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Ultrasound in Obstetrics & Gynecology :... Apr 2023Universal screening for cytomegalovirus (CMV) infection in pregnancy is not recommended in most countries. One of the major deterrents is the lack of effective prenatal... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
Universal screening for cytomegalovirus (CMV) infection in pregnancy is not recommended in most countries. One of the major deterrents is the lack of effective prenatal therapy. The role of valacyclovir therapy in reducing the risk of vertical transmission, symptomatic congenital CMV infection and adverse outcome is controversial. The main aim of this systematic review and meta-analysis was to investigate the safety and effectiveness of prenatal valacyclovir therapy in pregnancies with maternal CMV infection.
METHODS
MEDLINE, EMBASE and Cochrane databases and ClinicalTrials.gov were searched. The inclusion criteria were pregnancy with confirmed maternal CMV infection, treated or untreated with valacyclovir. The primary outcome was the incidence of congenital CMV infection confirmed by a positive CMV polymerase chain reaction result of the amniotic fluid. The secondary outcomes were symptomatic and asymptomatic infection, perinatal death, termination of pregnancy, anomalies detected on follow-up ultrasound, on fetal magnetic resonance imaging or at birth, severe and mild-to-moderate symptoms due to congenital CMV infection, neurological, visual and hearing symptoms, and adverse events related to valacyclovir. Risk of bias was assessed using the revised Cochrane risk-of-bias tool for randomized trials (RoB 2) or Risk Of Bias In Non-randomized Studies of Interventions (ROBINS-I) tool, as appropriate. Head-to-head meta-analyses were used to compare the risk of each of the explored outcomes according to whether pregnancies with maternal CMV infection were treated with prenatal valacyclovir therapy.
RESULTS
Eight studies (620 women) were included. Pregnancies treated with valacyclovir had a significantly lower risk of congenital CMV infection compared with those not receiving valacyclovir (three studies; 325 fetuses; pooled odds ratio (OR), 0.37 (95% CI, 0.21-0.64); I = 0%; P < 0.001). When stratifying the analysis according to gestational age at maternal infection, the risk of vertical transmission was significantly lower in pregnancies receiving valacyclovir following first-trimester maternal infection (three studies; 184 fetuses; pooled OR, 0.34 (95% CI, 0.15-0.74); I = 20.9%; P = 0.001), while there was no significant difference between the two groups in those acquiring CMV infection in the periconceptional period or in the third trimester of pregnancy. Only one study reported on the risk of vertical transmission in women infected in the second trimester, demonstrating a lower risk of congenital infection in women taking valacyclovir, although this was based on a small number of cases. Pregnancies treated with valacyclovir therapy had an increased likelihood of asymptomatic congenital CMV infection compared with those not receiving valacyclovir (two studies; 132 fetuses; pooled OR, 2.98 (95% CI, 1.18-7.55); I = 0%; P = 0.021), while there was no significant difference between the two groups in the risk of perinatal death (P = 0.923), termination of pregnancy (P = 0.089), anomalies detected at follow-up imaging assessment during pregnancy or at birth (P = 0.934) and symptoms due to CMV infection in the newborn (P = 0.092). The occurrence of all adverse events in pregnant individuals taking valacyclovir was 3.17% (95% CI, 1.24-5.93%) (six studies; 210 women), with 1.71% (95% CI, 0.41-3.39%) experiencing acute renal failure, which resolved after discontinuation of the drug. On GRADE assessment, the quality of evidence showing that valacyclovir reduced the risk of congenital CMV infection and adverse perinatal outcome was very low.
CONCLUSIONS
Prenatal valacyclovir administration in pregnancies with maternal CMV infection reduces the risk of congenital CMV infection. Further evidence is needed to elucidate whether valacyclovir can affect the course of infection in the fetus and the risk of symptomatic fetal or neonatal infection. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.
Topics: Female; Humans; Infant, Newborn; Pregnancy; Amniotic Fluid; Cytomegalovirus Infections; Infectious Disease Transmission, Vertical; Perinatal Death; Pregnancy Complications, Infectious; Prenatal Care; Valacyclovir
PubMed: 36484439
DOI: 10.1002/uog.26136 -
Journal of Microbiology, Immunology,... Feb 2021Since the outbreak of coronavirus disease 2019 (COVID-19) in late December 2019, it has brought significant harm and challenges to over 200 countries and regions around...
