Collateral Impact of Public Health and Social Measures on Respiratory Virus Activity during the COVID-19 Pandemic 2020–2021

The Characteristics of the Influenza Virus Epidemic Around the SARS-CoV-2 Epidemic Period in the Pudong New Area of Shanghai

OBJECTIVES

The concurrent impact of COVID-19 and influenza on disease burden is a topic of great concern. This discussion delves into the epidemiological characteristics of seasonal influenza activity in Shanghai within the context of the SARS-CoV-2 epidemic.

METHODS

From 2017 to 2023, a total of 11,081 patients having influenza-like illness (ILI) were included in this study for influenza virus detection. Reverse transcription polymerase chain reaction (RT-PCR) assays were conducted according to standardised protocols to identify the types and subtypes of influenza viruses. The positivity rate of the influenza virus among the sampled ILI cases served as a surrogate measure for estimating various influenza seasonal characteristics, such as periodicity, duration, peak occurrences, and the prevalent subtypes or lineages. Epidemiological aspects across different years and age groups were subjected to comprehensive analysis. For categorical variables, the Chi-square test or Fisher's exact test was employed, as deemed appropriate.

RESULTS

A total of 1553 (14.0%) tested positive for influenza virus pathogens. The highest positivity rate for influenza was observed in adults aged 25-59 years (18.8%), while the lowest rate was recorded in children under 5 years (3.8%). The influenza circulation patterns in Shanghai were characterised: (1) 2 years exhibited semiannual periodicity (2017-2018, 2022-2023); (2) 3 years displayed annual periodicity (2018-2019, 2019-2020, and 2021-2022); and (3) during 2020-2021, epidemic periodicities of seasonal influenza viruses disappeared. In terms of influenza subtypes, four subtypes were identified during 2017-2018. In 2018-2019 and 2019-2020, A/H3N2, A/H1N1, and B/Victoria were circulating. Notably, one case of B/Victoria was detected in 2020-2021. The epidemic period of 2021-2022 was attributed to B/Victoria, and during 2022-2023, the influenza A virus was the dominant circulating strain.

CONCLUSIONS

The seasonal epidemic period and the predominant subtype/lineage of influenza viruses around the SARS-CoV-2 epidemic period in Shanghai city are complex. This underscores the necessity for vigilant influenza control strategies amidst the backdrop of other respiratory virus pandemics.

Rise in complications of acute otitis media during and after the COVID-19 pandemic

PURPOSE

After the lifting of nonpharmaceutical interventions (NPIs) during the COVID-19 pandemic, clinical observation showed an increase in complications of acute otitis, followed by a rise in the number of mastoidectomies performed. The aim of this study was to record the number of mastoidectomies performed before, during and after the COVID-19 pandemic as an indicator for complications of acute otitis media.

METHODS

Data were collected from a tertiary hospital in a university setting, as well as from four major public health insurance companies in Germany. The data of 24,824,763 German citizens during a period from 2014 until 2023 were analyzed.

RESULTS

According to the data, during the COVID-19 pandemic, the number of mastoidectomies performed dropped by 54% for children aged 0-6 and by 62% for children aged 7-18. For adults, there were 30% fewer mastoidectomies performed between 2020 and 2022. After the lifting of most NPI's in the season from July 2022 to June 2023, there was a sharp increase in the number of mastoidectomies performed on patients of all ages.

CONCLUSIONS

During the COVID-19 pandemic, a decrease in the number of mastoidectomies performed was seen, suggesting a lower incidence of complicated acute otitis, most likely linked to the general decrease of upper airway infections due to NPI's. In contrast, a sharp increase in the incidence of complicated otitis occurred after the hygiene measures were lifted. The current development causes a more frequent performance of mastoidectomies, thus entailing a change in the challenges for everyday clinical practice.

