Clinical symptoms, comorbidities and health outcomes among outpatients infected with the common cold coronaviruses versus influenza virus.

BACKGROUND: Common cold coronaviruses (ccCoVs) and influenza virus are common infectious agents causing upper respiratory tract infections (RTIs). However, clinical symptoms, comorbidities, and health effects of ccCoV infection remain understudied. METHODS: A retrospective study evaluated 3,935 outpatients with acute upper RTI at a tertiary teaching hospital. The presence of ccCoV and influenza virus was determined by multiplex molecular assay. The demographic, clinical symptoms, and health outcomes were compared between patients with ccCoV (n = 205) and influenza (n = 417) infections. Multivariable logistic regression was employed to evaluate predictors and health outcomes over a one-year follow-up. RESULTS: Sore throat, nasal discharge, headache, and myalgia were more predominant in ccCoV infection; fever was common in influenza. Most patients reported moderate symptoms severity (49.8% ccCoV, 56.1% influenza). Subsequent primary care visits with symptoms of RTI within a year were comparable for both infections (27.3% ccCoV vs. 27.6% influenza). However, patients with influenza reported increased primary care visits for non-RTI episodes and all-cause hospital admission. Baseline comorbidities were associated with increased primary care visits with symptoms of RTI in either ccCoV (adjusted odds ratio [aOR] 2.5; 95% confidence interval [CI] 1.1-5.9; P = 0.034) or influenza (OR 1.9; 95% CI 1.1-3.1; P = 0.017) infections, due probably to the dysregulation of the host immune response following acute infections. In patients infected with influenza infection, dyslipidemia was a predictor for subsequent primary care visits with symptoms of RTI (unadjusted OR 1.8; 95% CI 1.0-3.0; P = 0.040). CONCLUSIONS: Both influenza and ccCoV infection pose significant disease burden, especially in patients with comorbidities. The management of comorbidities should be prioritized to mitigate poor health outcomes in infected individuals.

Application of longitudinal multilevel zero inflated Poisson regression in modeling of infectious diseases among infants in Ethiopia.

BACKGROUND: In sub-Saharan African countries, preventable and manageable diseases such as diarrhea and acute respiratory infections still claim the lives of children. Hence, this study aims to estimate the rate of change in the log expected number of days a child suffers from Diarrhea (NOD) and flu/common cold (NOF) among children aged 6 to 11 months at the baseline of the study. METHODOLOGY: This study used secondary data which exhibit a longitudinal and multilevel structure. Based on the results of exploratory analysis, a multilevel zero-inflated Poisson regression model with a rate of change in the log expected NOD and NOF described by a quadratic trend was proposed to efficiently analyze both outcomes accounting for correlation between observations and individuals through random effects. Furthermore, residual plots were used to assess the goodness of fit of the model. RESULTS: Considering subject and cluster-specific random effects, the results revealed a quadratic trend in the rate of change of the log expected NOD. Initially, low dose iron Micronutrient Powder (MNP) users exhibited a higher rate of change compared to non-users, but this trend reversed over time. Similarly, the log expected NOF decreased for children who used MNP and exclusively breastfed for six months, in comparison to their counterparts. In addition, the odds of not having flu decreased with each two-week increment for MNP users, as compared to non-MNP users. Furthermore, an increase in NOD resulted in an increase in the log expected NOF. Region and exclusive breastfeeding also have a significant relationships with both NOD and NOF. CONCLUSION: The findings of this study underscore the importance of commencing analysis of data generated from a study with exploratory analysis. The study highlights the critical role of promoting EBF for the first six months and supporting children with additional food after six months to reduce the burden of infectious diseases.

Effect of prenatal and postnatal exposure to home renovation on the risk of common cold in preschool children.

