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Tropical Medicine and Infectious Disease Sep 2022Salmonella enterica serovar Typhi (S. Typhi) that has developed resistance to many antimicrobials poses a serious challenge to public health. Hence, this study aimed to... (Review)
Review
Salmonella enterica serovar Typhi (S. Typhi) that has developed resistance to many antimicrobials poses a serious challenge to public health. Hence, this study aimed to systematically determine the prevalence of antimicrobial resistance (AMR) in S. Typhi isolated from the environment and humans as well as to ascertain the spread of the selected AMR genes in S. Typhi. This systematic review and meta-analysis were performed according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines, and the study protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO). A total of 2353 studies were retrieved from three databases, of which 42 studies fulfilled the selection criteria. The pooled prevalence of AMR S. Typhi (using a random-effect model) was estimated at 84.8% (95% CI; 77.3−90.2), with high heterogeneity (I2: 95.35%, p-value < 0.001). The high estimated prevalence indicates that control methods should be improved immediately to prevent the spread of AMR among S. Typhi internationally.
PubMed: 36288012
DOI: 10.3390/tropicalmed7100271 -
The Lancet. Infectious Diseases Apr 2019Efforts to quantify the global burden of enteric fever are valuable for understanding the health lost and the large-scale spatial distribution of the disease. We present... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Efforts to quantify the global burden of enteric fever are valuable for understanding the health lost and the large-scale spatial distribution of the disease. We present the estimates of typhoid and paratyphoid fever burden from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017, and the approach taken to produce them.
METHODS
For this systematic analysis we broke down the relative contributions of typhoid and paratyphoid fevers by country, year, and age, and analysed trends in incidence and mortality. We modelled the combined incidence of typhoid and paratyphoid fevers and split these total cases proportionally between typhoid and paratyphoid fevers using aetiological proportion models. We estimated deaths using vital registration data for countries with sufficiently high data completeness and using a natural history approach for other locations. We also estimated disability-adjusted life-years (DALYs) for typhoid and paratyphoid fevers.
FINDINGS
Globally, 14·3 million (95% uncertainty interval [UI] 12·5-16·3) cases of typhoid and paratyphoid fevers occurred in 2017, a 44·6% (42·2-47·0) decline from 25·9 million (22·0-29·9) in 1990. Age-standardised incidence rates declined by 54·9% (53·4-56·5), from 439·2 (376·7-507·7) per 100 000 person-years in 1990, to 197·8 (172·0-226·2) per 100 000 person-years in 2017. In 2017, Salmonella enterica serotype Typhi caused 76·3% (71·8-80·5) of cases of enteric fever. We estimated a global case fatality of 0·95% (0·54-1·53) in 2017, with higher case fatality estimates among children and older adults, and among those living in lower-income countries. We therefore estimated 135·9 thousand (76·9-218·9) deaths from typhoid and paratyphoid fever globally in 2017, a 41·0% (33·6-48·3) decline from 230·5 thousand (131·2-372·6) in 1990. Overall, typhoid and paratyphoid fevers were responsible for 9·8 million (5·6-15·8) DALYs in 2017, down 43·0% (35·5-50·6) from 17·2 million (9·9-27·8) DALYs in 1990.
INTERPRETATION
Despite notable progress, typhoid and paratyphoid fevers remain major causes of disability and death, with billions of people likely to be exposed to the pathogens. Although improvements in water and sanitation remain essential, increased vaccine use (including with typhoid conjugate vaccines that are effective in infants and young children and protective for longer periods) and improved data and surveillance to inform vaccine rollout are likely to drive the greatest improvements in the global burden of the disease.
