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The Cochrane Database of Systematic... Jul 2007Two typhoid vaccines are commercially available, Ty21a (oral) and Vi polysaccharide (parenteral), but neither is used routinely. Other vaccines, such as a new modified,... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Two typhoid vaccines are commercially available, Ty21a (oral) and Vi polysaccharide (parenteral), but neither is used routinely. Other vaccines, such as a new modified, conjugated Vi vaccine called Vi-rEPA, are in development.
OBJECTIVES
To evaluate vaccines for preventing typhoid fever.
SEARCH STRATEGY
In December 2006, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2006, Issue 3), MEDLINE, EMBASE, LILACS, and mRCT. We also searched relevant conference proceedings up to 2004 and scanned the reference lists of all included trials.
SELECTION CRITERIA
Randomized and quasi-randomized controlled trials (RCTs) comparing typhoid fever vaccines with other typhoid fever vaccines or an inactive agent (placebo or vaccine for a different disease).
DATA COLLECTION AND ANALYSIS
Two authors independently applied inclusion criteria and extracted data. We computed vaccine efficacy per year of follow up and cumulative three-year efficacy, stratifying for vaccine type and dose. We calculated relative risks (RR) and efficacy (1-RR as a percentage) with 95% confidence intervals (CI).
MAIN RESULTS
Of the 17 included RCTs, 10 evaluated efficacy (Ty21a: 5 trials; Vi polysaccharide: 4 trials, Vi-rEPA: 1 trial), and 11 reported on adverse events.Ty21a vaccine (3 doses). According to one trial (20,543 participants), this vaccine provided statistically significant protection in each of the first three years (one: 35%, 95% CI 8% to 54%; two: 58%, 95% CI 40% to 71%; three: 46%, 95% CI -6% to 72%), and the cumulative efficacy for 2.5 to 3 years was 48% (95% CI 34% to 58%). Four cluster-RCTs that did not adjust for clustering were not included in the meta-analyses. Compared with placebo, this vaccine was not associated with an increased rate of fever, vomiting, diarrhoea, nausea or abdominal pain, headache, or rash.Vi polysaccharide vaccine (1 dose). This vaccine provided protection in year one (68%, 95% CI 50% to 80%; 99,979 participants, 3 trials) and year two (60%, 95% CI 31% to 76%; 142,555 participants, 2 trials), but not in year three (11,384 participants, 1 trial). The three-year cumulative efficacy was 55% (95% CI 30% to 70%; 11,384 participants, 1 trial). Compared with placebo, there was no statistically significant difference in the incidence of fever or erythema, but local swelling was more common with the vaccine.Vi-rEPA vaccine (2 doses). In one trial of 12,008 participants, this vaccine provided protection in year one (94%, 95% CI 75% to 99%) and year two (87%, 95% CI 56% to 96%). Cumulative efficacy at 46 months (3.8 years) was 89% (95% CI 76% to 97%). No swelling or erythema occurred in the vaccine or placebo group; fever was more frequent in the vaccine group.
AUTHORS' CONCLUSIONS
The licensed Ty21a and Vi polysaccharide vaccines are efficacious. The new and unlicensed Vi-rEPA vaccine is as efficacious and may confer longer immunity.
Topics: Adolescent; Adult; Child; Child, Preschool; Humans; Randomized Controlled Trials as Topic; Salmonella typhi; Typhoid Fever; Typhoid-Paratyphoid Vaccines; Vaccines, Attenuated
PubMed: 17636661
DOI: 10.1002/14651858.CD001261.pub2 -
Tropical Medicine & International... Dec 2019Hospital-based studies of community-onset bloodstream infections (CO-BSI) are less resource-intensive to carry out than population-based incidence studies. We examined...
OBJECTIVES
Hospital-based studies of community-onset bloodstream infections (CO-BSI) are less resource-intensive to carry out than population-based incidence studies. We examined several metrics capturing the potential role of Salmonella Typhi as a cause of CO-BSI for making inferences about incidence.
