The drop in reported invasive pneumococcal disease among adults during the first COVID-19 wave in the Netherlands explained

A nationwide study of two decades of invasive pneumococcal disease in the Faroe Islands, 2000-2023

BACKGROUND

Invasive pneumococcal disease (IPD) remains a significant public health concern, particularly in vulnerable populations such as the elderly. This study focuses on the Faroe Islands, a unique setting for monitoring pneumococcal disease trends due to its high vaccination coverage and geographic isolation.

OBJECTIVE

To examine the prevalence, trends and serotype distribution of IPD in the Faroe Islands from 2000 to 2023, focusing on the impact of pneumococcal conjugate vaccines (PCVs) on disease incidence and serotype replacement.

METHODS

Eighty-six pneumococcal isolates, representing all registered cases of IPD in the Faroe Islands, were analysed during the study period. Data on patient demographics, serotype identification and vaccination history were collected from national health records. Temporal trends in vaccine-type (VT) and non-vaccine-type (nVT) serotypes were analysed, particularly following the introduction of PCV13 in 2010.

RESULTS

Following the introduction of PCV13, a shift from VT to nVT serotypes was observed, while the overall IPD rate remained stable. Notably, there was an increase in IPD cases among the elderly population. The analysis indicated that serotype replacement contributed to a rise in nVT cases despite reducing VT-related IPD.

CONCLUSIONS

The findings emphasise the need for ongoing evaluation of pneumococcal vaccine formulations and alternative strategies to address the increasing prevalence of nVT IPD. Higher-valency vaccines and sustained vaccination coverage are critical to mitigating the impact of serotype replacement and improving public health outcomes in the Faroe Islands.

Changes in the epidemiology and antimicrobial resistance patterns of Streptococcus pneumoniae from pediatric community acquired pneumonia patients attended in a Chinese hospital during the COVID-19 pandemic

PURPOSE

The COVID-19 pandemic has altered the infection dynamics of numerous pathogens. This study aimed to elucidate its impact on Streptococcus pneumoniae (S. pneumoniae) infections in children with community acquired pneumonia (CAP).

METHODS

A retrospective analysis was conducted in pediatric CAP patients admitted before (2018-2019) and during (2020-2022) the COVID-19 pandemic. The epidemiology and antimicrobial resistance (AMR) patterns of S. pneumoniae were compared to reveal the impact of the pandemic.

RESULTS

A total of 968 S. pneumoniae-associated pediatric CAP patients were enrolled. Although the positivity rate and gender of patients were stable across both periods, the age notably increased in 2021 and 2022. Additionally, significant changes were observed in the co-infections with several pathogens and the resistance rates to certain antibiotics during the COVID-19 pandemic. The resistance rate to clindamycin and quinupristin-dalfopristin increased, whereas the resistance rate to tetracycline, trimethoprim-sulfamethoxazole, telithromycin, and proportion of multi-drug resistant isolates decreased. The number of S. pneumoniae strains and resistant isolates exhibited similar seasonal patterns in 2018 and 2019, peaking in November or December with another minor peak in March or April. During the COVID-19 pandemic, there was a sharp decrease in February 2020 and no resurgence was observed at the end of 2022. Additionally, the minor peak was absent in 2020 and shifted to other months in 2021 and 2022.

CONCLUSIONS

The COVID-19 pandemic has markedly altered the infection spectrum of S. pneumoniae in pediatric CAP patients, as evidenced by shifts in the age of patients, respiratory co-infections, AMR patterns, and seasonal trends.

Cardiovascular events after invasive pneumococcal disease: a retrospective cohort study

OBJECTIVES

This study aims to understand the magnitude of and mechanisms underlying the development of cardiovascular events (CVEs) in patients with invasive pneumococcal disease (IPD). We aimed to identify factors that contribute to the occurrence of CVEs within 1 year after admission and discuss implications for patient care.

METHODS

A multicentered cohort study included adult patients from four Dutch hospitals who had a positive blood culture for Streptococcus pneumoniae and any type of clinical manifestation between 2012 and 2020. Disease characteristics and microbiological data were systematically collected from electronic patient files. The main outcome measures were the occurrence of stroke and acute coronary syndromes (ACS).

RESULTS

Of 914 eligible patients, 4.2% experienced a CVE within 1 year after admission for IPD. ACS mainly occurred in the first 2 weeks, whereas stroke developed throughout follow-up. Although ACS was positively associated with disease severity, the sole independent predictor was alcohol abuse (odds ratio [OR] 3.840, 95% confidence interval [CI] 1.108-13.303). Although stroke occurred in 6.3% of meningitis cases, the best clinical predictor of stroke was a body temperature >39.5 °C at admission (OR 3.117 [1.154-8.423]). In the adult IPD population aged <70 years, pneumococcal serotypes were the primary predictors of ACS (7F; OR 15.733 [1.812-136.632]) and stroke (22F; OR 7.320 [1.193-44.903]).

