Epidemiology Of Acute Respiratory Infections Research Articles

Epidemiological changes of acute respiratory infections in children: A single-center experience after COVID-19 lockdown.

Since the start of the COVID-19 pandemic, the epidemiology of acute respiratory infections (ARIs) has continually changed, making it difficult to predict. Our study aimed to evaluate epidemiological changes and clinical outcomes of ARIs in pediatric patients in the post-lockdown period. A single-center retrospective cross-sectional study was performed in one of the largest pediatric emergency departments in Lithuania during two cold seasons-from October 1, 2021, to April 30, 2022 (Season I) and in the same period in 2022-2023 (Season II). Patients under 18 years of age who had been tested for COVID-19 were enrolled in the study. Additional data about other respiratory pathogens in the study group (specifically influenza A/B, respiratory syncytial virus (RSV) and group A Streptococcus (GAS)), were included. During both seasons of our study, 19,366 children were screened for COVID-19. Positive tests for COVID-19 decreased from 14.5% in Season I to 5.9% in Season II, while at the same time, the rates of other infections increased significantly: influenza from 17.5% to 27.1%, RSV from 8.8% to 27.6%, and GAS from 8.4% to 44%, respectively. In Season II, COVID-19 infection presented in fewer admissions to pediatric intensive care (0.8% vs. 3.7%, p<0.01) and there were no deaths, while influenza presented in a higher proportion of hospitalizations (10.5% vs. 6.1%, p<0.01) and there was one death. The proportion of RSV hospitalizations also increased in Season II (34.6% vs. 44.0%, p<0.01). The early post-lockdown period saw a decline of COVID-19 and re-emergence of influenza, RSV and GAS infections in children. In Season II, COVID-19 cases became milder contrary to influenza. RSV infection contributed significantly to hospitalizations for respiratory infections in children in both seasons, particularly in Season II. Coinfections were not associated with a more severe course of the disease.

Respiratory Viruses and Mycoplasma Pneumoniae Surveillance Among Hospitalized Children with Acute Respiratory Infections - Wuhan City, Hubei Province, China, September-November 2023.

Acute respiratory infections (ARIs) are a significant contributor to illness and death in children. There has been a notable rise in the occurrence of ARIs and the associated pathogens in China, which has garnered worldwide attention. This study conducted a retrospective analysis of the clinical characteristics of children with ARIs in Wuhan City from September to November 2023. The study evaluated the epidemiological patterns of common respiratory viruses and Mycoplasma pneumoniae (MP), revealing a continued prevalence of MP and a growing trend of influenza. Our findings emphasize that the circulation of respiratory viruses and MP has not returned to pre-pandemic levels, underscoring the importance of enhancing surveillance for respiratory pathogens. The epidemiology of ARIs and the pathogens involved need to be emphasized. This highlights the importance of developing policies to protect children from respiratory pathogens such as MP, influenza, and respiratory syncytial virus.

Acute respiratory infection emergency access in a tertiary care children hospital in Italy, prior and after the SARS‐CoV‐2 emergence

The COVID-19 pandemic has changed the epidemiology of acute respiratory infections (ARIs) in children. The aims of the present study were to describe the epidemiological trend of ARI emergency visits and virology results prior and after the SARS-CoV-2 emergence and to estimate the association of ARI emergency department (ED) visits with respiratory viruses. This study was conducted at the Bambino Gesù Children's Hospital, a tertiary care children's hospital in the Lazio Region, Italy. The demographic and clinical information of children who accessed the ED and were diagnosed with ARI from January 1, 2018 to June 30, 2022 was retrospectively extracted from the electronic health records. The observed temporal trends in viruses diagnosed from respiratory samples were compared with the number of ARI ED visits over the same period through a multivariable linear regression model. During the study period, there were 72,959 ED admissions for ARIs and 33,355 respiratory samples resulted positive for viruses. Prior to the pandemic, respiratory syncytial virus (RSV) and influenza had a clear seasonal pattern, which was interrupted in 2020. In 2021-2022, RSV reached the highest peak observed during the study period, whereas influenza activity was minimal. The peaks of ARI ED visits corresponded to peaks of influenza, RSV, and rhinovirus in the 2018-2019 and 2019-2020 seasons, to SARS-CoV-2 and rhinovirus in 2020, and to RSV and parainfluenza in 2021-2022. ARI resulting in ED visits should be included in the ARI disease burden measurement for a more accurate measure of the impact of preventive measures.