Common cold is usually considered to be associated with outdoor climate, but the evidence linking with indoor environmental factors is lacking. The role of indoor renovations during which critical timing window on childhood common cold remains unclear. Therefore, we investigated the effect of exposure to new furniture and/or redecoration during prenatal and postnatal periods on the occurrence and duration of common cold in preschool children. We conducted a retrospective cohort study of 39 782 children aged 3-6 years in seven cities of China. The occurrence and duration of common cold in children, and their lifetime exposures to indoor new furniture and redecoration (including pregnancy, the first year of life, and after one year old) were assessed using a questionnaire administered by the parents. Associations between high frequency (>5 colds) and long duration (≥2 weeks per cold) of common cold during past 12 months and exposure to indoor new furniture/redecoration were examined by logistic regression models in terms of odds ratio (OR) and 95% confidence interval (CI). We found that the prevalence of high frequency and long duration of common cold in preschool children in China were, respectively, 9.2% and 11.9%. Frequent common cold was significantly associated with exposure to indoor new furniture/redecoration during pregnancy, first year, and after 1 year old, respectively, with the ORs (95% CI) = 1.25 (1.12-1.39), 1.11 (1.00-1.25), and 1.09 (1.01-1.18). Furthermore, childhood long duration per cold was associated with exposure to indoor new furniture/redecoration during pregnancy with OR (95% CI) of 1.14 (1.03-1.25) but not with postnatal exposure. We identified that prenatal exposure to home renovation was more critical than postnatal exposure for an increased risk of high frequency and long duration of common cold. Sensitivity analysis showed that the association between prenatal exposure to indoor renovations and the risk of childhood common cold was consistent and robust, and the associations were modified by some personal and indoor environmental factors. Our findings indicated that prenatal and postnatal exposure to home renovation played an important role in the risk of childhood common cold, supporting the hypothesis of "fetal origin of childhood infection."

Prospective cohort study of bedroom heating and risk of common cold in children.

BACKGROUND: In countries with mild winter climates and inadequate heating, the relationship between housing conditions and health outcomes in winter have not been well studied. The purpose of the present study was to evaluate the relationship between heater type and temperature factors in the bedroom and incidence of the common cold among children in Japan. METHODS: In this prospective cohort study, we distributed baseline questionnaires and temperature loggers in December 2019 and administered follow-up questionnaires in March 2020. We recruited children under the age of 15 years. We performed Poisson regression analysis and logistic regression analysis. RESULTS: Of 297 participants, air conditioners were the most prevalent (n = 105, 35%), followed by gas or kerosene heaters (n = 50, 17%), and floor heaters (n = 31, 10%). Air-conditioners were associated with higher incidence of all events related to the common cold, especially having a fever (adjusted incidence rate ratio (aIRR) = 1.84, 95% confidence interval (CI): 1.41-2.40). Gas or kerosene and floor heaters showed a lower incidence rate of some events related to the common cold, such as school or nursery school absence (aIRR = 0.55, 95% CI: 0.37-0.82 and aIRR = 0.39, 95% CI: 0.23-0.67, respectively). Bedroom temperature did not show a positive association, but children who always felt cold showed a higher incidence of some events related to the common cold. CONCLUSIONS: Our findings imply that the heating approach and modal thermal comfort, such as location of heating appliances, humidity, airflow, and radiant heat, may be more important for the onset of common cold in children than bedroom temperature itself.

Rhinovirus Incidence Rates Indicate We Are Tired of Non-pharmacological Interventions Against Coronavirus Disease 2019.

BACKGROUND: During the coronavirus disease 2019 (COVID-19) pandemic, the incidence of rhinovirus (RV) is inversely related to the intensity of non-pharmacological interventions (NPIs), such as universal mask wearing and physical distancing. METHODS: Using RV surveillance data, changes in the effect of NPIs were investigated in South Korea during the pandemic. The time to the first visible effect of NPIs after the onset of NPIs (T1), time to the maximum effect (T2), and duration of the maximum effect (T3) were measured for each surge. For each week, the RVdiff [(RV incidence during the pandemic) - (RV incidence within 5 years before the pandemic)] was calculated, and number of weeks for RVdiff to be below zero after NPIs (time to RVdiff ≤ 0) and number of weeks RVdiff remains below zero after NPIs (duration of RVdiff ≤ 0) were measured for each surge. RESULTS: During the study period, four surges of COVID-19 were reported. As the pandemic progressed, T1 and T2 increased, but T3 decreased. Additionally, the "time to RVdiff of ≤ 0" increased and "duration of RVdiff of ≤ 0" decreased. These changes became more pronounced during the third surge (mid-November 2020), before the introduction of the COVID-19 vaccine, and from the emergence of the delta variant. CONCLUSION: The effect of NPIs appears slower, the duration of the effect becomes shorter, and the intensity also decreases less than a year after the onset of the pandemic owing to people's exhaustion in implementing NPIs. These findings suggest that the COVID-19 response strategy must be completely overhauled.

