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Clinical Infectious Diseases : An... Jan 2020We conducted a systematic review to describe the frequency of mild, atypical, and asymptomatic infection among household contacts of pertussis cases and to explore the...
We conducted a systematic review to describe the frequency of mild, atypical, and asymptomatic infection among household contacts of pertussis cases and to explore the published literature for evidence of asymptomatic transmission. We included studies that obtained and tested laboratory specimens from household contacts regardless of symptom presentation and reported the proportion of cases with typical, mild/atypical, or asymptomatic infection. After screening 6789 articles, we included 26 studies. Fourteen studies reported household contacts with mild/atypical pertussis. These comprised up to 46.2% of all contacts tested. Twenty-four studies reported asymptomatic contacts with laboratory-confirmed pertussis, comprising up to 55.6% of those tested. Seven studies presented evidence consistent with asymptomatic pertussis transmission between household contacts. Our results demonstrate a high prevalence of subclinical infection in household contacts of pertussis cases, which may play a substantial role in the ongoing transmission of disease. Our review reveals a gap in our understanding of pertussis transmission.
Topics: Asymptomatic Infections; Bordetella pertussis; Family Characteristics; Humans; Infant; Prevalence; Whooping Cough
PubMed: 31257450
DOI: 10.1093/cid/ciz531 -
Heliyon Sep 2023Dengue infection is spreading worldwide. The clinical spectrum is broad and includes asymptomatic infections. This review provides an overview of the different... (Review)
Review
OBJECTIVES
Dengue infection is spreading worldwide. The clinical spectrum is broad and includes asymptomatic infections. This review provides an overview of the different proportions of asymptomatic infections described in epidemiological studies according to definitions, study designs, and detection methods.
METHODS
Medline and Embase databases were searched without restriction of date or language. Studies were included if they reported data on the incidence or prevalence of asymptomatic dengue infections. The data were summarized and classified according to the definitions of the term 'asymptomatic'.
RESULTS
A total of 74 studies were included. The mean proportion of asymptomatic infections among dengue-infected persons was 54% in 50 included studies. The prevalence of dengue infections detected in healthy persons was 0.2% in 24 included studies. The term 'asymptomatic' has been used to refer to 'clinically undetectable infection', but also to 'undiagnosed infection' or 'mild infection'. Only 8% were clinically undetectable laboratory-confirmed dengue infections.
CONCLUSION
The proportion of asymptomatic dengue infections varied greatly. Studies proving data on clinically undetectable laboratory-confirmed dengue infections were very few, but provided consistent results of low proportions of asymptomatic infections. These data challenge the assumption that the majority of dengue cases are asymptomatic.
PubMed: 37809992
DOI: 10.1016/j.heliyon.2023.e20069 -
Frontiers in Public Health 2022The comprehensive understanding of the characteristics of asymptomatic cases are helpful for the identification and management of patients with asymptomatic COVID-19... (Meta-Analysis)
Meta-Analysis
UNLABELLED
The comprehensive understanding of the characteristics of asymptomatic cases are helpful for the identification and management of patients with asymptomatic COVID-19 infection. Four electronic databases were searched from December 1, 2019 to February 8, 2022 for relevant articles. Data synthesis, subgroup analysis, and sensitivity analysis were performed on the included studies. and Q tests were applied to evaluate heterogeneity across studies. The risk of publication bias was assessed and visualized using a funnel plot. A total of 45 studies consisting of 2,655 patients with no symptoms at the screening point were included. Pooled results showed that in China, 65% of initial no-symptoms COVID-19 patients did not present any COVID-19-related symptom during follow-up or by end of disease course (asymptomatic infections). High proportions of initial no-symptoms COVID-19 patients (76%) and patients with asymptomatic infection (55%) had abnormal CT features at the screening point. High proportion of patients with asymptomatic infection had been detected Ig G (72%) and/or Ig M (57%) at the screening point. The chest CT scan and SARS-CoV-2-specific antibody testing could serve as effective supplementary methods to identify asymptomatic cases in the early stage of SARS-CoV-2 infection. However, the chest CT scan and the SARS-CoV-2-specific IgM and IgG testing should not replace reverse transcription-polymerase chain reaction (RT-PCR) for screening in asymptomatic patients. The combination of repeated RT-PCR, chest CT scans, and the SARS-CoV-2-specific IgM and IgG testing should be performed for those highly suspected SARS-CoV-2 infections.
SYSTEMATIC REVIEW REGISTRATION
https://www.crd.york.ac.uk/PROSPERO/#recordDetails, identifier: CRD 42021261130.
