Prevalence of human Salmonellosis in Ethiopia: a systematic review and meta-analysis

Hygienic status of beef butcher shop facilities and antibiotic resistance profile of Salmonella enterica in Ethiopia

The microbiological quality of meat is influenced by the conditions of hygiene prevailing during production and handling. Thus, this study aimed to assess the prevalence of Salmonella enterica and its antimicrobial resistance, load of hygiene indicator bacteria including E. coli (ECC), coliforms (CC), total coliform (TCC), Enterobacteriaceae (EB) and aerobic plate count (APC), and meat handler's food safety knowledge and hygiene practices in butcher shops in two cities, Addis Ababa and Hawassa in Ethiopia, during 2020 and 2021. A total of 360 samples of beef carcasses (n = 120), knives (n = 60), chopping boards (n = 60), weighing balance (n = 60), and personnel's hands (n = 60) were randomly collected for microbial analysis. Besides, 120 participants were selected to participate in a food safety knowledge and hygiene practices assessment. The S. enterica isolates were identified by agglutination test followed by qPCR targeting invA gene. Phenotypic antimicrobial resistance profiles of S. enterica were determined using disk diffusion assays as described in CLSI. The ECC, CC, TCC, EB, and APC populations were quantified by plating onto petrifilm plates. A structured questionnaire was used to determine food safety knowledge and hygiene practices of participants. Overall prevalence of S. enterica was 16.7% (95% CI, 8.3-26.7) and location seems to have no effect (p = 0.806). Only 20% of the S. enterica were resistant to ampicillin and tetracycline. However, the majority (80%) of S. enterica isolates were susceptible to the panel of 11 antimicrobials tested. The overall mean ± SD (log CFU/cm2) of ECC, CC, TCC, EB, and APC were 4.31 ± 1.15; 4.61 ± 1.33; 4.77 ± 1.32; 4.59 ± 1.38 and 5.87 ± 1.52, respectively. No significant difference (p = 0.123) in E. coli contamination was observed between samples of beef carcasses and chopping boards. The EB contamination showed no significant difference (p > 0.05) among sample sources. The APC contamination levels on beef carcass were significantly higher (p > 0.05) than other sample sources. A total of 56% (95% CI: 46.7 - 65.0) of the participants had poor knowledge and 65% (95% CI: 56.7 - 73.3) had poor hygiene practices towards food safety. This study highlighted the poor hygiene status of butcher facilities with a potential risk of beef safety. Thus, appropriate food safety control strategies and inspection is needed at retail establishments.

Changing Epidemiology and Antimicrobial Resistance of Bacterial Childhood Diarrhea: Insights from a 7-Year Study in an Iranian Referral Hospital

Acute gastroenteritis (AGE) poses a significant public health challenge for children in developing countries. Considering the high prevalence of AGE in Iranian children, the aim of this study was to investigate and analyze the patterns and changes in bacterial identification as well as antibiotic resistance in AG over the course of 7 years. From January 2015 to December 2021, a total of 15,300 pediatric patients with AGE were admitted to the Children's Medical Center, an Iranian academic referral hospital, Tehran, Iran. Among these cases, 8.9% (1329 individuals) yielded positive stool cultures. The predominant bacterial etiology of AGE was identified as Shigella sonnei (n = 424, 31.9%), and Salmonella group D (n = 367, 27.6%), followed by Shigella flexneri: 16.3% (217 cases), Salmonella group C (n = 152, 11.4%), Salmonella group B (n = 91, 6.8%), Escherichia coli (n = 65, 4.9%), Shigella boydii (n = 10, 0.75%), and Shigella dysenteriae (n = 3, 0.2%). Notably, S. sonnei exhibited high resistance rates to trimethoprim-sulfamethoxazole (97.6%) and nalidixic acid (95.3%). S. flexneri and S. boydii isolates displayed significant resistance to ampicillin (96.8% and 88.9%, respectively). Salmonella group D demonstrated elevated resistance to ciprofloxacin (81.3%) and nalidixic acid (88.5%), with notable sensitivity to trimethoprim-sulfamethoxazole and cefotaxime (97.3% and 97.5%, respectively). E. coli displayed resistance rates of 80%, 74%, and 66% to trimethoprim-sulfamethoxazole, cefotaxime, and ciprofloxacin, respectively. The fluctuating prevalence of S. sonnei and Salmonella group D, two predominant bacterial isolates associated with AGE, underscores the dynamic nature of these pathogens. The notable increase in antibiotic resistance observed in S. sonnei raises concerns, underscoring the critical need for judicious and careful antibiotic use.

Prevalence, Molecular Detection, and Antimicrobial Resistance of Salmonella Isolates from Poultry Farms across Central Ethiopia: A Cross-Sectional Study in Urban and Peri-Urban Areas

A cross-sectional study was conducted to assess the prevalence, molecular detection, and antimicrobial resistance of Salmonella isolates within 162 poultry farms in selected urban and peri-urban areas of central Ethiopia. A total of 1515 samples, including cloacal swabs (n = 763), fresh fecal droppings (n = 188), litter (n = 188), feed (n = 188), and water (n = 188), were bacteriologically tested. The molecular detection of some culture-positive isolates was performed via polymerase chain reaction (PCR) by targeting spy and sdfl genes for Salmonella Typhimurium and Salmonella Enteritidis, respectively. Risk factors for the occurrence of the bacterial isolates were assessed. Antimicrobial susceptibility testing of PCR-confirmed Salmonella isolates was conducted using 12 antibiotics. In this study, it was observed that 50.6% of the farms were positive for Salmonella. The overall sample-level prevalence of Salmonella was 14.4%. Among the analyzed risk factors, the type of production, breed, and sample type demonstrated a statistically significant association (p < 0.05) with the bacteriological prevalence of Salmonella. The PCR test disclosed that 45.5% (15/33) and 23.3% (10/43) of the isolates were positive for genes of Salmonella Typhimurium and Salmonella Enteritidis, respectively. The antimicrobial susceptibility test disclosed multi-drug resistance to ten of the tested antibiotics that belong to different classes. Substantial isolation of Salmonella Typhimurium and Salmonella Enteritidis in poultry and on poultry farms, along with the existence of multi-drug resistant isolates, poses an alarming risk of zoonotic and food safety issues. Hence, routine flock testing, farm surveillance, biosecurity intervention, stringent antimicrobial use regulations, and policy support for the sector are highly needed.

Occurrence of Diarrheagenic Pathogens and Their Coinfection Profiles in Diarrheic Under Five Children and Tracked Human Contacts in Urban and Rural Settings of Eastern Ethiopia

Diarrheagenic Escherichia coli, Campylobacter, Nontyphoidal Salmonella, and Shigella are common cause of childhood diarrhea in countries like Ethiopia, but data on their sources and coinfection profiles is limited. A cross sectional study was conducted from November 2021 to January 2023 to determine the prevalence, coinfection, and monthly occurrence rates of major diarrheagenic bacteria in diarrheic under five children and asymptomatic contacts at urban and rural settings in Ethiopia. A total of 345 stool samples were collected from; 262 diarrheic children visiting Hiwot Fana Hospital, Kersa, and Adelle Health Centers; and 83 caretakers and siblings through case based contact tracing. Samples were analyzed using standard laboratory procedures and the overall prevalence of enteric pathogens was 26.96%, with the highest isolation rate during the winter and peaks of 73.91% in February. The occurrence of the pathogens in children and tracked contacts was 27.86 and 24.09%, respectively. In our study, 8.53% coinfection and 23.66% single pathogen infection was recorded in diarrheic children. The study also showed 4.51 and 3.88% of diarrhea in children from urban and rural had attributed to bacterial coinfection, respectively. The most prevalent pathogen in diarrheic children was Diarrheagenic E. coli (10.31%), and followed by Campylobacter. On the other hand, Diarrheagenic E. coli was the second dominant bacteria following Shigella in the traced contacts, with prevalence of 8.43% and 9.64%, respectively. Based on the study site, the prevalence of Diarrheagenic E. coli and Nontyphoidal Salmonella was higher in children from urban than those from rural. However, the occurrence of each pathogen had no significant differences (P > .05) between settings. The high pathogens occurrence rate in the current study indicates the need for strong control strategies and better child carrying and treatment of diarrheal diseases at both urban and rural settings. Further studies on possible sources and factors attributing to the occurrence of enteric pathogens in children are also recommended.