Since the outbreak of coronavirus disease 2019 (COVID-19) in late December 2019, it has brought significant harm and challenges to over 200 countries and regions around the world. However, there is increasing evidence that many patients with COVID-19 are asymptomatic or have only mild symptoms, but they are able to transmit the virus to others. There are difficulties in screening for asymptomatic infections, which makes it more difficult for national prevention and control of this epidemic. This article reviews the characteristics, treatment, and outcomes of asymptomatic infections with COVID-19, hoping it would be helpful for early prevention and control of this severe public health threat worldwide.
Topics: Asymptomatic Infections; COVID-19; COVID-19 Nucleic Acid Testing; Disease Outbreaks; Humans; SARS-CoV-2; Treatment Outcome
PubMed: 32425996
DOI: 10.1016/j.jmii.2020.05.001 -
Journal of the American Geriatrics... Nov 2021To determine the associations of delirium with urinary tract infection (UTI) and asymptomatic bacteriuria (AB) in individuals aged 65 and older. (Meta-Analysis)
Meta-Analysis
OBJECTIVE
To determine the associations of delirium with urinary tract infection (UTI) and asymptomatic bacteriuria (AB) in individuals aged 65 and older.
METHODS
The protocol for this systematic review and meta-analysis was published on PROSPERO (CRD42020164341). Electronic databases were searched for relevant studies, professional associations and experts in the field were additionally contacted. Studies with control groups reporting associations between delirium and UTI as well as delirium and AB in older adults were included. The random effects model meta-analysis was conducted using odds ratios (ORs) with 95% confidence intervals (CIs) as effect size measures. The Newcastle-Ottawa scale was used to rate the studies' quality. Heterogeneity was assessed using the Q and I tests. The effects of potential moderators were investigated by both subgroup and meta-regression analyses. The risk of publication bias was evaluated using the funnel plot and Egger's test.
RESULTS
Twenty nine relevant studies (16,618 participants) examining the association between delirium and UTI in older adults were identified. The association between delirium and UTI was found to be significant (OR 2.67; 95% CI 2.12-3.36; p < 0.001) and persisted regardless of potential confounders. The association between delirium and AB in older adults in the only eligible study found (192 participants) was insignificant (OR 1.62; 95% CI 0.57-4.65; p = 0.37). All included studies were of moderate quality.
CONCLUSION
The results of this study support the association between delirium and UTI in older adults. Insufficient evidence was found to conclude on an association between delirium and AB in this age group. These findings are limited due to the moderate quality of the included studies and a lack of available research on the association between delirium and AB. Future studies should use the highest quality approaches for defining both delirium and UTI and consider AB in their investigations.
Topics: Aged; Bacteriuria; Delirium; Hospitals; Humans; Nursing Homes; Urinary Tract Infections
PubMed: 34448496
DOI: 10.1111/jgs.17418 -
The Cochrane Database of Systematic... Aug 2022Urinary tract infections (UTIs) are very common, affecting more than 7 million people worldwide. Whilst many people may only experience a single episode in their... (Review)
Review
BACKGROUND
Urinary tract infections (UTIs) are very common, affecting more than 7 million people worldwide. Whilst many people may only experience a single episode in their lifetime and are generally responsive to standard antibiotics, a significant proportion of adults and children (approximately 15% to 25%) are chronic symptomatic UTI sufferers. Certain population groups are at greater risk than others, such as immunosuppressed and people with chronic kidney disease. D-mannose is a sugar part of normal human metabolism found within most diets. The mechanism of action is to prevent bacterial adherence to the uroepithelial cells. The D-mannose-based inhibitors can block uropathogenic Escherichia coli adhesion and invasion of the uroepithelial cells. The bacteria are then understood to essentially be eliminated by urination. Early pilot studies on animals and humans have trialled concentrated forms of D-mannose (tablets or sachets) in doses ranging from 200 mg up to 2 to 3 g and found possible efficacy in reducing UTI symptoms or recurrence. Although the anti-adhesive effects of D-mannose have been well-established, only recently have we seen a small number of pilot studies and small clinical trials conducted.
OBJECTIVES
To assess the benefits and harms of D-mannose for preventing and treating UTIs in adults and children.
SEARCH METHODS
We searched the Cochrane Kidney and Transplant Register of Studies up to 22 February 2022 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.
