Campylobacter infection in children in Malawi is common and is frequently associated with enteric virus co-infections

Seasonal variation of diarrhoeal pathogens among Guinea-Bissauan children under five years of age

BACKGROUND

Diarrhoea remains a major cause of childhood morbidity and mortality in low-income countries (LICs). The frequency of diarrhoeal episodes may vary by season, yet few prospective cohort studies have examined seasonal variation among various diarrhoeal pathogens using multiplex qPCR to analyse bacterial, viral and parasitic pathogens.

METHODS

We combined our recent qPCR data of diarrhoeal pathogens (nine bacterial, five viral and four parasitic) among Guinea-Bissauan children under five years old with individual background data, dividing by season. The associations of season (dry winter and rainy summer) and the various pathogens were explored among infants (0-11 months) and young children (12-59 months) and those with and without diarrhoea.

RESULTS

Many bacterial pathogens, especially EAEC, ETEC and Campylobacter, and parasitic Cryptosporidium, prevailed in the rainy season, whereas many viruses, particularly the adenovirus, astrovirus and rotavirus proved common in the dry season. Noroviruses were found constantly throughout the year. Seasonal variation was observed in both age groups.

CONCLUSION

In childhood diarrhoea in a West African LIC, seasonal variation appears to favour EAEC, ETEC, and Cryptosporidium in the rainy and viral pathogens in the dry season.

Prevalence and antimicrobial resistance profiles of Campylobacter species in South Africa: a "One Health" approach using systematic review and meta-analysis

OBJECTIVES

This study investigated the prevalence and antibiotic resistance (AR) profiles of Campylobacter spp. isolated from animals, humans, and the environment in South Africa based on available published data.

METHODS

Original articles published from January 1, 1990 to January 1, 2021 were searched from PubMed, ScienceDirect, Google Scholar, Africa Index Medicus, Scopus, and African Journal Online databases. Data were analyzed with Comprehensive Meta-Analysis (version 3.0).

RESULTS

After screening, articles on animals (n = 25), humans (n = 7), environment (n = 3), animals/environment (n = 2), and a (n = 1) study on animals, humans, and the environment were included in this review. The pooled prevalence estimates (PPEs) were 28.8%, 16.4%, and 28.4% in animals, humans, and the environment, respectively. The Campylobacter jejuni and Campylobacter coli species were commonly isolated from humans, animals, and the environment in South Africa. The AR profiles were screened from 2032 Campylobacter spp., with the highest PPE of AR observed against clindamycin (76.9%) and clarithromycin (76.5%). Campylobacter isolates tested with the disk diffusion assay and minimum inhibitory concentration methods recorded an overall AR prevalence of 35.3% and 37.1%, respectively, whereas multidrug resistance PPE was 35.3%.

CONCLUSION

Regular surveillance of Campylobacter spp. prevalence and its antimicrobial resistance strains is recommended, as well as the formulation of a "One Health" approach for better management and control of Campylobacter spp. infection in South Africa.

Development and validation of a CRISPR interference system for gene regulation in Campylobacter jejuni

BACKGROUND

Campylobacter spp. are the leading cause of bacterial food-borne illness in humans worldwide, with Campylobacter jejuni responsible for 80% of these infections. There is an urgent need to understand fundamental C. jejuni biology for the development of new strategies to prevent and treat infections. The range of molecular tools available to regulate gene expression in C. jejuni is limited, which in turn constrains our ability to interrogate the function of essential and conditionally essential genes. We have addressed this by developing and utilising a CRISPR-based interference system known as CRISPRi in C. jejuni to control gene expression. To achieve this, a catalytically inactive ("dead") cas9 and sgRNA backbone from the Streptococcus pyogenes CRISPRi system was combined with C. jejuni-derived promoters of predetermined expression activities to develop a CRISPRi-based repression tool in C. jejuni strains M1Cam and 81-176.

RESULTS

The CRISPRi tool was validated through successful repression of the arylsulphatase-encoding gene astA using a range of sgRNA target sequences spanning the astA gene. The tool was also applied to target astA in an M1Cam CRISPR-Cas9 deletion strain, which showed that the presence of an endogenous CRISPR-Cas9 system did not affect the activity of the CRISPRi-based repression tool. The tool was further validated against the hippicurase-encoding gene hipO. Following this, the flagella genes flgR, flaA, flaB and both flaA and flaB were targeted for CRISPRi-based repression, which resulted in varying levels of motility reduction and flagella phenotypes as determined by phenotypical assays and transmission electron microscopy (TEM).

CONCLUSIONS

This is the first report of a CRISPRi-based tool in C. jejuni, which will provide a valuable resource to the Campylobacter community.

Reactive arthritis incidence in a community cohort following a large waterborne campylobacteriosis outbreak in Havelock North, New Zealand

OBJECTIVES

In August 2016, Campylobacter spp contaminated an untreated reticulated water supply resulting in a large-scale gastroenteritis outbreak affecting an estimated 8320 people. We aimed to determine the incidence of probable reactive arthritis (ReA) cases in individuals with culture-confirmed campylobacteriosis (CC), self-reported probable campylobacteriosis (PC) and those reporting no diarrhoea (ND).

DESIGN

We conducted a retrospective cohort study to identify incidence of probable ReA cases. We identified cases with new ReA symptoms using an adapted acute ReA (AReA) telephone questionnaire. Those reporting ≥1 symptom underwent a telephone interview with the study rheumatologist. Probable ReA was defined as spontaneous onset of pain suggestive of inflammatory arthritis in ≥1 previously asymptomatic joint for ≥3 days occurring ≤12 weeks after outbreak onset.

SETTING

Population-based epidemiological study in Havelock North, New Zealand.

PARTICIPANTS

We enrolled notified CC cases with gastroenteritis symptom onsets 5 August 2016-6 September 2016 and conducted a telephone survey of households supplied by the contaminated water source to enrol PC and ND cases.

RESULTS

One hundred and six (47.3%) CC, 47 (32.6%) PC and 113 (34.3%) ND cases completed the AReA telephone questionnaire. Of those reporting ≥1 new ReA symptom, 45 (75.0%) CC, 13 (68.4%) PC and 14 (82.4%) ND cases completed the rheumatologist telephone interview. Nineteen CC, 4 PC and 2 ND cases developed probable ReA, resulting in minimum incidences of 8.5%, 2.8% and 0.6% and maximum incidences of 23.9%, 12.4% and 2.15%.

DISCUSSION

We describe high probable ReA incidences among gastroenteritis case types during a very large Campylobacter gastroenteritis outbreak using a resource-efficient method that is feasible to employ in future outbreaks.

Prevalence, determinants, and antimicrobial susceptibility patterns of Campylobacter infection among under-five children with diarrhea at Governmental Hospitals in Hawassa city, Sidama, Ethiopia. A cross-sectional study

Background

Campylobacteriosis, is a zoonotic bacterial disease observed with a rising worldwide. It is becoming the most commonly recognized cause of bacterial gastroenteritis in under-five mortality in recent years. This study was done to determine the prevalence and determinants of Campylobacter infection among under-fives with acute watery diarrhea.

Methods

This institutional-based cross-sectional study was conducted at governmental and private health institutions in Hawassa city. All outpatient under-five children who met the inclusion criteria from April 2021 to August 2021 were enrolled in this study. Demographic and clinical data were obtained using a standardized data collection tool. Stool samples were collected from each participant with a sterile container and inoculated on a campylobacter agar media. The isolates were identified by using biochemical tests and a disc diffusion technique was performed to determine the antimicrobial sensitivity patterns of the isolates. Data were entered and analyzed using SPSS version 21. Descriptive and Logistic regression analysis was applied to determine the determinants of Campylobacter infection. P-value < 0.05 was considered statistically significant.