Predictors of Intestinal Parasites among Food Handlers in Goba Town, Southeast Ethiopia, 2020

Background

Globally, around 1.9 million people were dying due to food-borne diseases annually, and intestinal parasites infected one-third of the population, according to estimates and more prevalent in developing countries due to poverty. This study assessed predictors of intestinal parasites among food handlers working in Goba towns.

Methods

A laboratory-based cross-sectional study was conducted from October to December 2020. Clean, dry, and leak-proof stool cups were used to collect the samples. The SPSS version 20 computer software was used to enter and clean the data, code it, and analyze it. The researchers performed binary and multivariable logistic regression analyses, with a p value of 0.05 considered significant.

Result

A total of 98 (34%) of the 288 food workers tested positive for various intestinal parasites. Giardia lamblia was the most common parasite, with 42 (14.6%), followed by Entamoeba histolytica/dispar with 31 (10.8%), Ascaris lumbricoides with 8 (2.8%), Taenia species with 5 (1.7%), and E. vermicularis with 4 (1.4%). Six (2%) of the 98 positive food handlers had two infections. E. histolytica and G. lamblia were the most common parasites found in mixed infections. Hand washing with soap and water before handling food (AOR: 3.06, 95% CI: 1.16, 7.26) and untrimmed fingernail status (AOR: 2.3, 95% CI: 1.14, 4.34) were found to be strongly linked to intestinal parasite infection.

Conclusion

In this investigation, intestinal parasite species were found in 34% of stool samples. Independent predictors of intestinal parasite infection were fingernail status and hand washing with water and soap use before food handling. To control intestinal parasite infection among food handlers in the research area, personal hygiene and ambient cleanliness should be improved.

Isolation, identification and antimicrobial susceptibility profile of Salmonella isolated from poultry farms in Addis Ababa, Ethiopia

Background

Salmonella has been found to be the major cause of foodborne diseases and a serious public health problem in the world, with an increasing concern for the emergence and spread of antimicrobial‐resistant strains.

Method

A cross‐sectional study was conducted on poultry and poultry farms in Addis Ababa from February 2016 to April 2016 to determine the occurrence and evaluate the antimicrobial susceptibility profile of Salmonella isolates. A total of 200 samples consisting of the cloacal swab (n = 168), pooled litter (n = 12), hand swab (n = 8), pooled feed and water (n = 12) were collected separately from six poultry farms. The samples were examined for the presence of Salmonella through culturing on bacteriological media. Descriptive statistics, Pearson's Chi‐square (X²) and bivariate logistic regression were used in the analysis of the data. Accordingly, out of 200 samples, 23 (11.50%) were Salmonella positive, of which 21(12.50%) were in cloacal swab and 2(16.67%) in the pooled litter. There was no statistical association between the bacteriological status of sample type and Salmonella positivity (X² = 3.07, P = 0.545). However, there was a statistical association between farms and the rate of Salmonella isolation (X² = 22.21, P ≤ 0.00). The antimicrobial susceptibility testing for Salmonella isolates was conducted following the Kirby–Bauer disc diffusion method (1961).

Results

Out of 23 samples tested, 95.65% of them were resistant to at least one or more antimicrobials. Multiple drug resistances were observed for 69.56% of Salmonella isolates. The highest resistance (73.9%) was observed in kanamycin followed by tetracycline (65.2%) and streptomycin (56.3%). gentamycin was the most effective antibiotic (95.7%; sensitivity) followed by ciprofloxacin (78.3% sensitivity) and ampicillin (69.6% sensitivity.

Conclusion

This current study finding indicated that further detailed epidemiological and molecular studies are essential on the frequency and sources of acquisition of resistant genes.

Salmonellosis is an infectious and economically important disease of humans and animals caused by different Salmonella species.

Molecular Survey and Identification of Campylobacter spp. in Layer Farms in Central Ethiopia

Few data are available on Campylobacter spp. presence in chickens in Ethiopia. Due to its importance for both the poultry sector and public health, a sampling activity was planned to evaluate Campylobacter spp. presence in layer farms in Bishoftu and Mojo, Central Ethiopia. Twenty cloacal pooled samples were collected and tested with molecular assays for detection and Sanger-sequenced for species identification. As a secondary aim, samples were also tested for Salmonella spp. by PCR, and all samples were negative. On the other hand, 70% of cloacal swab pools were positive for Campylobacter spp.: 71.4% of the positive samples belonged to C. jejuni species, 21.4% to C. avium and 7.1% to C. helveticus. Campylobacter spp. was identified in almost all farms regardless of farm and flock size, age and hybrid types of the birds and antimicrobial treatment. Campylobacter jejuni is a common finding in chickens, whereas species such as C. avium and C. helveticus were newly reported in Ethiopia, revealing a variability that needs to be monitored in light of the public health significance of this pathogen.

Nontyphoidal Salmonella and Their Antimicrobial Susceptibility among Diarrheic Patients Attending Private Hospitals in Addis Ababa, Ethiopia

Nontyphoidal Salmonella (NTS) is one of the major causes of bacterial foodborne infection. It is mainly manifested by self-limiting gastroenteritis in healthy individuals but can also cause severe complications including blood stream infection and mortality. The emergence of multidrug-resistant strains of Salmonella is becoming a global public health concern. This study is aimed at estimating the prevalence of Salmonella, identifying serotypes involved, and investigating antimicrobial susceptibility of the isolates among diarrheic patients attending private hospitals in Addis Ababa. We collected a total of 298 stool samples from diarrheic patients attending five private hospitals in Addis Ababa and isolated Salmonella according to standard microbiological techniques; the isolates were serotyped using slide agglutination and microplate agglutination techniques. Antimicrobial susceptibility test of the isolates was carried out using Kirby-Bauer disc diffusion assay according to Clinical Laboratory Standards Institute guidelines. Fourteen stool samples (4.7%) were positive for Salmonella, and Salmonella Kiambu was the most dominant serovar (n = 7, 50%) followed by S. Saintpaul (n = 4, 28.6%) and S. Haifa (n = 2, 14.3%). Three (21.4%) of the isolates were resistant to sulfisoxazole and tetracycline each and 2 (14.3%) to ampicillin. Resistance to two antimicrobials was detected only in 2 (14.3%) of the isolates, and none of the isolates were resistant to more than two antimicrobials. In conclusion, the current study showed low prevalence of NTS in diarrheic patients attending private hospitals in Addis Ababa. Although multidrug resistance to several antimicrobials was not detected in the isolates, prudent use of antimicrobials is recommended to guaranty the long-term use of the available antimicrobials.

