Sexually Transmitted, Urinary Tract, and Gastrointestinal Tract Infections

2016 ◽  
pp. 521-538
Author(s):  
M. Rizwan Sohail
Keyword(s):  
Influenza A ◽  
The United States ◽  
Antigenic Drift ◽  
Influenza B ◽  
Sexually Transmitted ◽  
Influenza Pandemics ◽  
Population Immunity ◽  
Large Numbers ◽  
Seasonal Epidemics ◽  
Tract Infections

Influenza causes annual, seasonal epidemics that lead to tens of thousands of deaths each year in the United States. Two influenza A strains (H3N2 and H1N1) and 1 or 2 influenza B strains typically circulate during winter months and undergo minor antigenic mutations (antigenic drift) resulting in annual seasonal epidemics. Influenza pandemics occur more rarely (every 20-30 years) and are the result of major antigenic changes (antigenic shift) leading to large numbers of infections due to low levels of population immunity. In seasonal epidemics, 80% to 90% of deaths due to influenza occur in persons older than 65 years.

scholarly journals Epidemiological characteristics of four common respiratory viral infections in children

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Guohong Zhu ◽  
Dan Xu ◽  
Yuanyuan Zhang ◽  
Tianlin Wang ◽  
Lingyan Zhang ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Viral Infection ◽  
Influenza A ◽  
Multiple Infection ◽  
Influenza B ◽  
Preschool Period ◽  
Significant Difference ◽  
Different Seasons ◽  
Tract Infections ◽  
Epidemiological Characteristics

Abstract Background Viruses are the main infectious agents of acute respiratory infections in children. We aim to describe the epidemiological characteristics of viral pathogens of acute respiratory tract infections in outpatient children. Methods From April 2018 to March 2019, the results of viral detection using oral pharyngeal swabs from 103,210 children with acute respiratory tract infection in the outpatient department of the Children’s Hospital, Zhejiang University School of Medicine, were retrospectively analyzed. Viral antigens, including adenovirus (ADV), influenza A (FLUA), influenza B (FLUB) and respiratory syncytial virus (RSV), were detected by the colloidal gold method. Results At least one virus was detected in 38,355 cases; the positivity rate was 37.2%. A total of 1910 cases of mixed infection with two or more viruses were detected, and the positivity rate of multiple infection was 1.9%. The ADV positivity rate was highest in the 3–6-year-old group (18.7%), the FLUA positivity rate was highest in the > 6-year-old group (21.6%), the FLUB positivity rate was highest in the > 6-year-old group (6.6%), and the RSV positivity rate was highest in the < 1-year-old group (10.6%). There was a significant difference in the positivity rate of viral infection among different age groups (χ2 = 1280.7, P < 0.001). The rate of positive viral infection was highest in winter (47.1%). The ADV infection rate was highest in spring (18.2%). The rates of FLUA and FLUB positivity were highest in winter (28.8% and 3.6%, respectively). The rate of RSV positivity was highest in autumn (17.4%). The rate of positive viral infection in different seasons was significantly different (χ2 = 6459.1, P < 0.001). Conclusions Viral infection rates in children differ for different ages and seasons. The positivity rate of ADV is highest in the preschool period and that of RSV is highest in infants; that of FLU increases with age. The total positive rate of viral infection in different seasons is highest in winter, as is the rate of FLU positivity.

scholarly journals Influenza: An Emerging and Re-emerging Public Health Threat in Nepal

2018 ◽  
Vol 3 (2) ◽  
pp. 1-2
Author(s):  
Bishnu Prasad Upadhyay
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Winter Season ◽  
Emerging Infectious Diseases ◽  
Influenza Viruses ◽  
Influenza B ◽  
Influenza A Viruses ◽  
Influenza A H1n1 ◽  
New Variant ◽  
Seasonal Epidemics