METHODS
We systematically reviewed three databases for hospital-based studies of CO-BSI. We determined, by study, the prevalence and rank order of Salmonella among pathogenic bloodstream isolates, and the prevalence ratio of Salmonella Typhi to Escherichia coli (S:E ratio). We then describe these hospital-based study metrics in relation to population-based typhoid fever incidence data from a separate systematic review.
RESULTS
Forty-four studies met the inclusion criteria, of which 23 (52.3%) isolated Salmonella Typhi at least once. Among studies isolating Salmonella Typhi, the median (interquartile range) prevalence and rank order of Salmonella Typhi compared to other pathogens isolated in BSI was 8.3% (3.2-37.9%) and 3 (1-6), respectively. The median (interquartile range) S:E ratio was 1.0 (0.4-3.0). With respect to incidence, in Pemba Island, Tanzania, prevalence, rank order, S:E ratio, and incidence was 64.8%, 1, 9.2 and 110 cases per 100 000, respectively, and in Boulkiemdé, Burkina Faso, was 13.3%, 3, 2.3 and 249 cases per 100 000.
CONCLUSIONS
We describe considerable variation in place and time for Salmonella Typhi prevalence, rank order, and S:E ratio among hospital-based studies of CO-BSI. Data from simultaneous typhoid prevalence and incidence studies are limited. We propose that hospital-based study metrics warrant evaluation for making inference about typhoid incidence and as covariates in typhoid incidence models.
Topics: Bacteremia; Burkina Faso; Female; Hospitalization; Humans; Incidence; Male; Prevalence; Salmonella typhi; Tanzania; Typhoid Fever
PubMed: 31633858
DOI: 10.1111/tmi.13319 -
Clinical Rheumatology Jul 2019Piriformis pyomyositis is a rare form of purulent skeletal myositis. As previous studies concerning piriformis pyomyositis had lower level of evidence and no systematic...
Piriformis pyomyositis is a rare form of purulent skeletal myositis. As previous studies concerning piriformis pyomyositis had lower level of evidence and no systematic review has been published yet, we performed a systematic search to review and describe causes, symptoms, red flags, and available treatment options for piriformis pyomyositis. Using PubMed and PubMed Central databases, we found 21 articles describing 23 cases of piriformis pyomyositis. Based on the retrieved information, alongside acute sciatica like buttock and/or hip pain, high-grade fever, aggressive deep seated gluteal pain, neurological deficit of sciatic nerve distribution, positive straight leg raising test, and raised inflammatory biomarkers (erythrocyte sedimentation rate, ESR, C-reactive protein, CRP) provide clues for diagnosis of piriformis pyomyositis. Some cases were very ill but no death was documented. Staphylococcus aureus was the most common pathogen, but Group A as well as Group β Streptococcus, Salmonella typhi, Proteus mirabilis, Brucella melitensis, and Escherichia coli were also involved in the disorder. To treat the piriformis pyomyositis, broad-spectrum antibiotics were found to be useful; however, sometimes, antibiotic switching was warranted based on blood and tissue aspirate reports. Drainage and/or surgical exploration of the affected piriformis muscle were required in cases where antibiotics appeared ineffective. Piriformis pyomyositis is a rara avis and performing of prospective studies will hardly be feasible.
Topics: Anti-Bacterial Agents; Bacterial Infections; Humans; Low Back Pain; Piriformis Muscle Syndrome; Pyomyositis; Sciatica; Staphylococcal Infections
PubMed: 31049761
DOI: 10.1007/s10067-019-04552-y -
Antimicrobial Resistance and Infection... 2019Despite a high mortality rate in childhood, there is limited evidence on the causes and outcomes of paediatric bloodstream infections from low- and middle-income... (Meta-Analysis)
Meta-Analysis
Bacterial pathogens and resistance causing community acquired paediatric bloodstream infections in low- and middle-income countries: a systematic review and meta-analysis.
BACKGROUND
Despite a high mortality rate in childhood, there is limited evidence on the causes and outcomes of paediatric bloodstream infections from low- and middle-income countries (LMICs). We conducted a systematic review and meta-analysis to characterize the bacterial causes of paediatric bloodstream infections in LMICs and their resistance profile.