SELECTION CRITERIA
We included RCTs measuring and reporting the effect of D-mannose, in any combination and any formulation, to prevent or treat UTIs in adults and children, females and males, in any setting (including perioperative). Authors independently assessed the retrieved titles and abstracts and, where necessary, the full text to determine which satisfied the inclusion criteria.
DATA COLLECTION AND ANALYSIS
Data extraction was independently carried out by two authors using a standard data extraction form. Methodological quality of the included studies was assessed using the Cochrane risk of bias tool. Data entry was carried out by one author and cross-checked by another author. The certainty of the evidence was assessed using the GRADE approach.
MAIN RESULTS
We included seven RCTs (719 participants) in adult females and males who had either acute cystitis or a history of recurrent (at least two episodes in six months or three episodes in 12 months) UTIs (symptomatic or asymptomatic). Two were prevention studies, four were prevention and treatment studies (two perioperative and one in people with multiple sclerosis), and one was a treatment study. Time periods ranged from 15 days to six months. No two studies were comparable (by dose or treatments), and we could not undertake meta-analyses. Individual studies reported no clear evidence to determine whether D-mannose is more or less effective in preventing or treating UTIs. D-mannose (2 g) had uncertain effects on symptomatic and bacteriuria-confirmed UTIs when compared to no treatment (1 study, 205 participants; very low certainty evidence) and antibiotics (nitrofurantoin 50 mg) (1 study, 206 participants; very low certainty evidence). D-mannose, in combination with herbal supplements, had uncertain effects on symptomatic and bacteria-confirmed UTI and pain when compared to no treatment (1 study, 40 participants; very low certainty evidence). D-mannose 500 mg plus supplements (N-acetylcysteine and Morinda citrifolia fruit extract) had uncertain effects on symptomatic and bacteriuria-confirmed UTIs when compared to an antibiotic (prulifloxacin 400 mg) (1 study, 75 participants; very low certainty evidence). Adverse events were very few and poorly reported; none were serious (mostly diarrhoea and vaginal burning). Overall, the quality of the evidence is poor. Most studies were judged to have unclear or high risk of bias across most domains. Data was sparse and addressed very few outcomes. The GRADE evaluation was rated as very low certainty evidence due to very serious limitations in the study design or execution (high risk of bias across all studies) and sparse data (single study data and small sample sizes).
AUTHORS' CONCLUSIONS
There is currently little to no evidence to support or refute the use of D-mannose to prevent or treat UTIs in all populations. This review highlights the severe lack of high-quality RCTs testing the efficacy of D-mannose for UTIs in any population. Despite UTIs being one of the most common adult infections (affecting 50% of women at least once in their lifetime) and the growing global antimicrobial resistance, we found very few studies that adequately test this alternative treatment. Future research in this field requires, in the first instance, a single adequately powered RCT comparing D-mannose with placebo.
Topics: Adult; Anti-Bacterial Agents; Bacteriuria; Child; Female; Humans; Kidney; Male; Mannose; Urinary Tract Infections
PubMed: 36041061
DOI: 10.1002/14651858.CD013608.pub2 -
Gastroenterology May 2016Eradication of Helicobacter pylori infection has been reported to reduce the risk of gastric cancer among asymptomatic individuals in high-risk areas. The magnitude of... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND & AIMS
Eradication of Helicobacter pylori infection has been reported to reduce the risk of gastric cancer among asymptomatic individuals in high-risk areas. The magnitude of benefit of H pylori eradication in populations with different levels of gastric cancer risk and in different clinical scenarios is unclear. We performed a systematic review and meta-analysis of randomized controlled trials and observational studies to investigate the effects of H pylori eradication on the incidence of gastric cancer.
METHODS
We searched PubMed, Cochrane Library, and ClinicalTrials.gov, reviewing titles and abstracts of studies of the effects of eradication of H pylori infection on risk of gastric cancer, through May 2015. We also searched bibliographies of included studies, related reviews, and abstracts presented at Digestive Disease Week. Twenty-four eligible studies (22 research manuscripts and 2 abstracts) were included in our meta-analysis (715 incident gastric cancers among a total of 48,064 individuals/340,255 person-years). We assessed the effects, as well as their modification by baseline gastric cancer incidence, study design (randomized trial vs observational study), clinical scenario (asymptomatic infected individuals vs individuals after endoscopic resection of early gastric cancer), demographic characteristics of patients (age and sex), and duration of follow-up.