Infection incidence, timing and dose dependency in rheumatoid arthritis patients treated with rituximab: a retrospective cohort study

OBJECTIVES

Rituximab (RTX) is a safe and effective treatment for RA. However, there are some concerns about infection risk and preliminary data suggest dose and time dependency. This study aims to determine the infection incidence in a large real-life population of RA patients using RTX, with special focus on (ultra-)low dosing and time since last infusion.

METHODS

RA patients treated with 1000, 500 or 200 mg RTX per cycle between 2012 and 2021 at the Sint Maartenskliniek were included in a retrospective cohort study. Patient-, disease-, treatment- and infection characteristics were retrieved from electronic health records. Infection incidence rates, dose and time relations with RTX infusion were analysed using mixed-effects Poisson regression.

RESULTS

Among 490 patients, we identified 819 infections in 1254 patient years. Most infections were mild and respiratory tract infections were most common. Infection incidence rates were 41, 54 and 71 per 100 patient years for doses of 200, 500 and 1000 mg. Incidence rate ratio (IRR) was significantly lower for 200 mg compared with 1000 mg (adjusted IRR 0.35, 95% CI 0.17, 0.72, P = 0.004). In patients receiving 1000 or 500 mg RTX, infections seemed to occur more frequently within the first two months after infusion compared with later on in the treatment cycle, suggesting an association with peak concentration.

CONCLUSION

Ultra-low dosing (200 mg) of RTX is associated with a lower risk of infections in RA. Future interventions focusing on ultra-low dosing and slow release of RTX (e.g. by subcutaneous administration) may lower infection risk.

Norovirus in children under 2 years of age: an epidemiological study in Panama during the COVID-19 pandemic

Introduction

Norovirus infection is a common cause of acute gastroenteritis (AGE). Surveillance activities are important to aid investigation into effective norovirus control strategies, including vaccination. Here, we report ancillary findings related to the incidence, prevalence, and etiology of AGE caused by norovirus in Panama after adjustment of study methodology to comply with national coronavirus disease 2019 (COVID-19) mandates.

Methods

In January 2020, children aged <2 years began enrolling into an epidemiological study in Panama to estimate the burden of norovirus in preparation for evaluating upcoming prevention strategies. This included an observational, longitudinal, community-based AGE surveillance study and a hospital-based AGE surveillance study. For the longitudinal study, healthy children aged 5-18 months were enrolled from January 6 through March 23, 2020, with a follow-up of approximately 6 months. The last participant was contacted on September 23, 2020. For the hospital-based study, starting on January 21, 2020, children aged <2 years who were admitted to the Hospital del Niño Dr. José Renán Esquivel in Panama City due to AGE were evaluated. The last sample was collected on September 29, 2020. Collected stool samples were tested for norovirus as well as astrovirus, sapovirus, and various enteropathogens. Unfortunately, this study was disrupted by the subsequent implementation of disease transmission control procedures for the COVID-19 pandemic, and the study methodology was revised to comply with COVID-19 mandates.

Results

In the longitudinal surveillance cohort [N = 400 (Chiriquí, n = 239; Panama, n = 161)], a total of 185 AGE episodes were documented (Chiriquí, n = 85; Panama, n = 100) resulting in an overall AGE incidence of 11.6 (95% CI: 9.99-13.4) episodes per 100 child-months. The norovirus-related AGE incidence was 0.3 (95% CI: 0.10-0.73) episodes per 100 child-months (5/185 AGE episodes) and the prevalence of norovirus was 4.6% (13/282 stool samples collected). In the hospital-based surveillance cohort, at least one pathogen was detected in 50% of samples (44/88 stool samples collected) and norovirus prevalence was 6.8% (6/88 stool samples collected).

Discussion

This report demonstrates how the occurrence of the COVID-19 pandemic hindered the conduct of clinical trials. However, this also created unique research opportunities to investigate the potential impact of pandemic control measures on the etiology of infectious diarrheal disease.