Influenza virus type A and B are responsible for seasonal epidemics as well as pandemics in human. Influenza A viruses are further divided into two major groups namely, low pathogenic seasonal influenza (A/H1N1, A/H1N1 pdm09, A/H3N2) and highly pathogenic influenza virus (H5N1, H5N6, H7N9) on the basis of two surface antigens: hemagglutinin (HA) and neuraminidase (NA). Mutations, including substitutions, deletions, and insertions, are one of the most important mechanisms for producing new variant of influenza viruses. During the last 30 years; more than 50 viral threat has been evolved in South-East Asian countriesof them influenza is one of the major emerging and re-emerging infectious diseases of global concern. Similar to tropical and sub-tropical countries of Southeast Asia; circulation of A/H1N1 pdm09, A/H3N2 and influenza B has been circulating throughout the year with the peak during July-November in Nepal. However; the rate of infection transmission reach peak during the post-rain and winter season of Nepal.

scholarly journals Molecular Characterization of Seasonal Influenza A and B from Hospitalized Patients in Thailand in 2018–2019

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 977
Author(s):  
Kobporn Boonnak ◽  
Chayasin Mansanguan ◽  
Dennis Schuerch ◽  
Usa Boonyuen ◽  
Hatairat Lerdsamran ◽  
...  
Keyword(s):  
Amino Acid ◽  
Influenza A ◽  
Seasonal Influenza ◽  
Influenza Viruses ◽  
Surface Proteins ◽  
Antigenic Drift ◽  
Influenza B ◽  
Receptor Binding Site ◽  
Antigenic Sites ◽  
Ha Protein

Influenza viruses continue to be a major public health threat due to the possible emergence of more virulent influenza virus strains resulting from dynamic changes in virus adaptability, consequent of functional mutations and antigenic drift in surface proteins, especially hemagglutinin (HA) and neuraminidase (NA). In this study, we describe the genetic and evolutionary characteristics of H1N1, H3N2, and influenza B strains detected in severe cases of seasonal influenza in Thailand from 2018 to 2019. We genetically characterized seven A/H1N1 isolates, seven A/H3N2 isolates, and six influenza B isolates. Five of the seven A/H1N1 viruses were found to belong to clade 6B.1 and were antigenically similar to A/Switzerland/3330/2017 (H1N1), whereas two isolates belonged to clade 6B.1A1 and clustered with A/Brisbane/02/2018 (H1N1). Interestingly, we observed additional mutations at antigenic sites (S91R, S181T, T202I) as well as a unique mutation at a receptor binding site (S200P). Three-dimensional (3D) protein structure analysis of hemagglutinin protein reveals that this unique mutation may lead to the altered binding of the HA protein to a sialic acid receptor. A/H3N2 isolates were found to belong to clade 3C.2a2 and 3C.2a1b, clustering with A/Switzerland/8060/2017 (H3N2) and A/South Australia/34/2019 (H3N2), respectively. Amino acid sequence analysis revealed 10 mutations at antigenic sites including T144A/I, T151K, Q213R, S214P, T176K, D69N, Q277R, N137K, N187K, and E78K/G. All influenza B isolates in this study belong to the Victoria lineage. Five out of six isolates belong to clade 1A3-DEL, which relate closely to B/Washington/02/2009, with one isolate lacking the three amino acid deletion on the HA segment at position K162, N163, and D164. In comparison to the B/Colorado/06/2017, which is the representative of influenza B Victoria lineage vaccine strain, these substitutions include G129D, G133R, K136E, and V180R for HA protein. Importantly, the susceptibility to oseltamivir of influenza B isolates, but not A/H1N1 and A/H3N2 isolates, were reduced as assessed by the phenotypic assay. This study demonstrates the importance of monitoring genetic variation in influenza viruses regarding how acquired mutations could be associated with an improved adaptability for efficient transmission.