Results

A total of 235 under-five children were enrolled in this study with a 100% response rate. Of these 130 (55.3%) and 105(44.7%) were males and females respectively with the age range of 2 months to 60 months with the mean age of 25 months. The majority of the 150 (63.2%) were rural residents. Of 235 under-fives with acute watery diarrhea, 16 (6.8%) patients were found to have Campylobacter infection with (95% CI, 3.8–10.2%). Consumption of pasteurized milk (AOR: 0.12; 95% CI 0.02–0.75, P<0.05), presence of domestic animals like cats, hens, and cows (AOR: 0.09: 95% CI 0.01–0.67, P<0.05), absence of handwashing practice before food preparation (AOR: 3.63, 95% CI 1.15–11.46, P<0.05) showed significant association with campylobacter infection.

The antimicrobial susceptibility patterns of the isolated bacteria were 100% sensitivity to Azithromycin, Chloramphenicol, and Gentamicin, however; it was 100% resistant to Cephalothin. The associations of socio-demographic, environmental, and behavioral factors were compared and consumption of unpasteurized milk, the presence of domestic animal like the cat was significantly associated.

Conclusion

Campylobacter infection showed a comparatively low prevalence in under-fives with acute watery diarrhea. In this study contact with cats, consumption of unpasteurized milk were associated with Campylobacter infection. The treatment approach of Campylobacter infection must consider the sensitivity profile of antibiotics as indicated in the study. We, therefore, recommend further studies to determine the species responsible for Campylobacter infection with other co-morbidities and the susceptibility pattern for each species to indicate appropriate antibiotic therapy.

Genomic diversity and antimicrobial resistance of Campylobacter spp. from humans and livestock in Nigeria

Background

Campylobacter spp. are zoonotic pathogens, ubiquitous and are found naturally as commensals in livestock from where they can be transmitted to humans directly or through animal products. The genomic diversity and antimicrobial resistance profile of Campylobacter was investigated with a focus on C. jejuni and C. coli in humans and livestock (poultry and cattle) from Nigeria.

Methods

586 human stool samples and 472 faecal samples from livestock were cultured for thermophilic Campylobacter species on modified charcoal cefoperazone deoxycholate agar (mCCDA). Culture in combination with whole genome sequencing identified and confirmed the presence of Campylobacter in humans and animals from the study area. Further analysis of the sequences was performed to determine multilocus sequence types and genetic determinants of antimicrobial resistance to fluoroquinolone, betalactam, tetracycline and macrolide classes of antimicrobials.

Results

From the human stool samples tested, 50 (9%) were positive of which 33 (66%) were C. jejuni, 14 (28%) were C. coli while 3 (6%) were C. hyointestinalis. In livestock, 132 (28%) were positive. Thirty one (7%) were C. jejuni while 101 (21%) were C. coli. Whole genome sequencing and MLST of the isolates revealed a total of 32 sequence types (STs) identified from 47 human isolates while 48 STs were identified in 124 isolates from livestock indicating a population which was overall, genetically diverse with a few more dominant strains. The antimicrobial resistance profiles of the isolates indicated a higher prevalence of resistance in Campylobacter isolated from livestock than in humans. Generally, resistance was greatest for betalactams (42%) closely followed by fluoroquinolones (41%), tetracyclines (15%) and lastly macrolides (2%). Multidrug resistance to three or more antimicrobials was observed in 24 (13%) isolates from humans (n = 1, 4%) and chicken (n = 23, 96%).

Conclusions

This study has further contributed information about the epidemiology, genetic diversity and antimicrobial resistance profile of thermophilic Campylobacter in Nigeria.

Impact of sampling depth on pathogen detection in pit latrines

Wastewater based epidemiology (WBE) is increasingly used to provide decision makers with actionable data about community health. WBE efforts to date have primarily focused on sewer-transported wastewater in high-income countries, but at least 1.8 billion people in low- and middle-income countries (LMIC) use onsite sanitation systems such as pit latrines and septic tanks. Like wastewater, fecal sludges from such systems offer similar advantages in community pathogen monitoring and other epidemiological applications. To evaluate the distribution of enteric pathogens inside pit latrines-which could inform sampling methods for WBE in LMIC settings unserved by sewers-we collected fecal sludges from the surface, mid-point, and maximum-depth of 33 pit latrines in urban and peri-urban Malawi and analyzed the 99 samples for 20 common enteric pathogens via multiplex quantitative reverse transcription PCR. Using logistic regression adjusted for household population, latrine sharing, the presence of a concrete floor or slab, water source, and anal cleansing materials, we found no significant difference in the odds of detecting the 20 pathogens from the mid-point (adjusted odds ratio, aOR = 1.1; 95% confidence interval = 0.73, 1.6) and surface samples (aOR = 0.80, 95% CI = 0.54, 1.2) compared with those samples taken from the maximum depth. Our results suggest that, for the purposes of routine pathogen monitoring, pit latrine sampling depth does not strongly influence the odds of detecting enteric pathogens by molecular methods. A single sample from the pit latrines' surface, or a composite of surface samples, may be preferred as the most recent material contributed to the pit and may be easiest to collect.

A systematic review and meta-analysis reveal that Campylobacter spp. and antibiotic resistance are widespread in humans in sub-Saharan Africa

INTRODUCTION

Campylobacter spp. are zoonotic bacteria that cause gastroenteritis in humans worldwide, whose main symptom is diarrhea. In certain cases, extra intestinal manifestations may occur, such as Guillain Barré syndrome. The bacteria cause severe diarrhea mostly in children and in immunocompromised individuals. This review aims to address the prevalence of Campylobacter spp. in humans in sub-Saharan Africa. It also aims to understand the impact of HIV in the prevalence, as well as to report data on antibiotic resistance and propose research priorities.

METHODS

We followed PRISMA guidelines to find studies on the occurrence of Campylobacter spp. in humans in all countries from sub-Saharan Africa. Studies published between 2000 and 2020 were searched in PubMed, Cochrane Library, CINAHL, African Index Medicus, African Journals Online, Google Scholar and Science Direct. We have conducted a random-effect meta-analysis and calculated the proportion of resistant isolates to different antibiotics.

RESULTS AND DISCUSSION

We found 77 studies that described such occurrence in humans in 20 out of 53 sub-Saharan African countries. Campylobacter jejuni was the most prevalent species. Pooled prevalence was 9.9% (CI: 8.4%-11.6%). No major variations within the different sub-regions were found. Most studies reported Campylobacter spp. as the cause of diarrhea, mainly in children. Some studies reported the bacteria as a possible etiologic agent of acute flaccid paralysis and urinary tract infection. Campylobacter spp. presented a higher pooled prevalence in HIV infected patients, although not statistically significant. High proportions of resistant strains were reported for many antibiotics, including erythromycin and tetracycline.

CONCLUSION

Campylobacter spp. occur in sub-Saharan Africa, although information is scarce or inexistent for many countries. Research priorities should include investigation of the understudied species; extra intestinal manifestations; the impact of HIV infection and associated risk factors. Control strategies should be reinforced to contain the spread of this pathogen and drug resistance.

Characterization of Campylobacter associated gastric enteritis among patients with Human Immunodeficiency Virus (HIV) in a hospital in Accra, Ghana

BACKGROUND

Campylobacter infections in HIV positive patients often present with substantial mortality and morbidity when compared to HIV negative patients.

AIM

This study assessed the prevalence of Campylobacter, antibiotic resistance phenotypes and genetic factors, and risk of Campylobacter infection associated with living in close proximity to domestic animals in HIV patients with gastric enteritis at Korle-Bu Teaching Hospital, Accra, Ghana.

METHODS

Resistance to different antibiotics was assessed with Kirby-Bauer disk diffusion method. In addition, all the Campylobacter isolates were tested for ampicillin (blaOXA-61), erythromycin (aph-3-1), tetracycline tet(O), streptomycin (aadE), and the energy-dependent multi-drug efflux pump (cmeB) resistance genes using multiplex polymerase chain reaction.