Combined intravenous ribavirin and recombinant human interferon α1b aerosol inhalation for adenovirus pneumonia with plastic bronchitis in children: a case report and review of literature

Background

Human adenovirus (HAdV) infections in children can lead to profound pulmonary injury and are frequently associated with severe complications, particularly in cases concomitant with plastic bronchitis. Managing this condition presents significant challenges and carries an exceptionally high fatality rate. Regrettably, there are currently no specific antiviral agents that have demonstrated efficacy in treating severe adenovirus pneumonia in children.

Case presentation

We report a 10-month-old infant suffering from severe adenovirus pneumonia combined with plastic bronchitis (PB). He received intravenous ribavirin combined with recombinant human interferon α1b (INFα1b) aerosol inhalation and his condition eventually improved. No side effects occurred during the treatment, and the long-term prognosis was favorable.

Conclusion

In this case, the combination therapy of intravenous ribavirin and INFα1b seems to have contributed to the resolution of illness and may be considered for similar cases until stronger evidence is generated.

[Increased rate of complications of pediatric acute otitis media and sinusitis in 2022/2023]

BACKGROUND

Acute mastoiditis and orbital complications of acute rhinosinusitis are among the most common complications of pediatric infections in otolaryngology.

OBJECTIVE

The aim of this study was to investigate the frequency of pediatric acute mastoiditis in the setting of acute otitis media as well as pediatric orbital complications in the setting of acute rhinosinusitis. Data from before the pandemic were compared to data after the end of the COVID-19 restrictions.

MATERIALS AND METHODS

Included were hospitalized children who presented with acute mastoiditis from acute otitis media or with orbital complications from acute rhinosinusitis during the period from April 2017 to March 2023. Compared were three periods using descriptive statistics: April 2017 to March 2020 (before the pandemic in Germany), April 2020 to March 2022 (during the contact restrictions of the pandemic), and April 2022 to March 2023 (after the contact restrictions were lifted).

RESULTS

A total of 102 children (43 with acute mastoiditis, 42%, and 59 with orbital complications of acute sinusitis, 58%) were included. During the 2022/2023 period, more than twice as many children with acute mastoiditis and approximately three times as many children with orbital complications of acute rhinosinusitis were hospitalized compared to the average of the periods 2017/2018, 2018/2019, and 2019/2020. In the 2021/2022 period, the number of these patients was below the average of previous years.

CONCLUSION

This year's seasonal cluster of upper respiratory tract infections is associated with a higher-than-average incidence of orbital complications and mastoiditis.

Epidemiology and clinical features of respiratory syncytial virus (RSV) infection in hospitalized children during the COVID-19 pandemic in Gorgan, Iran

Background and Aims

Respiratory syncytial virus (RSV) is a leading cause of acute respiratory infection in infants and young children. Given the altered circulation patterns of respiratory viruses during the coronavirus disease pandemic-2019 (COVID-19), the study aimed to evaluate epidemiology and clinical features of RSV infections in hospitalized children during the COVID-19 pandemic in Gorgan, northeastern Iran. Molecular epidemiology studies on respiratory viral infections are necessary to monitor circulating viruses, disease severity, and clinical symptoms, in addition to early warning of new outbreaks.

Methods

Overall, 411 respiratory swab samples from hospitalized children from October 2021 to March 2022 were collected at Taleghani Children's Hospital, Gorgan, Iran. The incidence of RSV, as well as the circulating subgroups and genotypes, were investigated and confirmed using PCR methods. Additionally, all samples tested for severe acute respiratory syndrome-associated coronavirus 2 (SARS-CoV-2) and influenza, and demographic and clinical data were analyzed using SPSS software.

Results

The share of RSV, SARS-CoV-2, and influenza among hospitalized children with acute lower respiratory infections (ALRI) were 27%, 16.5%, and 4.1%, respectively. The RSV subgroup A (genotype ON1) was dominant over subgroup B (genotype BA9), with more severe clinical symptoms. Compared with the prepandemic era there were high numbers of hospitalized SARS-CoV-2 positive children and low numbers of other respiratory viruses. Despite this, the prevalence of ALRI-related RSV-disease among hospitalized children in our specialized pediatric center was higher than COVID-19 disease in the same cohort.