Spatial epidemiology of acute respiratory infections in children under 5 years and associated risk factors in India: District-level analysis of health, household, and environmental datasets.

In India, acute respiratory infections (ARIs) are a leading cause of mortality in children under 5 years. Mapping the hotspots of ARIs and the associated risk factors can help understand their association at the district level across India. Data on ARIs in children under 5 years and household variables (unclean fuel, improved sanitation, mean maternal BMI, mean household size, mean number of children, median months of breastfeeding the children, percentage of poor households, diarrhea in children, low birth weight, tobacco use, and immunization status of children) were obtained from the National Family Health Survey-4. Surface and ground-monitored PM2.5 and PM10 datasets were collected from the Global Estimates and National Ambient Air Quality Monitoring Programme. Population density and illiteracy data were extracted from the Census of India. The geographic information system was used for mapping, and ARI hotspots were identified using the Getis-Ord Gi* spatial statistic. The quasi-Poisson regression model was used to estimate the association between ARI and household, children, maternal, environmental, and demographic factors. Acute respiratory infections hotspots were predominantly seen in the north Indian states/UTs of Uttar Pradesh, Bihar, Delhi, Haryana, Punjab, and Chandigarh, and also in the border districts of Uttarakhand, Himachal Pradesh, and Jammu and Kashmir. There is a substantial overlap among PM2.5, PM10, population density, tobacco smoking, and unclean fuel use with hotspots of ARI. The quasi-Poisson regression analysis showed that PM2.5, illiteracy levels, diarrhea in children, and maternal body mass index were associated with ARI. To decrease ARI in children, urgent interventions are required to reduce the levels of PM2.5 and PM10 (major environmental pollutants) in the hotspot districts. Furthermore, improving sanitation, literacy levels, using clean cooking fuel, and curbing indoor smoking may minimize the risk of ARI in children.

Changing Epidemiology of Acute Viral Respiratory Infections in Hospitalized Children: The Post-Lockdown Effect.

Several reports highlighted how public health measures aimed at limiting severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) circulation have likely contributed to reducing the circulation of other respiratory viruses, particularly during the first year of the COVID-19 pandemic. We evaluated the epidemiology of acute respiratory infections in a large cohort of hospitalized children during the third year of the pandemic (2021–2022). We retrospectively analyzed data from the health records of children (<14 years) hospitalized for acute respiratory infections between 1 July 2021 and 31 March 2022. A total of 1763 respiratory panels were collected. Overall, 1269 (72%) panels hadpositive results for at least one pathogen. Most positive panels (53.8%) belonged to patients aged 1–12 months. The most detected pathogen was respiratory syncytial virus (RSV) (57.8% of positive panels). The RSV peak occurred in November 2021. Nine hundred and forty-five (74.5%) panels were positive for one pathogen while three hundred and twenty-four (25.5%) showed multiple infections. Patients with multiple infections were significantly older than those with a single infection. The 2021–2022 peak of RSV infection in Italy occurred earlier than in the previous pre-pandemic seasons. A high number of children have been hospitalized because of acute viral infections also due to less aggressive viruses.

Changing Epidemiology of Acute Respiratory Infections in Under-Two Children in Dhaka, Bangladesh.