Prevalence and epidemiological distribution of selected foodborne pathogens in human and different environmental samples in Ethiopia: a systematic review and meta-analysis

Bacterial Foodborne Pathogens (FBP) are the commonest cause of foodborne illness or foodborne diseases (FBD) worldwide. They contaminate food at any stages in the entire food chain, from farm to dining-table. Among these, the Diarrheagenic Escherichia coli (DEC), Non typhoidal Salmonella (NTS), Shigella spp. and Campylobacter spp. are responsible for a large proportion of illnesses, deaths; and, particularly, as causes of acute diarrheal diseases. Though existing studies indicate the problem may be severe in developing countries like Ethiopia, the evidence is commonly based on fragmented data from individual studies. A review of published and unpublished manuscripts was conducted to obtain information on major FBP and identify the gaps in tracking their source attributions at the human, animal and environmental interface. A total of 1753 articles were initially retrieved after restricting the study period to between January 2000 and July 2020. After the second screening, only 51 articles on the humans and 43 on the environmental sample based studies were included in this review. In the absence of subgroups, overall as well as human stool and environmental sample based pooled prevalence estimate of FBP were analyzed. Since, substantial heterogeneity is expected, we also performed a subgroup analyses for principal study variables to estimate pooled prevalence of FBP at different epidemiological settings in both sample sources. The overall random pooled prevalence estimate of FBP (Salmonella, pathogenic Escherichia coli (E. coli), Shigella and Campylobacter spp.) was 8%; 95% CI: 6.5-8.7, with statistically higher (P <  0.01) estimates in environmental samples (11%) than in human stool (6%). The subgroup analysis depicted that Salmonella and pathogenic E. coli contributed to 5.7% (95% CI: 4.7-6.8) and 11.6% (95% CI: 8.8-15.1) respectively, of the overall pooled prevalence estimates of FBD in Ethiopia. The result of meta-regression showed, administrative regional state, geographic area of the study, source of sample and categorized sample size all significantly contributed to the heterogeneity of Salmonella and pathogenic E. coli estimates. Besides, the multivariate meta- regression indicated the actual study year between 2011 and 2015 was significantly associated with the environmental sample-based prevalence estimates of these FBP. This systematic review and meta-analysis depicted FBP are important in Ethiopia though majority of the studies were conducted separately either in human, animal or environmental samples employing routine culture based diagnostic method. Thus, further FBD study at the human, animal and environmental interface employing advanced diagnostic methods is needed to investigate source attributions of FBD in one health approach.

Assessment of beef carcass contamination with Salmonella and E. coli O 157 in slaughterhouses in Bishoftu, Ethiopia

Background

Salmonella and E. coli O157 are common causes of foodborne diseases. Evisceration and de-hiding steps can lead to carcass contamination during slaughter operation. In Ethiopia, information on the association between the presence of these pathogens in the rectal content and/or on the hide of cattle and their presence on the carcass is lacking.

Methods

The aim of this study was to assess the sources of beef carcass contamination with Salmonella and E. coli O157 during slaughter. Rectal contents and hide- and carcass-swabs (from three sites: foreleg, brisket and hind leg) were collected from 70 beef cattle at two small scale slaughterhouses. Isolates were genotyped by the Pulsed Field Gel Electrophoresis method and tested for resistance against 14 microbial drugs.

Results

Salmonella was detected at equal proportions (7.1%) in rectal content samples and hide swabs. E. coli O157 was detected in 8.6% of the rectal contents and 4.3% of the hide swabs. The proportion of contaminated carcasses was 8.6% for Salmonella and 7.1% for E. coli O157. Genetic linkage between the Salmonella and E. coli O157 isolates from the rectal contents and/or hides and carcasses were observed only in a few cases (2 and 1 carcasses, respectively) indicating the limited direct transfer of the pathogens from the feces and/or hide to the carcass during slaughter. Most carcasses became positive by cross contamination. All the S. Typhimurium isolates (n = 8) were multidrug resistant being resistant to ampicillin, chloramphenicol, sulfamethoxazole and tetracycline. The two S. Dublin isolates were resistant to colistin. All E. coli O157 isolates were susceptible to the antimicrobials tested.

Conclusion

The results indicated that cross contamination may be an important source for carcass contamination.

Seroconfirmed Typhoid Fever and Knowledge, Attitude, and Practices among Febrile Patients Attending at Injibara General Hospital, Northwest Ethiopia

Introduction

Typhoid fever (TF) is a febrile global health problem caused by Salmonella enterica serovar Typhi (S. Typhi) with relatively high prevalence in low- and middle-income countries including Ethiopia. Identifying local prevalence and gaps in knowledge, attitude, and practice (KAP) towards TF is recommended by the World Health Organization to implement preventive measures. Therefore, this study determined the prevalence of S. Typhi and KAP of febrile patients towards TF in Injibara General Hospital, Northwest Ethiopia.

Methods

Hospital-based cross-sectional study was conducted from January to March 2020. A total of 237 patients were included conveniently. Data on KAP and demographic variables were collected using a structured questionnaire by face-to-face interview. After the interview, 5 ml venous blood was collected and processed using the Widal test following the manufacturer's instruction. Mean scores and percentages were used to determine the level of KAP. Multivariable analysis was done to correlate KAPs with TF. P value < 0.05 was considered statistically significant.

Results

The overall prevalence of S. Typhi was 25.7%. The highest seroprevalence was observed among the age group of 30-34 years (33.3%) and patients with no education. The majority of participants know the major ways of TF transmission (59.1-90.7%) and prevention (81.4%) methods. However, the misconception on the route of TF transmission was observed in 13.5-36.7% of participants. About 65.4% and 67.5% of study participants were considered knowledgeable and had good preventive practice towards TF, respectively. Being a student (AOR = 0.227, CI = 0.053 − 0.965) and considering mosquito bite as transmission routes (AOR = 2.618, CI = 1.097 − 6.248) were significantly associated with TF.

Conclusion

High S. Typhi prevalence was observed in the study area. Moreover, the misconception on the transmission of typhoid fever and educational level was a risk factor for TF. Thus, health facilities should incorporate topics on typhoid fever as part of their health education system within health facilities and in the community.

Prevalence, Antimicrobial Resistance, and Molecular Characterization of Salmonella in Cattle, Beef, and Diarrheic Patients in Bishoftu, Ethiopia

Within Ethiopia, there is a lack of information on the genetic relatedness of Salmonella from cattle, beef, and diarrheic patients and its potential transmission from cattle to humans through consumption of contaminated beef. The objective of this study was to assess the prevalence and determine the serotypes, genetic relatedness, and antimicrobial resistance of Salmonella in cattle in two local slaughterhouses, in beef at retail shops, and in diarrheic patients in the only hospital in Bishoftu, Ethiopia. Salmonella was detected in 2.5% (6/240) of cattle samples, in 8.7% (11/127) of beef samples, and in 2.3% (5/216) of the diarrheic patients. Four Salmonella serotypes: Salmonella Typhimurium, Salmonella Eastbourne, Salmonella Saintpaul, and Salmonella Cotham were identified. Salmonella Typhimurium and Salmonella Eastbourne were isolated from cattle and beef, whereas Salmonella Saintpaul and Salmonella Cotham were isolated only from diarrheic patients. Except for serotype Salmonella Saintpaul, all isolates were grouped into five pulsotypes, of which two pulsotypes contained isolates from cattle and beef. Isolates from humans represented unique pulsotypes. Among the 22 Salmonella isolates tested, 95.5% were resistant to at least 1 of the 14 antimicrobials tested. Three Salmonella isolates originating from cattle were multidrug resistant. One human isolate was susceptible to all antimicrobials tested. More specifically, resistance to ampicillin, sulfamethoxazole, tetracycline, tigecycline, and trimethoprim were observed. The most frequently observed resistance was to sulfamethoxazole (90.9%, 20/22) followed by trimethoprim (22.7%, 5/22). The study revealed considerable Salmonella contamination of beef at retail shops, antimicrobial resistance to commonly used antimicrobials, and shared genetically similar Salmonella serotypes between cattle and beef; the link with humans could not be established. Still, the findings of Salmonella in cattle and beef, the propensity of transfer of Salmonella from cattle to beef coupled with the common consumption of raw/undercooked beef are likely to pose public health risk in Ethiopia.