Topics: Antibodies, Viral; Asymptomatic Infections; COVID-19; Humans; Immunoglobulin G; Immunoglobulin M; SARS-CoV-2
PubMed: 35433622
DOI: 10.3389/fpubh.2022.808471 -
PloS One 2021In Sub-Saharan Africa (SSA), where malaria transmission is stable, malaria infection in pregnancy adversely affects pregnant women, fetuses, and newborns and is often... (Meta-Analysis)
Meta-Analysis
BACKGROUND
In Sub-Saharan Africa (SSA), where malaria transmission is stable, malaria infection in pregnancy adversely affects pregnant women, fetuses, and newborns and is often asymptomatic. So far, a plethora of primary studies have been carried out on asymptomatic malaria infection in pregnant women in SSA. Nevertheless, no meta-analysis estimated the burden of asymptomatic malaria infection in pregnant women in SSA, so this meta-analysis was carried out to bridge this gap.
METHODS
PubMed, Web of Science, Scopus, Embase, and ProQuest were systematically searched for relevant studies published until 4 August 2020, and also the expansion of the search was performed by October 24, 2020. We assessed heterogeneity among included studies using I-squared statistics (I2). Publication bias was assessed by visual inspection of the funnel plot and further quantitatively validated by Egger's and Begg's tests. The pooled prevalence and pooled odds ratio (OR) and their corresponding 95% Confidence Interval (CI) were estimated using the random-effects model in Stata 15 software.
RESULTS
For this meta-analysis, we included 35 eligible studies. The overall prevalence estimate of asymptomatic Plasmodium infection prevalence was 26.1%% (95%CI: 21-31.2%, I2 = 99.0%). According to species-specific pooled prevalence estimate, Plasmodium falciparum was dominant species (22.1%, 95%CI: 17.1-27.2%, I2 = 98.6%), followed by Plasmodium vivax, Plasmodium malariae and Plasmodium ovale, respectively, found to be 3% (95%CI: 0-5%, I2 = 88.3%), 0.8% (95%CI: 0.3-0.13%, I2 = 60.5%), and 0.2% (95%CI: -0.01-0.5%, I2 = 31.5%). Asymptomatic malaria-infected pregnant women were 2.28 times more likely anemic (OR = 2.28, 95%CI: 1.66-3.13, I2 = 56.3%) than in non-infected pregnant women. Asymptomatic malaria infection was 1.54 times higher (OR = 1.54, 95%CI: 1.28-1.85, I2 = 11.5%) in primigravida women compared to multigravida women.
CONCLUSION
In SSA, asymptomatic malaria infection in pregnant women is prevalent, and it is associated with an increased likelihood of anemia compared to non-infected pregnant women. Thus, screening of asymptomatic pregnant women for malaria and anemia should be included as part of antenatal care.
Topics: Africa South of the Sahara; Asymptomatic Infections; Coinfection; Female; Humans; Malaria; Plasmodium falciparum; Pregnancy; Pregnancy Complications, Parasitic; Prenatal Care; Prevalence
PubMed: 33793584
DOI: 10.1371/journal.pone.0248245 -
JAMA Sep 2021The 2014 US Preventive Services Task Force (USPSTF) recommendation statement supported the effectiveness of screening for chlamydia and gonorrhea in asymptomatic,...
IMPORTANCE
The 2014 US Preventive Services Task Force (USPSTF) recommendation statement supported the effectiveness of screening for chlamydia and gonorrhea in asymptomatic, sexually active women 24 years or younger and in older women at increased risk for infection, although evidence for screening in men was insufficient.
OBJECTIVE
To update the 2014 USPSTF review on screening for chlamydial and gonococcal infection in adults and adolescents, including those who are pregnant.
DATA SOURCES
Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Ovid MEDLINE (January 1, 2014, through May 28, 2020) with surveillance through May 21, 2021.
STUDY SELECTION
Randomized clinical trials and observational studies of screening effectiveness, accuracy of risk stratification and alternative screening methods, accuracy of tests, and screening harms.
DATA EXTRACTION AND SYNTHESIS
One investigator abstracted data; a second checked accuracy. Two investigators independently assessed study quality.
MAIN OUTCOMES AND MEASURES
Complications of infection; infection transmission or acquisition; diagnostic accuracy of anatomical site-specific testing and collection methods; screening harms.