METHODS
We searched Pubmed and Embase databases between January 1st 1990 and October 30th 2019, combining MeSH and free-text terms for "sepsis" and "low-middle-income countries" in children. Two reviewers screened articles and performed data extraction to identify studies investigating children (1 month-18 years), with at least one blood culture. The main outcomes of interests were the rate of positive blood cultures, the distribution of bacterial pathogens, the resistance patterns and the case-fatality rate. The proportions obtained from each study were pooled using the Freeman-Tukey double arcsine transformation, and a random-effect meta-analysis model was used.
RESULTS
We identified 2403 eligible studies, 17 were included in the final review including 52,915 children (11 in Africa and 6 in Asia). The overall percentage of positive blood culture was 19.1% [95% CI: 12.0-27.5%]; 15.5% [8.4-24.4%] in Africa and 28.0% [13.2-45.8%] in Asia. A total of 4836 bacterial isolates were included in the studies; 2974 were Gram-negative (63.9% [52.2-74.9]) and 1858 were Gram-positive (35.8% [24.9-47.5]). In Asia, typhi (26.2%) was the most commonly isolated pathogen, followed by (7.7%) whereas in Africa, (17.8%) and (16.8%) were predominant followed by (10.7%). was more likely resistant to methicillin in Africa (29.5% vs. 7.9%), whereas was more frequently resistant to third-generation cephalosporins (31.2% vs. 21.2%), amikacin (29.6% vs. 0%) and ciprofloxacin (36.7% vs. 0%) in Asia. The overall estimate for case-fatality rate among 8 studies was 12.7% [6.6-20.2%]. Underlying conditions, such as malnutrition or HIV infection were assessed as a factor associated with bacteraemia in 4 studies each.
CONCLUSIONS
We observed a marked variation in pathogen distribution and their resistance profiles between Asia and Africa. Very limited data is available on underlying risk factors for bacteraemia, patterns of treatment of multidrug-resistant infections and predictors of adverse outcomes.
Topics: Adolescent; Africa; Anti-Bacterial Agents; Asia; Bacteremia; Bacteria; Child; Child Health; Child, Preschool; Community-Acquired Infections; Developing Countries; Drug Resistance, Bacterial; Humans; Infant; Microbial Sensitivity Tests; Observational Studies as Topic; Poverty; Sepsis
PubMed: 31893041
DOI: 10.1186/s13756-019-0673-5 -
The Cochrane Database of Systematic... Oct 2008Enteric fever (typhoid and paratyphoid fever) is potentially fatal. Infection with drug-resistant strains of the causative organism Salmonella enterica serovar Typhi or... (Comparative Study)
Comparative Study Meta-Analysis Review
BACKGROUND
Enteric fever (typhoid and paratyphoid fever) is potentially fatal. Infection with drug-resistant strains of the causative organism Salmonella enterica serovar Typhi or Paratyphi increases morbidity and mortality. Azithromycin may have better outcomes in people with uncomplicated forms of the disease.
OBJECTIVES
To compare azithromycin with other antibiotics for treating uncomplicated enteric fever.
SEARCH STRATEGY
In August 2008, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2008, Issue 3), MEDLINE, EMBASE, LILACS, and mRCT. We also searched conference proceedings, reference lists, and contacted researchers and a pharmaceutical company.
SELECTION CRITERIA
Randomized controlled trials comparing azithromycin with other antibiotics for treating children and adults with uncomplicated enteric fever confirmed by cultures of S. Typhi or Paratyphi in blood and/or stool.
DATA COLLECTION AND ANALYSIS
Both authors independently extracted data and assessed the risk of bias. Dichotomous data were presented and compared using the odds ratio, and continuous data were reported as arithmetic means with standard deviations and were combined using the mean difference (MD). Both were presented with 95% confidence intervals (CI).