Conclusions

Studying the epidemiology of respiratory viruses and determining the circulating strains can contribute to effective infection control and treatment strategies.

COVID-19 Pandemic: Therapeutic Strategies and Vaccines

Severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2), a highly pathogenic and transmissible virus, has spurred an impressive accumulation of knowledge [...].

An overview on viral interference during SARS-CoV-2 pandemic

Respiratory viruses represent the most frequent cause of mortality, morbidity and high healthcare costs for emergency visits and hospitalization in the pediatric age. Respiratory viruses can circulate simultaneously and can potentially infect the same host, determining different types of interactions, the so-called viral interference. The role of viral interference has assumed great importance since December 2019, when the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) came on the scene. The aim of this narrative review is to present our perspective regarding research in respiratory virus interference and discuss recent advances on the topic because, following SARS-CoV-2 restrictions mitigation, we are experimenting the co-circulation of respiratory viruses along with SARS-CoV-2. This scenario is raising many concerns about possible virus-virus interactions, both positive and negative, and the clinical, diagnostic and therapeutic management of these coinfections. Moreover, we cannot rule out that also climatic conditions and social behaviours are involved. Thus, this situation can lead to different population epidemic dynamics, including changes in the age of the targeted population, disease course and severity, highlighting the need for prospective epidemiologic studies and mathematical modelling able to predict the timing and magnitude of epidemics caused by SARS-CoV-2/seasonal respiratory virus interactions in order to adjust better public health interventions.

Global prevalence of respiratory virus infections in adults and adolescents during the COVID-19 pandemic: A systematic review and meta-analysis

OBJECTIVES

Since the beginning of the COVID-19 pandemic, efforts have been made to contain the spread of the virus. However, the epidemiological burden of other respiratory viruses during the pandemic is unclear. We aim to address the epidemiology of respiratory viruses on adults/adolescents since the beginning of the pandemic.

METHODS

We systematically searched five databases and performed a meta-analysis to explore the pooled prevalence of respiratory viruses in different geographical regions, age groups, and periods and compared the prevalence between COVID-19 cases and non-COVID-19 patients.

RESULTS

Enteroviruses/rhinoviruses were highly prevalent compared to other viruses. Different viruses were dominant in different regions. No significant differences in prevalence were found between different age groups, except for human metapneumovirus. There was an increase in prevalence of non-SARS-CoV-2 viruses in the second half of the pandemic (July 2021-December 2022). Comparison of COVID-19 and non-COVID patients showed a higher prevalence in the non-COVID group, significant for influenza, seasonal coronaviruses, and human parainfluenza viruses.

CONCLUSION

Our findings indicate that enteroviruses/rhinoviruses were less impacted by healthcare measures compared with other respiratory viruses. The relaxation of measures in the second half led to an increased pooled prevalence of infections. Several factors may explain the lower prevalence among individuals infected with COVID-19.

Respiratory viruses in rural Zambia during the second year of the COVID-19 pandemic

Objectives

Limited data on respiratory infections are available from sub-Saharan Africa during the COVID-19 pandemic. The objective of this study was to evaluate the burden of respiratory viruses in rural Zambia from 2019-2021.

Methods

Surveillance was initiated at Macha Hospital in Zambia in December 2018. Each week, patients with respiratory symptoms were enrolled from the outpatient clinic. Nasopharyngeal samples were collected and tested for respiratory pathogens. The prevalence of respiratory symptoms and viruses in 2021 was compared to results from 2019 and 2020.

Results

After seeing few cases of influenza virus and respiratory syncytial virus in 2020, a return to prepandemic levels was observed in 2021. Rhinovirus/enterovirus, parainfluenza virus 1-4, and adenovirus circulated from 2019 to 2021, while human metapneumovirus and human coronaviruses (HKU1, 229E, OC43, and NL63 subtypes) were observed sporadically. SARS-CoV-2 was observed consistently in 2021 after being first identified in December 2020. The proportion of participants with co-infections in 2021 (11.6%) was significantly higher than in 2019 (6.9%) or 2020 (7.7%).