Objectives: Risk factors for acute respiratory infections (ARIs) in community settings are not fully understood, especially in low-income countries. We examined the incidence and risk factors associated with ARIs in under-two children from the Microbiota and Health study.Methods: Children from a peri-urban area of Dhaka (Bangladesh) were followed from birth to 2 years of age by both active surveillance of ARIs and regular scheduled visits. Nasopharyngeal samples were collected during scheduled visits for detection of bacterial facultative respiratory pathogens. Information on socioeconomic, environmental, and household conditions, and mother and child characteristics were collected. A hierarchical modeling approach was used to identify proximate determinants of ARIs.Results: Of 267 infants, 87.3% experienced at least one ARI episode during the first 2 years of life. The peak incidence of ARIs was 330 infections per 100 infant-years and occurred between 2 and 4 months of age. Season was the main risk factor (rainy monsoon season, incidence rate ratio [IRR] 2.43 [1.92–3.07]; cool dry winter, IRR 2.10 [1.65–2.67] compared with hot dry summer) in the first 2 years of life. In addition, during the first 6 months of life, young maternal age (<22 years; IRR 1.34 [1.01–1.77]) and low birth weight (<2,500 g; IRR 1.39 [1.03–1.89]) were associated with higher ARI incidence.Conclusions: Reminiscent of industrialized settings, cool rainy season rather than socioeconomic and hygiene conditions was a major risk factor for ARIs in peri-urban Bangladesh. Understanding the causal links between seasonally variable factors such as temperature, humidity, crowding, diet, and ARIs will inform prevention measures.

Epidemiology of acute respiratory infections among under-fives in a rural community of Trivandrum district, Kerala

Background: More than 2 million children die from pneumonia each year, accounting for almost 18 percent of under five deaths worldwide. Childhood ARI is a significant public health problem in India, although robust epidemiological data are not available on its incidence. In recent years, the burden posed by ARI in underdeveloped and developing countries has stimulated global concern. The objective of the study was to study the occurrence of acute respiratory infections (ARI) in children under the age of five years in Nellanad Panchayat, Trivandrum district and to study the factors associated with ARI in children under five years of age.Methods: A community based cross-sectional study was conducted among 375 children below the age of five years.Results: Occurrence of ARI was found to be 52%. A significant association was found between ARI and under-nutrition, low birth weight, poor breast feeding practices, poor parental education, exposure to passive smoking and inadequate indoor ventilation.Conclusions: The study points towards the importance of basic health promotional measures like good antenatal care, proper breast feeding practices, proper nutrition of the child and socio-economic improvement in prevention and control of ARI.

Acute respiratory infections among returning Hajj pilgrims—Jordan, 2014

BackgroundThe emergence of Middle East Respiratory Syndrome coronavirus (MERS-CoV) has prompted enhanced surveillance for respiratory infections among pilgrims returning from the Hajj, one of the largest annual mass gatherings in the world. ObjectivesTo describe the epidemiology and etiologies of respiratory illnesses among pilgrims returning to Jordan after the 2014 Hajj. Study designSurveillance for respiratory illness among pilgrims returning to Jordan after the 2014 Hajj was conducted at sentinel health care facilities using epidemiologic surveys and molecular diagnostic testing of upper respiratory specimens for multiple respiratory pathogens, including MERS-CoV. ResultsAmong the 125 subjects, 58% tested positive for at least one virus; 47% tested positive for rhino/enterovirus. No cases of MERS-CoV were detected. ConclusionsThe majority of pilgrims returning to Jordan from the 2014 Hajj with respiratory illness were determined to have a viral etiology, but none were due to MERS-CoV. A greater understanding of the epidemiology of acute respiratory infections among returning travelers to other countries after Hajj should help optimize surveillance systems and inform public health response practices.

Lithuanian Paradox in Epidemiology of Acute Respiratory Infections and Influenza: Is it the Realm for Cultural and Spiritual Interpretation?

Lithuanian Paradox in Epidemiology of Acute Respiratory Infections and Influenza: Is it the Realm for Cultural and Spiritual Interpretation?

Epidemiology of acute respiratory infections in children - preliminary results of a cohort in a rural north Indian community.

BackgroundDespite acute respiratory infections being a major cause of death among children in developing countries including India, there is a lack of community-based studies that document its burden and aetiology.MethodsA dynamic cohort of children aged 0–10 years was established in four villages in a north Indian state of Haryana from August 2012 onwards. Trained health workers conducted weekly home visits to screen children for acute respiratory infection (ARI) defined as one of the following: cough, sore throat, nasal congestion, earache/discharge, or breathing difficulty. Nurses clinically assessed these children to grade disease severity based on standard age-specific guidelines into acute upper or lower respiratory infection (AURI or ALRI) and collected nasal/throat swabs for pathogen testing.ResultsOur first year results show that ARI incidence in 0–10 years of age was 5.9 (5.8–6.0) per child-year with minimal gender difference, the ALRI incidence in the under-five age group was higher among boys (0.43; 0.39–0.49) as compared to girls (0.31; 0.26–0.35) per child year. Boys had 2.4 times higher ARI-related hospitalization rate as compared to girls.ConclusionARI impose a significant burden on the children of this cohort. This study platform aims to provide better evidence for prevention and control of pneumonia in developing countries.