Prevalence and antimicrobial resistance patterns of Salmonella isolates in human stools and animal origin foods in Ethiopia: A systematic review and meta-analysis

OBJECTIVE

Foodborne diseases caused by non-typhoid Salmonella and the emergence of antimicrobial resistance remain as a public health challenge, especially in developing countries. The current study aimed to estimate the pooled prevalence and the antimicrobial resistance patterns of non-typhoid Salmonella in Ethiopia.

METHODS

Literature search was conducted from major electronic databases and indexing services. Both published and unpublished studies addressing the prevalence and antimicrobial resistance profiles of Salmonella in Ethiopia from 2010 to 2020 and those studies reported sample size and the numbers of isolates/number of positive samples were included in the study. Data were extracted using format prepared in Microsoft Excel. The identified data were exported to EndNote to remove duplicated studies, then after the remained articles were screened using title, abstract, and full text to identify studies that meet the inclusion criteria and finally appraised for methodological validity using JBI guideline. The pooled prevalence of Salmonella and its drug resistance pattern was computed by a random-effects model. I2 test statistic was used to test heterogeneity across studies. The presence of publication bias was evaluated using the Begg's and Egger's tests.

RESULTS

A total of 49 eligible articles, 33 of them on human stools, 15 of them on animal origin foods, and one both on human stools and animal origin foods, were included in the study. The pooled prevalence of Salmonella among human stools and animal origin foods in Ethiopia was 4.8% (95% CI: 3.9, 5.9) and 7.7% (95% CI: 5.6, 10.4), respectively. The subgroup analysis detected high pooled prevalence, 7.6% (95% CI: 5.3, 10.7) among outpatients and low, 3.7% (95% CI: 2.6, 5.1) in food handlers. The pooled resistant level of Salmonella was 80.6% (95% CI 72.6, 86.7) for ampicillin and 63.5% (95% CI 53.7, 72.4) for tetracycline. Low pooled resistance pattern was reported in ciprofloxacin, 8.7% (95% CI 5.6, 13.3) and ceftriaxone 12.2% (95% CI 7.9, 18.3). There was some sort of publication bias.

CONCLUSION

High pooled prevalence of Salmonella among human stools and animal origin foods which were 4.8% and 7.7% respectively, and high Salmonella resistance, >72% to ampicillin and tetracycline were detected in Ethiopia. Antimicrobial stewardship efforts and infection control strategies are required to mitigate this major public health concern.

Shared Extended-Spectrum β-Lactamase-Producing Salmonella Serovars between Agricultural and Aquatic Environments Revealed through invA Amplicon Sequencing

The presence of antibiotic-resistant Salmonella spp. in the environment is of great public health interest, worldwide. Furthermore, its extended-spectrum β-lactamase (ESBL)-producing strains constitute an emerging global health concern due to their limited treatment options in hospital. Therefore, this study aimed at characterising and tracking nonresistant and ESBL-producing Salmonella spp. from agricultural settings to nearby water sources highlighting their antibiotic resistance genes (ARG) and virulence factor (VF) distribution using a combination of both culture-dependent and independent methods. Furthermore, this study investigated the diversity and shared serovars among sampled matrices using amplicon sequencing of the invasion gene A (invA) of Salmonella spp. The results showed that soil had the highest prevalence of Salmonella spp. (62.5%, 65/104) and ESBL-producing Salmonella (34.6%, 36/104). For typed ARG, the most commonly detected gene was blaOXA with 75% (30/40), followed by blaCTX-M 67.5% (27/40),blaTEM 40% (16/40) and sul1 30% (12/40) gene; blaSHV gene was not detected in isolated ESBL-producing Salmonella spp. For VF, the most detected gene was invA (96.9%, 38/40), followed by spaM (17.5%, 7/40), spiC (40%, 16/40), orfL (32.5%, 13/40), misL 32.5% (13/40) and pipD 32.5 (13/40). For diversity analysis, soil, manure, irrigation water and nearby freshwater revealed 81, 68, 12 and 9 serovars, respectively. Soil, manure, irrigation water and freshwater stream samples shared five serovars, which indicated circulation of ESBL-producing Salmonella spp. within the agricultural environment and nearby water sources. Soil is therefore identified as one of the major reservoirs of ESBL-producing Salmonella spp. It is concluded that agricultural environment contamination may have a direct relationship with the presence of antibiotic-producing Salmonella in freshwater streams.

The in vitro Effects of the Probiotic Strain, Lactobacillus casei ZX633 on Gut Microbiota Composition in Infants With Diarrhea

We investigated the in vitro effects of Lactobacillus casei ZX633 on gut microorganism composition in infants with diarrhea. For this purpose, 103 feces samples from healthy infants (healthy group) and 300 diarrhea samples from infants (diarrhea group) were collected, and diarrhea feces were treated with L. casei ZX633, which was previously isolated from healthy infant feces (treatment group). We used microbial dilution plate methods, high performance liquid chromatography (HPLC) and high-throughput sequencing approaches to analyze viable main microorganism counts, short chain fatty acid (SCFA) concentrations, and intestinal microbiota composition in feces, respectively. Our data showed that L. casei ZX633 supplementation increased the numbers of Escherichia coli, yeasts, lactic acid bacteria (LAB) and aerobic-bacteria, raised propionic acid levels but reduced four other SCFAs, which are close to the healthy group. Alpha diversity results indicated that microbial diversity and richness decreased in treatment group. Bacterial community analyses revealed that microbial structures of the treatment group tended toward the healthy group; i.e., Escherichia-Shigella and Clostridioides abundance increased, and there was a reduction in the abundance of Streptococcus, Bacteroides, Enterococcus and Veillonella. In conclusion, L. casei ZX633 isolated from healthy infant feces, may be effective in improving infant diarrhea microbiota, potentially providing a new probiotic strain to reduce the incidence of diarrhea associated with bacterial disease in infants.

Prevalence and Antimicrobial Resistance Pattern of Salmonella, Shigella, and Intestinal Parasites and Associated Factor among Food Handlers in Dilla University Student Cafeteria, Dilla, Ethiopia

BACKGROUND

Food-borne disease is mostly caused by unsafe food handling and processing as well as poor hygienic practice. Recently, it is a worldwide and local burden to the human health. It is estimated that about one-third of the world population is affected by food-borne diseases annually and become a global public health problem. Hence, this study aimed to determine the prevalence, antimicrobial susceptibility patterns, and associated risk factors of Shigella, Salmonella, and intestinal parasites among food handlers in Dilla University, Southern Ethiopia.

METHODS

An institutional-based cross-sectional study was conducted from November to September 2018/2019. A structured questionnaire was used for the collection of data on sociodemographic characteristics. Parasite and bacterial identification, as well as susceptibility testing, was done using standard parasitological and bacteriological procedures.