Conclusion

Declines in influenza virus and respiratory syncytial virus were reversed once public health measures were lifted. Respiratory viruses contributed to a significant burden of respiratory infections in 2021. This study provides important information about respiratory viruses in this changing context and underrepresented region.

Impact of public health measures and new introducing variants on Respiratory syncytial virus recrudescence in Taiwan during the COVID-19 pandemic

OBJECTIVES

Respiratory syncytial virus (RSV) causes clinically significant distress in children and adults. Non-pharmaceutical interventions against SARS-CoV-2 have affected the seasonal activity of common respiratory pathogens. This seems exceptionally true regarding RSV's seasonal circulation, hence we have investigated the changes in the epidemiology of RSV in Taiwan during the pandemic.

MATERIALS

A prospective surveillance of RSV among hospitalized children was carried out between 2020 and 2022 in central Taiwan. Of all PCR-detected RSV, genotype and evolutionary analysis were further investigated. Demographics and clinical features were compared between each outbreak.

RESULTS

Throughout the consecutive three years of the SARS-CoV-2 pandemic, RSV outbreaks took place in Taiwan first in 2020 and a second time in 2022. We enrolled 80 and 105 hospitalized child cases, in each surge respectively. The RSV G protein genomic analysis revealed that RSV ON1 and RSV BA9 were separately contributing to these two outbreaks, and evolutionary evidence indicated these RSV variants are new to Taiwan, with their own featured sets of mutations. Clinically, a shift in age of RSV infected children was found, but the clinical severity was not worse and remained independent of RSV genotype.

CONCLUSIONS

There were two delayed RSV surges after the relaxation of public measures during the pandemic in Taiwan, and both outbreaks were driven by new RSV genetic variants rather than cryptic circulation of the previous genetic clusters in Taiwan. These findings highlight the importance of continued surveillance on the trend and evolution of RSV after the COVID-19 pandemic.

Rebound mortality rate of Legionella pneumonia in Japan

Legionella pneumonia is a fatal disease caused by Legionella pneumophila, a bacterium belonging to the genus Legionella. The incidence of this disease has been increasing since 2005 and has continued to increase following the COVID-19 pandemic in Japan. Furthermore, Legionella pneumonia mortality rates have increased slightly since the pandemic due to some plausible reasons. The increased proportion of older patients with legionellosis might affect it because advanced age is a major risk factor for disease mortality. Additionally, physicians were focused on COVID-19 while examining febrile patients; therefore, they might have missed the early diagnosis of other respiratory infections, including Legionella pneumonia.

The impact of the COVID-19 pandemic on chlamydia infection in South Korea: a comparison between the pre-pandemic and during-pandemic periods

Background

Prior to COVID-19 pandemic, a yearly upward trajectory in the number of chlamydia infection cases was observed in South Korea. However, in response to the COVID-19 pandemic, Korea implemented several public health and social measures, which were shown to have an impact on the epidemiology of other infectious diseases. This study aimed to estimate the impact of the COVID-19 pandemic on the incidence and number of reported chlamydia infections in South Korea.

Methods

Using the monthly number of reported chlamydia infection data between 2017 and 2022, we compared the trends in the reported numbers, and the incidence rates (IR) of chlamydia infection stratified by demographic characteristics (sex, age group, and region) in the pre- and during COVID-19 pandemic period (January 2017-December 2019 and January 2020-December 2022).

Results

We observed an irregular downward trajectory in the number of chlamydia infection in the during-pandemic period. A 30% decrease in the total number of chlamydia infection was estimated in the during-pandemic compared to the pre-pandemic period, with the decrease greater among males (35%) than females (25%). In addition, there was a decrease in the cumulative incidence rate of the during COVID-19 pandemic period (IR: 0.43; 95% CI: 0.42-0.44) compared to the pre-pandemic period (IR: 0.60; 95% CI: 0.59-0.61).

