agent of campylobacteriosis, which is generally a self-limited illness and therefore does not require treatment. However, when patients are immunocompromised or have other co-morbidities, antimicrobial treatment may be necessary for clinical treatment of campylobacteriosis, macrolides and fluoroquinolones are the drugs of choices. However, the increase in antimicrobial resistance of Campylobacter to clinically important antibiotics may become insurmountable. Because of the transmission between poultry and humans, the poultry industry must now allocate resources to address the problem by reducing Campylobacter as well as antimicrobial use, which may reduce resistance. This review will focus on the incidence of antibiotic-resistant Campylobacter in poultry, the clinical consequences of this resistance, and the mechanisms of antibiotic resistance associated with Campylobacter.

Assessing the Impact of Animal Husbandry and Capture on Anemia among Women and Children in Low- and Middle-Income Countries: A Systematic Review

Animal husbandry and capture (AHC) may mitigate anemia among women and children by supplying a source of micronutrient-rich animal source foods (ASF), yet may concurrently increase exposure to anemia-inducing pathogens such as Plasmodium spp., helminths, and enteropathogens. We conducted a systematic literature review to assess the relation between AHC and anemia among women of reproductive age, school-aged children, and children aged <5 y in low- and middle-income countries (LMICs). We used a 2-stage screening process, in which 1 reviewer searched 4 databases (PubMed, Web of Science, EMBASE, and Global Health) with predetermined search terms for relevant articles. Two reviewers then independently screened studies using a priori exclusion criteria, yielding a total of 23 articles included in the final review. We evaluated evidence from observational studies assessing animal-dependent livelihoods and livestock ownership, and interventions that promoted livestock and fish production. We found little consistency in anemia outcomes across the several AHC exposures and population groups. Poultry production interventions had modest benefits on anemia among women and children, although whether these improvements were a result of increased ASF consumption, or a result of the combined treatment study design could not be determined. Observational studies identified chicken ownership, and no other livestock species, as a risk factor for anemia among young children. However, there was limited evidence to evaluate pathways underlying these associations. Studies tended to rely on self-reported fever and diarrhea to assess illness, and no study directly assessed linkages between AHC, pathogen burden, and anemia. Thus, there is insufficient evidence to conclude whether AHC improves or worsens anemia among women and children in LMICs. Given the current interest in promoting animal production among low-income households, future studies with robust measures of livestock ownership, ASF consumption, pathogen burden, and anemia status are needed to understand the nuances of this complex and potentially contradictory relation.

Human Intestinal Enteroids: New Models to Study Gastrointestinal Virus Infections

Human rotavirus (HRV) and human norovirus (HuNoV) infections are recognized as the most common causes of epidemic and sporadic cases of gastroenteritis worldwide. The study of these two human gastrointestinal viruses is important for understanding basic virus-host interactions and mechanisms of pathogenesis and to establish models to evaluate vaccines and treatments. Despite the introduction of live-attenuated vaccines to prevent life-threatening HRV-induced disease, the burden of HRV illness remains significant in low-income and less-industrialized countries, and small animal models or ex vivo models to study HRV infections efficiently are lacking. Similarly, HuNoVs remained non-cultivatable until recently. With the advent of non-transformed human intestinal enteroid (HIE) cultures, we are now able to culture and study both clinically relevant HRV and HuNoV in a biologically relevant human system. Methods described here will allow investigators to use these new culture techniques to grow HRV and HuNoV and analyze new aspects of virus replication and pathogenesis.

Subclinical Enteric Parasitic Infections and Growth Faltering in Infants in São Tomé, Africa: A Birth Cohort Study

The associations between enteric pathogenic parasites and growth in infants in São Tomé were explored using a refined anthropometric approach to recognize early growth faltering. A birth cohort study was conducted with follow-up to 24 months of age. Microscopic examination for protozoa and soil-transmitted helminths was performed. Anthropometric assessments included: z-scores for weight-for-length (WLZ), length-for-age (LAZ), weight (WAVZ) and length velocities (LAVZ), length-for-age difference (LAD), and wasting and stunting risk (≤-1 SD). Generalized additive mixed effects regression models were used to explore the associations between anthropometric parameters and enteric parasitic infections and cofactors. A total of 475 infants were enrolled, and 282 completed the study. The great majority of infants were asymptomatic. Giardia lamblia was detected in 35.1% of infants in at least one stool sample, helminths in 30.4%, and Cryptosporidium spp. in 14.7%. Giardia lamblia and helminth infections were significantly associated with mean decreases of 0.10 in LAZ and 0.32 in LAD, and of 0.16 in LAZ and 0.48 in LAD, respectively. Cryptosporidium spp. infection was significantly associated with a mean decrease of 0.43 in WAVZ and 0.55 in LAVZ. The underestimated association between subclinical parasitic enteric infections and mild growth faltering in infants should be addressed in public health policies.

Overweight and obesity epidemic in Ghana-a systematic review and meta-analysis

Background

In many low and middle income countries (LMICs), the distribution of adulthood nutritional imbalance is shifting from a predominance of undernutrition to overnutrition. This complex problem poses a huge challenge to governments, non-state actors, and individuals desirous of addressing the problem of malnutrition in LMICs. The objective of this study was to systematically review the literature towards providing an estimate of the prevalence of overweight and obesity among adult Ghanaians.

Methods

This study followed the recommendations outlined in the PRISMA statement. Searches were performed in PubMed, Science Direct, google scholar, Africa Journals Online (AJOL) and the WHO African Index Medicus database. This retrieved studies (published up to 31st March 2016) that reported overweight and obesity prevalence among Ghanaians. All online searches were supplemented by reference screening of retrieved papers to identify additional studies.

Results

Forty-three (43) studies involving a total population of 48,966 sampled across all the ten (10) regions of Ghana were selected for the review. Our analysis indicates that nearly 43% of Ghanaian adults are either overweight or obese. The national prevalence of overweight and obesity were estimated as 25.4% (95% CI 22.2–28.7%) and 17.1% (95% CI = 14.7–19.5%), respectively. Higher prevalence of overweight (27.2% vs 16.7%) and obesity (20.6% vs 8.0%) were estimated for urban than rural dwellers. Prevalence of overweight (27.8% vs 21.8%) and obesity (21.9% vs 6.0%) were also significantly higher in women than men. About 45.6% of adult diabetes patients in Ghana are either overweight or obese. At the regional level, about 43.4%, 36.9%, 32.4% and 55.2% of residents in Ashanti, Central, Northern and Greater Accra region, respectively are overweight or obese. These patterns generally mimic the levels of urbanization. Per studies’ publication years, consistent increases in overweight and obesity prevalence were observed in Ghana in the period 1998–2016.

Conclusions

There is a high and rising prevalence of overweight and obesity among Ghanaian adults. The possible implications on current and future population health, burden of chronic diseases, health care spending and broader economy could be enormous for a country still battling many infectious and parasitic diseases. Public health preventive measures that are appropriate for the Ghanaian context, culturally sensitive, cost-effective and sustainable are urgently needed to tackle this epidemic.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-3901-4) contains supplementary material, which is available to authorized users.