Epidemiology and pathogenesis of influenza

1999 ◽  
Vol 44 (suppl_2) ◽  
pp. 3-9 ◽  
Author(s):  
Maria C. Zambon
Keyword(s):  
Neutralizing Antibodies ◽  
Influenza A ◽  
Systemic Disease ◽  
Influenza Viruses ◽  
The Body ◽  
Antigenic Drift ◽  
Host Cells ◽  
Influenza B ◽  
Systemic Complications ◽  
Segmented Genome

Abstract Influenza A, B and C all have a segmented genome, although only certain influenza A subtypes and influenza B cause severe disease in humans. The two major proteins of influenza are the surface glycoproteins—haemagglutinin (HA) and neuraminidase (NA). HA is the major antigen for neutralizing antibodies and is involved in the binding of virus particles to receptors on host cells. Pandemics are a result of novel virus subtypes of influenza A, created by reassortment of the segmented genome (antigenic shift), whereas annual epidemics are a result of evolution of the surface antigens of influenza A and B virus (antigenic drift). The rapid evolution of influenza viruses highlights the importance of surveillance in identifying novel circulating strains. Infectivity of influenza depends on the cleavage of HA by specific host proteases, whereas NA is involved in the release of progeny virions from the cell surface and prevents clumping of newly formed virus. In birds, the natural hosts of influenza, the virus causes gastrointestinal infection and is transmitted via the faeco-oral route. Virulent avian influenza strains, which cause systemic disease, have an HA that is cleaved by proteases present in all cells of the body, rather than by proteases restricted to the intestinal tract. In mammals, replication of influenza subtypes appears restricted to respiratory epithelial cells. Most symptoms and complications, therefore, involve the respiratory tract. However, systemic complications are sometimes observed and other viral genes besides the HA, including the NA, may be involved in determination of virulence of influenza strains in mammals.

scholarly journals The evolution of human influenza viruses

2001 ◽  
Vol 356 (1416) ◽  
pp. 1861-1870 ◽  
Author(s):  
Alan J. Hay ◽  
Victoria Gregory ◽  
Alan R. Douglas ◽  
Yi Pu Lin
Keyword(s):  
Influenza A ◽  
Influenza Viruses ◽  
Antigenic Drift ◽  
Influenza B ◽  
Mixed Infections ◽  
Human Influenza ◽  
Influenza A Viruses ◽  
Genetic Reassortment ◽  
Influenza Ah1n1 ◽  
Novel Influenza A

The evolution of influenza viruses results in (i) recurrent annual epidemics of disease that are caused by progressive antigenic drift of influenza A and B viruses due to the mutability of the RNA genome and (ii) infrequent but severe pandemics caused by the emergence of novel influenza A subtypes to which the population has little immunity. The latter characteristic is a consequence of the wide antigenic diversity and peculiar host range of influenza A viruses and the ability of their segmented RNA genomes to undergo frequent genetic reassortment (recombination) during mixed infections. Contrasting features of the evolution of recently circulating influenza AH1N1, AH3N2 and B viruses include the rapid drift of AH3N2 viruses as a single lineage, the slow replacement of successive antigenic variants of AH1N1 viruses and the co–circulation over some 25 years of antigenically and genetically distinct lineages of influenza B viruses. Constant monitoring of changes in the circulating viruses is important for maintaining the efficacy of influenza vaccines in combating disease.

scholarly journals Serious acute respiratory syndrome: a case series in a municipality region of central Brazil

2020 ◽  
Vol 36 (3) ◽  
Author(s):  
Cácia Régia  De Paula ◽  
Eliane Lemes  De Morais ◽  
Patrícia de Sá  Barros ◽  
Ludmila Grego  Maia ◽  
Bruno Bordin  Pelazza ◽  
...  
Keyword(s):  
Influenza A ◽  
Case Series ◽  
Antiviral Drugs ◽  
Full Recovery ◽  
Antigenic Drift ◽  
Influenza B Virus ◽  
Influenza B ◽  
Care Hospital ◽  
Case Series Study ◽  
B Virus