Conclusions

We identified decrease in the number of chlamydia infection during COVID-19 pandemic which is likely due to underdiagnosis and underreporting for the infection. Therefore, strengthening surveillance for sexually transmitted infections including chlamydia is warranted for an effective and timely response in case of an unexpected rebound in the number of the infections.

Comparison of 14 respiratory pathogens among hospitalized children during and after the COVID-19 outbreak in Chaoshan area

BACKGROUND

Since January 2020, measures has been adopted in the Chaoshan area to limit the spread of COVID-19. Restrictions were removed after August 2020. At the same time, children returned to school. We previously reported the changes of 14 main respiratory pathogens in hospitalized children before and during the COVID-19 outbreak in Chaoshan area. However, the changes of respiratory pathogen spectrum in hospitalized children after the epidemic are still unknown, which will be elucidated in this study.

METHODS

There are 6201 children hospitalized with respiratory tract infection were enrolled in the study, which were divided into two groups: 2533 from outbreak group (1 January 2020-31 December 2020), and 3668 from post-outbreak group (1 January 2021-31 December 2021). Pharyngeal swab samples were collected. 14 respiratory tract pathogens were detected by liquid chip technology.

RESULTS

The positive rate of pathogen detection is significantly lower in the outbreak group (65.42%, 1657/2533) than that in the post-outbreak group (70.39%, 2582/3668; χ² = 17.15, P < 0.05). The Influenza A virus (FluA) detection rate was 1.9% (49) in 2020, but 0% (0) in 2021. The detection rates of Bordetella pertussis (BP) decreased from 1.4% (35) in 2020 to 0.5% (17) in 2021. In contrast, the detection rates of  Influenza B virus (FluB), Cytomegalovirus (CMV), Haemophilus influenzae (HI), Streptococcus pneumoniae (SP) increased from 0.3% (8), 24.7% (626), 2.0% (50) and 19.4% (491) in 2020 to 3.3% (121), 27.9% (1025), 4.6% (169), 22.8% (836) in 2021, respectively (P < 0.01).

CONCLUSIONS

The detection rates of pathogens such as FluA, FluB, CMV, HI, SP, BP were statistically different between 2020 and 2021. From 2020 to 2021, the positive rates of Flu, CMV, HI and SP increased, while the positive rates of FluA and BP decreased. After the COVID-19 prevention and control measures are gradually relaxed, the positive rate of respiratory pathogens in children aged from 6 months to 6 years will increase.

Disruption of seasonal enterovirus and parechovirus detections in the CSF and plasma of children during the COVID-19 pandemic

BACKGROUND

Enteroviruses (EV) and parechovirus (PeV) are a common cause of CNS infection in children. Both viruses demonstrate consistent seasonal patterns, with detections mainly in the summer-fall months. While research has shown COVID-19 pandemic-related disruption of traditional seasonality of respiratory pathogens, the pandemic's impact on non-respiratory pathogens is less understood. The aim of this study was to quantify the EV/PeV seasonal variations during pre-COVID years compared to variations observed during the COVID pandemic.

METHODS

Patients with EV/PeV testing of CSF/plasma between January 2012 through September 2022 were identified. Restricted cubic spline methods were used to model the detections. Poisson models were utilized to model pre-COVID (2012-2019) EV/PeV detections. The expected seasonal trends from these models were then compared to the observed EV/PeV detections during the COVID pandemic (2020-2022).

RESULTS

A total of 5199 patients were included. The annual pre-pandemic proportion of EV detections ranged between 7.5%-20.3%. PeV exhibited a biennial pattern with peak proportions between 8.0%-16.3%. EV/PeV detections during the COVID pandemic period, especially during 2020 and 2021, were considerably lower than would have been expected based on pre-pandemic modeling. However, PeV detections from January through September 2022 nearly reached the pre-pandemic modeled expectation, including instances of exceeded expectations.