RESULTS

Out of a total of 140 (97 females and 43 males) tested patients, 71 (50.7%) patients were positive for Campylobacter coli. Female patients aged within 31-40 years (31.6%) and 41-50 years (31.6%) had high frequency of Campylobacter infection. Most of the infected patients lived in close proximity to chickens (53.5%), however, some patients (14.1%) lived in close proximity to goats. Phenotypic resistance evaluation revealed widespread resistance to ampicillin (100%), tetracycline (100%), ciprofloxacin (71.8%), erythromycin (69%), and gentamicin (49.3%). However, limited no of isolates contained blaOXA-61 (1.41%), cmeB (7.0%) and tet(O (7.0%) resistance genes.

CONCLUSION

HIV patients with gastric enteritis were infected with resistant Campylobacter coli. Further studies are required to examine correlation of infected patients with C. coli and risk of living in close proximity to poultry birds. There is the need for routine investigation of Campylobacter in patients with gastroenteritis in order to assist in the development of strategies for combating diseases involving resistant zoonotic bacteria strains.

Genomic epidemiology of Campylobacter jejuni associated with asymptomatic pediatric infection in the Peruvian Amazon

Campylobacter is the leading bacterial cause of gastroenteritis worldwide and its incidence is especially high in low- and middle-income countries (LMIC). Disease epidemiology in LMICs is different compared to high income countries like the USA or in Europe. Children in LMICs commonly have repeated and chronic infections even in the absence of symptoms, which can lead to deficits in early childhood development. In this study, we sequenced and characterized C. jejuni (n = 62) from a longitudinal cohort study of children under the age of 5 with and without diarrheal symptoms, and contextualized them within a global C. jejuni genome collection. Epidemiological differences in disease presentation were reflected in the genomes, specifically by the absence of some of the most common global disease-causing lineages. As in many other countries, poultry-associated strains were likely a major source of human infection but almost half of local disease cases (15 of 31) were attributable to genotypes that are rare outside of Peru. Asymptomatic infection was not limited to a single (or few) human adapted lineages but resulted from phylogenetically divergent strains suggesting an important role for host factors in the cryptic epidemiology of campylobacteriosis in LMICs.

Prevalence and susceptibility to antibiotics from Campylobacter jejuni and Campylobacter coli isolated from chicken meat in southern Benin, West Africa

Objective

Poultry is commonly considered to be the primary vehicle for Campylobacter infection in humans. The aim of this study is to assess the risk of Campylobacteriosis in chicken meat consumers in southern Benin by assessing the prevalence and resistance profile of Campylobacter coli and Campylobacter jejuni isolated from chicken thigh in Southern Benin.

Results

The contamination rate of Campylobacter in the samples was 32.8%. From this percentage, 59.5% were local chicken thighs and 40.5% of imported chicken thighs (p = 0.045). After molecular identification, on the 256 samples analyzed, the prevalence of C. jejuni was 23.4% and 7.8% for C. coli, with a concordance of 0.693 (Kappa coefficient of concordance) with the results from phenotypic identification. Seventy-two-point seven percent of Campylobacter strains were resistant to Ciprofloxacin, 71.4% were resistant to Ampicillin and Tetracycline. 55.8% of the strains were multi-drug resistant.

Risk factors and transmission pathways associated with infant Campylobacter spp. prevalence and malnutrition: A formative study in rural Ethiopia

Early infection from enteropathogens is recognised as both a cause and effect of infant malnutrition. Specifically, evidence demonstrates associations between growth shortfalls and Campylobacter infection, endemic across low-income settings, with poultry a major source. Whilst improvements in water, sanitation and hygiene (WASH) should reduce pathogen transmission, interventions show inconsistent effects on infant health. This cross-sectional, formative study aimed to understand relationships between infant Campylobacter prevalence, malnutrition and associated risk factors, including domestic animal husbandry practices, in rural Ethiopia. Thirty-five households were visited in Sidama zone, Southern Nations, Nationalities and Peoples' region. Infant and poultry faeces and domestic floor surfaces (total = 102) were analysed for presumptive Campylobacter spp. using selective culture. Infant anthropometry and diarrhoeal prevalence, WASH facilities and animal husbandry data were collected. Of the infants, 14.3% were wasted, 31.4% stunted and 31.4% had recent diarrhoea. Presumptive Campylobacter spp. was isolated from 48.6% of infant, 68.6% of poultry and 65.6% of floor surface samples. Compared to non-wasted infants, wasted infants had an increased odds ratio (OR) of 1.41 for a Campylobacter-positive stool and 1.81 for diarrhoea. Positive infant stools showed a significant relationship with wasting (p = 0.026) but not stunting. Significant risk factors for a positive stool included keeping animals inside (p = 0.027, OR 3.5), owning cattle (p = 0.018, OR 6.5) and positive poultry faeces (p<0.001, OR 1.34). Positive floor samples showed a significant correlation with positive infant (p = 0.023), and positive poultry (p = 0.013, OR 2.68) stools. Ownership of improved WASH facilities was not correlated with lower odds of positive stools. This formative study shows a high prevalence of infants positive for Campylobacter in households with free-range animals. Findings reaffirm contaminated floors as an important pathway to infant pathogen ingestion and suggest that simply upgrading household WASH facilities will not reduce infection without addressing the burden of contamination from animals, alongside adequate separation in the home.

Anthropogenic landscapes increase Campylobacter jejuni infections in urbanizing banded mongoose (Mungos mungo): A one health approach

Background

Campylobacter is a common, but neglected foodborne-zoonotic pathogen, identified as a growing cause of foodborne disease worldwide. Wildlife and domestic animals are considered important reservoirs, but little is known about pathogen infection dynamics in free-ranging mammalian wildlife particularly in sub-Saharan Africa. In countries like Botswana, there is significant overlap between humans and wildlife, with the human population having one of the highest HIV infection rates in the world, increasing vulnerability to infection.

Methodology/Principal findings

We investigated Campylobacter occurrence in archived human fecal samples (children and adults, n = 122, 2011), feces from free-ranging banded mongooses (Mungos mungo, n = 201), surface water (n = 70), and river sediment samples (n = 81) collected in 2017 from the Chobe District, northern Botswana. Campylobacter spp. was widespread in humans (23.0%, 95% CI 13.9–35.4%), with infections dominantly associated with C. jejuni (82.1%, n = 28, 95% CI 55.1–94.5%). A small number of patients presented with asymptomatic infections (n = 6). While Campylobacter spp. was rare or absent in environmental samples, over half of sampled mongooses tested positive (56%, 95% CI 45.6–65.4%). Across the urban-wilderness continuum, we found significant differences in Campylobacter spp. detection associated with the type of den used by study mongooses. Mongooses utilizing man-made structures as den sites had significantly higher levels of C. jejuni infection (p = 0.019) than mongooses using natural dens. Conversely, mongooses using natural dens had overall higher levels of detection of Campylobacter at the genus level (p = 0.001).

Conclusions

These results suggest that landscape features may have important influences on Campylobacter species exposure and transmission dynamics in wildlife. In particular, data suggest that human-modified landscapes may increase C. jejuni infection, a primarily human pathogen, in banded mongooses. Pathogen circulation and transmission in urbanizing wildlife reservoirs may increase human vulnerability to infection, findings that may have critical implications for both public and animal health in regions where people live in close proximity to wildlife.

Campylobacter infections are increasing worldwide but we still know little about the true burden of disease in the developing world, and even less about the role of wildlife and environmental reservoirs in human exposure and infection. Here we take a one-health approach evaluating Campylobacter infections in humans, banded mongooses (Mungos mungo), and the environment. We found evidence of widespread infection with Campylobacter spp. infecting nearly a quarter of sampled adults and children (23.0%, n = 122, 2011), dominantly with C. jejuni. Banded mongooses live in close association with humans in the area and over half of the animals sampled were found positive for Campylobacter spp. (56%, n = 201, 2017). Infection with C. jejuni was greater among mongooses utilizing human-made structures as den sites than those using natural dens. These data suggest that wildlife utilization of anthropogenic landscapes may increase C. jejuni exposure and infection. In turn, pathogen circulation and transmission in urbanizing wildlife reservoirs may increase human vulnerability to infection, particularly impoverished populations, where greater environmental exposures are expected.