The influenza B virus is more stable than influenza A, with less antigenic drift and consequent immunologic stability, and does not undergo the process of antigenic shift, its participation in epidemics is minimal, being of lesser academic interest. The aim of this work was to describe the occurrence of a series of SARS cases in a municipality in the Central region of Brazil. This is a case series study with a descriptive and quantitative approach of Serious Acute Respiratory Syndrome (SARS) in institutionalized individuals and a health professional from a long-term institution in the municipality where the study was conducted. The variables studied were: age, comorbidities, vaccination status, date of symptoms onset, symptoms, occurrence of death, information regarding provided care (hospital care, exams, and medications). The study was approved by the Research Ethics Committee of the Federal University of Goiás (UFG), under opinion number 2.167.287. Case 1 was diagnosed with influenza B, treated with antibiotic therapy, with no antiviral drugs administered, and culminated in death. Cases 2 and 3 were confirmed as influenza B, being treated with antiviral drugs and discharged due to full recovery. Case 4 was confirmed as influenza B virus by epidemiological link, treated with antiviral drugs and discharged due to full recovery. An early diagnosis, adequate clinical management, transmissible disease research based on the 11 health promotion steps and actions can promote the reduction of morbimortality by influenza type B.

scholarly journals Anomalous influenza seasonality in the United States and the emergence of novel influenza B viruses

2021 ◽  
Vol 118 (5) ◽  
pp. e2012327118
Author(s):  
Rebecca K. Borchering ◽  
Christian E. Gunning ◽  
Deven V. Gokhale ◽  
K. Bodie Weedop ◽  
Arash Saeidpour ◽  
...  
Keyword(s):  
United States ◽  
Influenza A ◽  
Reproduction Number ◽  
Influenza Season ◽  
The United States ◽  
Influenza B ◽  
Relative Dynamics ◽  
2009 H1n1 ◽  
Kinetics Of ◽  
Early Activity

The 2019/2020 influenza season in the United States began earlier than any season since the 2009 H1N1 pandemic, with an increase in influenza-like illnesses observed as early as August. Also noteworthy was the numerical domination of influenza B cases early in this influenza season, in contrast to their typically later peak in the past. Here, we dissect the 2019/2020 influenza season not only with regard to its unusually early activity, but also with regard to the relative dynamics of type A and type B cases. We propose that the recent expansion of a novel influenza B/Victoria clade may be associated with this shift in the composition and kinetics of the influenza season in the United States. We use epidemiological transmission models to explore whether changes in the effective reproduction number or short-term cross-immunity between these viruses can explain the dynamics of influenza A and B seasonality. We find support for an increase in the effective reproduction number of influenza B, rather than support for cross-type immunity-driven dynamics. Our findings have clear implications for optimal vaccination strategies.

scholarly journals Syncope and Influenza B: A Case of an Arresting Association

2018 ◽  
Vol 2018 ◽  
pp. 1-4
Author(s):  
Alan Lucerna ◽  
James Lee ◽  
James Espinosa
Keyword(s):  
Influenza A ◽  
The United States ◽  
Permanent Pacemaker ◽  
Cardiac Complications ◽  
Influenza B ◽  
Sinus Arrest ◽  
Cardiac Events ◽  
Severe Bradycardia ◽  
Pacemaker Placement ◽  
Multiple Episodes

Influenza is a contagious viral illness that usually presents with upper respiratory and pulmonary symptoms. While generally self-limited, pulmonary, renal, metabolic, neurologic, and cardiac complications have all been described in the literature. Here we describe a case of a 46-year-old male with multiple episodes of syncope, found to have severe bradycardia, sinus arrest, and positive influenza B, requiring permanent pacemaker placement. The viruses responsible for the flu can be differentiated into four types: A, B, C, and D. The two primary viruses responsible for the seasonal winter epidemic influenza in the United States are Human Influenza A and B viruses. It has been postulated that the influenza virus may be responsible for activating acute inflammatory cytokines, which then alter electrical conduction properties of endothelial cells. Although there have been cases of sinus arrest in association with influenza, some requiring pacemaker placement, our patient’s presentation with multiple episodes of syncope with severe bradycardia and sinus arrest requiring permanent pacemaker placement, in association with influenza B, is very unusual and possibly unique. Since emergency physicians are at the forefront in the diagnosis, treatment, and disposition of these patients, awareness of influenza triggered cardiac events is essential and lifesaving, especially in unvaccinated patients.

