Burden and Seasonality of Viral Acute Respiratory Tract Infections among Outpatients in Southern Sri Lanka

Molecular Epidemiology and Clinical Characteristics of an Outbreak on Respiratory Virus Coinfection in Gansu, China

This study aims to analyze the epidemiological and pathogenic characteristics of an outbreak primarily caused by respiratory syncytial virus (RSV), human rhinovirus (HRV), and human metapneumovirus (HMPV) in a kindergarten and primary school. The outbreak was investigated by field epidemiological investigation, and the common respiratory pathogens were screened by RT-PCR detection technology. The attack rate of this outbreak was 63.95% (110/172). Main symptoms included cough (85.45%), sore throat (60.91%), and sneezing (60.00%). Multifactorial logistic regression analysis revealed that continuous handwashing and mouth and nose covering when sneezing were protective factors. All 15 collected throat swab specimens tested positive for viruses, with HMPV as the predominant pathogen (80.00%), followed by HRV (53.33%), and two cases of positive respiratory syncytial virus (13.33%). Among them, six samples showed coinfections of HMPV and HRV, and one had coinfections of HMPV and RSV, resulting in a coinfection rate of 46.67%. Genetic sequencing indicated that the HMPV genotype in this outbreak was A2c, and the HRV genotype was type A, resulting in a coinfection outbreak of HMPV, HRV, and RSV in schools and kindergartens, suggesting that multi-pathogen surveillance of respiratory tract infections should be strengthened.

Determining the timing of respiratory syncytial virus (RSV) epidemics: a systematic review, 2016 to 2021; method categorisation and identification of influencing factors

BackgroundThere is currently no standardised approach to estimate respiratory syncytial virus (RSV) epidemics' timing (or seasonality), a critical information for their effective prevention and control.AimWe aimed to provide an overview of methods to define RSV seasonality and identify factors supporting method choice or interpretation/comparison of seasonal estimates.MethodsWe systematically searched PubMed and Embase (2016-2021) for studies using quantitative approaches to determine the start and end of RSV epidemics. Studies' features (data-collection purpose, location, regional/(sub)national scope), methods, and assessment characteristics (case definitions, sampled population's age, in/outpatient status, setting, diagnostics) were extracted. Methods were categorised by their need of a denominator (i.e. numbers of specimens tested) and their retrospective vs real-time application. Factors worth considering when choosing methods and assessing seasonal estimates were sought by analysing studies.ResultsWe included 32 articles presenting 49 seasonality estimates (18 thereof through the 10% positivity threshold method). Methods were classified into eight categories, two requiring a denominator (1 retrospective; 1 real-time) and six not (3 retrospective; 3 real-time). A wide range of assessment characteristics was observed. Several studies showed that seasonality estimates varied when methods differed, or data with dissimilar assessment characteristics were employed. Five factors (comprising study purpose, application time, assessment characteristics, healthcare system and policies, and context) were identified that could support method choice and result interpretation.ConclusionMethods and assessment characteristics used to define RSV seasonality are heterogeneous. Our categorisation of methods and proposed framework of factors may assist in choosing RSV seasonality methods and interpretating results.

Influenza Vaccination Implementation in Sri Lanka: A Cost-Effectiveness Analysis

Influenza causes an estimated 3 to 5 million cases of severe illness annually, along with substantial morbidity and mortality, particularly in low- and middle-income countries (LMICs). Currently, Sri Lanka has no influenza vaccination policies and does not offer vaccination within the public healthcare sector. Therefore, we performed a cost-effectiveness analysis of influenza vaccine implementation for the Sri Lankan population. We designed a static Markov model that followed a population cohort of Sri Lankans in three age groups, 0-4, 5-64, and 65+ years, through two potential scenarios: trivalent inactivated vaccination (TIV) and no TIV across twelve-monthly cycles using a governmental perspective at the national level. We also performed probabilistic and one-way sensitivity analyses to identify influential variables and account for uncertainty. The vaccination model arm reduced influenza outcomes by 20,710 cases, 438 hospitalizations, and 20 deaths compared to no vaccination in one year. Universal vaccination became cost-effective at approximately 98.01% of Sri Lanka's 2022 GDP per capita (incremental cost-effectiveness ratio = 874,890.55 Rs/DALY averted; 3624.84 USD/DALY averted). Results were most sensitive to the vaccine coverage in the 5-64-year-old age group, the cost of the influenza vaccine dose in the 5-64-years-old age group, vaccine effectiveness in the under-5-years-old age group, and the vaccine coverage in the under-5-years-old age group. No value for a variable within our estimated ranges resulted in ICERs above Rs. 1,300,000 (USD 5386.15) per DALY adverted. Providing influenza vaccines was considered highly cost-effective compared to no vaccines. However, large-scale national studies with improved data are needed to better inform estimates and determine the impact of vaccination implementation.