RESULTS
Twenty-seven studies were included (N = 179 515). Chlamydia screening compared with no screening was significantly associated with reduced risk of pelvic inflammatory disease (PID) in 2 of 4 trials and with reduced hospital-diagnosed PID (0.24% vs 0.38%); relative risk, 0.6 [95% CI, 0.4-1.0]), but not clinic-diagnosed PID or epididymitis, in the largest trial. In studies of risk prediction instruments in asymptomatic women, age younger than 22 years demonstrated comparable accuracy to extensive criteria. Sensitivity of chlamydial testing was similar at endocervical (89%-100%) and self- and clinician-collected vaginal (90%-100%) sites for women and at meatal (100%), urethral (99%), and rectal (92%) sites for men but lower at pharyngeal sites (69.2%) for men who have sex with men. Sensitivity of gonococcal testing was 89% or greater for all anatomical samples. False-positive and false-negative testing rates were low across anatomical sites and collection methods.
CONCLUSIONS AND RELEVANCE
Screening for chlamydial infection was significantly associated with a lower risk of PID in young women. Risk prediction criteria demonstrated limited accuracy beyond age. Testing for asymptomatic chlamydial and gonococcal infections was highly accurate at most anatomical sites, including urine and self-collected specimens. Effectiveness of screening in men and during pregnancy, optimal screening intervals, and adverse effects of screening require further evaluation.
Topics: Adolescent; Adult; Asymptomatic Diseases; Chlamydia Infections; Female; Gonorrhea; Humans; Male; Mass Screening; Pelvic Inflammatory Disease; Practice Guidelines as Topic; Pregnancy; Risk Factors; Sensitivity and Specificity; Sexual Behavior; Young Adult
PubMed: 34519797
DOI: 10.1001/jama.2021.10577 -
JAMA Pediatrics Oct 2021Detection of Clostridioides difficile has frequently been described in asymptomatic infants and children, but accurate estimates across the age spectrum are unavailable. (Meta-Analysis)
Meta-Analysis
IMPORTANCE
Detection of Clostridioides difficile has frequently been described in asymptomatic infants and children, but accurate estimates across the age spectrum are unavailable.
OBJECTIVE
To assess the prevalence of C difficile detection among asymptomatic children across the age spectrum.
DATA SOURCES
This systematic review and meta-analysis included a search of the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, CINAHL, Scopus, and Web of Science for articles published from January 1, 1990, to December 31, 2020. Search terms included Clostridium difficile, Peptoclostridium difficile, Clostridioides difficile, CDF OR CDI OR c diff OR c difficile, Clostridium infections OR cd positive diarrhea OR cd positive diarrhea OR Clostridium difficile OR Peptoclostridium difficile OR pseudomembranous colitis OR pseudomembranous enterocolitis, enterocolitis, and pseudomembranous. These were combined with the following terms: bacterial colonization and colonization OR colonized OR colonizing OR epidemiology OR prevalence OR seroprevalence.
STUDY SELECTION
Studies were screened independently by 2 authors. Studies were included if they reported testing for C difficile among asymptomatic children (ie, children without diarrhea) younger than 18 years.
DATA EXTRACTION AND SYNTHESIS
Data were extracted independently and in duplicate by 2 reviewers. Preferred Reporting Items for a Systematic Review and Meta-analysis (PRISMA) guidelines were used. Data were pooled using a random-effects model.
MAIN OUTCOMES AND MEASURES
The primary outcome was prevalence of C difficile detection among asymptomatic children. Secondary outcomes included prevalence of toxigenic vs nontoxigenic strains of C difficile and prevalence of C difficile detection stratified by geographic region, income status, testing method, and year of testing.
RESULTS
A total of 95 studies with 19 186 participants were included. Rates of detection of toxigenic or nontoxigenic C difficile were greatest among infants aged 6 to 12 months (41%; 95% CI, 32%-50%) and decreased to 12% (95% CI, 7%-18%) among children aged 5 to 18 years. The prevalence of toxigenic C difficile colonization was lower, peaking at 14% (95% CI, 8%-21%) among infants aged 6 to 12 months and decreasing to 6% (95% CI, 2%-11%) among children older than 5 years. Although prevalence differed by geographic region (ie, North and South America vs Europe: β, -0.151, P = .001; North and South America vs Western Pacific: β, 0.136, P = .007), there was no difference by testing method (ie, culture vs polymerase chain reaction: β, 0.069, P = .052; culture vs enzyme immunoassay: β, -0.178, P = .051), income class (low-middle income vs high income: β, -0.144, P = .23; upper-middle vs high income: β, -0.020, P = .64), or period (before 1990 vs 2010-2020: β, -0.125, P = .19; 1990-1999 vs 2010-2020: β, -0.037, P = .42; 2000-2009 vs 2010-2020: β, -0.006, P = .86).