RESULTS

Of the total 220 food handlers included in the study, 38.6%, 9.5%, and 3.2% were positive for intestinal parasites, Salmonella, and Shigella species, respectively. A. lumbricoides (11.4%) was the predominant parasite isolated followed by E. histolytica (7.7%). From the total Salmonella isolates, serogroup D was the most frequent isolate and from the total Shigella species, Shigella flexneri was the predominant isolate. In this study, through irregular medical checkups, those who drunk unpasteurized milk and ate raw meat were significantly associated with intestinal parasites. Both Salmonella and Shigella species were highly resistant to ampicillin (81%) and amoxicillin-clavulanic acid (>70%). Salmonella isolates are highly sensitive to cefotaxime and ceftriaxone, while Shigella is highly sensitive to ciprofloxacin and norfloxacin. MDR was recorded in 71.4% of all bacterial isolates.

CONCLUSION

The presence of a high prevalence of intestinal parasites, Salmonella, and Shigella species that were resistant to the commonly prescribed drugs is a treat to the children and the community at large. Therefore, measures including health education, improvement of safe water supply, sanitation facilities, and continuous monitoring of microbiological and antimicrobial surveillance are crucial.

Infectious and parasitic diseases of poultry in Ethiopia: a systematic review and meta-analysis

In Ethiopia, poultry production is an important source of domestic food and nutrition security while providing income for nearly 80% of Ethiopians. However, several infectious and parasitic diseases hamper poultry production. To date, evidence on the nationwide burden of specific diseases has not been collated to inform targeting of poultry health interventions. The objective of this systematic review is to summarize and analyze the literature on poultry diseases since 2000. A detailed systematic review protocol was designed according to Cochrane collaboration, Strengthening the Reporting of Observational Studies in Epidemiology (STROBE), and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statements. The review revealed that 14 infectious and parasitic diseases of poultry were reported in 110 published studies from 2000 to 2017, and 81.82% (90/110) of the studies covered 6 diseases: Newcastle disease (ND), infectious bursal disease (IBD), avian coccidiosis, helminth infestation, ecto-parasite infestation, and Salmonella infection. The pooled prevalence estimates of ND and IBD were 44% (95% confidence interval [CI]: 27 to 63) and 41% (95% CI: 23 to 60), respectively. Among the parasitic diseases, avian coccidiosis, helminth infestation, and ecto-parasite infestation had estimated pooled prevalences of 37% (95% CI: 30 to 44), 62% (95% CI: 45 to 78), and 50% (95% CI: 33 to 68), respectively. The pooled prevalence estimate of Salmonella infection was found to be 51% (95% CI: 32 to 70). Most of the studies were conducted in central Ethiopia, in the State of Oromia, and focused on extensive farming systems. While the number of studies was low, the overall trend of disease reporting in the literature is increasing (Y = 0.99X-3.34). In conclusion, the high-pooled prevalence estimates of diseases and the scarcity of reported data for all of Ethiopia indicate an important data gap on infectious-disease distribution in the country. While the high-pooled prevalence points towards the need for intervention to control poultry diseases, there is also a need to ensure all diseases that result in production losses and public health risks are studied appropriately in all Ethiopian production systems.

Prevalence and Antibiotic Resistance Pattern of Salmonella Isolated from Caecal Contents of Exotic Chicken in Debre Zeit and Modjo, Ethiopia

A cross-sectional study was conducted between December, 2013, and May, 2014, to determine the prevalence and antibiotic resistance feature of Salmonella isolated from broilers slaughtered in Debre Zeit and Modjo towns, Ethiopia. A total of 384 caecal content samples were collected for microbiological examination following the standard techniques and procedures outlined by the International Organization for Standardization to isolate Salmonella. The sensitivity of the isolates subjected to nine antimicrobials was tested by the Kirby-Bauer disk diffusion method. The overall prevalence of Salmonella was 14.6%, and its occurrence differ significantly by farm (p < 0.05). The occurrence of the bacteria was not statistically different in the midland (15.2%) and lowland (13.3%) (p > 0.05) and between males (13.5%) and females (15.6) (p > 0.05). Of the 50 isolates, 48 were resistant to at least one drug. Multidrug resistance was recorded in 43 (86.0%) of the isolates. The study demonstrated considerable prevalence and high antimicrobial resistant Salmonella in exotic chicken and indicates the potential importance of chickens as source of foodborne salmonellosis and multiple antimicrobial resistance of Salmonella. Improving the hygienic practice of farms could help to reduce the occurrence of Salmonella in farms. Further studies are needed to describe the risk factors associated with the emergence of drug-resistant Salmonella in chicken.

Prevalence of enteric non-typhoidal Salmonella in humans in the Middle East and North Africa: A systematic review and meta-analysis

To enhance efforts related to controlling foodborne pathogens in the Middle East and North Africa (MENA), information on epidemiology of non-typhoidal Salmonella enterica (hereafter termed "Salmonella") is limited. We quantified the overall regional and country-specific Salmonella prevalence in different human populations and identified the most common serotypes. Published literature of Salmonella prevalence was systematically reviewed and reported following the Preferred Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Pooled Salmonella prevalence measures were estimated using a random-effects model. We identified 46 research reports that reported 84 Salmonella prevalence measures in 15 out of 24 countries in MENA. There were 252,831 tested humans with 6,356 Salmonella-positive cases. The pooled Salmonella prevalence in MENA was estimated at 6.6% (95% confidence interval (CI): 5.4%-7.9%). The highest pooled Salmonella prevalence measures were in Morocco (17.9%, 95% CI: 5.7%-34.8%, 1997-2012), Tunisia (10.2%, 95% CI: 4.3%-18.0%, 1988-2009) and Sudan (9.2%, 95% CI: 6.5%-12.2%, 2006-2008), while the lowest were in Jordan (1.1%, 95% CI: 0.1%-3.0%, 1993-2010), Oman (1.2%, 95% CI: 1.2%-1.3%, 1998-2002) and Palestine (1.2%, 95% CI: 0.4%-2.1%, 1999-2011). In MENA, Salmonella pooled prevalence in gastrointestinal symptomatic, gastrointestinal asymptomatic and food handlers population groups was 13.0% (95% CI: 7.6%-19.6%), 11.4% (95% CI: 2.2%-25.7%) and 3.8% (95% CI: 1.0%-8.0%), respectively. Salmonella prevalence was 14.5% (95% CI: 8.7%-26.1%) in studies tested <100 subjects, whereas 4.6% (95% CI: 3.6%-5.8%) in studies tested ≥100 subjects. Salmonella Enteritidis (29.8%) and Typhimurium (23.6%) were the most common serotypes. Salmonella was a common foodborne pathogen in MENA countries, particularly in North African countries. Findings inform the scientific community, the public and the decision-makers with Salmonella prevalence and gaps in evidence in MENA to support control and prevention strategies and could leverage more research studies.

A cross-sectional study of enteric fever among febrile patients at Ambo hospital: prevalence, risk factors, comparison of Widal test and stool culture and antimicrobials susceptibility pattern of isolates

Background

Enteric fever is one of the common infectious diseases of humans. The objectives of this study were to:1) estimate the prevalence of enteric fever among febrile patients visiting Ambo hospital; 2) comparison of Widal test and stool culture;3) evaluation of the antimicrobial susceptibility of isolates; and 4) assess potential risk factors to acquire enteric fever infection.

Methods

Blood and stool samples were collected from 372 febrile patients with symptoms clinically similar to enteric fever. Widal test was used for testing sera while stool culturing and bacterial identification was done using WHO standard methods. Susceptibility testing was done using Kirby-Bauer disc diffusion method. Chi-Square test and Logistic Regression analysis were used to analyze the data.