More than just a common cold: Endemic coronaviruses OC43, HKU1, NL63, and 229E associated with severe acute respiratory infection and fatality cases among healthy adults.

Respiratory viral infection can cause severe disease and hospitalization, especially among children, the elderly, and patients with comorbidities. In Brazil, the official surveillance system of severe acute respiratory infection (SARI) investigates influenza A (IAV) and B (IBV) viruses, respiratory syncytial virus (RSV), adenovirus (HAdV), and parainfluenza viruses (hPIV 1-3). In Rio Grande do Sul (RS), Brazil, many fatalities associated with SARI between 2013 and 2017 occurred among patients without underlying diseases and for whom the causative agent had not been identified using official protocols. This cross-sectional study analyzed the presence of coronaviruses (HCoV), bocavirus (HBoV), metapneumovirus (hMPV), and rhinovirus in patients who died of SARI despite not having comorbidities, and that were negative for IAV, IBV, RSV, HAdV, and hPIV. Nasopharyngeal aspirates/swabs from patients were used for nucleic acid extraction. The presence of HCoVs OC43, HKU1, NL63, and 229E; HBoV; hMPV; and rhinovirus was assessed by quantitative reverse transcription-polymerase chain reaction. Clinical data were also analyzed. Between 2013 and 2017, 16 225 cases of SARI were reported in RS; 9.8% of the patients died; 20% of all fatal cases were patients without comorbidities and for whom no pathogen was detected using standard protocols. Analysis of 271 of these cases identified HCoV in nine cases; HBoV, hMPV, and rhinovirus were detected in 3, 3, and 10 cases, respectively. Of note, patients infected with HCoV were adults. Results reinforce the importance of including coronaviruses in diagnostic panels used by official surveillance systems because besides their pandemic potential, endemic HCoVs are associated to severe disease in healthy adults.

Low circulation of Influenza A and coinfection with SARS-CoV-2 among other respiratory viruses during the COVID-19 pandemic in a region of southern Brazil.

With the arrival of coronavirus disease 2019 (COVID-19) in Brazil in February 2020, several preventive measures were taken by the population aiming to avoid severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection including the use of masks, social distancing, and frequent hand washing then, these measures may have contributed to preventing infection also by other respiratory viruses. Our goal was to determine the frequencies of Influenza A and B viruses (FLUAV/FLUBV), human mastadenovirus C (HAdV-C), Enterovirus 68 (EV-68), and rhinovirus (RV) besides SARS-CoV-2 among hospitalized patients suspect of COVID-19 with cases of acute respiratory disease syndrome (ARDS) in the period of March to December 2020 and to detect possible coinfections among them. Nucleic acid detection was performed using reverse-transcription quantitative polymerase chain reaction (RT-qPCR) in respiratory samples using naso-oropharyngeal swabs and bronchoalveolar lavage. A total of 418 samples of the 987 analyzed (42.3%) were positive for SARS-CoV-2, 16 (1.62%) samples were positive for FLUAV, no sample was positive for FLUBV or EV-68, 67 (6.78%) samples were positive for HAdV-C, 55 samples were positive for RV 1/2 (26.3%) and 37 for RV 2/2 (13.6%). Coinfections were also detected, including a triple coinfection with SARS-CoV-2, FLUAV, and HAdV-C. In the present work, a very low frequency of FLUV was reported among hospitalized patients with ARDS compared to the past years, probably due to preventive measures taken to avoid COVID-19 and the high influenza vaccination coverage in the region in which this study was performed.

Circulation of human coronaviruses OC43 and 229E in Córdoba, Argentina.