RESULTS
After adjustment for baseline gastric cancer incidence, individuals with eradication of H pylori infection had a lower incidence of gastric cancer than those who did not receive eradication therapy (pooled incidence rate ratio = 0.53; 95% confidence interval: 0.44-0.64). There was little heterogeneity among studies. Baseline gastric cancer incidence modified the benefit of H pylori eradication (P = .037 for interaction); the incidence rate ratio of gastric cancer decreased in a nonlinear fashion with increasing baseline incidence of gastric cancer (P = .018, in comparison with the linear model). The benefit also modestly increased with age (P = .023 for interaction), but this might be due to correlation between age and baseline gastric cancer incidence. Eradication provided significant benefit for asymptomatic infected individuals (pooled incidence rate ratio, 0.62; 95% CI: 0.49-0.79) and individuals after endoscopic resection of gastric cancers (pooled incidence rate ratio, 0.46; 95% CI: 0.35-0.60). The benefits of H pylori eradication did not differ with study design, sex, or follow-up period.
CONCLUSIONS
In a systematic review and meta-analysis, we associated eradication of H pylori infection with a reduced incidence of gastric cancer. The benefits of eradication vary with baseline gastric cancer incidence, but apply to all levels of baseline risk.
Topics: Anti-Bacterial Agents; Drug Therapy, Combination; Helicobacter Infections; Helicobacter pylori; Humans; Incidence; Odds Ratio; Protective Factors; Proton Pump Inhibitors; Risk Assessment; Risk Factors; Stomach Neoplasms; Treatment Outcome
PubMed: 26836587
DOI: 10.1053/j.gastro.2016.01.028 -
International Journal of Infectious... Sep 2023The burden of asymptomatic dengue infections is understudied. Therefore, we systematically reviewed the literature to estimate the global prevalence of asymptomatic... (Meta-Analysis)
Meta-Analysis
OBJECTIVES
The burden of asymptomatic dengue infections is understudied. Therefore, we systematically reviewed the literature to estimate the global prevalence of asymptomatic dengue infections.
METHODS
We searched cross-sectional studies reporting the prevalence of asymptomatic dengue infections from PubMed, Scopus, and Embase. Prevalence of asymptomatic dengue infections was pooled and reported as proportions with a 95% confidence interval (CI). This systematic review protocol was a priori registered in The International Prospective Register of Systematic Reviews (Reg: No. CRD42020218446).
RESULTS
We included 41 studies with 131,953 cases in our analysis. The overall pooled prevalence of asymptomatic dengue infections was 59.26% (95% CI: 43.76-74.75, I = 99.93%), with 65.52% (95% CI: 38.73-92.32, I = 99.95%) during outbreaks and 30.78% (95% CI: 21.39-40.16, I = 98.78%) during non-outbreak periods. The pooled prevalence among the acutely infected individuals was 54.52% (95% CI: 17.73-46.76, I = 99.91%), whereas, among primary and secondary asymptomatic dengue infections, it was 65.36% (95% CI: 45.76-84.96, I = 98.82) and 48.99% (95% CI: 27.85-70.13, I = 99.08%) respectively.
CONCLUSION
The majority of dengue cases are asymptomatic and may play a significant role in disease transmission. Public health strategies aimed at dengue outbreak response and mitigation of disease burden should include early detection of asymptomatic cases.
Topics: Humans; Prevalence; Cross-Sectional Studies; Asymptomatic Infections; Coinfection; Dengue
PubMed: 37463631
DOI: 10.1016/j.ijid.2023.07.010 -
Archives of Disease in Childhood Oct 2016Leukaemia is the most common cancer of childhood, accounting for a third of cases. In order to assist clinicians in its early detection, we systematically reviewed all... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
Leukaemia is the most common cancer of childhood, accounting for a third of cases. In order to assist clinicians in its early detection, we systematically reviewed all existing data on its clinical presentation and estimated the frequency of signs and symptoms presenting at or prior to diagnosis.
DESIGN
We searched MEDLINE and EMBASE for all studies describing presenting features of leukaemia in children (0-18 years) without date or language restriction, and, when appropriate, meta-analysed data from the included studies.
RESULTS
We screened 12 303 abstracts for eligibility and included 33 studies (n=3084) in the analysis. All were cohort studies without control groups. 95 presenting signs and symptoms were identified and ranked according to frequency. Five features were present in >50% of children: hepatomegaly (64%), splenomegaly (61%), pallor (54%), fever (53%) and bruising (52%). An additional eight features were present in a third to a half of children: recurrent infections (49%), fatigue (46%), limb pain (43%), hepatosplenomegaly (42%), bruising/petechiae (42%), lymphadenopathy (41%), bleeding tendency (38%) and rash (35%). 6% of children were asymptomatic on diagnosis.