FUNDING
Bill & Melinda Gates Foundation.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Cause of Death; Child; Child, Preschool; Disabled Persons; Female; Global Burden of Disease; Humans; Incidence; Infant; Life Expectancy; Male; Mass Vaccination; Middle Aged; Paratyphoid Fever; Quality-Adjusted Life Years; Risk Factors; Salmonella enterica; Sanitation; Typhoid Fever; Typhoid-Paratyphoid Vaccines; Young Adult
PubMed: 30792131
DOI: 10.1016/S1473-3099(18)30685-6 -
Alimentary Pharmacology & Therapeutics Apr 2014Carcinoma of the gall-bladder is the fifth commonest gastrointestinal tract cancer and is endemic in several countries. An association of chronic typhoid carriage and... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Carcinoma of the gall-bladder is the fifth commonest gastrointestinal tract cancer and is endemic in several countries. An association of chronic typhoid carriage and carcinoma of the gall-bladder has been reported.
AIM
To clarify whether chronic Salmonella typhi carrier state is associated with carcinoma of the gall-bladder.
METHODS
A systematic search was conducted using MEDLINE, PubMed, EMBASE, Current Contents, Cochrane library, Google Scholar, Science Direct and Web of Science. Original data were abstracted from each study and used to calculate a pooled odds ratio (OR) and 95% confidence interval (95% CI).
RESULTS
Of the articles selected, only 17 studies met full criteria for analysis. The overall OR for chronic S. typhi carrier state was 4.28(95% CI: 1.84-9.96). Most of the studies were from South Asia especially India and China. When a subgroup analysis was performed according to region, a significant association was observed in South-East Asia (OR: 4.13, 95% CI: 2.87-5.94, P value <0.01). Chronic S. typhi carrier state was associated with carcinoma of the gall-bladder based on detection methods of S. typhi antibody levels (OR: 3.52, 95% CI: 2.48-5.00, P value <0.01) and even more so on culture (OR: 4.14, 95% CI: 2.41-7.12, P value <0.01). The association was prominent in controls without gallstones (OR: 5.86, 95% CI: 3.84-8.95, P value <0.01) when compared with controls with gallstones (OR: 2.71, 95% CI: 1.92-3.83, P value <0.01).
CONCLUSIONS
Chronic S. typhi carrier state is an important risk factor among patients with carcinoma of the gall-bladder. Given the high risk associated with this carrier state, management options should include either elective cholecystectomy or careful monitoring using ultrasound.
Topics: Carrier State; Chronic Disease; Gallbladder Neoplasms; Gallstones; Humans; Risk Factors; Salmonella typhi; Typhoid Fever
PubMed: 24612190
DOI: 10.1111/apt.12655 -
The American Journal of Tropical... Dec 2020Understanding patterns and trends of antimicrobial resistance (AMR) in Typhi can guide empiric treatment recommendations and contribute to country decisions about...
Understanding patterns and trends of antimicrobial resistance (AMR) in Typhi can guide empiric treatment recommendations and contribute to country decisions about typhoid conjugate vaccine (TCV) introduction. We systematically reviewed PubMed and Web of Science for articles reporting the proportion of Typhi isolates resistant to individual antimicrobials worldwide from any time period. Isolates resistant to chloramphenicol, ampicillin, and trimethoprim-sulfamethoxazole were classified as multidrug resistant (MDR), and isolates that were MDR plus resistant to a fluoroquinolone and a third-generation cephalosporin were extensively drug resistant (XDR). Among the 198 articles eligible for analysis, a total of 55,459 Typhi isolates were tested for AMR (median 80; range 2-5,191 per study). Of isolates from 2015 through 2018 in Asia, 1,638 (32.6%) of 5,032 were MDR, 167 (5.7%) of 2,914 were resistant to third-generation cephalosporins, and 148 (8.3%) of 1,777 were resistant to azithromycin. Two studies from Pakistan reported 14 (2.6%) of 546 isolates were XDR. In Africa, the median proportion of Typhi isolates that were MDR increased each consecutive decade from 1990 to 1999 through 2010 to 2018. Typhi has developed resistance to an increasing number of antimicrobial classes in Asia, where XDR Typhi is now a major threat, whereas MDR has expanded in Africa. We suggest continued and increased surveillance is warranted to inform empiric treatment decisions and that AMR data be incorporated into country decisions on TCV introduction.