Results

The apparent and true prevalence of enteric fever were 56.2% (95% confidence interval [CI]: 50.97–61.29%) and 57.52% (95% CI: 52.3–62.6%) respectively, while, the culture prevalence was 2.7% (95% CI: 1.30–4.89%). Isolation rates of S. Typhi and S. Paratyphi were 0.8% (95% CI: 0.17–2.34%) and 1.9% (95% CI: 0.76–3.84%) respectively. The isolates showed 100% resistance to amoxicillin, bacitracin, erythromycin, 80%resistance to cefotaxime and streptomycin and 20% for chloramphenicol. The sensitivity, specificity, positive and negative predictive values of Widal test was 80.0, 44.5, 3.8 and 98.8% respectively. Multivariable logistic regression analysis revealed that age (adjusted odds ratio [aOR] = 2.45; 95% CI: 1.38–4.37; P = 0.002), religion (aOR = 15.57, 95% CI: 3.01–80.64; P = 0.001), level of education (aOR = 2.60, 95% CI: 1.27–5.28; P = 0.009), source of water (aOR = 2.20, 95% CI: 1.21–3.98; P = 0.009), raw milk (aOR =2.19, 95% CI:1.16–4.16; P = 0.016) and raw meat consumption (aOR = 1.80, 95% CI: 1.07–3.01; P = 0.026) are the predictors of enteric fever seropositivity.

Conclusions

Patients were wrongly diagnosed and treated for enteric fever by Widal test. Therefore, rapid tests with better sensitivity and specificity are needed for the diagnosis of enteric fever. Provision of safe water and health education are vital to bring behavioral change towards raw food consumption.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-3917-3) contains supplementary material, which is available to authorized users.

Typhoid fever: clinical presentation and associated factors in febrile patients visiting Shashemene Referral Hospital, southern Ethiopia

Objective

Although typhoid fever is a major public health problem in Ethiopia, data is not available in the study area. Therefore, this study aimed to determine the prevalence, clinical presentation at the time of diagnosis and associated factors of typhoid fever among febrile patients visiting Shashemene Referral Hospital, southern Ethiopia. A cross-sectional study was conducted from January 1, 2016, to October 30, 2016. Socio-demographic and clinical data were collected using a structured questionnaire. A blood sample was collected and inoculated into Tryptic soy broth.

Results

A total of 421 adult febrile patients suspected of typhoid fever were included in the study. Of these, the overall prevalence of culture-confirmed typhoid fever was 5.0% (21/421). The prevalence of typhoid fever was significantly associated with rural residence (8.4%). As compared to the urban resident, the rural resident was 3.6 times more likely found to have culture-confirmed typhoid fever. The prevalence of typhoid fever was significantly associated with those patients whose water source was spring 7 (12.3%) and river 7 (13.2%). All of those study participants who used treated water were culture negative. Fever for ≥ 5 days, abdominal pain, and skin rash independently predicted blood culture-confirmed typhoid fever.

Burden of intestinal pathogens and associated factors among asymptomatic food handlers in South Ethiopia: emphasis on salmonellosis

Objective

The study aims to assess the burden of intestinal parasites and Salmonellosis among asymptomatic food handlers at meal serving facilities in Sodo town. Antibiotic resistance was also common and increasing among Salmonella isolates with multidrug resistance as current concern.

Result

Community based cross-sectional study was carried out from 387 food handlers working in meal serving facilities. Food handlers, 159(41%) had one or more intestinal parasites. A. lumbricoides was the most prevalent parasite 30(7.8%), followed by Taenia species 26(6.7%) and Hook worm 23(5.9%). A total number of 35 Salmonella isolates were found of which Sero-group D was the most frequent, 17(48.5%) followed by Sero-group C, 12(34.3%), and B 6(17.1%). Ten (2.5%) isolates were Salmonella typhi. Raw meat eating, hand washing after toilet and after touching dirty materials showed significant association with intestinal pathogens. Salmonella isolates were highly resistant to ampicillin (85.7%), amoxicillin and tetracycline 74.3% each. Multidrug resistance prevalence of 81.8% was identified. Periodic screening of food handlers is important in order to prevent the transmission of intestinal parasites and Salmonellosis. Treatment needs to be based on accurate laboratory detection to mitigate the spread of drug resistant Salmonella strains.

Electronic supplementary material

The online version of this article (10.1186/s13104-018-3610-4) contains supplementary material, which is available to authorized users.

Diagnosis and Treatment of Human Salmonellosis in Addis Ababa City, Ethiopia

BACKGROUND

Diagnosis using reliable tools and treatment following in vitro antimicrobial susceptibility tests are critical to proper addressing of antibiotic-resistant Salmonella infection.

METHODOLOGY

A cross-sectional study was conducted to assess the practice of diagnosis and treatment of salmonellosis in Addis Ababa. Tube Widal test (for blood samples only), culture, biochemical and carbohydrate fermentation, serotyping, and antimicrobial susceptibility tests were employed for both blood and stool samples.

RESULTS

Of all the diseases listed in the diagnosis, nontyphoidal (n = 72, 13.71%) and typhoidal (n = 47, 8.95%) salmonellosis were the second and third common diseases. Among the 288 blood samples, almost half were positive for O, H, or both antigens. However, only 1 (0.68%) of the positive blood samples yielded Salmonella isolate during culture. The study demonstrated low specificity (0.68%) and positive predictive value (48.78%) of Widal test. Conversely, the test showed 100% sensitivity and negative predictive values. Salmonella isolates were identified from 7 (7.07%) of 99 stool samples. Two-thirds of salmonellosis suspected patients received antibiotic treatment. However, only half of the confirmed salmonellosis patients were treated with appropriate antibiotics. All of the isolates were susceptible to ciprofloxacin and ceftriaxone but resistant to ampicillin.

CONCLUSIONS

Majority of the patients who participated in this study were wrongly diagnosed using symptoms, clinical signs, and tube Widal test. Consequently, most of the patients received inappropriate treatment.

Prevalence and antimicrobial susceptibility of Salmonella and Shigella spp. among children with gastroenteritis in an Iranian referral hospital

BACKGROUND

Gastroenteritis is one of the leading cause of illnesses through the world, especially in developing countries.Salmonella and Shigella infections are considered as the main public health problems in children. The aim of this study was to detect the prevalence and antimicrobial susceptibility of Salmonella and Shigella spp. among children with gastroenteritis in an Iranian referral hospital.

METHODS

During April 2013 to April 2014, all medical records of children with gastroenteritis admitted to a pediatric medical center were evaluated. Positive stool cultures of children were evaluated and frequency of Salmonella and Shigella spp. and their antimicrobial susceptibility were detected.

RESULTS

In this study, 676 patients with the mean age of 24.94 months were enrolled. Eighty-eight (42%) Salmonella spp., 85 (40%) Shigella spp., 33 (16%) E. coli and 5(2%) candida albicans were isolated from 211 positive stool cultures. Among 85 Shigella spp. isolates, S. sonnei, S. flexneri and other Shigella spp. were isolated from 39 (46%) isolates, 36(42%) and 10(12%), respectively. Among 88 isolated Salmonella spp., 36 (41%) isolates were Salmonella Serogroup D, 26 (30%) were Salmonella Serogroup B, 20 (23%) isolates were Salmonella Serogroup C and 6 (7%) were other Salmonella spp. isolates. Thirty-eight percent of Salmonella serogroup B were resistant to nalidixic acid, while higher frequency of nalidixic acid resistant was found in Salmonella serogroup C and Salmonella serogroup D. The higher frequency of ampicillin resistant was found in Shigella spp. than Salmonella spp. High frequency of cefotaxime resistant was seen in S. sonei and S. flexneri (77% and 56%, respectively), whereas more than 90% of Salmonella serogroup B, C and D were susceptible to this antibiotic.