CONCLUSIONS
Over 50% of children with leukaemia have palpable livers, palpable spleens, pallor, fever or bruising on diagnosis. Abdominal symptoms such as anorexia, weight loss, abdominal pain and abdominal distension are common. Musculoskeletal symptoms such as limp and joint pain also feature prominently. Children with unexplained illness require a thorough history and focused clinical examination, which should include abdominal palpation, palpation for lymphadenopathy and careful scrutiny of the skin. Occurrence of multiple symptoms and signs should alert clinicians to possible leukaemia.
Topics: Abdominal Pain; Adolescent; Child; Child, Preschool; Contusions; Early Detection of Cancer; Exanthema; Fever; Gastrointestinal Diseases; Hemorrhage; Hepatomegaly; Humans; Infant; Infant, Newborn; Infections; Leukemia; Musculoskeletal Diseases; Recurrence; Skin Diseases; Splenomegaly
PubMed: 27647842
DOI: 10.1136/archdischild-2016-311251 -
Deutsches Arzteblatt International May 2010Urinary tract infections (UTI) are among the leading reasons for treatment in adult primary care medicine, accounting for a considerable percentage of antibiotic... (Review)
Review
BACKGROUND
Urinary tract infections (UTI) are among the leading reasons for treatment in adult primary care medicine, accounting for a considerable percentage of antibiotic prescriptions. Because this problem is so common and so significant in routine clinical practice, a high level of diagnostic accuracy is essential. Antibiotics should not be prescribed excessively, particularly in view of the increasing prevalence of antibiotic resistance.
METHOD
Systematic review of relevant articles that were retrieved by a search of the Medline, Embase, and Cochrane Library databases. The recommendations of selected international guidelines were also taken into account, as were the German national quality standards for microbiological diagnosis.
RESULTS
The diagnosis of UTI by clinical criteria alone has an error rate of approximately 33%. The use of refined diagnostic algorithms does not completely eliminate uncertainty.
CONCLUSION
With the aid of a small number of additional diagnostic criteria, antibiotic treatment for UTI can be provided more specifically and thus more effectively. Differentiating UTI from asymptomatic bacteriuria, which usually requires no treatment, can lower the frequency of unnecessary antibiotic prescriptions.
Topics: Adolescent; Adult; Aged; Algorithms; Anti-Bacterial Agents; Bacterial Infections; Bacteriuria; Child; Colony-Forming Units Assay; Cystitis; Drug Resistance, Multiple, Bacterial; Female; Humans; Male; Microbial Sensitivity Tests; Middle Aged; Practice Guidelines as Topic; Pregnancy; Primary Health Care; Quality Assurance, Health Care; Risk Factors; Urinary Tract Infections; Young Adult
PubMed: 20539810
DOI: 10.3238/arztebl.2010.0361 -
The Cochrane Database of Systematic... Nov 2019Asymptomatic bacteriuria is a bacterial infection of the urine without any of the typical symptoms that are associated with a urinary infection, and occurs in 2% to 15%... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Asymptomatic bacteriuria is a bacterial infection of the urine without any of the typical symptoms that are associated with a urinary infection, and occurs in 2% to 15% of pregnancies. If left untreated, up to 30% of mothers will develop acute pyelonephritis. Asymptomatic bacteriuria has been associated with low birthweight and preterm birth. This is an update of a review last published in 2015.
OBJECTIVES
To assess the effect of antibiotic treatment for asymptomatic bacteriuria on the development of pyelonephritis and the risk of low birthweight and preterm birth.
SEARCH METHODS
For this update, we searched the Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) on 4 November 2018, and reference lists of retrieved studies.
SELECTION CRITERIA
Randomised controlled trials (RCT) comparing antibiotic treatment with placebo or no treatment in pregnant women with asymptomatic bacteriuria found on antenatal screening. Trials using a cluster-RCT design and quasi-RCTs were eligible for inclusion, as were trials published in abstract or letter form, but cross-over studies were not.
DATA COLLECTION AND ANALYSIS
Two review authors independently assessed trials for inclusion and risk of bias, extracted data, and checked for accuracy. We assessed the quality of the evidence using the GRADE approach.