MAIN RESULTS
Seven trials involving 773 participants met the inclusion criteria. The trials used adequate methods to generate the allocation sequence and conceal allocation, and were open label. Three trials exclusively included adults, two included children, and two included both adults and children; all were hospital inpatients. One trial evaluated azithromycin against chloramphenicol and did not demonstrate a difference for any outcome (77 participants, 1 trial). When compared with fluoroquinolones in four trials, azithromycin significantly reduced clinical failure (OR 0.48, 95% CI 0.26 to 0.89; 564 participants, 4 trials) and duration of hospital stay (MD -1.04 days, 95% CI -1.73 to -0.34 days; 213 participants, 2 trials); all four trials included people with multiple-drug-resistant or nalidixic acid-resistant strains of S. Typhi or S. Paratyphi. We detected no statistically significant difference in the other outcomes. Compared with ceftriaxone, azithromycin significantly reduced relapse (OR 0.09, 95% CI 0.01 to 0.70; 132 participants, 2 trials) and not other outcome measures. Few adverse events were reported, and most were mild and self limiting.
AUTHORS' CONCLUSIONS
Azithromycin appears better than fluoroquinolone drugs in populations that included participants with drug-resistant strains. Azithromycin may perform better than ceftriaxone.
Topics: Adolescent; Adult; Anti-Bacterial Agents; Azithromycin; Child; Humans; Paratyphoid Fever; Randomized Controlled Trials as Topic; Typhoid Fever
PubMed: 18843701
DOI: 10.1002/14651858.CD006083.pub2 -
The American Journal of Tropical... Sep 2018Typhoid and paratyphoid fever continue to significantly contribute to global morbidity and mortality. Disease burden is higher in low-and middle-income settings where...
Typhoid and paratyphoid fever continue to significantly contribute to global morbidity and mortality. Disease burden is higher in low-and middle-income settings where surveillance programs are rare and little systematic information exists at population level. This review evaluates national, regional, and global trends in the incidence of typhoid fever and of related morbidity and mortality. A literature search in Medline, Embase, and Web of Science was conducted in June 2016, followed by screening and data extraction in duplicate. Studies reporting blood culture estimates of typhoid or paratyphoid morbidity and mortality were included in the analysis. Our search yielded 5,563 unique records, of which 1978 were assessed for relevance with 219 records meeting the eligibility criteria. serotype Typhi was the most commonly reported organism (91%), with the occurrence of typhoidal (either incidence or prevalence) being the most commonly reported outcome (78%), followed by typhoid fever mortality, ileal perforation morbidity, and perforation mortality, respectively. Fewer than 50% of studies stratified outcomes by age or urban/rural locality. Surveillance data were available from 29 countries and patient-focused studies were available from 32 countries. Our review presents a mixed picture with declines reported in many regions and settings but with large gaps in surveillance and published data. Regional trends show generally high incidence rates in South Asia, sub-Saharan Africa, and East Asia and Pacific where the disease is endemic in many countries. Significant increases have been reported in certain countries but should be explored in the context of long-term trends and underlying at-risk populations.
Topics: Global Health; Humans; Paratyphoid Fever; Public Health; Typhoid Fever; Water Microbiology
PubMed: 30047364
DOI: 10.4269/ajtmh.18-0034 -
The Cochrane Database of Systematic... Nov 2012Non-typhoidal Salmonella (NTS) commonly causes diarrhoea, and is usually self-limiting, although sometimes people become ill with sepsis and dehydration. Routine... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Non-typhoidal Salmonella (NTS) commonly causes diarrhoea, and is usually self-limiting, although sometimes people become ill with sepsis and dehydration. Routine antibiotic use for this infection could result in persistent colonization and the spread of resistant bacterial strains.
OBJECTIVES
To assess the efficacy and safety of giving antibiotics to people with NTS diarrhoea.
SEARCH METHODS
We searched the Cochrane Infectious Diseases Group trials register (up to August 2012), the Cochrane Controlled Trials Register (CENTRAL) published in The Cochrane Library (up to Issue 8 2012); and MEDLINE, African Index Medicus, CINAHL, EMBASE, LILACS, and the Science Citation Index, all up to 6 August 2012. We also searched the metaRegister of Controlled Trials (mRCT) for both completed and on going trials and reference lists of relevant articles.