Prevalence, Risk Factors, and Antimicrobial Resistance Profiles of Thermophilic Campylobacter Species in Humans and Animals in Sub-Saharan Africa: A Systematic Review

Thermophilic Campylobacter species are clinically important aetiologies of gastroenteritis in humans throughout the world. The colonization of different animal reservoirs by Campylobacter poses an important risk for humans through shedding of the pathogen in livestock waste and contamination of water sources, environment, and food. A review of published articles was conducted to obtain information on the prevalence and antimicrobial resistance (AMR) profiles of thermophilic Campylobacter species in humans and animals in sub-Saharan Africa (SSA). Electronic databases, namely, PubMed, Google Scholar, Research4life-HINARI Health, and Researchgate.net, were searched using the following search terms “thermophilic Campylobacter,” “Campylobacter jejuni,” “Campylobacter coli,” “diarrhea/diarrhoea,” “antimicrobial resistance,” “antibiotic resistance,” “humans,” “animals,” “Sub-Saharan Africa,” and “a specific country name.” Initially, a total of 614 articles were identified, and the lists of references were screened in which 22 more articles were identified. After screening, 33 articles on humans and 34 on animals and animal products were included in this review. In humans, Nigeria reported the highest prevalence (62.7%), followed by Malawi (21%) and South Africa (20.3%). For Campylobacter infections in under-five children, Kenya reported 16.4%, followed by Rwanda (15.5%) and Ethiopia (14.5%). The country-level mean prevalence in all ages and under-five children was 18.6% and 9.4%, respectively. The prevalence ranged from 1.7%–62.7% in humans and 1.2%–80% in animals. The most reported species were C. jejuni and C. coli. The AMR to commonly used antimicrobials ranged from 0–100% in both humans and animals. Poultry consumption and drinking surface water were the main risk factors for campylobacteriosis. The present review provides evidence of thermophilic Campylobacter occurrence in humans and animals and high levels of AMR in SSA, emphasizing the need for strengthening both national and regional multisectoral antimicrobial resistance standard surveillance protocols to curb both the campylobacteriosis burden and increase of antimicrobial resistance in the region.

Magnitude of Rotavirus A and Campylobacter jejuni infections in children with diarrhea in Twin cities of Rawalpindi and Islamabad, Pakistan

Background

Acute diarrhea is a leading cause of morbidity and mortality in children particularly in developing countries of Asia and Africa. The present study was conducted to detect the two most important pathogens, rotavirus and Campylobacter Jejuni in children suffering with diarrhea in Rawalpindi and Islamabad, Pakistan in 2014. The clinical and epidemiological aspects of the disease were also investigated.

Methods

A total of 500 stool samples were collected from children presented with clinical signs and symptoms of acute diarrhea. The samples were initially screened for the presence of rotavirus A (RVA) via ELISA (Enzyme-linked immunosorbent assay) and RT-PCR (Reverse Transcriptase PCR) and then were analysed for C. jejuni by using species specific PCR assay.

Results

The detection rate of RVA was 26.4% (132/500) while, Campylobacter was detected in 52% (260/500) of samples with C. jejuni accounted for 48.2% (241/500) of all study cases. Co-infection of C. jejuni with RVA was identified in 21.8% of all cases. Children with RVA and C. jejuni co-infection showed a higher probability (p = 0.01) to be dehydrated. A significant association (p = 0.02) was found between C. jejuni positive status and fever in children. The median age of children with both RVA and C. jejuni infection was 6–11 months. The RVA detection rate was high in winter months of the year while, C. jejuni infections were documented high in summer over 1 year study period.

Conclusions

The overall results have demonstrated the high prevalence of C. jejuni in Rawalpindi, Islamabad, Pakistan in 2014. The results of present study will not only help to calculate disease burden caused by C. jejuni and rotavirus but also will provide critical information to health authorities in planning public health care strategies against these pathogens.

Human campylobacteriosis: A public health concern of global importance

Campylobacter species are among the leading cause of bacterial foodborne and waterborne infections. In addition, Campylobacter is one of the major causative agent of bacterial gastrointestinal infections and the rise in the incidence of Campylobacter infections have been reported worldwide. Also, the emergence of some Campylobacter species as one of the main causative agent of diarrhea and the propensity of these bacteria species to resist the actions of antimicrobial agents; position them as a serious threat to the public health. This paper reviews Campylobacter pathogenicity, infections, isolation and diagnosis, their reservoirs, transmission pathways, epidemiology of Campylobacter outbreaks, prevention and treatment option, antibiotics resistance and control of antibiotics use.

Campylobacter at the Human-Food Interface: The African Perspective

The foodborne pathogen Campylobacter is a major cause of human gastroenteritis, accounting for an estimated annual 96 million cases worldwide. Assessment of the true burden of Campylobacter in the African context is handicapped by the under-reporting of diarrhoeal incidents and ineffective monitoring and surveillance programmes of foodborne illnesses, as well as the minimal attention given to Campylobacter as a causative agent of diarrhoea. The present review of the literature highlights the variability in the reported occurrence of Campylobacter in humans and animal food sources across different countries and regions in Africa. Campylobacter infection is particularly prevalent in the paediatric population and has been isolated from farm animals, particularly poultry, and foods of animal origin. The reported prevalence of Campylobacter in children under the age of five years ranges from 2% in Sudan to 21% in South Africa. In poultry, the prevalence ranges from 14.4% in Ghana to 96% in Algeria. This review also highlights the alarming trend of increased Campylobacter resistance to clinically important antimicrobials, such as ciprofloxacin and erythromycin, in humans and food animals in Africa. This review adds to our understanding of the global epidemiology of Campylobacter at the human–food animal interface, with an emphasis from the African perspective. Interinstitutional and intersectoral collaborations, as well as the adoption of the One Health approach, would be useful in bridging the gaps in the epidemiological knowledge of Campylobacter in Africa.

Enhanced microbiological surveillance reveals that temporal case clusters contribute to the high rates of campylobacteriosis in a model agroecosystem

Infections by pathogenic Campylobacter species were determined in diarrheic (n = 2,217) and non-diarrheic control (n = 104) people in Southwestern Alberta (SWA), Canada over a 1-year period using specialized and conventional isolation, and direct PCR. Overall, 9.9% of diarrheic individuals were positive for C. jejuni (9.1%), C. upsaliensis (0.6%), and C. coli (0.5%). No C. lari was detected. Four diarrheic individuals were co-infected with C. jejuni and C. coli, and four different individuals were co-infected with C. jejuni and C. upsaliensis. Two control individuals were positive for C. jejuni. Approximately 50% of stools containing C. jejuni and/or C. coli were deemed negative by conventional isolation. Direct PCR for C. jejuni was less effective than culture-based detection. Most C. jejuni infections occurred in people living in the urban centers, but the prevalence of the bacterium was lower in females than males living in urban locations, and both males and females living in rural locations. Although C. jejuni was detected throughout the year, a trend for higher infection rates was observed in the late spring to early fall with a peak in August. Forty-six C. jejuni subtype clusters were identified, including 44 temporal case clusters attributed to 28 subtype groupings. The majority of infections (70.3%) were linked to subtypes associated with beef cattle. We conclude that many occurrences of pathogenic Campylobacter species were not detected by the conventional laboratory methodology, and temporal case clusters of C. jejuni subtypes associated with cattle contribute to the high rates of campylobacteriosis in SWA.