CONCLUSIONS

A significant disruption in expected seasonal EV/PeV detections was observed during the early phases of the COVID-19 pandemic. However, testing that occurred during summer-fall of 2022, when social mitigation initiatives were relaxed, showed a rapid increase in detections. Additional data are needed to further understand which public health initiatives are effective at decreasing EV/PeV transmission.

The Impact of the COVID-19 Pandemic on Respiratory Syncytial Virus Infection: A Narrative Review

Respiratory syncytial virus (RSV) is one of the most common respiratory viruses. It not only affects young children but also the elderly and immunocompromised patients. After the emergence of SARS-CoV-2 and the corona virus disease 2019 (COVID-19) era, a dramatic reduction in RSV activity was found, which coincided with the implementation of public health and social measures (PHSMs). However, the correlation is more complicated than we initially thought. After PHSMs were gradually lifted, a seasonality shift and a delayed RSV outbreak with greater number of infected patients were found in numerous countries, such as Israel, Australia, South Africa, New Zealand, France, United States, and Japan. Several hypotheses and possible reasons explaining the interaction between SARS-CoV-2 and RSV were mentioned. Since RSV vaccinations are still under investigation, administration of palivizumab should be considered in high-risk patients. In the post-COVID-19 era, greater attention should be paid to a further resurgence of RSV. In this narrative review, we conducted a thorough review of the current knowledge on the epidemiology of RSV during the COVID-19 era, the out-of-season outbreak of RSV, and the data on co-infection with RSV and SARS-CoV-2.

Measles cases in Split-Dalmatia County (a Croatian tourist region), in May-July 2019: outbreak report and lessons learnt

BACKGROUND

Measles elimination was accomplished in Croatia in 2016. Split-Dalmatia County, with population of ca. 425 000 inhabitants, is among the most important Croatian tourist areas with numerous seasonal workers coming during summer months. In both 2018 and 2019, more than 3 million tourists visited this county. In 2000-2018, there were no measles cases in this county, or their number was low (1-3 cases per year).

METHODS

After measles was clinically suspected, all contacts were traced and contacted. Detection of specific IgM/IgG antibodies and real-time reverse transcription-polymerase chain reaction detection of viral RNA were used for laboratory confirmation. Sequencing and genotyping were performed for strains' molecular epidemiology analysis.

RESULTS

Six epidemiologically unlinked measles virus occurrences happened in Split-Dalmatia County in 15 May-19 July 2019. Causative viral strains belonged to genotypes B3 and D8. Four were single imported cases. Ten patients belonged to two separate clusters within domicile population. Multiple individual and public health measures were implemented. In total, 483 contacts were identified, 64.2% within healthcare system where two persons contracted the disease.

CONCLUSIONS

Besides the importance of timely vaccination of children, the lessons learned from this outbreak point to the need of stricter implementation of other aspects of Croatian measles prevention programme, such as checking of vaccination status in early adulthood. Despite the fact that measles elimination within domicile population in this tourist region has been accomplished and maintained for years, continuous public health workers' efforts are still necessary for identification and diminishment of populational pockets of susceptibility.

Epidemiology and Transmission Dynamics of Infectious Diseases and Control Measures

The epidemiology and transmission dynamics of infectious diseases must be understood at the individual and community levels to improve public health decision-making for real-time and integrated community-based control strategies. Herein, we explore the epidemiological characteristics for assessing the impact of public health interventions in the community setting and their applications. Computational statistical methods could advance research on infectious disease epidemiology and accumulate scientific evidence of the potential impacts of pharmaceutical/nonpharmaceutical measures to mitigate or control infectious diseases in the community. Novel public health threats from emerging zoonotic infectious diseases are urgent issues. Given these direct and indirect mitigating impacts at various levels to different infectious diseases and their burdens, we must consider an integrated assessment approach, 'One Health', to understand the dynamics and control of infectious diseases.