SELECTION CRITERIA
Randomized controlled trials (RCTs) comparing any antibiotic treatment for diarrhoea caused by NTS species with placebo or no antibiotic treatment. We selected trials that included people of all ages who were symptomatic for NTS infection. Examples of symptoms included fever, abdominal pain, vomiting and diarrhoea. We excluded trials where the outcomes were not reported separately for the NTS subgroup of patients. Two review authors independently applied eligibility criteria prior to study inclusion.
DATA COLLECTION AND ANALYSIS
Two review authors independently extracted data on pre-specified outcomes and independently assessed the risk of bias of included studies. The primary outcome was the presence of diarrhoea between two to four days after treatment. The quality of evidence was assessed using the GRADE methods.
MAIN RESULTS
Twelve trials involving 767 participants were included. No differences were detected between the antibiotic and placebo/no treatment arms for people with diarrhoea at two to four days after treatment (risk ratio (RR) 1.75, 95% confidence interval (CI) 0.42 to 7.21; one trial, 46 participants; very low quality evidence). No difference was detected for the presence of diarrhoea at five to seven days after treatment (RR 0.83, 95% CI 0.62 to 1.12; two trials, 192 participants; very low quality evidence), clinical failure (RR 0.88, 95% CI 0.62 to 1.25; seven trials, 440 participants; very low quality evidence). The mean difference for diarrhoea was 0 days (95% CI -0.54 to 0.54; 202 participants, four studies; low quality evidence);for fever was 0.27 days (95% CI -0.11 to 0.65; 107 participants, two studies; very low quality evidence); and for duration of illness was 0 days (95% CI -0.68 to 0.68; 116 participants, two studies; very low quality evidence). Quinolone antibiotic treatment resulted in a significantly higher number of negative stool cultures for NTS during the first week of treatment (microbiological failure: RR 0.33, 95% CI 0.20 to 0.56; 166 participants, four trials).Antibiotic treatment meant passage of the same Salmonella serovar one month after treatment was almost twice as likely (RR 1.96, 95% CI 1.29 to 2.98; 112 participants, three trials), which was statistically significant. Non-severe adverse drug reactions were more common among the patients who received antibiotic treatment.
AUTHORS' CONCLUSIONS
There is no evidence of benefit for antibiotics in NTS diarrhoea in otherwise healthy people. We are uncertain of the effects in very young people, very old people, and in people with severe and extraintestinal disease. A slightly higher number of adverse events were noted in people who received antibiotic treatment for NTS.
Topics: Adult; Anti-Bacterial Agents; Child; Child, Preschool; Diarrhea; Gastroenteritis; Gastrointestinal Diseases; Humans; Infant; Randomized Controlled Trials as Topic; Salmonella Infections; Salmonella paratyphi A; Salmonella typhi
PubMed: 23152205
DOI: 10.1002/14651858.CD001167.pub2 -
PLoS Neglected Tropical Diseases May 2019Typhoid fevers are infections caused by the bacteria Salmonella enterica serovar Typhi (Salmonella Typhi) and Paratyphi A, B and C (Salmonella Paratyphi). Approximately... (Comparative Study)
Comparative Study
BACKGROUND
Typhoid fevers are infections caused by the bacteria Salmonella enterica serovar Typhi (Salmonella Typhi) and Paratyphi A, B and C (Salmonella Paratyphi). Approximately 17.8 million incident cases of typhoid fever occur annually, and incidence is highest in children. The accuracy of current diagnostic tests of typhoid fever is poorly understood. We aimed to determine the comparative accuracy of available tests for the pediatric population.
METHODS
We first conducted a systematic literature review to identify studies that compared diagnostic tests for typhoid fever in children (aged ≤15 years) to blood culture results. We applied a Bayesian latent-class extension to a network meta-analysis model. We modelled known diagnostic properties of bone marrow culture and the relationship between bone marrow and blood culture as informative priors in a Bayesian framework. We tested sensitivities for the proportion of negative blood samples that were false as well as bone marrow sensitivity and specificity.