Clinical application of a multiplex genetic pathogen detection system remaps the aetiology of diarrhoeal infections in Shanghai

Background

Culture-based diagnostic methods cannot achieve rapid and precise diagnoses for the identification of multiple diarrhoeal pathogens (DPs). A high-throughput multiplex genetic detection system (HMGS) was adapted and evaluated for the simultaneous identification and differentiation of infectious DPs and a broad analysis of DP infection aetiology.

Results

DP-HMGS was highly sensitive and specific for DP detection compared with culture-based techniques and was similar to singleplex real-time PCR. The uniform level of sensitivity of DP-HMGS for all DPs allowed us to remap the aetiology of acute diarrhoeal infections in Shanghai, correcting incidences of massively underdiagnosed DP species with accuracy approaching that of sequencing-based methods. The most frequent DPs were enteropathogenic Escherichia coli, rotavirus and Campylobacter jejuni. DP-HMGS detected two additional causes of infectious diarrhoea that were previously missed by routine culture-based methods: enterohemorrhagic E. coli and Yersinia enterocolitica. We demonstrated the age dependence of specific DP distributions, especially the distributions of rotavirus, intestinal adenovirus and Clostridium difficile in paediatric patients as well as those of dominant bacterial infections in adults, with a distinct “top 3” pattern for each age group. Finally, the multiplexing capability and high sensitivity of DP-HMGS allowed the detection of infections co-induced by multiple pathogens (approximately 1/3 of the cases), with some DPs preferentially co-occurring as infectious agents.

Conclusions

DP-HMGS has been shown to be a rapid, specific, sensitive and appropriate method for the simultaneous screening/detection of polymicrobial DP infections in faecal specimens. Widespread use of DP-HMGS is likely to advance routine diagnostic and clinical studies on the aetiology of acute diarrhoea.

Electronic supplementary material

The online version of this article (10.1186/s13099-018-0264-7) contains supplementary material, which is available to authorized users.

Staphylococcus aureus lipoproteins augment inflammatory responses in poly I:C-primed macrophages

Secondary bacterial infection contributes to severe inflammation following viral infection. Among foodborne pathogenic bacteria, Staphylococcus aureus is known to exacerbate severe inflammatory responses after infection with single-stranded RNA viruses such as influenza viruses. However, it has not been determined if S. aureus infection enhances inflammatory responses after infection with RNA enteric viruses, including rotavirus, which is a double-stranded RNA virus. We therefore investigated the molecular mechanisms by which a cell wall component of S. aureus enhanced inflammatory responses during enteric viral infection using poly I:C-primed macrophages, which is a well-established model for double-stranded RNA virus infection. S. aureus lipoproteins enhanced IL-6 as well as TNF-α production in poly I:C-primed macrophages. Pam2CSK4, a mimic of Gram-positive bacterial lipoproteins and S. aureus lipoproteins, also significantly enhanced IL-6 production in poly I:C-primed macrophages. While IFN-β expression was increased in poly I:C-primed macrophages treated with Pam2CSK4 or S. aureus lipoproteins, the level of IL-6 enhancement in poly I:C-primed macrophages was decreased in the presence of anti-IFN-α/β receptor antibody, suggesting that IFN-β plays an important role in enhanced IL-6 production. Phosphatidylinositol-3-kinase, Akt, ERK and NF-κB were also involved in the enhanced IL-6 production. Collectively, these results suggest that S. aureus lipoproteins induce excessive inflammatory responses in the presence of poly I:C.

Thermophilic Campylobacter - Neglected Foodborne Pathogens in Cambodia, Laos and Vietnam

Thermophilic Campylobacter are the most common bacterial cause of gastroenteritis in humans worldwide. Poultry and poultry products are the main sources for human infections. Epidemiological data concerning campylobacteriosis in Asia are limited. Overall, it is difficult to accurately assess the burden of Campylobacter infections. South-East Asia including Cambodia, Laos and Vietnam is known as a hotspot for emerging diseases. Campylobacteriosis is a problem of public health concern in these countries, hence. Epidemiological data are scarce. This is influenced by the limited number of laboratory facilities and lack of equipment and awareness in physicians and veterinarians resulting in the lack of surveys. This review lists articles and reports on Campylobacter and campylobacteriosis in these developing third world countries. Subjects are prevalence of thermophilic Campylobacter in humans, animals and food and their resistance to several antibiotics.

Quantification of Campylobacter jejuni contamination on chicken carcasses in France

Highly prevalent in poultry, Campylobacter is a foodborne pathogen which remains the primary cause of enteritis in humans. Several studies have determined prevalence and contamination level of this pathogen throughout the food chain. However it is generally performed in a deterministic way without considering heterogeneity of contamination level. The purpose of this study was to quantify, using probabilistic tools, the contamination level of Campylobacter spp. on chicken carcasses after air-chilling step in several slaughterhouses in France. From a dataset (530 data) containing censored data (concentration <10CFU/g), several factors were considered, including the month of sampling, the farming method (standard vs certified) and the sampling area (neck vs leg). All probabilistic analyses were performed in R using fitdistrplus, mc2d and nada packages. The uncertainty (i.e. error) generated by the presence of censored data was small (ca 1 log₁₀) in comparison to the variability (i.e. heterogeneity) of contamination level (3 log₁₀ or more), strengthening the probabilistic analysis and facilitating result interpretation. The sampling period and sampling area (neck/leg) had a significant effect on Campylobacter contamination level. More precisely, two "seasons" were distinguished: one from January to May, another one from June to December. During the June-to-December season, the mean Campylobacter concentration was estimated to 2.6 [2.4; 2.8] log₁₀ (CFU/g) and 1.8 [1.5; 2.0] log₁₀ (CFU/g) for neck and leg, respectively. The probability of having >1000CFU/g (higher limit of European microbial criterion) was estimated to 35.3% and 12.6%, for neck and leg, respectively. In contrast, during January-to-May season, the mean contamination level was estimated to 1.0 [0.6; 1.3] log₁₀ (CFU/g) and 0.6 [0.3; 0.9] log₁₀ (CFU/g) for neck and leg, respectively. The probability of having >1000CFU/g was estimated to 13.5% and 2.0% for neck and leg, respectively. An accurate quantification of contamination level enables industrials to better adapt their processing and hygiene practices. These results will also help in refining exposure assessment models.

Evaluation of the Field Performance of ImmunoCard STAT!® Rapid Diagnostic Test for Rotavirus in Dadaab Refugee Camp and at the Kenya-Somalia Border

Rotavirus commonly causes diarrhea in children, leading to hospitalization and even death. Rapid diagnostic tests are feasible alternatives for determining rotavirus outbreaks in refugee camps that have inadequate laboratory capacity. We evaluated the field performance of ImmunoCard STAT!^® Rotavirus (ICS-RV) in Dadaab Refugee Camp and at the Kenya–Somalia border. From May to December 2014, we prospectively enrolled children aged < 5 years hospitalized with acute diarrhea, defined as ≥ 3 episodes of loose stool in 24 hours for < 7 days. Stool samples were collected and tested by trained surveillance clerks using ICS-RV per manufacturer's instructions. The field performance characteristics of ICS-RV were evaluated against the gold standard test, Premier^™ Rotaclone^® enzyme immunoassay. The operational characteristics were evaluated using World Health Organization (WHO) ASSURED criteria to determine whether ICS-RV is appropriate as a point-of-care test by administering a standard questionnaire and observing surveillance clerks performing the test. We enrolled 213 patients with a median age of 10 months (range = 1–48); 58.2% were male. A total of 71 (33.3%) and 60 (28.2%) patients tested positive for rotavirus infection by immunoassay and ICS-RV, respectively. The sensitivity, specificity, and positive and negative predictive values of ICS-RV compared with the immunoassay were 83.1% (95% confidence interval [CI] = 72.3–91.0), 99.3% (95% CI = 96.1–100), 98.3% (95% CI = 91.1–100), and 92.1% (95% CI = 86.6–95.5), respectively. The ICS-RV fulfilled the WHO ASSURED criteria for point-of-care testing. ICS-RV is a field-ready point-of-care test with good field performance and operational characteristics. It can be useful in determining rotavirus outbreaks in resource-limited settings.