Topics: Anti-Bacterial Agents; Drug Resistance, Bacterial; Global Health; Humans; Salmonella Infections; Salmonella typhi
PubMed: 32996447
DOI: 10.4269/ajtmh.20-0258 -
The Lancet. Global Health Apr 2024Typhoid is a serious public health threat in many low-income and middle-income countries. Several vaccines for typhoid have been recommended by WHO for typhoid... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Typhoid is a serious public health threat in many low-income and middle-income countries. Several vaccines for typhoid have been recommended by WHO for typhoid prevention in endemic countries. This study aimed to review the efficacy of typhoid vaccines against culture-confirmed Salmonella enterica serovar Typhi.
METHODS
We searched the Cochrane Central Register of Controlled Trials, MEDLINE, and Embase for studies published in English between Jan 1, 1986 and Nov 2, 2023. We included randomised controlled trials (RCTs) comparing typhoid vaccines with a placebo or another vaccine. This meta-analysis evaluated the efficacy and safety of several typhoid vaccines, including live attenuated oral Ty21a vaccine, Vi capsular polysaccharide (Vi-PS), Vi polysaccharide conjugated to recombinant Pseudomonas aeruginosa exotoxin A vaccine (Vi-rEPA), and Vi-tetanus toxoid conjugate vaccine (TCV). The certainty of evidence for key outcomes was evaluated using Grading of Recommendations, Assessment, Development, and Evaluations methodology. The outcome of interest was typhoid fever confirmed by the isolation of Salmonella enterica serovar Typhi in blood and adverse events following immunisation. This study is registered with PROSPERO (CRD42021241043).
FINDINGS
We included 14 RCTs assessing four different vaccines (Ty21a: four trials; Vi-PS: five trials; Vi-rEPA: one trial; TCV: four trials) involving 585 253 participants. All trials were conducted in typhoid endemic countries and the age of participants ranged from 6 months to 50 years. The pooled efficacy against typhoid fever was 45% (95% CI 33-55%; four trials; 247 649 participants; I 59%; moderate certainty) for Ty21a and 58% (44-69%; five trials; 214 456 participants; I 34%; moderate certainty) for polysaccharide Vi-PS. The cumulative efficacy of two doses of Vi-rEPA vaccine at 2 years was 91% (88-96%; one trial; 12 008 participants; moderate certainty). The pooled efficacy of a single shot of TCV at 2 years post-immunisation was 83% (77-87%; four trials; 111 130 participants; I 0%; moderate certainty). All vaccines were safe, with no serious adverse effects reported in the trials.
INTERPRETATION
The existing data from included trials provide promising results regarding the efficacy and safety of the four recommended typhoid vaccines. TCV and Vi-rEPA were found to have the highest efficacy at 2 years post-immunisation. However, follow-up data for Vi-rEPA are scarce and only TCV is pre-qualified by WHO. Therefore, roll-out of TCV into routine immunisation programmes in typhoid endemic settings is highly recommended.
FUNDING
There was no funding source for this study.
Topics: Humans; Infant; Salmonella typhi; Typhoid Fever; Typhoid-Paratyphoid Vaccines; Pseudomonas aeruginosa Exotoxin A; Vaccines, Attenuated; Vaccines, Conjugate; Tetanus Toxoid; Polysaccharides
PubMed: 38485426
DOI: 10.1016/S2214-109X(23)00606-X -
PloS One 2018Wide-ranging evidence on the occurrence of fluoroquinolone (FQ) resistance genetic determinants in African Salmonella strains is not available. The main objectives of... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Wide-ranging evidence on the occurrence of fluoroquinolone (FQ) resistance genetic determinants in African Salmonella strains is not available. The main objectives of this study were to assess the heterogeneity, estimate pooled proportions and describe the preponderance of FQ-resistance determinants in typhoidal and non-typhoidal Salmonella (NTS) isolates of Africa.
METHODS
Genetic and phenotypic data on 6103 Salmonella isolates were considered. Meta- and frequency analyses were performed depending on the number of studies by category, number of isolates and risks of bias. A random effects model was used to assess heterogeneity and estimate pooled proportions. Relative and cumulative frequencies were calculated to describe the overall preponderance of FQ-resistance determinants in quinolone resistant isolates.