CONCLUSIONS AND RELEVANCE
In this systematic review and meta-analysis, C difficile colonization rates among children were greatest at 6 to 12 months of age and decreased thereafter. These estimates may provide context for interpreting C difficile test results among young children.
Topics: Adolescent; Child; Child, Preschool; Clostridioides difficile; Clostridium Infections; Female; Humans; Infant; Male; Prevalence; Seroepidemiologic Studies
PubMed: 34338715
DOI: 10.1001/jamapediatrics.2021.2328 -
Journal of Infection and Public Health Mar 2022Understanding the transmissibility and pathogenicity of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is crucial for control policies, but evidence... (Meta-Analysis)
Meta-Analysis Review
Transmissibility and pathogenicity of the severe acute respiratory syndrome coronavirus 2: A systematic review and meta-analysis of secondary attack rate and asymptomatic infection.
BACKGROUND
Understanding the transmissibility and pathogenicity of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is crucial for control policies, but evidence remains limited.
METHODS
We presented a systematic and meta-analytic summary concerning the transmissibility and pathogenicity of COVID-19.
RESULTS
A total of 105 studies were identified, with 35042 infected cases and 897912 close contacts. 48.6% (51/105) of studies on secondary transmissions were from China. We estimated a total SIR of 7.8% (95% confidence interval [CI], 6.8%-8.8%), SAR of 6.6% (95% CI, 5.7%-7.5%), and symptomatic infection ratio of 86.9% (95%CI, 83.9%-89.9%) with a disease series interval of 5.84 (95%CI, 4.92-6.94) days. Household contacts had a higher risk of both symptomatic and asymptomatic infection, and transmission was driven between index cases and second-generation cases, with little transmission occurring in second-to-later-generation cases (SIR, 12.4% vs. 3.6%). The symptomatic infection ratio was not significantly different in terms of infection time, generation, type of contact, and index cases.
CONCLUSIONS
Our results suggest a higher risk of infection among household contacts. Transmissibility decreased with generations during the intervention. Pathogenicity of SARS-CoV-2 varied among territories, but didn't change over time. Strict isolation and medical observation measures should be implemented.
Topics: Asymptomatic Infections; COVID-19; Contact Tracing; Family Characteristics; Humans; Incidence; SARS-CoV-2; Virulence
PubMed: 35123279
DOI: 10.1016/j.jiph.2022.01.015 -
Parasites & Vectors Jun 2016The epidemiology of soil-transmitted helminth (STH) and Plasmodium co-infections need better understanding. The findings of the individual studies are inconclusive. A... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The epidemiology of soil-transmitted helminth (STH) and Plasmodium co-infections need better understanding. The findings of the individual studies are inconclusive. A systematic review was conducted to synthesize evidence on the association of STH infection with the prevalence and density of Plasmodium falciparum infection, and its effect on anaemia among children in sub-Saharan Africa (SSA).
METHODS
Relevant studies published before March 6, 2015 were identified by searching Medline (via Pubmed), Embase, Cochrane Library and CINAHL without any language restriction. Studies on P. falciparum and STH co-infection among children in SSA except for case studies were included in this study. Studies were screened for eligibility and data extracted independently by two authors. The primary outcome assessed was the prevalence of P. falciparum infection and the secondary outcomes included P. falciparum density and prevalence of anaemia. Heterogeneity was assessed using Cochrane Q and Moran's I (2) and publication bias was evaluated using Egger test. A random-effects model was used to estimate the summary odds ratio (OR) and the corresponding 95 % confidence intervals (CI).
RESULTS
Out of 2985 articles screened, 11 articles were included in the systematic review; of these seven were considered in the meta-analysis. Of the 11 studies with 7458 study participants, seven were cross-sectional, one prospective cohort and three were randomized controlled trials. Four studies examined the outcome for hookworms, one for Ascaris lumbricoides and six for pooled (at least one) STH species. Eight studies measured prevalence/incidence of uncomplicated P. falciparum infection, two calculated prevalence of asymptomatic P. falciparum infection, three evaluated P. falciparum density and four considered prevalence of P. falciparum infection related anaemia/mean haemoglobin reduction. The odds of asymptomatic/uncomplicated P. falciparum infection were higher among children infected with STH than those uninfected with intestinal helminths (summary Odds Ratio [OR]: 1.4; 95 % Confidence Interval [CI]: 1.05-1.87; I (2) = 36.8 %). Plasmodium falciparum density tended to be higher among children infected with STH than those uninfected with intestinal helminths. However, STH infection was associated with lower odds of P. falciparum infection related anaemia (summary OR: 0.5; 95 % CI: 0.21-0.78; I (2) = 43.3 %).