Characterization of rotavirus infection in children with acute gastroenteritis in Bengo province, Northwestern Angola, prior to vaccine introduction

BACKGROUND

Rotavirus group A (RVA) is considered the leading cause of pediatric diarrhea, responsible for the high burden of diarrheal diseases in sub-Saharan Africa. Despite recent studies, the existent data are scarce for some African countries like Angola, a country with one of the highest RVA-related death estimates. The aim of this study was to determine the RVA detection rate and circulating genotypes in children less than five years of age with acute gastroenteritis attended at the Bengo General Hospital in Caxito, Bengo province, Angola, before vaccine introduction.

METHODS

Between September 2012 and December 2013, 342 fecal specimens were collected from children enrolled. Positive samples for RVA by immunochromatographic rapid test were G and P-typed by hemi-nested type-specific multiplex PCR, and subgrouped for the VP6 gene. VP4 and VP7 genes from a subset of samples were sequenced for phylogenetic analysis.

RESULTS

During the study period, a high RVA detection rate was registered (25.1%, 86/342). The age group most affected by RVA infection includes children under 6 months of age (p<0.01). Vomiting was highly associated with RVA infection (72.1%; p<0.001). From the 86 RVA-positive samples, 72 (83.7%) were genotyped. The most prevalent genotype was G1P[8] (34/72; 47.2%), followed by the uncommon G1P[6] (21/72; 29.2%), and G2P[4] (9/72; 12.5%). Only two G-types were found: G1 (60/72; 83.3%) and G2 (11/72; 15.3%). Among the P-genotypes, P[8] was the most prevalent (34/72; 47.2%), followed by P[6] (22/72; 30.6%) and P[4] (9/72; 12.5%). In the phylogenetic trees, the identified G and P-types clustered tightly together and with reference sequences in specific monophyletic groups, with highly significant bootstrap values (≥92%).

CONCLUSION

This pre-vaccination study revealed, for the first time for Bengo province (Angola), the RVA genotype profile, including phylogenetic relationships, and a high RVA detection rate, supporting the immediate introduction of a RVA vaccine in the national immunization programme.

New Approaches on Quantification of Campylobacter jejuni in Poultry Samples: The Use of Digital PCR and Real-time PCR against the ISO Standard Plate Count Method

Campylobacteriosis is the most frequently reported bacterial food-borne illness in the European Union and contaminated broiler meat is considered the most important source of infection in humans. The aim of the present study was to evaluate real-time PCR (qPCR) and digital PCR (dPCR) for quantification of Campylobacter jejuni in 75 broiler neck-skin samples collected from a poultry slaughterhouse, and to compare them with the ISO 10272-2 standard plate count method. For qPCR standard curve, C. jejuni-negative neck-skin samples were spiked with C. jejuni suspension with a known number of bacterial cells. The observed CFU/g values by qPCR correlated greatly with the expected values and qPCR showed good performance with the reliable limit of detection (rLOD) and limit of quantification (LOQ) of three and 31 target copies per reaction, respectively. However, both rLOD (1219 CFU/g) and LOQ (12,523 CFU/g) were beyond the EFSA-proposed critical limit of 500-1,000 CFU/g of neck skin. Although C. jejuni cell counts were ≤1,000 CFU/g in only 7/75 samples by plate counting, they were ≤LOQ in 60/75 and ≤rLOD in 26/75 (≤1,000 CFU/g in 24/75) samples by qPCR. A strong and statistically significant correlation was observed between qPCR and dPCR. Both PCR-based methods correlated significantly with the plate count method; however, the correlation was moderate. Using the Bland-Altman analysis, an average agreement was noted between all three methods, although with a large standard deviation. A significant bias toward overestimation in dPCR was observed, probably due to the relatively high number of false positive calls. The linear dynamic range was comparable in both PCR-based methods; however, qPCR proved to be more suitable for routine use. In the future, the establishment of a reliable molecular quantification of C. jejuni in poultry samples showing a wide range of contamination levels down to the proposed critical limit is needed to enable time- and cost-effective surveillance throughout all stages in the food production chain. As both rLOD and LOQ were beyond this limit, a modification of the procedure is suggested to include less sample dilution prior to DNA extraction to enable PCR-based quantification of C. jejuni at the proposed microbiological criteria.

Exploiting Bacterial Whole-Genome Sequencing Data for Evaluation of Diagnostic Assays: Campylobacter Species Identification as a Case Study

The application of whole-genome sequencing (WGS) to problems in clinical microbiology has had a major impact on the field. Clinical laboratories are now using WGS for pathogen identification, antimicrobial susceptibility testing, and epidemiological typing. WGS data also represent a valuable resource for the development and evaluation of molecular diagnostic assays, which continue to play an important role in clinical microbiology. To demonstrate this application of WGS, this study used publicly available genomic data to evaluate a duplex real-time PCR (RT-PCR) assay that targets mapA and ceuE for the detection of Campylobacter jejuni and Campylobacter coli, leading global causes of bacterial gastroenteritis. In silico analyses of mapA and ceuE primer and probe sequences from 1,713 genetically diverse C. jejuni and C. coli genomes, supported by RT-PCR testing, indicated that the assay was robust, with 1,707 (99.7%) isolates correctly identified. The high specificity of the mapA-ceuE assay was the result of interspecies diversity and intraspecies conservation of the target genes in C. jejuni and C. coli Rare instances of a lack of specificity among C. coli isolates were due to introgression in mapA or sequence diversity in ceuE The results of this study illustrate how WGS can be exploited to evaluate molecular diagnostic assays by using publicly available data, online databases, and open-source software.

Risk factors associated with Campylobacter detected by PCR in humans and animals in rural Cambodia

Campylobacter are worldwide-occurring zoonotic bacteria, with the species Campylobacter jejuni and C. coli commonly associated with diarrhoea in children in low-income countries. In this cross-sectional study, the prevalence of C. jejuni and C. coli in human and livestock faecal samples was detected by PCR and zoonotic risk factors associated with human Campylobacter positivity were identified. In total 681 humans and 753 livestock (chickens, ducks, pigs, cattle) from 269 households were sampled. Children aged <16 years were more frequently Campylobacter positive (19%) than adults (8%) and multilevel logistic models revealed that human C. jejuni positivity was associated with the following household practices: home-slaughtering [odds ratio (OR) 2·4, P = 0·01], allowing animals access to sleeping and food preparation areas (OR 2·8, P = 0·02), and eating undercooked meat (OR 6·6, P = 0·05), while frequent consumption of beef was protective (OR 0·9, P = 0·05). Associations were stronger for home-slaughtering (OR 4·9, P = 0·004) with C. jejuni infection in children only. Campylobacter was highly prevalent in pigs (72%) and chickens (56%) and risk factors associated with human Campylobacter positivity were identified throughout the meat production chain. The findings underline the importance of studying source attributions throughout the production chain and the need for upgraded understanding of Campylobacter epidemiology in low-income countries.

Detection of enterotoxigenic E. coli in hospitalised children with and without diarrhoea in Blantyre, Malawi

BACKGROUND

Enterotoxigenic E. coli (ETEC) is an important cause of diarrhoea among children in developing countries. The burden of ETEC infection was investigated for the first time in children in Malawi.

METHODS

Faecal samples obtained from children < 5 years of age hospitalised with diarrhoea in Blantyre, Malawi over a 10-year period (1997-2007) before introduction of the rotavirus vaccine were examined by PCR for ETEC heat-labile (LT) and heat-stable (STh and STp) enterotoxins. Children hospitalised without diarrhoea were enrolled over a 2-year period as a comparison group.

