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Infectious Disease Clinics of North... Mar 2014Urinary tract infection (UTI) is a commonly diagnosed infection in older adults. Despite consensus guidelines developed to assist providers in diagnosing UTI,... (Review)
Review
Urinary tract infection (UTI) is a commonly diagnosed infection in older adults. Despite consensus guidelines developed to assist providers in diagnosing UTI, distinguishing symptomatic UTI from asymptomatic bacteriuria (ASB) in older adults is problematic, as many older adults do not present with localized genitourinary symptoms. This article summarizes the recent literature and guidelines on the diagnosis and management of UTI and ASB in older adults.
Topics: Aged; Algorithms; Anti-Bacterial Agents; Asymptomatic Infections; Bacteriuria; Humans; Middle Aged; Phytotherapy; Practice Guidelines as Topic; Proanthocyanidins; Risk Factors; Urinary Tract Infections; Vaccinium macrocarpon
PubMed: 24484576
DOI: 10.1016/j.idc.2013.10.004 -
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 -
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 -
Pathogens and Global Health Dec 2022Presently in India, high endemic zones of malaria are shifting towards low endemic zones and in this changing scenario, tackling the asymptomatic and low-density...
Presently in India, high endemic zones of malaria are shifting towards low endemic zones and in this changing scenario, tackling the asymptomatic and low-density infections (LDI) would be an important factor. Role of the asymptomatic and LDI in transmitting parasites successfully to mosquito vectors needs to be systematically investigated. We here highlight the limited work done on the burden of asymptomatic Plasmodium infections in India with an emphasis on its infectiousness, and infrastructure available for the detection of LDI. Studies reporting the threshold of gametocytes required for transmission of parasites are lacking for Indian malaria vectors. In the wake of malaria elimination target by 2030, specific point of care test is required to be developed for the detection of low density infections and/or asymptomatic patients. Also, mapping of asymptomatic malaria burden pan India and the role of LDI in vector infectivity would guide the way forward in achieving malaria elimination goal in India.
Topics: Animals; Humans; Malaria, Falciparum; Plasmodium falciparum; Malaria; Mosquito Vectors; India; Asymptomatic Infections
PubMed: 35979713
DOI: 10.1080/20477724.2022.2113304 -
Infectious Diseases of Poverty Jun 2020
Topics: Asymptomatic Infections; Betacoronavirus; COVID-19; China; Coronavirus Infections; Humans; Pandemics; Pneumonia, Viral; SARS-CoV-2
PubMed: 32564770
DOI: 10.1186/s40249-020-00679-2 -
Maternal & Child Nutrition Jan 2023Inadequate diet and frequent symptomatic infections are considered major causes of growth stunting in low-income countries, but interventions targeting these risk...
Inadequate diet and frequent symptomatic infections are considered major causes of growth stunting in low-income countries, but interventions targeting these risk factors have achieved limited success. Asymptomatic infections can restrict growth, but little is known about their role in global stunting prevalence. We investigated factors related to length-for-age Z-score (LAZ) at 24 months by constructing an interconnected network of various infections, biomarkers of inflammation (as assessed by alpha-1-acid glycoprotein [AGP]), and growth (insulin-like growth factor 1 [IGF-1] and collagen X biomarker [CXM]) at 18 months, as well as other children, maternal, and household level factors. Among 604 children, there was a continuous decline in mean LAZ and increased mean length deficit from birth to 24 months. At 18 months of age, the percentage of asymptomatic children who carried each pathogen was: 84.5% enterovirus, 15.5% parechovirus, 7.7% norovirus, 4.6% rhinovirus, 0.6% rotavirus, 69.6% Campylobacter, 53.8% Giardia lamblia, 11.9% malaria parasites, 10.2% Shigella, and 2.7% Cryptosporidium. The mean plasma IGF-1 concentration was 12.5 ng/ml and 68% of the children had systemic inflammation (plasma AGP concentration >1 g/L). Shigella infection was associated with lower LAZ at 24 months through both direct and indirect pathways, whereas enterovirus, norovirus, Campylobacter, Cryptosporidium, and malaria infections were associated with lower LAZ at 24 months indirectly, predominantly through increased systemic inflammation and reduced plasma IGF-1 and CXM concentration at 18 months.
Topics: Child, Preschool; Humans; Infant; Asymptomatic Infections; Biomarkers; Cryptosporidiosis; Cryptosporidium; Growth Disorders; Inflammation; Insulin-Like Growth Factor I; Malaria
PubMed: 36111423
DOI: 10.1111/mcn.13417 -
Epidemiologic Reviews Jan 2019The epidemiology of Middle East respiratory syndrome coronavirus (MERS-CoV) since 2012 has been largely characterized by recurrent zoonotic spillover from dromedary... (Review)
Review
The epidemiology of Middle East respiratory syndrome coronavirus (MERS-CoV) since 2012 has been largely characterized by recurrent zoonotic spillover from dromedary camels followed by limited human-to-human transmission, predominantly in health-care settings. The full extent of infection of MERS-CoV is not clear, nor is the extent and/or role of asymptomatic infections in transmission. We conducted a review of molecular and serological investigations through PubMed and EMBASE from September 2012 to November 15, 2018, to measure subclinical or asymptomatic MERS-CoV infection within and outside of health-care settings. We performed retrospective analysis of laboratory-confirmed MERS-CoV infections reported to the World Health Organization to November 27, 2018, to summarize what is known about asymptomatic infections identified through national surveillance systems. We identified 23 studies reporting evidence of MERS-CoV infection outside of health-care settings, mainly of camel workers, with seroprevalence ranges of 0%-67% depending on the study location. We identified 20 studies in health-care settings of health-care worker (HCW) and family contacts, of which 11 documented molecular evidence of MERS-CoV infection among asymptomatic contacts. Since 2012, 298 laboratory-confirmed cases were reported as asymptomatic to the World Health Organization, 164 of whom were HCWs. The potential to transmit MERS-CoV to others has been demonstrated in viral-shedding studies of asymptomatic MERS infections. Our results highlight the possibility for onward transmission of MERS-CoV from asymptomatic individuals. Screening of HCW contacts of patients with confirmed MERS-CoV is currently recommended, but systematic screening of non-HCW contacts outside of health-care facilities should be encouraged.