Epidemiology of acute respiratory infections in children in Guangzhou: a three-year study.

Acute Respiratory Infections (ARI) are some of the most common human diseases worldwide. However, they have a complex and diverse etiology, and the characteristics of the pathogens involved in respiratory infections in developing countries are not well understood. In this work, we analyzed the characteristics of 17 common respiratory pathogens in children (≤14 years old) with ARI in Guangzhou, southern China over a 3-year period using real-time polymerase chain reaction. Pathogens were identified in 2361/4242 (55.7%) patients, and the positivity rate varied seasonally. Ten of the 17 pathogens investigated showed positivity rates of more than 5%. The most frequently detected pathogens were respiratory syncytial virus (768/2361, 32.5%), influenza A virus (428/2361, 18.1%), enterovirus (138/2361, 13.3%), Mycoplasma pneumoniae (267/2361, 11.3%) and adenovirus (213/2361, 9.0%). Co-pathogens were common and found in 503 of 2361 (21.3%) positive samples. When ranked according to frequency of occurrence, the pattern of co-pathogens was similar to that of the primary pathogens, with the exception of human bocavirus, human coronavirus and human metapneumovirus. Significant differences were found in age prevalence in 10 of the 17 pathogens (p≤0.009): four basic patterns were observed, A: detection rates increased with age, B: detection rates declined with age, C: the detection rate showed distinct peaks or D: numbers of patients were too low to detect a trend or showed no significant difference among age groups (p>0.05). These data will be useful for planning vaccine research and control strategies and for studies predicting pathogen prevalence.

Human parainfluenza virus-associated respiratory tract infection among children and genetic analysis of HPIV-3 strains in Beijing, China.

The relevance of human parainfluenza viruses (HPIVs) to the epidemiology of acute respiratory infections (ARI) in China is unclear. From May 2008 to September 2010, 443 nasopharyngeal aspirates (NPAs) from hospitalized pediatric patients (age from 1 to 93 months) in Beijing were collected and screened for HPIVs and other common respiratory viruses by real-time RT-PCR. Sixty-two of 443 samples were positive for HPIVs with 4 positive for HPIV-2 and 58 positive for HPIV-3, indicating that HPIV-3 was the predominant virus present during the study period. A phylogenetic tree based on all the available HN (hemagglutinin-neuraminidase) sequences of HPIV-3 indicated that three distinct clusters (A,B, and C) were circulating with some temporal and regional clustering. Cluster C was further divided into sub-clusters, C1, C2, C3 and C4. HPIV-3 from Beijing isolates belonged to sub-cluster C3, and were grouped with the isolates from two Provinces of China and the neighboring country of Japan. Genetic analysis based on entire HN gene revealed that the HPIV-3 isolates from Beijing were highly similar with 97.2%–100% identity at the nucleotide level and these could be divided into two closely related lineages, C3a and C3b. These findings suggested that there was co-circulation of multiple lineages of HPIV-3 in the Beijing region during the study period. This is the first study to describe the epidemiology and molecular characterization of HPIVs in China.

The Impact of the H1n1 Influenza Pandemic on Clinical Presentations and Viral Epidemiology of Acute Respiratory Infection in Preschool Children in Brazil

We assessed the impact of the H1N1 influenza pandemic on acute respiratory infection in young children from low-income families in Brazil. Influenza (specifically H1N1) detection in acute respiratory infection quintupled during the pandemic and, during its peak, it was associated with 30% of all acute respiratory infection visits to the emergency department. H1N1 was also associated with increased risk of hospitalization and coinfection.