MAIN RESULTS
We included 15 studies, involving over 2000 women. Antibiotic treatment compared with placebo or no treatment may reduce the incidence of pyelonephritis (average risk ratio (RR) 0.24, 95% confidence interval (CI) 0.13 to 0.41; 12 studies, 2017 women; low-certainty evidence). Antibiotic treatment may be associated with a reduction in the incidence of preterm birth (RR 0.34, 95% CI 0.13 to 0.88; 3 studies, 327 women; low-certainty evidence), and low birthweight babies (average RR 0.64, 95% CI 0.45 to 0.93; 6 studies, 1437 babies; low-certainty evidence). There may be a reduction in persistent bacteriuria at the time of delivery (average RR 0.30, 95% CI 0.18 to 0.53; 4 studies; 596 women), but the results were inconclusive for serious adverse neonatal outcomes (average RR 0.64, 95% CI 0.23 to 1.79, 3 studies; 549 babies). There were very limited data on which to estimate the effect of antibiotics on other infant outcomes, and maternal adverse effects were rarely described. Overall, we judged only one trial at low risk of bias across all domains; the other 14 studies were assessed as high or unclear risk of bias. Many studies lacked an adequate description of methods, and we could only judge the risk of bias as unclear, but in most studies, we assessed at least one domain at high risk of bias. We assessed the quality of the evidence for the three primary outcomes with GRADE software, and found low-certainty evidence for pyelonephritis, preterm birth, and birthweight less than 2500 g.
AUTHORS' CONCLUSIONS
Antibiotic treatment may be effective in reducing the risk of pyelonephritis in pregnancy, but our confidence in the effect estimate is limited given the low certainty of the evidence. There may be a reduction in preterm birth and low birthweight with antibiotic treatment, consistent with theories about the role of infection in adverse pregnancy outcomes, but again, the confidence in the effect is limited given the low certainty of the evidence. Research implications identified in this review include the need for an up-to-date cost-effectiveness evaluation of diagnostic algorithms, and more evidence to learn whether there is a low-risk group of women who are unlikely to benefit from treatment of asymptomatic bacteriuria.
Topics: Anti-Bacterial Agents; Asymptomatic Infections; Bacteriuria; Female; Humans; Infant, Low Birth Weight; Infant, Newborn; Pregnancy; Pregnancy Complications, Infectious; Pregnancy Outcome; Premature Birth; Pyelonephritis; Randomized Controlled Trials as Topic
PubMed: 31765489
DOI: 10.1002/14651858.CD000490.pub4 -
The Cochrane Database of Systematic... Mar 2018Helicobacter pylori (H pylori) infection has been implicated in a number of malignancies and non-malignant conditions including peptic ulcers, non-ulcer dyspepsia,... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Helicobacter pylori (H pylori) infection has been implicated in a number of malignancies and non-malignant conditions including peptic ulcers, non-ulcer dyspepsia, recurrent peptic ulcer bleeding, unexplained iron deficiency anaemia, idiopathic thrombocytopaenia purpura, and colorectal adenomas. The confirmatory diagnosis of H pylori is by endoscopic biopsy, followed by histopathological examination using haemotoxylin and eosin (H & E) stain or special stains such as Giemsa stain and Warthin-Starry stain. Special stains are more accurate than H & E stain. There is significant uncertainty about the diagnostic accuracy of non-invasive tests for diagnosis of H pylori.
OBJECTIVES
To compare the diagnostic accuracy of urea breath test, serology, and stool antigen test, used alone or in combination, for diagnosis of H pylori infection in symptomatic and asymptomatic people, so that eradication therapy for H pylori can be started.
SEARCH METHODS
We searched MEDLINE, Embase, the Science Citation Index and the National Institute for Health Research Health Technology Assessment Database on 4 March 2016. We screened references in the included studies to identify additional studies. We also conducted citation searches of relevant studies, most recently on 4 December 2016. We did not restrict studies by language or publication status, or whether data were collected prospectively or retrospectively.
SELECTION CRITERIA
We included diagnostic accuracy studies that evaluated at least one of the index tests (urea breath test using isotopes such as C or C, serology and stool antigen test) against the reference standard (histopathological examination using H & E stain, special stains or immunohistochemical stain) in people suspected of having H pylori infection.