RESULTS

ETEC was detected in 205 (10.6%) of 1941 children with diarrhoea. The most prevalent toxin type was STh (6·6%), followed by LT (2·1%) and STp (0·9%). ETEC infection was most prevalent in infants aged 6-11 months. Co-infection with rotavirus was common. ETEC was detected in 37 (7·3%) of 507 children without diarrhoea.

CONCLUSION

The burden of ETEC infection in young Malawian children is substantial and should become a focus of diarrhoea prevention efforts in the post-rotavirus vaccine era.

Etiology of Diarrhea in Children Younger Than 5 Years Attending the Bengo General Hospital in Angola

BACKGROUND

Diarrheal disease is among the leading causes of death in children younger than 5 years, especially in developing countries. The aim of this study was to investigate the most frequent etiological agents of diarrhea and its associated factors in children younger than 5 years attending the Bengo General Hospital in Angola.

METHODS

From September 2012 through December 2013, stool samples were collected from 344 children presenting with diarrhea to investigate the presence of viral, bacterial and parasitic agents. Relevant sociodemographic and clinical data were obtained from parents and caregivers.

RESULTS

An enteric pathogen was detected in 66.6% of stool samples: Cryptosporidium spp. (30.0%), rotavirus (25.1%), Giardia lamblia (21.6%), diarrheagenic Escherichia coli (6.3%), Ascaris lumbricoides (4.1%), adenovirus (3.8%), Strongyloides stercoralis (3.5%), astrovirus (2.6%), Hymenolepis nana (1.7%), Entamoeba histolytica/dispar (0.9%), Taenia spp. (0.6%), Trichuris trichiura (0.3%) and Entamoeba histolytica (0.3%). Children younger than 12 months were more frequently infected with Cryptosporidium spp. compared with older children (age: 12-59 months), independently of sex, season, lethargy and wasting [odds ratio (OR): 3.5, 95% confidence interval (95% CI): 2.0-6.2]. Age (OR: 5.0, 95% CI: 2.6-9.3), vomiting (OR: 2.7, 95% CI: 1.5-4.8) and type of admission (inpatients, OR: 0.5, 95% CI: 0.3-0.9) were significantly associated with rotavirus infection.

CONCLUSIONS

This study demonstrates high rates of infection with an enteric pathogen, particularly in children younger than 12 months, emphasizing the need to address diarrheal disease in this age group.

Campylobacteriosis: the role of poultry meat

The incidence of human infections caused by Campylobacter jejuni and Campylobacter coli, the main bacterial agents of gastrointestinal disease, has been increasing worldwide. Here, we review the role of poultry as a source and reservoir for Campylobacter. Contamination and subsequent colonization of broiler flocks at the farm level often lead to transmission of Campylobacter along the poultry production chain and contamination of poultry meat at retail. Yet Campylobacter prevalence in poultry, as well as the contamination level of poultry products, vary greatly between different countries so there are differences in the intervention strategies that need to be applied. Temporal patterns in poultry do not always coincide with those found in human infections. Studies in rural and urban areas have revealed differences in Campylobacter infections attributed to poultry, as poultry seems to be the predominant reservoir in urban, but not necessarily in rural, settings. Furthermore, foreign travel is considered a major risk factor in acquiring the disease, especially for individuals living in the northern European countries. Intervention strategies aimed at reducing Campylobacter colonization in poultry and focused at the farm level have been successful in reducing the number of Campylobacter cases in several countries. Increasing farm biosecurity and education of consumers are likely to limit the risk of infection. Overall, poultry is an important reservoir and source of human campylobacteriosis, although the contribution of other sources, reservoirs and transmission warrants more research.

Global Epidemiology of Campylobacter Infection

Campylobacter jejuni infection is one of the most widespread infectious diseases of the last century. The incidence and prevalence of campylobacteriosis have increased in both developed and developing countries over the last 10 years. The dramatic increase in North America, Europe, and Australia is alarming, and data from parts of Africa, Asia, and the Middle East indicate that campylobacteriosis is endemic in these areas, especially in children. In addition to C. jejuni, there is increasing recognition of the clinical importance of emerging Campylobacter species, including Campylobacter concisus and Campylobacter ureolyticus. Poultry is a major reservoir and source of transmission of campylobacteriosis to humans. Other risk factors include consumption of animal products and water, contact with animals, and international travel. Strategic implementation of multifaceted biocontrol measures to reduce the transmission of this group of pathogens is paramount for public health. Overall, campylobacteriosis is still one of the most important infectious diseases that is likely to challenge global health in the years to come. This review provides a comprehensive overview of the global epidemiology, transmission, and clinical relevance of Campylobacter infection.

Challenges of Sanitary Compliance Related to Trade in Products of Animal Origin in Southern Africa

Irrespective of the existence of potentially pathogenic organisms carried by animals, foods of animal origin remain the prime nutrition of humans world-wide. As such, food safety continues to be a global concern primarily to safeguard public health and to promote international trade. Application of integrated risk-based quality assurance procedures on-farm and at slaughterhouses plays a crucial role in controlling hazards associated with foods of animal origin. In the present paper we examine safety assurance systems and associated value chains for foods of animal origin based on historical audit results of some Southern African countries with thriving export trade in animal products, mainly to identify areas for improvement. Among the key deficiencies identified were: i) failure to keep pace with scientific advances related to the ever-changing food supply chain; ii) lack of effective national and regional intervention strategies to curtail pathogen transmission and evolution, notably the zoonotic Shiga toxin-producing Escherichia coli; and iii) a lack of effective methods to reduce contamination of foods of wildlife origin. The introduction of foods of wildlife origin for domestic consumption and export markets seriously compounds already existing conflicts in legislation governing food supply and safety. This analysis identifies gaps required to improve the safety of foods of wildlife origin.

Prevalence of classic, MLB-clade and VA-clade Astroviruses in Kenya and The Gambia

BACKGROUND

Infectious diarrhea leads to significant mortality in children, with 40 % of these deaths occurring in Africa. Classic human astroviruses are a well-established etiology of diarrhea. In recent years, seven novel astroviruses have been discovered (MLB1, MLB2, MLB3, VA1/HMO-C, VA2/HMO-B, VA3/HMO-A, VA4); however, there have been few studies on their prevalence or potential association with diarrhea.

METHODS

To investigate the prevalence and diversity of these classic and recently described astroviruses in a pediatric population, a case-control study was performed. Nine hundred and forty nine stools were previously collected from cases of moderate-to-severe diarrhea and matched controls of patients less than 5 years of age in Kenya and The Gambia. RT-PCR screening was performed using pan-astrovirus primers.

RESULTS

Astroviruses were present in 9.9 % of all stool samples. MLB3 was the most common astrovirus with a prevalence of 2.6 %. Two subtypes of MLB3 were detected that varied based on location in Africa. In this case-control study, Astrovirus MLB1 was associated with diarrhea in Kenya, whereas Astrovirus MLB3 was associated with the control state in The Gambia. Classic human astrovirus was not associated with diarrhea in this study. Unexpectedly, astroviruses with high similarity to Canine Astrovirus and Avian Nephritis Virus 1 and 2 were also found in one case of diarrhea and two control stools respectively.

CONCLUSIONS

Astroviruses including novel MLB- and VA-clade members are commonly found in pediatric stools in Kenya and The Gambia. The most recently discovered astrovirus, MLB3, was the most prevalent and was found more commonly in control stools in The Gambia, while astrovirus MLB1 was associated with diarrhea in Kenya. Furthermore, a distinct subtype of MLB3 was noted, as well as 3 unanticipated avian or canine astroviruses in the human stool samples. As a result of a broadly reactive PCR screen for astroviruses, new insight was gained regarding the epidemiology of astroviruses in Africa, where a large proportion of diarrheal morbidity and mortality occur.

Update on the burden of Campylobacter in developing countries

PURPOSE OF REVIEW

Recent work has added to the understanding of the burden of Campylobacter jejuni, C. coli, and non-jejuni/coli Campylobacter strains in children living in the developing world.