RESULTS
We found 510 comparisons from 196 studies and 57 specific to the pediatric population. IgM-based tests outperformed their IgG-based counterparts for ELISA and Typhidot tests. The lateral flow IgG test performed comparatively well with 92% sensitivity (72% to 98% across scenario analyses) and 94% specificity. The most sensitive test of those investigated for the South Asian pediatric population was the Reverse Passive Hemagglutination Assay with 99% sensitivity (98% - 100% across scenario analyses). Adding a Widal slide test to other typhoid diagnostics did not substantially improve diagnostic performance beyond the single test alone, however, a lateral flow-based IgG rapid test combined with the typhoid/paratyphoid (TPT) assay yielded improvements in sensitivity without substantial declines in specificity and was the best performing combination test in this setting.
CONCLUSION
In the pediatric population, lateral-flow IgG, TPT and Reverse Passive Hemagglutination tests had high diagnostic accuracy compared to other diagnostics. Combinations of tests may provide a feasible option to increase diagnostic sensitivity. South Asia has the most informed set of data on typhoid diagnostic testing accuracy, and the evidence base in other important regions needs to be expanded.
Topics: Adolescent; Antibodies, Bacterial; Bayes Theorem; Child; Child, Preschool; Diagnostic Tests, Routine; Female; Humans; Male; Reagent Kits, Diagnostic; Salmonella typhi; Sensitivity and Specificity; Typhoid Fever; Young Adult
PubMed: 31067228
DOI: 10.1371/journal.pntd.0007303 -
Clinical Infectious Diseases : An... Jun 2017Children bear a substantial proportion of the enteric fever disease burden in endemic areas. Controversy persists regarding which age groups are most affected, leading... (Meta-Analysis)
Meta-Analysis Review
Children bear a substantial proportion of the enteric fever disease burden in endemic areas. Controversy persists regarding which age groups are most affected, leading to uncertainty about optimal intervention strategies. We performed a systematic review and meta-analysis of studies in Asia and Africa to compare the relative proportion of children with enteric fever in the age groups <5 years, 5-9 years, and 10-14 years. Overall, studies conducted in Africa showed a relatively smaller occurrence of disease in the youngest age group, whereas in Asia the picture was more mixed with a very large degree of heterogeneity in estimates. The clinical features of enteric fever reviewed here differ between younger and older children and adults, likely leading to further uncertainty over disease burden. It is evident from our review that preschool children and infants also contribute a significant proportion of disease burden but have not been adequately targeted via vaccination programs, which have been focusing primarily on school-based vaccination campaigns.
Topics: Adolescent; Africa; Age Factors; Asia; Child; Child, Preschool; Cost of Illness; Female; Humans; Immunization Programs; Infant; Male; Paratyphoid Fever; Prevalence; Salmonella paratyphi A; Salmonella typhi; Typhoid Fever
PubMed: 28369224
DOI: 10.1093/cid/cix229 -
BMC Infectious Diseases Jan 2016The control of typhoid fever being an important public health concern in low and middle income countries, improving typhoid surveillance will help in planning and... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The control of typhoid fever being an important public health concern in low and middle income countries, improving typhoid surveillance will help in planning and implementing typhoid control activities such as deployment of new generation Vi conjugate typhoid vaccines.
METHODS
We conducted a systematic literature review of longitudinal population-based blood culture-confirmed typhoid fever studies from low and middle income countries published from 1(st) January 1990 to 31(st) December 2013. We quantitatively summarized typhoid fever incidence rates and qualitatively reviewed study methodology that could have influenced rate estimates. We used meta-analysis approach based on random effects model in summarizing the hospitalization rates.
RESULTS
Twenty-two papers presented longitudinal population-based and blood culture-confirmed typhoid fever incidence estimates from 20 distinct sites in low and middle income countries. The reported incidence and hospitalizations rates were heterogeneous as well as the study methodology across the sites. We elucidated how the incidence rates were underestimated in published studies. We summarized six categories of under-estimation biases observed in these studies and presented potential solutions.
CONCLUSIONS
Published longitudinal typhoid fever studies in low and middle income countries are geographically clustered and the methodology employed has a potential for underestimation. Future studies should account for these limitations.
Topics: Databases, Factual; Developing Countries; Hospitalization; Humans; Incidence; Longitudinal Studies; Salmonella typhi; Typhoid Fever
PubMed: 26822522
DOI: 10.1186/s12879-016-1351-3