Epidemiology of respiratory viral infections in two long-term refugee camps in Kenya, 2007-2010

BackgroundRefugees are at risk for poor outcomes from acute respiratory infections (ARI) because of overcrowding, suboptimal living conditions, and malnutrition. We implemented surveillance for respiratory viruses in Dadaab and Kakuma refugee camps in Kenya to characterize their role in the epidemiology of ARI among refugees.MethodsFrom 1 September 2007 through 31 August 2010, we obtained nasopharyngeal (NP) and oropharyngeal (OP) specimens from patients with influenza-like illness (ILI) or severe acute respiratory infections (SARI) and tested them by RT-PCR for adenovirus (AdV), respiratory syncytial virus (RSV), human metapneumovirus (hMPV), parainfluenza viruses (PIV), and influenza A and B viruses. Definitions for ILI and SARI were adapted from those of the World Health Organization. Proportions of cases associated with viral aetiology were calculated by camp and by clinical case definition. In addition, for children < 5 years only, crude estimates of rates due to SARI per 1000 were obtained.ResultsWe tested specimens from 1815 ILI and 4449 SARI patients (median age = 1 year). Proportion positive for virus were AdV, 21.7%; RSV, 12.5%; hMPV, 5.7%; PIV, 9.4%; influenza A, 9.7%; and influenza B, 2.6%; 49.8% were positive for at least one virus. The annual rate of SARI hospitalisation for 2007-2010 was 57 per 1000 children per year. Virus-positive hospitalisation rates were 14 for AdV; 9 for RSV; 6 for PIV; 4 for hMPV; 5 for influenza A; and 1 for influenza B. The rate of SARI hospitalisation was highest in children < 1 year old (156 per 1000 child-years). The ratio of rates for children < 1 year and 1 to < 5 years old was 3.7:1 for AdV, 5.5:1 for RSV, 4.4:1 for PIV, 5.1:1 for hMPV, 3.2:1 for influenza A, and 2.2:1 for influenza B. While SARI hospitalisation rates peaked from November to February in Dadaab, no distinct seasonality was observed in Kakuma.ConclusionsRespiratory viral infections, particularly RSV and AdV, were associated with high rates of illness and make up a substantial portion of respiratory infection in these two refugee settings.

Viral aetiology and epidemiology of acute respiratory infections in hospitalized Saudi children.

A total of 1429 Saudi children of either sex and under 5 years of age who were admitted to King Khalid University Hospital, Riyadh during a three year period (April 1993–March 1996) with complaints suggestive of acute respiratory tract infections (ARTI) were investigated for viral aetiology of the infection. Viruses could be detected in 522 (37 per cent) cases with respiratory syncytial virus (RSV) the most commonly detected (79 per cent) followed by parainfluenza type 3 (8 per cent). Detection of influenza A, B and adenoviruses accounted for 6 per cent, 3 per cent and 2 per cent respectively. Except for parainfluenza virus type 3 the peak of activity of the respiratory viruses was during the winter months (October–February). Parainfluenza virus type 3 could be detected all year round but epidemics can occur in the hottest months of the year (June–August) when the temperature can exceed 40°C. Association between clinical manifestation, type of causative agent, and age was evaluated in 137 infected Saudi children in the first year of the study (April 1993–March 1994). The majority of our cases presented with bronchiolltis (58 per cent) while only 26 per cent had bronchopneumonla. There was a significant association between bronchiolitis and lower age groups (0–6 months), with RSV as the major causative agent of bronchiolitis cases (88 per cent).

A community-based study of acute respiratory infections among preschool children in Syria.

A longitudinal community-based study of the epidemiology of acute respiratory infections (ARI) in children less than 5 years old was carried out in a low income peri-urban area of Syria. A total of 1030 children were followed up by weekly morbidity surveillance for a period of 24 weeks, starting September 1989. The results revealed that, on average, a child suffered 3.4 episodes of ARI per 100 child-days at risk. The average prevalence of ARI was 23 per cent of time of observation. The peak age-specific incidence occurred in children 6-12 months old for cough/cold, and in children 0-5 months for pneumonia. Male children experienced higher incidence and prevalence of ARI. The most frequently reported symptoms were nasal discharge and cough.