CONCLUSIONS

Adverse CVEs were not uncommon after IPD diagnosis and deserve attention, especially in the high-risk groups we identified in our study population. Whether specific serotypes play a role in the development of CVE requires substantiation in further research.

The Impact of the COVID-19 Pandemic on the Incidence of Herpes Zoster: A Narrative Literature Review

Coronavirus disease 2019 (COVID-19) has had a broad impact on health services and health outcomes. During the pandemic, there were numerous reports of herpes zoster (HZ) in people with COVID-19 and in COVID-19 vaccine recipients. The aim of this review is to elucidate the global effects of the COVID-19 pandemic on HZ. It is postulated that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection produces an immunosuppressive state that favours varicella zoster virus (VZV) reactivation. Three large cohort studies (a multinational study and studies from the USA and Spain) that excluded individuals vaccinated against HZ reported significantly increased risk of HZ following COVID-19 infection, especially in people aged ≥ 50 years. In contrast, a large study from Israel that did not consider HZ vaccination status reported no such increase. Cases of HZ following COVID-19 vaccination have been reported and may be the result of attenuated cell-mediated immunity. This phenomenon appears to vary by vaccine type. Some (but not all) large analyses have reported a significant positive relationship between receipt of mRNA vaccines for COVID-19 and development of HZ. These include analyses of health records databases in Israel and Hong Kong and of spontaneous case reports in the US Vaccine Adverse Event Reporting System (VAERS) database. Routine vaccinations, including shingles vaccine programmes, were disrupted by the COVID-19 pandemic. It is estimated that missed shingles vaccinations may have resulted in 63,117 avoidable HZ cases in the USA. Now that the World Health Organization has declared an end to the COVID-19 pandemic as a health emergency and routine vaccination services have resumed, there is a need to increase awareness of HZ and HZ vaccination.Graphical abstract available for this article.

Persistence of Pneumococcal Carriage among Older Adults in the Community despite COVID-19 Mitigation Measures

Reported rates of invasive pneumococcal disease were markedly lower than normal during the 2020/2021 winter in the Northern Hemisphere, the first year after the start of the COVID-19 pandemic. However, little is known about rates of carriage of pneumococcus among adults during this period. Between October 2020-August 2021, couples in the Greater New Haven Area, USA, were enrolled if both individuals were aged 60 years and above and did not have any individuals under the age of 60 years living in the household. Saliva samples and questionnaires regarding social activities and contacts and medical history were obtained every 2 weeks for a period of 10 weeks. Following culture-enrichment, extracted DNA was tested using qPCR for pneumococcus-specific sequences piaB and lytA. Individuals were considered positive for pneumococcal carriage when Ct values for piaB were ≤40. Results. We collected 567 saliva samples from 95 individuals (47 household pairs and 1 singleton). Of those, 7.1% of samples tested positive for pneumococcus, representing 22/95 (23.2%) individuals and 16/48 (33.3%) households. Study participants attended few social events during this period. However, many participants continued to have regular contact with children. Individuals who had regular contact with preschool and school-aged children (i.e., 2 to 9 year olds) had a higher prevalence of carriage (15.9% versus 5.4%). Despite COVID-19-related disruptions, a large proportion of older adults continued to carry pneumococcus. Prevalence was particularly high among those who had contact with school-aged children, but carriage was not limited to this group. IMPORTANCE Carriage of Streptococcus pneumoniae (pneumococcus) in the upper respiratory tract is considered a prerequisite to invasive pneumococcal disease. During the first year of the COVID-19 pandemic, markedly lower rates of invasive pneumococcal disease were reported worldwide. Despite this, by testing saliva samples with PCR, we found that older adults continued to carry pneumococcus at pre-pandemic levels. Importantly, this study was conducted during a period when transmission mitigation measures related to the COVID-19 pandemic were in place. However, our observations are in line with reports from Israel and Belgium where carriage was also found to persist in children. In line with this, we observed that carriage prevalence was particularly high among the older adults in our study who maintained contact with school-aged children.

Changes in the Incidence of Invasive Pneumococcal Disease in Calgary, Canada, during the SARS-CoV-2 Pandemic 2020-2022

We describe the impact of non-pharmaceutical interventions (NPIs) during the COVID-19 pandemic on invasive pneumococcal disease (IPD) in Calgary. IPD declined significantly worldwide during 2020 and 2021. This may be due to the reduced transmission of and decrease in circulating viruses that often co-infect with the opportunistic pneumococcus. Pneumococcus has not been shown to frequently co-infect or cause secondary infection with SARS-CoV-2. We examined and compared incidence rates in Calgary per quarter in the pre-vaccine, post-vaccine, 2020 and 2021 (pandemic) and 2022 (late pandemic) eras. We also conducted a time series analysis from 2000-2022 allowing for change in trend at introduction of vaccines and for initiation of NPIs during the COVID-19 pandemic. Incidence declined in 2020/2021 but by the end of 2022 had begun to rapidly recover to near pre-vaccine rates. This recovery may be related to the high rates of viral activity in the winter of 2022 along with childhood vaccines being delayed during the pandemic. However, a large proportion of the IPD caused in the last quarter of 2022 was serotype 4, which has caused outbreaks in the homeless population of Calgary in the past. Further surveillance will be important to understand IPD incidence trends in the post-pandemic landscape.