RESULTS
The pooled proportion of gyrA mutants (Salmonella enterica serovar Typhi, Salmonella enterica serovar Typhimurium, and Salmonella enterica serovar Enteritidis) was estimated at 5.7% (95% Confidence interval (CI) = 2.6, 9.8; Tau squared (T2) = 0.1105), and was higher in S. Typhi than in S. Typhimurium (odds ratio (OR) = 3.3, 95%CI = 2, 5.7). The proportions of each of gyrB and parC mutants, and strains with Plasmid Mediated Quinolone Resistance genes (qnrA, qnrB and qnrS) were low (≤ 0.3%). Overall, 23 mutant serotypes were identified, and most strains had mutations at codons encoding Ser83 and Asp87 of gyrA (82%, 95%CI = 78, 86).
CONCLUSIONS
Mutations at gyrA appear to account for ciprofloxacin non-susceptibility in most clinical Salmonella strains in Africa. The estimates could be harnessed to develop a mismatch-amplification mutation-assay for the detection of FQ-resistant strains in Africa.
Topics: Africa; Drug Resistance, Bacterial; Fluoroquinolones; Molecular Epidemiology; Mutation; Salmonella
PubMed: 29432492
DOI: 10.1371/journal.pone.0192575 -
Annals of Clinical Microbiology and... May 2016Blood culture is often used in definitive diagnosis of typhoid fever while, bone marrow culture has a greater sensitivity and considered reference standard. The... (Review)
Review
Blood culture is often used in definitive diagnosis of typhoid fever while, bone marrow culture has a greater sensitivity and considered reference standard. The sensitivity of blood culture measured against bone marrow culture results in measurement bias because both tests are not fully sensitive. Here we propose a combination of the two cultures as a reference to define true positive S. Typhi cases. Based on a systematic literature review, we identified ten papers that had performed blood and bone marrow culture for S. Typhi in same subjects. We estimated the weighted mean of proportion of cases detected by culture measured against true S. Typhi positive cases using a random effects model. Of 529 true positive S. Typhi cases, 61 % (95 % CI 52-70 %) and 96 % (95 % CI 93-99 %) were detected by blood and bone marrow cultures respectively. Blood culture sensitivity was 66 % (95 % CI 56-75 %) when compared with bone marrow culture results. The use of blood culture sensitivity as a proxy measure to estimate the proportion of typhoid fever cases detected by blood culture is likely to be an underestimate. As blood culture sensitivity is used as a correction factor in estimating typhoid disease burden, epidemiologists and policy makers should account for the underestimation.
Topics: Blood Culture; Bone Marrow; False Negative Reactions; False Positive Reactions; Humans; Salmonella typhi; Sensitivity and Specificity; Typhoid Fever
PubMed: 27188991
DOI: 10.1186/s12941-016-0147-z -
Orthopaedic Surgery Jun 2021The aim of this systematic review was to characterize the clinical features of adults with Salmonella osteomyelitis and summarize diagnosis and treatment methods to...
The aim of this systematic review was to characterize the clinical features of adults with Salmonella osteomyelitis and summarize diagnosis and treatment methods to provide guidance for clinicians. This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We conducted a literature search in the PubMed, EMBASE, and Cochrane Library databases. Article screening and data extraction were performed by two reviewers individually. All the included studies were independently evaluated by two reviewers using the Methodological Index for Non-Randomized Studies (MINORS) criteria. A total of 67 articles published between 1970 and 2019 were selected, which include 69 patients with an average age of 47.5 years (range, 18-79).The majority of cases (47.76%) occurred in immunocompetent adults without common risk factors. Aspiration and biopsy cultures were all positive in Salmonella osteomyelitis patients who underwent aspiration or biopsy. All infections were monomicrobial, and a total of 12 different serotypes were identified. The three most commonly reported Salmonella serotypes were Salmonella typhi (19 cases), Salmonella typhimurium (12 cases), and Salmonella enteritidis (11 cases). Only 12 of the 67 cases in our data (17.91%) had diarrhea symptoms, and 44 of the 67 cases (65.67%) had fever symptoms. Fifty-nine of the 67 cases (88.06%) had local inflammatory manifestations, such as erythema, swelling, and tenderness in the affected area. The commonly reported involved sites were the vertebrae, femur, and tibia. Antibiotic therapy alone was utilized in 30 cases, and 24 patients (80.00%) were eventually cured. In total, 75.68% of patients achieved satisfactory results after treatment with surgery and antibiotics. Third-generation cephalosporins were most commonly utilized, and antibiotic treatment was administered for an average of 11.3 weeks (95% CI, 8.31-14.37 weeks). Salmonella osteomyelitis should be considered in patients without any common risk factors. Aspiration or biopsy can facilitate the identification of pathogens to guide antibiotic choice. Empirical therapy with a third-generation cephalosporin is recommended until the susceptibility of the strain is determined.