CONCLUSION

In conclusion, Shigella and Salmonella serogroups can be considered as important etiological agents of acute diarrhea in children. Since the prevalence of antibiotic resistance is increasing in recent years in Iran, further studies on the prevalence, antimicrobial susceptibility pattern and mechanisms of antibiotic resistance in these species is highly recommended.

Prevalence and Antimicrobial Resistance of Salmonella Isolated from Animal-Origin Food Items in Gondar, Ethiopia

Salmonella has been found to be the major cause of foodborne diseases and a serious public health problem in the world, with an increasing concern for the emergence and spread of antimicrobial-resistant strains. A cross-sectional study was conducted between February 2014 and December 2015 on food items of animal origin to assess the prevalence and antimicrobial resistance profiles of Salmonella isolates using standard bacteriological methods. The overall prevalence rate of 5.5% was recorded from the total analyzed food items of animal origin. Salmonella isolates were detected from 12% of raw meat, 8% of minced meat, 2.9% of burger samples, 18% of raw eggs, and 6% of raw milk. Furthermore, antimicrobial susceptibility test identified 47.6% resistant Salmonella isolates, 28.6% intermediately sensitive isolates, and 23.8% susceptible isolates. Among Salmonella isolates tested, 42.6%, 28.6%, and 14.3% were found to be relatively resistant to tetracycline, sulfamethoxazole-trimethoprim, and ampicillin, respectively, while 9.5%–19% were intermediately resistant to tetracycline, amoxicillin, ampicillin, cephalothin, and nitrofurantoin. Therefore, our findings provide the prevalence and drug resistance of Salmonella from foods of animal origin and contribute information to scientists as well as public health researchers to minimize the prevalent and resistant foodborne Salmonella species in Ethiopia.

Salmonella Serogroup C: Current Status of Vaccines and Why They Are Needed

Nontyphoidal Salmonella (NTS; i.e., Salmonella enterica organisms that do not cause typhoid or paratyphoid) are responsible for 94 million infections and 155,000 deaths worldwide annually, 86% of which are estimated to be foodborne. Although more than 50 serogroups and 2,600 serovars have been described, not all Salmonella serovars cause disease in humans and animals. Efforts are being made to develop NTS vaccines, with most approaches eliciting protection against serovars Typhimurium and Enteritidis (serogroups B [O:4] and D [O:9], respectively), as they are widely considered the most prevalent. Here, we show that serogroup C (O:6,7, O:6,8, or O:8 epitopes) is the most common serogroup in the United States, and the prevalence of serovars from this serogroup has been increasing in Europe and the United States over the last decade. They are also the most commonly isolated serovars from healthy cattle and poultry, indicating the underlying importance of surveillance in animals. Four out of the 10 most lethal serovars in the United States are serogroup C, and reports from African countries suggest that strains within this serogroup are highly antibiotic resistant. Serogroup C consists of highly diverse organisms among which 37 serovars account for the majority of human cases, compared to 17 and 11 serovars for serogroups B and D, respectively. Despite these concerning data, no human vaccines targeting serogroup C NTS are available, and animal vaccines are in limited use. Here, we describe the underestimated burden represented by serogroup C NTS, as well as a discussion of vaccines that target these pathogens.

Impact of co-infections with enteric pathogens on children suffering from acute diarrhea in southwest China

Background

Acute diarrhea is a global health problem, resulting in high morbidity and mortality in children. It has been suggested that enteric pathogen co-infections play an important role in gastroenteritis, but most research efforts have only focused on a small range of species belonging to a few pathogen groups. This study aimed to assess the impact of co-infections with a broad range of enteric pathogens on children aged below five years who suffer from acute diarrhea in southwest China.

Method

A total of 1020 subjects (850 diarrhea cases and 170 healthy controls) were selected from four sentinel hospitals in Kunming, Yunnan province, southwest China, from June 2014 to July 2015. Stool specimens were collected to detect five virus (rotavirus group A, RVA; norovirus, NoV; Sapovirus, SaV; astrovirus, As; and adenovirus, Ad), seven bacterial (diarrheagenic Escherichia coli, DEC; non-typhoidal Salmonella, NTS; Shigella spp.; Vibrio cholera; Vibrio parahaemolyticus; Aeromonas spp.; and Plesiomonas spp.), and three protozoan (Cryptosporidium spp., Giardia lamblia, and Blastocystis hominis, B. hominis) species using standard microbiologic and molecular methods. Data were analyzed using the partial least square regression technique and chi-square test.

Results

At least one enteric pathogen was detected in 46.7 % (n = 397) of acute gastroenteritis cases and 13.5 % (n = 23) of healthy controls (χ² = 64.4, P < 0.05). Single infection with RVA was associated with acute diarrhea (26.5 % vs. 5.8 %, P < 0.05). The prevalence of a single infection with B. hominis in diarrhea cases was higher than in healthy controls (3.1 % vs. 0.5 %, OR = 4.7, 95 % CI: 1.01–112.0). Single infection with NoV GII was not associated with diarrhea (4.4 % vs. 3.5 %, OR = 1.2, 95 % CI: 0.5–3.3). Single infections with bacterial species were not observed. The prevalence of co-infections with two enteric pathogens in diarrhea cases was higher than in asymptomatic children (20.1 % vs. 5.3 %, P < 0.05). RVA-NoV GII was the most common co-infection in symptomatic children (4.4 %), with it aggravating the severity of diarrhea.

Conclusions

Although it is clear that RVA has an overwhelming impact on diarrhea illnesses in children, co-infection with other enteric pathogens appears to also aggravate diarrhea severity. These findings should serve as evidence for public health services when planning and developing intervention programs.

Electronic supplementary material

The online version of this article (doi:10.1186/s40249-016-0157-2) contains supplementary material, which is available to authorized users.

Non-typhoidal Salmonella serotypes, antimicrobial resistance and co-infection with parasites among patients with diarrhea and other gastrointestinal complaints in Addis Ababa, Ethiopia

BACKGROUND

Non-typhoidal Salmonella (NTS) is an important public health problem worldwide. Consumption of animal-derived food products and direct and/or indirect contact with animals are the major routes of acquiring infection with NTS. Published information, particularly on the serotype distribution of NTS among human patients with gastroenteritis and associated risk factors, is scarce in Ethiopia. This study investigated the prevalence, risk factors, serotype distribution and antimicrobial susceptibility of Salmonella species among diarrheic out-patients attending health centers in Addis Ababa and patients with various gastrointestinal complaints at Tikur Anbessa Specialized Hospital (TASH).

METHODS

Stool samples were cultured for Salmonella species according to the WHO Global Foodborne Infections Network laboratory protocol. Salmonella serotyping was conducted using slide agglutination and microplate agglutination techniques. Antibiotic susceptibility testing was performed using the disk diffusion method according to Clinical and Laboratory Standards Institute guidelines.