CONCLUSIONS
The findings suggest that STH infection may increase susceptibility to asymptomatic/uncomplicated P. falciparum infection but may protect malaria-related anaemia in children. Future studies should investigate the effect of STH infection upon the incidence of severe P. falciparum infection among children in SSA.
Topics: Africa South of the Sahara; Child; Coinfection; Helminthiasis; Humans; Malaria, Falciparum; Plasmodium falciparum; Soil
PubMed: 27306987
DOI: 10.1186/s13071-016-1594-2 -
BMJ Clinical Evidence Sep 2008Postoperative pulmonary infections are associated with cough, phlegm, shortness of breath, chest pain, temperature above 38 degrees C, and pulse rate above 100 a minute.... (Review)
Review
INTRODUCTION
Postoperative pulmonary infections are associated with cough, phlegm, shortness of breath, chest pain, temperature above 38 degrees C, and pulse rate above 100 a minute. Up to half of people may have asymptomatic chest signs after surgery, and up to a quarter develop symptomatic disease. The main risk factor is the type of surgery, with higher risks associated with surgery to the chest, abdomen, and head and neck compared with other operations. Other risk factors include age over 50 years, chronic obstructive pulmonary disease (COPD), smoking, hypoalbuminemia, and being functionally dependent.
METHODS AND OUTCOMES
We conducted a systematic review and aimed to answer the following clinical question: What are the effects of interventions to prevent postoperative pulmonary infections? We searched: Medline, Embase, The Cochrane Library, and other important databases up to May 2007 (BMJ Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
RESULTS
We found 17 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
CONCLUSIONS
In this systematic review we present information relating to the effectiveness and safety of the following interventions: advice to stop smoking preoperatively, anaesthesia, lung expansion techniques, and postoperative nasogastric decompression.
Topics: Abdomen; Humans; Lung Diseases; Postoperative Complications; Postoperative Period; Risk Factors; Smoking
PubMed: 19445796
DOI: No ID Found -
Clinical Radiology Nov 2020To determine the overall rate of chest imaging findings in asymptomatic cases, describe the most common patterns found, and determine the rate of later symptom... (Meta-Analysis)
Meta-Analysis
AIM
To determine the overall rate of chest imaging findings in asymptomatic cases, describe the most common patterns found, and determine the rate of later symptom development in these initially asymptomatic cases.
MATERIALS AND METHODS
The PubMed and EMBASE databases were searched until 1 May 2020, for studies examining the proportion of positive chest imaging findings in asymptomatic cases diagnosed with COVID-19 and a random-effects meta-analysis of proportions was performed. Heterogeneity was assessed using the I statistic.
RESULTS
Among 858 non-duplicate studies, seven studies with a total of 231 asymptomatic cases met the inclusion criteria. In the primary analysis, the pooled estimate of the overall rate of positive chest computed tomography (CT) findings among asymptomatic cases was 63% (95% confidence interval [CI]: 44-78%). Among 155/231 cases that were followed up for later symptom development, 90/155 remained asymptomatic and 65/155 developed symptoms during the study period (that ranged between seven and 30 days of follow-up). The pooled estimate of the rate of positive chest CT findings was 62% (95% CI: 38-81%) in cases that remained asymptomatic, while it was 90% (95% CI: 49-99%) in cases that developed symptoms. Among CT findings, the pooled estimate of the overall rate of ground-glass opacities (GGO) at CT alone was 71% (95% CI: 50-86%). Among other CT findings reported, 22/231 patients had GGO with consolidation, 7/231 patients had stripe shadows with or without GGO, and 8/231 patients had GGO with interlobular septal thickening. Among initially asymptomatic cases with positive CT findings, the pooled estimate of the overall rate of later symptom development was 26% (95% CI: 14-43%).
CONCLUSION
In COVID-19, asymptomatic cases can have positive chest CT findings, and COVID-19 should be considered among cases with CT abnormalities even when there are no other symptoms. There is a need for close clinical monitoring of asymptomatic cases with radiographic findings as a significant percentage will develop symptoms.
Topics: Asymptomatic Diseases; COVID-19; Coronavirus Infections; Databases, Factual; Disease Transmission, Infectious; Female; Humans; Incidence; Infection Control; Male; Pandemics; Pneumonia, Viral; Radiography, Thoracic; Risk Assessment; Severe Acute Respiratory Syndrome; Tomography, X-Ray Computed
PubMed: 32861461
DOI: 10.1016/j.crad.2020.07.025