Topics: Adult; Humans; Osteomyelitis; Salmonella Infections
PubMed: 33942967
DOI: 10.1111/os.12912 -
International Journal of Environmental... Aug 2022Water- and food-related health issues have received a lot of attention recently because food-poisoning bacteria, in particular, are becoming serious threats to human... (Review)
Review
Water- and food-related health issues have received a lot of attention recently because food-poisoning bacteria, in particular, are becoming serious threats to human health. Currently, techniques used to detect these bacteria are time-consuming and laborious. To overcome these challenges, the colorimetric strategy is attractive because it provides simple, rapid and accurate sensing for the detection of spp. bacteria. The aim of this study is to review the progress regarding the colorimetric method of nucleic acid for detection. A literature search was conducted using three databases (PubMed, Scopus and ScienceDirect). Of the 88 studies identified in our search, 15 were included for further analysis. bacteria from different species, such as Typhimurium, Enteritidis, Typhi and Paratyphi A, were identified using the colorimetric method. The limit of detection (LoD) was evaluated in two types of concentrations, which were colony-forming unit (CFU) and CFU per mL. The majority of the studies used spiked samples (53%) rather than real samples (33%) to determine the LoDs. More research is needed to assess the sensitivity and specificity of colorimetric nucleic acid in bacterial detection, as well as its potential use in routine diagnosis.
Topics: Colorimetry; Humans; Limit of Detection; Nucleic Acids; Salmonella; Sensitivity and Specificity
PubMed: 36078284
DOI: 10.3390/ijerph191710570 -
PLoS Neglected Tropical Diseases Oct 2018The temporal and spatial change in trends of antimicrobial resistance (AMR) in typhoid have not been systematically studied, and such information will be critical for...
BACKGROUND
The temporal and spatial change in trends of antimicrobial resistance (AMR) in typhoid have not been systematically studied, and such information will be critical for defining intervention, as well as planning sustainable prevention strategies.
METHODOLOGY AND FINDINGS
To identify the phenotypic trends in AMR, 13,833 individual S. Typhi isolates, reported from 1973 to 2018 in 62 publications, were analysed to determine the AMR preponderance over time. Separate analyses of molecular resistance determinants present in over 4,000 isolates reported in 61 publications were also conducted. Multi-drug resistant (MDR) typhoid is in decline in Asia in a setting of high fluoroquinolone resistance while it is on the increase in Africa. Mutations in QRDRs in gyrA (S83F, D87N) and parC (S80I) are the most common mechanisms responsible for fluoroquinolone resistance. Cephalosporin resistant S. Typhi, dubbed extensively drug-resistant (XDR) is a real threat and underscores the urgency in deploying the Vi-conjugate vaccines.
CONCLUSION
From these observations, it appears that AMR in S. Typhi will continue to emerge leading to treatment failure, changes in antimicrobial policy and further resistance developing in S. Typhi isolates and other Gram-negative bacteria in endemic regions. The deployment of typhoid conjugate vaccines to control the disease in endemic regions may be the best defence.
Topics: Anti-Bacterial Agents; Drug Resistance, Bacterial; Genes, Bacterial; Genotype; Global Health; Humans; Phenotype; Salmonella typhi; Typhoid Fever
PubMed: 30307935
DOI: 10.1371/journal.pntd.0006779