RECENT FINDINGS

New diagnostic modalities and carefully designed field studies are demonstrating that the burden of Campylobacter diarrhea in children in the developing world has been greatly underestimated. Furthermore, there is emerging recognition of an association between Campylobacter infection and malnutrition. Important progress has been made toward a Campylobacter jejuni vaccine. Finally, evidence of antibiotic resistance continues to be an important issue that is accentuated by the realization that the burden of disease is greater than previously recognized.

SUMMARY

Additional research is needed to refine our understanding of the epidemiology of Campylobacter infections in developing countries, in particular to improve estimates of the burden of Campylobacter diarrhea in endemic settings, to determine the impact of recurrent Campylobacter infections on child development, and to describe the prevalence and clinical significance of non-jejuni/coli Campylobacter infections. Progressive antibiotic resistance of isolates argues for augmented and expanded control measures of antibiotics in livestock. Continued work in vaccine development is warranted as is the extension of data available on the serotypes related to burden in different areas of the world and the relationship of serotypes to disease severity.

Loop-Mediated Isothermal Amplification (LAMP) for Detection of Campylobacter jejuni and C. coli in Thai Children with Diarrhea

Campylobacter species are common causes of bacterial diarrhea, and Campylobacter jejuni and C. coli are known as the predominant causative agents in humans. Recent studies suggested that loop-mediated isothermal amplification (LAMP) is an efficient and practical tool for rapid detection of C. jejuni and C. coli in clinical samples. We used LAMP to screen 151 stool samples for Campylobacter; these samples were collected in 2012 from Thai children with diarrhea. The PCR method discriminated C. jejuni and C. coli among the detected Campylobacter strains; these species were subjected to sequencing of the hipO gene (in C. jejuni) or the ask gene (in C. coli). The results suggest that the prevalence of Campylobacter infection among Thai children with diarrhea is 8.6%, and C. jejuni is the most prevalent species.

Detection of Campylobacter in human faecal samples in Fiji

INTRODUCTION

Data on campylobacteriosis in developed countries are well documented; in contrast, few studies on campylobacteriosis have been conducted in developing countries. This study was undertaken to test for Campylobacter in human faecal samples sent to the two major pathology laboratories in Fiji.

METHODS

A total of 408 diarrhoeal faecal samples were collected from the two major hospital pathology laboratories in Central Fiji (Suva) and Western Fiji (Lautoka) between December 2012 and February 2013 and from June to July 2013. Samples were analysed for the presence of Campylobacter using polymerase chain reaction (PCR) based methods.

RESULTS

Campylobacter was detected in 241/408 (59.1%) of samples tested using PCR. Samples from children aged less than five accounted for 21.6% of positive cases.

DISCUSSION

Campylobacter was detected in 59.1% of diarrhoeal samples collected from the two main laboratories in Fiji. A high proportion of children under five years with Campylobacter has been reported in other countries and could be due to parents being more likely to seek medical attention. Further studies are required to confirm the species of Campylobacter that are predominantly associated with gastroenteritis in Fiji.

Campylobacter infection in a cohort of rural children in Moramanga, Madagascar

Background

Campylobacter infection is the most common cause of bacterial gastroenteritis in developing countries, including Madagascar. Reports of pathogenicity have not been consistent and repeated exposures over time seem to lead to the development of protective immunity in developing areas. We conducted this study to support evidence for these hypotheses by exploring the association between infection and age, the reoccurrence of infection and the pathogenicity of Campylobacter.

Methods

We carried out a community-based longitudinal study of children under the age of 24 months in two rural villages in Moramanga, Madagascar. Children were visited twice a week and a stool specimen was collected in cases of diarrhoea. Stools specimens were collected bimonthly from all children enrolled, regardless of symptoms. Children were followed-up until the age of 36 months.

Results

Between January 2010 and May 31^st 2012, 508 children were included in the cohort. We detected 319 episodes of Campylobacter infection in total, and 43.3% (n = 220) of the children had at least one episode of intestinal Campylobacter infection. The rate of Campylobacter isolation from stool specimens was 9.3%. The annual incidence rate for symptomatic Campylobacter infection was 0.05 episodes/child. The probability of Campylobacter infection was highest between the ages of six and 23 months. Taking children under six months of age as the reference group, the age-specific odds ratio for the association was 5.0 (95% CI: 2.9-8.6) for children aged six to 11 months, 5.7 (95% CI: 3.3-10.0) for children aged 12 to 17 months and 3.3 (95% CI: 1.8-5.8) for children aged 18 to 23 months. A second episode of infection occurred 63 days after the first episode in children with primary infections, and after 137 days in children with multiple infections (p < 0.01). First episodes of Campylobacter infection were associated with diarrhoea (odds ratio = 16.1; 95% CI: 1.8-140.8).

Conclusion

Our findings suggest that protective immunity to Campylobacter may be acquired over time, following repeated exposures. However, Campylobacter infection prevention measures should be reinforced in the first year of life, as this age seems to be associated with the highest risk of diarrhoea during Campylobacter infection.

Detection of Campylobacter in stool and determination of significance by culture, enzyme immunoassay, and PCR in developing countries

Campylobacter is a common bacterial enteropathogen that can be detected in stool by culture, enzyme immunoassay (EIA), or PCR. We compared culture for C. jejuni/C. coli, EIA (ProSpecT), and duplex PCR to distinguish Campylobacter jejuni/C. coli and non-jejuni/coli Campylobacter on 432 diarrheal and matched control stool samples from infants in a multisite longitudinal study of enteric infections in Tanzania, Bangladesh, and Peru. The sensitivity and specificity of culture were 8.5% and 97.6%, respectively, compared with the results of EIA and 8.7% and 98.0%, respectively, compared with the results of PCR for C. jejuni/C. coli. Most (71.6%) EIA-positive samples were positive by PCR for C. jejuni/C. coli, but 27.6% were positive for non-jejuni/coli Campylobacter species. Sequencing of 16S rRNA from 53 of these non-jejuni/coli Campylobacter samples showed that it most closely matched the 16S rRNA of C. hyointestinalis subsp. lawsonii (56%), C. troglodytis (33%), C. upsaliensis (7.7%), and C. jejuni/C. coli (2.6%). Campylobacter-negative stool spiked with each of the above-mentioned Campylobacter species revealed reactivity with EIA. PCR detection of Campylobacter species was strongly associated with diarrhea in Peru (odds ratio [OR] = 3.66, P < 0.001) but not in Tanzania (OR = 1.56, P = 0.24) or Bangladesh (OR = 1.13, P = 0.75). According to PCR, Campylobacter jejuni/C. coli infections represented less than half of all infections with Campylobacter species. In sum, in infants in developing country settings, the ProSpecT EIA and PCR for Campylobacter reveal extremely high rates of positivity. We propose the use of PCR because it retains high sensitivity, can ascertain burden, and can distinguish between Campylobacter infections at the species level.

Molecular diagnosis of Arcobacter and Campylobacter in diarrhoeal samples among Portuguese patients

The present study was conducted to investigate the prevalence and diversity of Arcobacter and Campylobacter spp. in 298 stool samples of patients with diarrhoea, collected from 22 Portuguese hospitals, between September and November 2012. Detection of Arcobacter and Campylobacter spp. was performed using molecular-based detection techniques, such as real-time fluorescence resonance energy transfer PCR, species-specific PCR, and sequencing of amplified PCR products. Overall, 1.3% of the samples were positive for Arcobacter butzleri and 0.3% for Arcobacter cryaerophilus. Campylobacter spp. were found in 31.9% of diarrhoeic faeces. Campylobacter jejuni and Campylobacter concisus were the most prevalent species (13.7% and 8.0%, respectively). The prevalence of Arcobacter and Campylobacter spp. was significantly different between children and adults (39.7% versus 22.8%, P = 0.003). We underline the high prevalence of these pathogens in diarrhoeal samples among Portuguese patients, with particular relevance in the paediatric age group.