This is the first study of respiratory infections in Córdoba, Argentina, caused by endemic human coronavirus (HCoV)-OC43 and HCOV-229E, which circulated during 2011-2012 at a 3% rate, either as single or multiple infections. They were detected mainly in children, but HCoV-229E was also found in adults. HCoV-229E was detected in five out of 631 samples (0.8%), and HCoV-OC43 was found in 14 out of 631 (2.2%) samples. Clinical manifestations ranged from fever to respiratory distress, and a significant association of HCoV-229E with asthma was observed. Further studies and surveillance are needed to provide better clinical insights, early diagnosis, and medical care of patients, as well as to contribute to epidemiology modeling and prevention.

Trends in adaptation of fifteen European countries population to SARS-CoV-2 in March-May 2020: Can Taiwanese experience be adopted?

BACKGROUND: The purpose of the work is to analyze population adaptation to SARS-CoV-2 in Europe in March-May 2020, predict herd immunity formation in the nearest several months on the basis of our SIR modified epidemiological model of the virus spread and elaborate recommendations to governments regarding a second wave of COVID-19 pandemic. METHODS: Outer (1,006,512 RT-PCR tests results for SARS-CoV-2) and proprietary (34,660 respiratory samples) epidemiological data was used. Fifteen European countries were studied. Dates of research: March 2 - May 22, 2020. RESULTS: As of April 21, 2020, the mean population infection rate (PIR) for the European countries considered, was 9.66%. It decreased to 6.85% by May 22, 2020. The model predicted 5.68% PIR, giving accuracy of 79.40%. SARS-CoV-2 basic reproduction number is limited by an extremum that may be observed for closed communities. A concept of effective reproduction number is introduced as a function of r0 with maximum at r0 = 4.671 and value reff. = 0.315 for the full-lockdown mode and r0 = 5.539 and reff. = 0.552 for the no-lockdown mode of SARS-CoV-2 containment. Full-lockdown and no-lockdown modes resulted in the outcomes not strikingly different from each other in terms of herd immunity values. CONCLUSION: In case of a second wave of COVID-19 disease in Europe, it will coincide with seasonal common cold surge, spanning from mid-September 2020 to mid-February 2021, with a median in November-December 2020. Strict epidemiological surveillance must be observed in Europe at that time.

Changes in the proportion and severity of patients with fever or common cold symptoms utilizing an after-hours house call medical service during the COVID-19 pandemic in Tokyo, Japan: a retrospective cohort study.

BACKGROUND: Trends in the characteristics and disease severity of patients using an after-hours house call (AHHC) medical service changed during the coronavirus disease (COVID-19) pandemic. However, there have been no reports on this issue since the start of the COVID-19 pandemic. This study aimed to investigate patients' tendencies to utilize an AHHC medical service for fever or common cold symptoms during the COVID-19 pandemic. METHODS: This retrospective cohort study compared the characteristics and disease severity of patients with fever or common cold symptoms utilizing an AHHC medical service offered by a single large company between the control period (December 1, 2018 to April 30, 2019) and the COVID-19 pandemic exposure period (December 1, 2019 to April 30, 2020). We also assessed the proportion of these patients in relation to all patients calling the service for any reason. RESULTS: During the control and COVID-19 pandemic exposure periods, a total of 6462 and 10,003 patients consulted the AHHC medical service, respectively. Of these, 5335 (82.6%) and 7423 (74.2%) patients had fever and common cold symptoms, respectively, during the control and COVID-19 pandemic exposure periods (P < 0.001). The corresponding median (interquartile range) ages were 8 (3-11) and 10 (4-33) years, respectively. The distribution of disease severity differed between the groups. The proportions of patients with mild, moderate, and severe illness were 71.1, 28.7, and 0.2% in the control period and 42.3, 56.7, and 0.9% in the COVID-19 pandemic exposure period, respectively (P < 0.001). CONCLUSIONS: During the COVID-19 pandemic, the proportion of patients with fever or common cold symptoms was lower than that in the control period, but disease severity was significantly higher.

SARS-CoV-2 coinfections: Could influenza and the common cold be beneficial?

The novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread around the world, causing serious illness and death and creating a heavy burden on the healthcare systems of many countries. Since the virus first emerged in late November 2019, its spread has coincided with peak circulation of several seasonal respiratory viruses, yet some studies have noted limited coinfections between SARS-CoV-2 and other viruses. We use a mathematical model of viral coinfection to study SARS-CoV-2 coinfections, finding that SARS-CoV-2 replication is easily suppressed by many common respiratory viruses. According to our model, this suppression is because SARS-CoV-2 has a lower growth rate (1.8/d) than the other viruses examined in this study. The suppression of SARS-CoV-2 by other pathogens could have implications for the timing and severity of a second wave.

Good Relationships With Parents During Childhood as Buffers of the Association Between Childhood Disadvantage and Adult Susceptibility to the Common Cold.

OBJECTIVE: Children reared by parents of low socioeconomic status (SES) go on to have elevated rates of physical health problems and premature mortality. However, many children reared in low-SES families remain healthy throughout the life-span. Here, secondary analyses of archival data tested the hypothesis that a positive relationship with parents during childhood acts as a buffer of the increased risk of adult susceptibility to infectious illness associated with low childhood SES. METHODS: One hundred seventy-six healthy adults reported their childhood SES and the quality of their relationships with their parents during childhood. Relationship quality was defined as parental care, love and support, lack of conflict with parents, and family cohesiveness. Afterward, participants were exposed to a respiratory virus and monitored in quarantine for 5 days for the development of a "common cold" as indicated by infection and objective markers of illness. RESULTS: The increased risk of developing a cold associated with being reared in a low SES household was attenuated by a positive relationship with parents during childhood (b(SE) = 0.08 (0.03), p = .010). This buffering of disease risk held up across the four components of relationship quality (p values < .05). The association was independent of adult SES, demographics, prechallenge immunity to the virus, current levels of neuroticism and stress, parental divorce during childhood, and number of siblings (p values < .05). CONCLUSIONS: Individuals with positive relationships with their parents during childhood are buffered from the increased risk of adult susceptibility to an infectious disease associated with low childhood SES.

Seasonality and coinfection of bronchiolitis: epidemiological specificity and consequences in terms of prophylaxis in tropical climate.

OBJECTIVE: To describe the viruses involved, seasonality and coinfection in hospitalised children with suspected bronchiolitis. METHODS: Over the period 1/07/2007 to 31/12/2008, all children hospitalised for bronchiolitis in the paediatric ward were prospectively included, and had respiratory syncytial virus (RSV) screenings. We retrospectively tested all samples for RSVA, RSVB, rhinovirus (RV), human metapneumovirus, parainfluenza 1, 2, 3, 4, influenza A and influenza B. RESULTS: 198 children were tested, and 23% were negative for all viruses. RSVA was predominant in 2008 (64% of all viruses) and RSVB in 2007 (66% of all viruses). RV was frequent during both seasons (24% of all viruses). Flu was not found during the study period. Virus distribution was similar regardless of season or age, and identical to typical patterns in temperate countries. Coinfections were less frequent than in temperate regions because respiratory virus seasons seem to be better separated. The bronchiolitis season started in August and finished in December with a peak in October. CONCLUSION: The specific seasonality of bronchiolitis infection requires palivizumab prophylaxis starting in early July for high-risk infants.

OBJECTIF: Décrire les virus impliqués, la saisonnalité et la coinfection chez les enfants hospitalisés avec une suspicion de bronchiolite. MÉTHODES: Au cours de la période du 01/07/2007 au 31/12/2008, tous les enfants hospitalisés pour bronchiolite dans le service de pédiatrie ont été prospectivement inclus et soumis à un dépistage du virus respiratoire syncytial (VRS). Nous avons testé rétrospectivement tous les échantillons pour RSVA, RSVB, rhinovirus (RV), métapneumovirus humain, Parainfluenza 1, 2, 3, 4, Influenza A, et Influenza B. RÉSULTATS: 198 enfants ont été testés et 23% étaient négatifs pour tous les virus. RSVA était prédominant en 2008 (64% de tous les virus) et RSVB en 2007 (66% de tous les virus). RV était fréquent pendant les deux saisons (24% de tous les virus). La grippe n'a pas été trouvée pendant la période d'étude. La distribution des virus était similaire quelle que soit la saison ou l'âge, et identique aux modèles typiques dans les pays tempérés. Les coinfections étaient moins fréquentes que dans les régions tempérées car les saisons virales respiratoires semblent mieux séparées. La saison des bronchiolites a commencé en août et s'est terminée en décembre avec un pic en octobre. CONCLUSION: La saisonnalité spécifique de l'infection bronchiolite nécessite une prophylaxie au palivizumab débutant en juillet pour les nourrissons à haut risque.