Tonsillopharyngitis 1994

Acute infections of the upper respiratory tract, including those of the tonsils and pharynx, are the most common affliction of humans; their tendency to occur with much greater frequency in children makes them especially important to the pediatrician. A host of microbial agents can cause these infections, but only a few are responsive to antimicrobial agents. Because of the paucity of definitive laboratory tools that allow easy recognition of the cause of most acute respiratory infections, it is important for the practicing pediatrician to have other methods to aid in the clinical management of children who have these infections. This review will discuss the etiology and epidemiology of acute respiratory infections that involve primarily the tonsils and pharynx, with emphasis on how this knowledge can guide clinicians in their management. The groundwork for this approach will be laid by suggesting a classification of upper respiratory tract infections that involve the tonsils and pharynx. Causative agents will be enumerated and put into perspective. The major factors associated with the occurrence of acute upper respiratory tract infections will be discussed. Finally, treatment of the patient who has tonsillopharyngitis will be presented. Uncomplicated acute tonsillopharyngitis will be emphasized primarily and the role of complications only mentioned.

Acute Respiratory Infections

During the past decade, recognition of the significance of pneumonia for childhood mortality has greatly increased. Etiologic studies have clarified the role of Streptococcus pneumoniae and H. influenzae as the pathogens most responsible for childhood pneumonia in developing countries. Case management intervention strategies using community health workers to identify cases of pneumonia by counting respiratory rate and observing chest indrawing have been shown to reduce ARI-related mortality. Although research is underway to develop more effective vaccines against Streptococcus pneumoniae and non-type b H. influenzae, effective case management will remain the most realistic method of reducing mortality in the next decade. Important gaps remain in our understanding of the pathogenesis, etiology, and epidemiology of acute respiratory infections. Our understanding is complicated by the multiplicity of viral and bacterial agents and their interrelationships, by an abundance of interacting host risk factors, and by diverse social, cultural, and environmental factors. However, sufficient knowledge is available to support the implementation of the WHO case management intervention strategies, which will save the lives of the many children now dying because of pneumonia.

Epidemiology of Acute Respiratory Infections in Children of Developing Countries

Acute respiratory infections cause four and a half million deaths among children every year, the overwhelming majority occurring in developing countries. Pneumonia unassociated with measles causes 70% of these deaths; post-measles pneumonia, 15%; pertussis, 10%; and bronchiolitis and croup syndromes, 5%. Both bacterial and viral pathogens are responsible for these deaths. The most important bacterial agents are Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus. The data on bacterial etiology of pneumonia during the first 3 months of life are limited, and almost no information on the role of chlamydia and pertussis in this age period is available. The distribution of viral pathogens in developing countries can be summarized as follows: respiratory syncytial virus, 15%-20%; parainfluenza viruses, 7%-10%; and influenza A and B viruses and adenovirus, 2%-4%. Mixed viral and bacterial infections occur frequently. Risk factors that increase the incidence and severity of lower respiratory infection in developing countries include large family size, lateness in the birth order, crowding, low birth weight, malnutrition, vitamin A deficiency, lack of breast feeding, pollution, and young age. Effective interventions for prevention and medical case management are urgently needed to save the lives of many children predisposed to severe disease.

Epidemiology of acute respiratory infections in young children from Thailand

A prospective evaluation of the epidemiology and presentations of acute respiratory infections in children younger than 5 years of age admitted to Children's Hospital Bangkok (1988 to 1989) was supported by the World Health Organization. There were 226 patients with the inclusion criteria: 1 to 5 years of age; duration of illness less than 2 weeks; no prior antibiotic therapy; and low socioeconomic status. The disease categories included: croup, 19 cases; bronchiolitis, 60 cases; and pneumonia, 147 cases. Pathogens isolated were: respiratory syncytial virus (40); parainfluenza III (1); influenza B (1); and adenovirus (1); bacterial infections were proved in 23 cases. No significant differences in clinical features between bacterial and viral pneumonia were found. Interstitial radiographic patterns were more common in viral pneumonia whereas alveolar patterns were more common in bacterial pneumonia. However, 91% of mixed radiographic patterns (interstitial and alveolar) in chest films were from viral pneumonia.