Topics: Adult; Aged; Asymptomatic Infections; Coronavirus Infections; Female; Humans; Male; Middle Aged; Middle East Respiratory Syndrome Coronavirus; Registries; World Health Organization
PubMed: 31781765
DOI: 10.1093/epirev/mxz009 -
Virology Journal Apr 2023Norovirus is a leading cause of acute gastroenteritis among children. Previous studies based on symptomatic infections indicated that mutations, rather than...
BACKGROUND
Norovirus is a leading cause of acute gastroenteritis among children. Previous studies based on symptomatic infections indicated that mutations, rather than recombination drove the evolution of the norovirus ORF2. These characteristics were found in hospital-based symptomatic infections, whereas, asymptomatic infections are frequent and contribute significantly to transmission.
METHODS
We conducted the first norovirus molecular epidemiology analysis covering both symptomatic and asymptomatic infections derived from a birth cohort study in the northern China.
RESULTS
During the study, 14 symptomatic and 20 asymptomatic norovirus infections were detected in 32 infants. Out of the 14 strains that caused symptomatic infections, 12 strains were identified as GII.3[P12], and others were GII.4[P31]. Conversely, 17 asymptomatic infections were caused by GII.4[P31], two by GII.2[P16], and one by GII.4[P16]. Regardless of symptomatic and asymptomatic infections, the mutations were detected frequently in the ORF2 region, and almost all recombination were identified in the RdRp-ORF2 region. The majority of the mutations were located around the predefined epitope regions of P2 subdomain indicating a potential for immune evasion.
CONCLUSION
The role of symptomatic as well as asymptomatic infections in the evolution of norovirus needs to be evaluated continuously.
Topics: Humans; Infant; Asymptomatic Infections; Caliciviridae Infections; Cohort Studies; East Asian People; Feces; Genotype; Molecular Epidemiology; Norovirus; Phylogeny
PubMed: 37016444
DOI: 10.1186/s12985-023-02024-z -
Phytopathology Oct 2021is an invasive, broad host range pathogen that causes ramorum blight and sudden oak death in forest landscapes of western North America. In commercial nurseries,...
is an invasive, broad host range pathogen that causes ramorum blight and sudden oak death in forest landscapes of western North America. In commercial nurseries, asymptomatic infections of nursery stock by and other species create unacceptable risk and complicate inspection and certification programs designed to prevent introduction and spread of these pathogens. In this study, we continue development of a volatile organic compound (VOC)-based test for detecting asymptomatic infections of in sp. We confirmed detection of from volatiles collected from asymptomatic root-inoculated plants in a nursery setting, finding that the VOC profile of infected plants is detectably different from that of healthy plants, when measured from both ambient VOC emissions and VOCs extracted from leaf material. Predicting infection status was successful from ambient volatiles, which had a mean area under the curve (AUC) value of 0.71 ± 0.17, derived from corresponding receiver operating characteristic curves from an extreme gradient boosting discriminant analysis. This finding compares with that of extracted leaf volatiles, which resulted in a lower AUC value of 0.51 ± 0.21. In a growth chamber, we contrasted volatile profiles of asymptomatic plants having roots infected with one of three pathogens: , , and . Each pathogen induced unique and measurable changes, but generally the infections reduced volatile emissions until 17 weeks after inoculation, when emissions trended upward relative to those of mock-inoculated controls. Forty-five compounds had significant differences compared with mock-inoculated controls in at least one host-pathogen combination.
Topics: Asymptomatic Infections; North America; Phytophthora; Plant Diseases; Rhododendron
PubMed: 33616417
DOI: 10.1094/PHYTO-10-20-0472-R -
Journal of Mathematical Biology Apr 2023We formulate a general age-of-infection epidemic model with two pathways: the symptomatic infections and the asymptomatic infections. We then calculate the basic...
We formulate a general age-of-infection epidemic model with two pathways: the symptomatic infections and the asymptomatic infections. We then calculate the basic reproduction number [Formula: see text] and establish the final size relation. It is shown that the ratio of accumulated counts of symptomatic patients and asymptomatic patients is determined by the symptomatic ratio f which is defined as the probability of eventually becoming symptomatic after being infected. We also formulate and study a general age-of-infection model with disease deaths and with two infection pathways. The final size relation is investigated, and the upper and lower bounds for final epidemic size are given. Several numerical simulations are performed to verify the analytical results.
Topics: Humans; Asymptomatic Infections; Epidemics; Basic Reproduction Number; Probability; Models, Biological
PubMed: 37154967
DOI: 10.1007/s00285-023-01920-w