DATA COLLECTION AND ANALYSIS
Two review authors independently screened the references to identify relevant studies and independently extracted data. We assessed the methodological quality of studies using the QUADAS-2 tool. We performed meta-analysis by using the hierarchical summary receiver operating characteristic (HSROC) model to estimate and compare SROC curves. Where appropriate, we used bivariate or univariate logistic regression models to estimate summary sensitivities and specificities.
MAIN RESULTS
We included 101 studies involving 11,003 participants, of which 5839 participants (53.1%) had H pylori infection. The prevalence of H pylori infection in the studies ranged from 15.2% to 94.7%, with a median prevalence of 53.7% (interquartile range 42.0% to 66.5%). Most of the studies (57%) included participants with dyspepsia and 53 studies excluded participants who recently had proton pump inhibitors or antibiotics.There was at least an unclear risk of bias or unclear applicability concern for each study.Of the 101 studies, 15 compared the accuracy of two index tests and two studies compared the accuracy of three index tests. Thirty-four studies (4242 participants) evaluated serology; 29 studies (2988 participants) evaluated stool antigen test; 34 studies (3139 participants) evaluated urea breath test-C; 21 studies (1810 participants) evaluated urea breath test-C; and two studies (127 participants) evaluated urea breath test but did not report the isotope used. The thresholds used to define test positivity and the staining techniques used for histopathological examination (reference standard) varied between studies. Due to sparse data for each threshold reported, it was not possible to identify the best threshold for each test.Using data from 99 studies in an indirect test comparison, there was statistical evidence of a difference in diagnostic accuracy between urea breath test-C, urea breath test-C, serology and stool antigen test (P = 0.024). The diagnostic odds ratios for urea breath test-C, urea breath test-C, serology, and stool antigen test were 153 (95% confidence interval (CI) 73.7 to 316), 105 (95% CI 74.0 to 150), 47.4 (95% CI 25.5 to 88.1) and 45.1 (95% CI 24.2 to 84.1). The sensitivity (95% CI) estimated at a fixed specificity of 0.90 (median from studies across the four tests), was 0.94 (95% CI 0.89 to 0.97) for urea breath test-C, 0.92 (95% CI 0.89 to 0.94) for urea breath test-C, 0.84 (95% CI 0.74 to 0.91) for serology, and 0.83 (95% CI 0.73 to 0.90) for stool antigen test. This implies that on average, given a specificity of 0.90 and prevalence of 53.7% (median specificity and prevalence in the studies), out of 1000 people tested for H pylori infection, there will be 46 false positives (people without H pylori infection who will be diagnosed as having H pylori infection). In this hypothetical cohort, urea breath test-C, urea breath test-C, serology, and stool antigen test will give 30 (95% CI 15 to 58), 42 (95% CI 30 to 58), 86 (95% CI 50 to 140), and 89 (95% CI 52 to 146) false negatives respectively (people with H pylori infection for whom the diagnosis of H pylori will be missed).Direct comparisons were based on few head-to-head studies. The ratios of diagnostic odds ratios (DORs) were 0.68 (95% CI 0.12 to 3.70; P = 0.56) for urea breath test-C versus serology (seven studies), and 0.88 (95% CI 0.14 to 5.56; P = 0.84) for urea breath test-C versus stool antigen test (seven studies). The 95% CIs of these estimates overlap with those of the ratios of DORs from the indirect comparison. Data were limited or unavailable for meta-analysis of other direct comparisons.
AUTHORS' CONCLUSIONS
In people without a history of gastrectomy and those who have not recently had antibiotics or proton ,pump inhibitors, urea breath tests had high diagnostic accuracy while serology and stool antigen tests were less accurate for diagnosis of Helicobacter pylori infection.This is based on an indirect test comparison (with potential for bias due to confounding), as evidence from direct comparisons was limited or unavailable. The thresholds used for these tests were highly variable and we were unable to identify specific thresholds that might be useful in clinical practice.We need further comparative studies of high methodological quality to obtain more reliable evidence of relative accuracy between the tests. Such studies should be conducted prospectively in a representative spectrum of participants and clearly reported to ensure low risk of bias. Most importantly, studies should prespecify and clearly report thresholds used, and should avoid inappropriate exclusions.
Topics: Adult; Antigens, Bacterial; Biomarkers; Breath Tests; Child; Feces; Helicobacter Infections; Helicobacter pylori; Humans; Prevalence; Urea
PubMed: 29543326
DOI: 10.1002/14651858.CD012080.pub2