Rapid Detection of Viral Pneumonia in Children with Primary Immunodeficiency

2020 ◽  
Vol 29 (3) ◽  
pp. 129-136
Author(s):  
Safaa M. EL-Ageery ◽  
Rabab A. Ali ◽  
Mayada S. Zeid
Keyword(s):  
Influenza Virus ◽  
Multiplex Pcr ◽  
Primary Immunodeficiency ◽  
Influenza A ◽  
Viral Pneumonia ◽  
Parainfluenza Virus ◽  
Influenza B ◽  
Acid Extraction ◽  
Tract Infections ◽  
Single Reaction

Background: In children with primary immunodeficiency (PID), the most common types of infection are respiratory tract infections, among which viral pneumonia representing the majority. Early diagnosis and treatment can prevent or diminish the respiratory complications. Multiplex polymerase chain reaction (Multiplex PCR) can permit amplification of a lot of viruses all together in a single reaction mixture. Objective: Determining different viruses causing pneumonia in children with PID by multiplex PCR. Methodology: A cross-sectional study included 33 nasopharyngeal swabs collected from children suffering from PID with clinical respiratory signs of pneumonia. For each collected sample, nucleic acid extraction and multiplex PCR were done using primers specific for influenza A, influenza B, adenovirus, respiratory syncytial virus (RSV), cytomegalovirus (CMV), parainfluenza virus 1 (PIV1), parainfluenza virus 2 (PIV2), parainfluenza virus 3 (PIV3) and human coronavirus (HCoV-NL63). Results: Viruses were detected in 11 nasopharyngeal samples (11/33, 33.33%). Viral pneumonia was mostly found in children with severe combined immune deficiency (5/11; 45.45%), followed by children with common variable immunodeficiency (3/11; 27.27%) and children with hyper Ig E syndrome, hyper Ig M syndrome and selective Ig A deficiency (1/11; 9.09%) for each. RSV and CMV were the most common detected viruses; each virus was detected in 3 cases. Influenza virus A was detected in 2 cases and adenovirus, PIV1 and PIV3 each was detected in one case. Influenza virus B, PIV2 and HCoV-NL63 were not detected in any sample. No viruses were detected in the nasopharyngeal swabs taken from children with chronic granulomatous disease. No mixed viral infection was detected in any sample. Conclusion: Severe viral pneumonia is frequent in the children with PID. Multiplex PCR has a major benefit, as it allows simultaneous amplification of several viruses in a single reaction mixture with cost-effective diagnosis.

Renal and Genitourinary Emergencies

2019 ◽  
pp. 293-303
Author(s):  
Michelle Storkan
Keyword(s):  
United States ◽  
Emergency Department ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Sexually Transmitted Infection ◽  
The United States ◽  
Common Reason ◽  
Transmitted Infection ◽  
Sexually Transmitted ◽  
Tract Infections

Renal and genitourinary complaints are common presentations to the emergency department. Urinary tract infections are among the top three sites of infection in patients presenting to the emergency department. Nephrolithiasis is also a common reason for patients to present due to the severe associated pain. Greater than 20 million patients in the United States are diagnosed with a sexually transmitted infection yearly and many of these present to the emergency department due to the associated discomfort and related symptoms. Other conditions related to the renal and genitourinary systems, though less common, are important for emergency providers to be adept at managing.

Sign in / Sign up

Export Citation Format

Share Document