Exploration of self-medication practice in Pokhara valley of Nepal.

BACKGROUND: Self-medication (SM) is the practice of consuming medication without the consultation of physician. The drugs most commonly self-medicated are paracetamol, analgesics, ranitidine, oral rehydration solution and antibiotics. The objective of the study was to assess the SM status and its causes in Pokhara valley of Nepal. METHOD: The study was conducted among the people residing in Pokhara metropolitan city. The study duration was of 4 months from April to July, 2018. The study population were patients attending health general and oral health screening programs at Baidam, Birauta, Hemja and Pame areas of Pokhara. Structured questionnaire was used to collect demographics of the patients and the details of the usage of self-medication. RESULT: Out of 201 patients, 38.2% patients were found to be self-medicating. The most common illness sought for SM was ache (headache, body ache) in 50% subjects followed by cough and cold in 31% and gastritis in 23%. Paracetamol was the drug consumed by 16 subjects followed by nimesulide by 11. Lack of knowledge about the disadvantages of SM led to self-medication in 65% of respondents. The personnel most commonly consulted for medication were pharmacists (60%). CONCLUSION: The trend of SM is high in Pokhara valley. The comedics were consulted most often for SM due to lack of knowledge of consultation to physicians. The public should be made aware about SM.

Illnesses Encountered During Medical Volunteering in Takeo Province, Cambodia.

Background and Objectives: Medical volunteering seeks to meet the clinical needs of underserved areas, but has been criticized for difficulties in addressing local health issues and resultant lack of sustainability. Our team has visited rural Cambodia annually since 2012. This study reports the illnesses encountered during the recent mission and share our experiences to improve the efficiency of medical volunteering. Materials and Methods: Infrastructure, such as public electricity or water, was unavailable, hence most medical care and records were hand-performed. We categorized (1) primary diagnoses (chief complaints) by duration of symptoms, and (2) primary and secondary diagnoses (illnesses that were not related to the chief complaint) by severity of illness since patients commonly reported multiple symptoms. Blood pressure and anthropometric values were also checked and analyzed. Results: We encountered 317 adult and 141 pediatric patients. Among adults, 61.3% had persistent chronic (>6 month) symptoms of their chief complaints. The commonest diagnoses of chronic symptoms were musculoarthritis (31.5%) and gastroesophageal reflux disease and/or gastritis (21.7%). Hypertension and/or cardiac problems were relatively common among males (13.6%). The most common diagnosis among the severest cases (specialized or intensive care recommended) was cardiac problems (14.8%), often with abnormalities in sonography or electrocardiogram. For children, the overwhelming majority of diagnoses were related to acute symptoms and low severity, and approximately half were cases of the common cold. Commonly prescribed drugs were antacids or mucosal protectors (31.3%), Non-steroidal anti-inflammatory drugs (NSAIDs) or other painkillers (27.6%), and antiparasites (17.7%) in adults, and NSAIDs (44.7%) and antiparasites (23.2%) in children. Among adults, 32.7% were diagnosed with hypertension, and body mass index (p = 0.003) and age (p < 0.001) were both correlated with hypertension and its grade. Conclusion: Our study offers practical help to volunteer health workers planning to visit Southeast Asia.

An Intensive, Active Surveillance Reveals Continuous Invasion and High Diversity of Rhinovirus in Households.