The Impact of COVID-19 Public Health Measures on Detection of Other Respiratory Viruses in Children during the Winter of 2020–2021 in Hangzhou, China

Objective Acute respiratory tract infection (ARTI) is one of the main diseases in childhood. This study aimed to monitor the distribution of respiratory tract viruses in children with ARTI in the impact of coronavirus disease 2019 (COVID-19).

Methods We conducted surveillance of 2019 novel coronavirus, human metapneumovirus, respiratory syncytial virus, human adenovirus, human parainfluenza virus 1–3, and influenza A and B virus by using quantitative real-time polymerase chain reaction.

Results During the winter of 2020 to 2021, among the 1,442 throat swabs we collected, 937 (64.98%, 937/1,442) were positive for respiratory viruses. Respiratory syncytial virus was the most frequently detected respiratory virus (34.12%, 492/1,442) and 2019 novel coronavirus and influenza A and B virus were not detected in the study period. Coinfection was observed in 156 positive samples including 149 samples of double infection and 7 of triple infection. The positive rate of viral respiratory tract infection in infants less than 6 months was the highest (72.95%) in the study period.

Conclusion There are some differences in the distribution of respiratory viruses in children after the outbreak of COVID-19 in Hangzhou, China.

Clinical and epidemiological characteristics of influenza virus infection in hospitalized children with acute respiratory infections in Sri Lanka

Influenza viruses (Inf-V) are an important cause of acute respiratory infection (ARI) in children. This study was undertaken to describe the clinical and epidemiological characteristics of Inf-V infections in a sample of hospitalized children with ARI. Nasopharyngeal aspirates (NPA) from 500 children between 1 month to 5 years old with symptoms of ARI were collected at the Teaching Hospital Kegalle Sri Lanka From May 2016 to June 2018, NPAs were tested for influenza A (Inf-A) and B (Inf-B) viruses, human respiratory syncytial virus (hRSV), human parainfluenza virus (hPIV) 1–3 using an immunofluorescence assay. The Inf-V were then subtyped using a multiplex RT-PCR. Inf-V were detected in 10.75% (54/502) of the hospitalized children with ARI and in that 5.57% (28/502) were positive for Inf-A and 5.17% (26/502) were positive for Inf-B. Of the 54 Inf-V positive children, 33 were aged between 6 and 20 months. Of the 28 children infected with Inf-A, 15 had uncharacterized lower respiratory infection, 7 had bronchopneumonia and 6 had bronchiolitis. Of the 26 children infected with Inf-B, 11 had uncharacterized lower respiratory infection, 10 had bronchiolitis, and 4 had bronchopneumonia. Inf-B circulated throughout the year with a few peaks, one in June and then in August followed by November to December in 2016 and one in April 2017 and January 2018. Inf-A circulated throughout the year with a major peak in March to April 2017 and July 2018. ARI was more common in boys compared to girls. Majority of the children infected with Inf-V were diagnosed with uncharacterized lower respiratory infection and mild to moderate bronchiolitis. Inf-V infections were prevalent throughout the year in the study area of Sri Lanka with variations in the type of the circulating virus.

Viral burden and diversity in acute respiratory tract infections in hospitalized children in wet and dry zones of Sri Lanka

The present study was done to identify the viral diversity, seasonality and burden associated with childhood acute respiratory tract infection (ARTI) in Sri Lanka. Nasopharyngeal aspirates (NPA) of hospitalized children (1 month-5 years) with ARTI were collected in 2 centers (wet and dry zones) from March 2013 to August 2014. Respiratory viral antigen detection by immunofluorescence assay (IFA) was used to identify the infecting viruses. IFA negative 100 NPA samples were tested for human metapeumovirus (hMPV), human bocavirus and corona viruses by polymerase chain reaction. Of the 443 and 418 NPAs, 37.2% and 39.4% were positive for any of the 8 different respiratory viruses tested from two centers studied. Viral co-infection was detected with respiratory syncytial virus (RSV) in both centers. Peak viral detection was noted in the wet zone from May-July 2013 and 2014 and in the dry zone from December-January 2014 suggesting a local seasonality for viral ARTI. RSV showed a clear seasonality with a direct correlation of monthly RSV infections with rainy days in the wet zone and an inverse correlation with temperature in both centers. The case fatality rate was 2.7% for RSV associated ARTI. The overall disability adjusted life years was 335.9 and for RSV associated ARTI it was 241.8. RSV was the commonly detected respiratory virus with an annual seasonality and distribution in rainy seasons in the dry and wet zones of Sri Lanka. Identifying the virus and seasonality will contribute to employ preventive measures and reduce the empirical use of antibiotics in resource limited settings.