RESULTS

A total of 59 (6.2 %) stool samples, out of 957 were culture positive for Salmonella species. Fifty-five (7.2 %) of 765 diarrheic patients from health centers and 4 (2.1 %) of 192 patients from TASH were culture positive for Salmonella species. Multivariable logistic regression analysis after adjusting for all other variables revealed statistically significant association of Salmonella infection with consumption of raw vegetables (OR = 1.91, 95 % CI = 1.29-2.83, χ(2) = 4.74, p = 0.025) and symptom of watery diarrhea (OR = 3.3, 95 % CI = 1.23-8.88, χ(2) = 10.54, p = 0.005). Eleven serotypes were detected, and the most prominent were S. Typhimurium (37.3 %), S. Virchow (34 %), and S. Kottbus (10.2 %). Other serotypes were S. Miami, S. Kentucky, S. Newport, S. Enteritidis, S. Braenderup, S. Saintpaul, S. Concord and S. V:ROUGH-O. Resistance to three or more antimicrobials was detected in 27 (40.3 %) of the isolates. Resistance to five or more antimicrobials was detected in 17 (25.4 %). Resistance to individual antimicrobials was found at varying proportions: streptomycin (50; 74.6 %), nitrofurantoin (27; 40.3 %), sulfisoxazole (26; 38.8 %), kanamycin (23; 34.3 %), cephalothin (12; 17.9 %), and ampicillin (11; 16.4 %) respectively. Two S. Kentucky, one S. Typhimurium and one S. Concord isolates were multi-drug resistant to more than 10 antimicrobials.

CONCLUSIONS

The study demonstrated significant association of Salmonella infection with consumption of raw vegetables. There was no significant association of Salmonella infection with co-occurring parasites. The study also showed the dominance of S. Typhimurium and S. Virchow in primary health care units. Overall, prevalence of MDR was low compared to previous studies. Although their proportion was low, S. Kentucky and S. Concord demonstrated wider spectrum of MDR. Continuous monitoring of circulating serotypes, antimicrobial resistance profile and characterization on molecular resistance determinants is essential for proper treatment of patients and for identifying potential environmental origins of antimicrobial resistance.

Prevalence of Salmonella in raw animal products in Ethiopia: a meta-analysis

BACKGROUND

The contributions of animal products to human salmonellosis differ across countries, and source attribution is a major step in prioritizing control measures. The objectives of this study were to estimate the prevalence of Salmonella in raw animal products in Ethiopia by using meta-analytical methods.

RESULTS

The odds of Salmonella contaminated meat was more than twice higher in markets than in slaughter houses [Odds ratio (OR) = 2.25 (95% Confidence Interval [CI] = 1.75, 2.89)]. The source species significantly affected meat contamination in slaughter houses (P < 0.05) but not in the markets (P > 0.05). The pooled estimates of Salmonella contaminated goat carcasses, beef carcasses, minced beef and milk were 3.86%, 4.53%, 8.34% and 10.76% respectively.

CONCLUSIONS

The estimates demonstrate the extent of contamination, and imply the need for safety intervention measures to reduce the risks of contamination of animal products and human illnesses.

A meta-analysis of the proportion of animal Salmonella isolates resistant to drugs used against human salmonellosis in Ethiopia

Background

The emergence and spread of drug resistant Salmonellae of both human and animal origins are global concerns and worrisome in countries where the risk of infection is high and treatment options are limited. The objective of this study was to estimate the proportions of animal isolates resistant to antimicrobials used against human salmonellosis in Ethiopia.

Methods

Published studies on the antimicrobial resistance features of Salmonellae isolated from food animals of Ethiopia were searched in Medline, Google Scholar and the lists of references of articles. Eligible studies were selected by using inclusion and exclusion criteria and data were extracted. The extracted data included the host species, the numbers of isolates and the numbers of ampicillin, co-trimoxazole, chloramphenicol, ceftriaxone and ciprofloxacin resistant isolates. The risks of bias were assessed and the percentages of the variations of the estimates attributable to heterogeneities were quantified. Pooled proportions were estimated by the DerSimonian and Laird random effects model.

Results

Five hundred and fifty four Salmonellae isolated from cattle, camels, sheep, goats and pigs were tested with a variety of antimicrobials. The percentages of the variations attributable to heterogeneities were low for chloramphenicol and ceftriaxone (I² = 0) and high for ampicillin, co-trimoxazole and ciprofloxacin resistance estimates (I² > 75%). The pooled estimate of ampicillin resistant isolates was higher in slaughtered ruminants (17.28%) than in pigs (3.95%), (p < 0.001). The pooled estimates of co-trimoxazole resistant isolates in true ruminants (4.35%) and pigs (1.12%) were not significantly different (p > 0.05). The overall pooled estimates of chloramphenicol and ceftriaxone resistant isolates were 2.24% and 1.25%, respectively. Seven serotypes have been reported to be resistant to antimicrobials uncommonly used in veterinary clinical practice in Ethiopia.

Conclusions

Among Salmonellae of farm animals, there exist strains that are resistant to drugs used in the therapeutic management of human salmonellosis in Ethiopia. Intervention measures should be taken to ensure the prudent use of antimicrobials and curb the spread of high risk strains across the country.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-015-0835-x) contains supplementary material, which is available to authorized users.

A meta-analysis of the prevalence of Salmonella in food animals in Ethiopia

BACKGROUND

The globalization of the food supply and the increased movements of people, animals and goods have increased the threat of Salmonella infections in several countries. The objective of this study was to estimate the prevalence of Salmonella in food animals in Ethiopia by using meta-analytical methods.

RESULTS

The prevalence of Salmonella in slaughtered cattle, sheep, goats and pigs were 7.07%, 8.41%, 9.01% and 43.81% respectively. The occurrence of Salmonella was significantly higher in pigs than in slaughtered true ruminants (p <0.001) but not significantly different between cattle, sheep and goats (p >0. 05). S. Mishmarhaemek, S. Infantis and S. Hadar were the predominant isolates in cattle, small ruminants and pigs respectively. S. Typhimurium was isolated from all host species.

CONCLUSIONS

All food animals are considerable reservoirs of Salmonella and pose a significant risk to public health. Safety measures in slaughter houses and butcheries and education of the public could reduce the risk of transmission of Salmonella from animals to humans.

A meta-analysis of the proportion of antimicrobial resistant human Salmonella isolates in Ethiopia

BACKGROUND

Antimicrobial resistant Salmonella is a global problem and recently, a strain on the verge of pan-resistance was reported. In Ethiopia, the therapeutic management of Salmonellosis is difficult because drug sensitivity tests are not routinely carried out and treatment alternatives are not available in most health care facilities. The objectives of this study were to estimate the temporal changes and proportions of drug resistant isolates in Ethiopia.

METHODS

Published studies on drug resistant Salmonella isolates were searched in Medline, Google Scholar and the lists of references of articles. Eligible studies were selected by using inclusion and exclusion criteria. Generic, methodological and statistical information were extracted from the eligible studies. The extracted data included the proportions of ampicillin, co-trimoxazole, chloramphenicol, ceftriaxone, ciprofloxacin and multi-drug resistant isolates. Pooled proportions were estimated by a random effects model.

RESULTS

The odds of multi-drug resistant isolates in the 2000s was higher than before the 1990s (OR =18.86, 95% CI = 13.08, 27.19). The pooled proportions of ampicillin, co-trimoxazole, chloramphenicol, ciprofloxacin and multi-drug resistant isolates in the 2000s were 86.01%, 68.01%, 62.08%, 3.61% and 79.56% respectively. S. Concord (>97%) was resistant to ampicillin, co-trimoxazole, chloramphenicol and ceftriaxone.

CONCLUSION

The proportion of drug resistant isolates has increased since the 1970s. All drugs currently used for the treatment of Salmonellosis but ciprofloxacin are not reliable for an empirical therapy. Alternative drugs should be included in the essential drug list and measures should be taken to re-enforce the drug use policy.