We report on infection patterns in 5 households (78 participants) delineating the natural history of human rhinovirus (HRV). Nasopharyngeal collections were obtained every 3-4 days irrespective of symptoms, over a 6-month period, with molecular screening for HRV and typing by sequencing VP4/VP2 junction. Overall, 311/3468 (8.9%) collections were HRV positive: 256 were classified into 3 species: 104 (40.6%) HRV-A; 14 (5.5%) HRV-B, and 138 (53.9%) HRV-C. Twenty-six known HRV types (13 HRV-A, 3 HRV-B, and 10 HRV-C) were identified (A75, C1, and C35 being most frequent). We observed continuous invasion and temporal clustering of HRV types in households (range 5-13 over 6 months). Intrahousehold transmission was independent of clinical status but influenced by age. Most (89.0%) of HRV infection episodes were limited to <14 days. Individual repeat infections were frequent (range 1-7 over 6 months), decreasing with age, and almost invariably heterotypic, indicative of lasting type-specific immunity and low cross-type protection.

Associations of maternal upper respiratory tract infection/influenza during early pregnancy with congenital heart disease in offspring: evidence from a case-control study and meta-analysis.

BACKGROUND: Evidences regarding the associations between maternal upper respiratory tract infection/influenza during pregnancy and the risk of congenital heart disease (CHD) is still controversial. This study was specifically designed to examine the associations by a case-control study and a meta-analysis of the published evidences and our finding. METHODS: A hospital-based case-control study involving 262 children with simple CHD and 262 children with complex CHD, along with 262 control children, was conducted through June, 2016 to December, 2017. All children were aged 0-2 years old. Furthermore, a meta-analysis based on both previously published studies and our case-control study was performed. RESULTS: In the case-control study, after adjusting for possible confounders, maternal upper respiratory tract infection/influenza during early pregnancy was found to be related to an increased risk of CHD (OR = 3.40 and 95% CI: 2.05-5.62 for simple CHD; OR = 2.39 and 95% CI: 1.47-3.88 for complex CHD). After a meta-analysis, the adverse impact was still kept significant (OR = 1.47 and 95% CI: 1.28-1.67 for simple CHD; OR = 1.44 and 95% CI: 1.14-1.75 for complex CHD). The very similar associations were also observed among single type of CHD, herein, ventricular septal defects (VSD) and tetralogy of fallot (TOF) in the case-control study. In the subsequent meta-analysis, however, the significant association only existed in VSD. CONCLUSIONS: Although there is still conflicting in TOF, the results are overall consistent, which provide new enforced evidence that maternal upper respiratory tract infection/influenza during early pregnancy, in general, play an important role in the occurrence of CHD.

Respiratory virus transmission dynamics determine timing of asthma exacerbation peaks: Evidence from a population-level model.

Asthma exacerbations exhibit a consistent annual pattern, closely mirroring the school calendar. Although respiratory viruses--the "common cold" viruses--are implicated as a principal cause, there is little evidence to link viral prevalence to seasonal differences in risk. We jointly fit a common cold transmission model and a model of biological and environmental exacerbation triggers to estimate effects on hospitalization risk. Asthma hospitalization rate, influenza prevalence, and air quality measures are available, but common cold circulation is not; therefore, we generate estimates of viral prevalence using a transmission model. Our deterministic multivirus transmission model includes transmission rates that vary when school is closed. We jointly fit the two models to 7 y of daily asthma hospitalizations in adults and children (66,000 events) in eight metropolitan areas. For children, we find that daily viral prevalence is the strongest predictor of asthma hospitalizations, with transmission reduced by 45% (95% credible interval =41-49%) during school closures. We detect a transient period of nonspecific immunity between infections lasting 19 (17-21) d. For adults, hospitalizations are more variable, with influenza driving wintertime peaks. Neither particulate matter nor ozone was an important predictor, perhaps because of the large geographic area of the populations. The school calendar clearly and predictably drives seasonal variation in common cold prevalence, which results in the "back-to-school" asthma exacerbation pattern seen in children and indirectly contributes to exacerbation risk in adults. This study provides a framework for anticipating the seasonal dynamics of common colds and the associated risks for asthmatics.