Knowledge, Perceptions, and Attitudes Regarding Antibiotic Use for Lower Respiratory Tract Infections: Insights from Patients in Sri Lanka

Antibiotic resistance is an emerging global public health threat. One of the main drivers of this threat is the inappropriate use of antibiotics. In Sri Lanka, antibiotic consumption is increasing, but little is known locally about how patients perceive antibiotics. We conducted a qualitative study to gain a better understanding of the knowledge, perceptions, and attitudes of patients regarding antibiotics and antibiotic resistance. Semi-structured interviews involving 18 patients with lower respiratory tract infection (LRTI) admitted to a large, public tertiary care hospital in southern Sri Lanka were conducted. Interviews were analyzed to identify themes regarding the patients' knowledge of LRTI etiology and treatment, perceptions and attitudes toward LRTI treatment, including antibiotics, and patient-physician communication. Most patients mentioned multiple care visits and the use of multiple pharmaceuticals prior to admission. Patients sought a quick resolution to their ailments and frequently visited several private physicians to obtain a satisfying answer. Self-medication was also common. Patients reused prescriptions for antibiotics, kept antibiotics for later use after prematurely stopping their course of treatment, and bought over-the-counter antibiotics. Patients' knowledge of disease etiology and antibiotics was poor. Only a few patients were aware of antibiotic resistance. Despite the desire to receive more information regarding disease and treatment, patient-provider communication was limited and mainly confined to prescription instructions. This qualitative study performed in Sri Lanka suggests that inappropriate use of antibiotics is a multifactorial problem. To improve antibiotic use, a multifactorial approach that includes educating the public, increasing awareness among physicians, and implementing systems-level changes to restrict access to antibiotics is urgently needed.

Epidemiological characteristics of four common respiratory viral infections in children

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.

Outbreak of severe acute respiratory infection in Southern Province, Sri Lanka in 2018: a cross-sectional study

OBJECTIVES

To determine aetiology of illness among children and adults presenting during outbreak of severe respiratory illness in Southern Province, Sri Lanka, in 2018.

DESIGN

Prospective, cross-sectional study.

SETTING

1600-bed, public, tertiary care hospital in Southern Province, Sri Lanka.

PARTICIPANTS

410 consecutive patients, including 371 children and 39 adults, who were admitted with suspected viral pneumonia (passive surveillance) or who met case definition for acute respiratory illness (active surveillance) in May to June 2018.

RESULTS

We found that cocirculation of influenza A (22.6% of cases), respiratory syncytial virus (27.8%) and adenovirus (AdV) (30.7%; type B3) was responsible for the outbreak. Mortality was noted in 4.5% of paediatric cases identified during active surveillance. Virus type and viral coinfection were not significantly associated with mortality.

CONCLUSIONS

This is the first report of intense cocirculation of multiple respiratory viruses as a cause of an outbreak of severe acute respiratory illness in Sri Lanka, and the first time that AdV has been documented as a cause of a respiratory outbreak in the country. Our results emphasise the need for continued vigilance in surveying for known and emerging respiratory viruses in the tropics.

A review on disease burden and epidemiology of childhood parainfluenza virus infections in Asian countries

Human parainfluenza viruses (HPIVs) are an important cause of acute respiratory tract infections (ARTIs) in children less than 5 years, second only to human respiratory syncytial viruses (HRSVs). Generally, patients infected with HPIVs are treated in outpatient clinics, yet also contribute to ARTI-associated hospitalization in children. Although HPIV infections are well studied in developed countries, these infections remain under-investigated and not considered in the routine laboratory diagnosis of childhood ARTI in many developing countries in Asia. We performed an extensive literature search on the prevalence, epidemiology, and burden of HPIV infections in children less than 5 years in Asia using PubMed and PubMed Central search engines. Based on the literature, the prevalence of HPIV infection in Asia ranges from 1% to 66%. According to many studies, HPIV-3 is the major virus circulating among children; however, several studies failed to detect HPIV-4 due to unavailability of diagnostic tools. In Asian countries, HPIV contributes a substantial disease burden in children. The data in this review should assist researchers and public health authorities to plan preventive measures, including accelerating research on vaccines and antiviral drugs.

Use of clinical algorithms and rapid influenza testing to manage influenza-like illness: a cost-effectiveness analysis in Sri Lanka

Background

Acute respiratory infections are a common reason for antibiotic overuse. We previously showed that providing Sri Lankan clinicians with positive rapid influenza test results was associated with a reduction in antibiotic prescriptions. The economic impact of influenza diagnostic strategies is unknown.

Methods

We estimated the incremental cost per antibiotic prescription avoided with three diagnostic strategies versus standard care when managing Sri Lankan outpatients with influenza-like illness (ILI): (1) influenza clinical prediction tool, (2) targeted rapid influenza testing and (3) universal rapid influenza testing. We compared findings with literature-based estimates of the cost of antimicrobial resistance attributable to each antibiotic prescription.