Impact of COVID-19 Pandemic and Lockdown on the Epidemiology of RSV-Mediated Bronchiolitis: Experience from Our Centre

Background: The COVID-19 pandemic has dramatically affected the global epidemiology of other infectious respiratory diseases, leading to a significant decrease in their incidence. Hence, we aimed to characterize the epidemiology of RSV-bronchiolitis in children. Methods: children aged ≤2 years diagnosed with RSV-mediated bronchiolitis admitted to our Unit from October 2018 to December 2021, were retrospectively enrolled. Results: We included 95 patients (M/F = 46/49; mean age 7.56 ± 6.6 months). Specifically, 17 infants in 2018, 34 in 2019, 0 during 2020 lockdown, 1 during 2020 post-lockdown, and 43 in 2021. Incidence was significantly lower in 2020 compared with 2018, 2019 and 2021 (p < 0.05). No differences were found concerning need for respiratory support. Discussion: Several factors related to SARS-CoV-2 pandemic, especially restrictive measures, may have contributed to a significant reduction in hospitalizations due to RSV. The new outbreak in RSV infection-related hospitalizations reported between October and December 2021 has been suggested it may be due to an increased number of susceptible individuals to RSV infection. Conclusion: The experience of the SARS-CoV-2 outbreak has led to a marked decrease in other viral respiratory infections, such as RSV. This may pave the way for new approaches in preventing respiratory infections, highlighting the role of preventive measures.

Simultaneous Detection of SARS-CoV-2 and Influenza Virus in Wastewater of Two Cities in Southeastern Germany, January to May 2022

Dependent on the excretion pattern, wastewater monitoring of viruses can be a valuable approach to characterizing their circulation in the human population. Using polyethylene glycol precipitation and reverse transcription-quantitative PCR, the occurrence of RNA of SARS-CoV-2 and influenza viruses A/B in the raw wastewater of two treatment plants in Germany between January and May 2022 was investigated. Due to the relatively high incidence in both exposal areas (plant 1 and plant 2), SARS-CoV-2-specific RNA was determined in all 273 composite samples analyzed (concentration of E gene: 1.3 × 10⁴ to 3.2 × 10⁶ gc/L). Despite a nation-wide low number of confirmed infections, influenza virus A was demonstrated in 5.2% (concentration: 9.8 × 10² to 8.4 × 10⁴ gc/L; plant 1) and in 41.6% (3.6 × 10³ to 3.0 × 10⁵ gc/L; plant 2) of samples. Influenza virus B was detected in 36.0% (7.2 × 10² to 8.5 × 10⁶ gc/L; plant 1) and 57.7% (9.6 × 10³ to 2.1 × 10⁷ gc/L; plant 2) of wastewater samples. The results of the study demonstrate the frequent detection of two primary respiratory viruses in wastewater and offer the possibility to track the epidemiology of influenza by wastewater-based monitoring.

Travel in the Time of COVID: A Review of International Travel Health in a Global Pandemic

Purpose of Review

This review critically considers the impact of the COVID-19 pandemic on global travel and the practice of travel medicine, highlights key innovations that have facilitated the resumption of travel, and anticipates how travel medicine providers should prepare for the future of international travel.

Recent Findings

Since asymptomatic transmission of the virus was first recognized in March 2020, extensive efforts have been made to characterize the pattern and dynamics of SARS-CoV-2 transmission aboard commercial aircraft, cruise ships, rail and bus transport, and in mass gatherings and quarantine facilities. Despite the negative impact of further waves of COVID-19 driven by the more transmissible Omicron variant, rapid increases of international tourist arrivals are occurring and modeling anticipates further growth. Mitigation of spread requires an integrated approach that combines masking, physical distancing, improving ventilation, testing, and quarantine. Vaccines and therapeutics have played a significant role in reopening society and accelerating the resumption of travel and further therapeutic innovation is likely.

Summary

COVID-19 is likely to persist as an endemic infection, and surveillance will assume an even more important role. The pandemic has provided an impetus to advance technology for telemedicine, to adopt mobile devices and GPS in contact tracing, and to apply digital applications in research. The future of travel medicine should continue to harness these novel platforms in the clinical, research, and educational arenas.