Results

Standard care was less expensive than other strategies across all parameter values in one-way sensitivity analyses. The incremental cost per antibiotic prescription avoided with clinical prediction versus standard care was US$3.0, which was lower than the base-case estimate of the cost of antimicrobial resistance per ILI antibiotic prescription (US$12.5). The incremental cost per antibiotic prescription avoided with targeted testing and universal testing versus standard care were both higher than the base-case cost of antimicrobial resistance per ILI antibiotic prescription: US$49.1 and US$138.3, respectively. To obtain a cost-effectiveness ratio lower than US$12.5 with targeted testing versus standard care, the test price must be <US$2.6. At a higher threshold of US$28.7, the test price must be <US$7.7.

Conclusion

Clinical prediction tools and targeted rapid influenza testing may be cost-saving strategies in Sri Lanka when accounting for the societal cost of antimicrobial resistance.

Respiratory Viral Infection: An Underappreciated Cause of Acute Febrile Illness Admissions in Southern Sri Lanka

The contribution of respiratory viruses to acute febrile illness (AFI) burden is poorly characterized. We describe the prevalence, seasonality, and clinical features of respiratory viral infection among AFI admissions in Sri Lanka. We enrolled AFI patients ≥ 1 year of age admitted to a tertiary care hospital in southern Sri Lanka, June 2012-October 2014. We collected epidemiologic/clinical data and a nasal or nasopharyngeal sample that was tested using polymerase chain reaction (Luminex NxTAG, Austin, TX). We determined associations between weather data and respiratory viral activity using the Spearman correlation and assessed respiratory virus seasonality using a Program for Appropriate Technology definition. Bivariable and multivariable regression analyses were conducted to identify features associated with respiratory virus detection. Among 964 patients, median age was 26.2 years (interquartile range 14.6-39.9) and 646 (67.0%) were male. One-fifth (203, 21.1%) had respiratory virus detected: 13.9% influenza, 1.4% human enterovirus/rhinovirus, 1.4% parainfluenza virus, 1.1% respiratory syncytial virus, and 1.1% human metapneumovirus. Patients with respiratory virus identified were younger (median 9.8 versus 27.7 years, P < 0.001) and more likely to have respiratory signs and symptoms. Influenza A and respiratory viral activity peaked in February-June each year. Maximum daily temperature was associated with influenza and respiratory viral activity (P = 0.03 each). Patients with respiratory virus were as likely as others to be prescribed antibiotics (55.2% versus 52.6%, P = 0.51), and none reported prior influenza vaccination. Respiratory viral infection was a common cause of AFI. Improved access to vaccines and respiratory diagnostics may help reduce disease burden and inappropriate antibiotic use.

Congenital cytomegalovirus, parvovirus and enterovirus infection in Mozambican newborns at birth: A cross-sectional survey

Background

Congenital cytomegalovirus (cCMV) infection is the most prevalent congenital infection acquired worldwide, with higher incidence in developing countries and among HIV-exposed children. Less is known regarding vertical transmission of parvovirus B19 (B19V) and enterovirus (EV). We aimed to assess the prevalence of CMV, B19V and EV vertical transmission and compare results of screening of congenital CMV obtained from two different specimens in a semirural Mozambican maternity.

Methods

A cross sectional study was conducted among pregnant mothers attending Manhiça District Hospital upon delivery. Information on maternal risk factors was ascertained. Dried umbilical cord (DUC) samples were collected in filter paper for CMV, B19V and EV detection by real-time polymerase chain reaction (RT-PCR), and nasopharyngeal aspirates (NPA) to test for CMV by RT-PCR. Maternal blood samples and placental biopsy samples were also obtained to investigate CMV maternal serology, HIV status and immunopathology.

Results

From September 2014 to January 2015, 118 mothers/newborn pairs were recruited. Prevalence of maternal HIV infection was 31.4% (37/118). CMV RT-PCR was positive in 3/115 (2.6%) of DUC samples and in 3/96 (6.3%) of NPA samples obtained from neonates. The concordance of the RT-PCR assay through DUC with their correspondent NPA sample was moderate (Kappa = 0.42 and p<0.001. No differences on cCMV prevalence were found among HIV-exposed and unexposed. All (100%) mothers were seropositive for CMV IgG. RT-PCR of EV and B19V in DUC were both negative in all screened cases. No histological specific findings were found in placental tissues. No risk factors associated to vertical transmission of these viral infections were found.

Conclusions

This study indicates the significant occurrence of vertical transmission of CMV in southern Mozambique. Larger studies are needed to evaluate the true burden, clinical relevance and consequences of congenital infections with such pathogens in resource-constrained settings.