The effects of the COVID-19 pandemic on community respiratory virus activity

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused substantial global morbidity and deaths, leading governments to turn to non-pharmaceutical interventions to slow down the spread of infection and lessen the burden on health care systems. These policies have evolved over the course of the COVID-19 pandemic, including after the availability of COVID-19 vaccines, with regional and country-level differences in their ongoing use. The COVID-19 pandemic has been associated with changes in respiratory virus infections worldwide, which have differed between virus types. Reductions in respiratory virus infections, including by influenza virus and respiratory syncytial virus, were most notable at the onset of the COVID-19 pandemic and continued in varying degrees through subsequent waves of SARS-CoV-2 infections. The decreases in community infection burden have resulted in reduced hospitalizations and deaths associated with non-SARS-CoV-2 respiratory infections. Respiratory virus evolution relies on the maintaining of a diverse genetic pool, but evidence of genetic bottlenecking brought on by case reduction during the COVID-19 pandemic has resulted in reduced genetic diversity of some respiratory viruses, including influenza virus. By describing the differences in these changes between viral species across different geographies over the course of the COVID-19 pandemic, we may better understand the complex factors involved in community co-circulation of respiratory viruses.

First and second wave dynamics of emergency department utilization during the COVID-19 pandemic: A retrospective study in 3 hospitals in The Netherlands

OBJECTIVE

During certain phases of the COVID-19 pandemic, a decrease was observed in emergency department (ED) utilization. Although this phenomenon has been thoroughly characterized for the first wave (FW), second wave (SW) studies are limited. We examined the changes in ED utilization between the FW and SW, compared to 2019 reference periods.

STUDY DESIGN AND METHODS

We performed a retrospective analysis of ED utilization in 3 Dutch hospitals in 2020. The FW and SW (March-June and September-December, respectively) were compared to the reference periods in 2019. ED visits were labeled as (non-)COVID-suspected.

RESULTS

During the FW and SW ED visits decreased by 20.3% and 15.3%, respectively, when compared to reference periods in 2019. During both waves high urgency visits significantly increased with 3.1% and 2.1%, and admission rates (ARs) increased with 5.0% and 10.4%. Trauma related visits decreased by 5.2% and 3.4%. During the SW we observed less COVID-related visits compared to the FW (4,407 vs 3,102 patients). COVID-related visits were significantly more often in higher need of urgent care and ARs were at least 24.0% higher compared to non-COVID visits.

CONCLUSION

During both COVID-19 waves, ED visits were significantly reduced. ED patients were more often triaged as high urgent, the ED length of stay was longer and ARs were increased compared to the reference period in 2019, reflecting a high burden on ED resources. During the FW, the reduction in ED visits was most pronounced. Here, ARs were also higher and patient were more often triaged as high urgency. These findings stress the need to gain better insight into the motives of patients to delay or avoid emergency care during pandemics, as well as to better prepare EDs for future outbreaks.

Detection of pneumococcus during hospitalization for SARS-CoV-2

Background

Infections with respiratory viruses [e.g. influenza and respiratory syncytial virus (RSV)] can increase the risk of severe pneumococcal infections. Likewise, pneumococcal coinfection is associated with poorer outcomes in viral respiratory infection. However, there are limited data describing the frequency of pneumococcus and SARS-CoV-2 coinfection and the role of coinfection in influencing COVID-19 severity. We, therefore, investigated the detection of pneumococcus in COVID-19 inpatients during the early pandemic period.

Methods

The study included patients aged 18 years and older, admitted to the Yale-New Haven Hospital who were symptomatic for respiratory infection and tested positive for SARS-CoV-2 during March-August 2020. Patients were tested for pneumococcus through culture-enrichment of saliva followed by RT-qPCR (to identify carriage) and serotype-specific urine antigen detection (UAD) assays (to identify presumed lower respiratory tract pneumococcal disease).

Results

Among 148 subjects, the median age was 65 years; 54.7% were male; 50.7% had an ICU stay; 64.9% received antibiotics; and 14.9% died while admitted. Pneumococcal carriage was detected in 3/96 (3.1%) individuals tested by saliva RT-qPCR. Additionally, pneumococcus was detected in 14/127 (11.0%) individuals tested by UAD, and more commonly in severe than moderate COVID-19 [OR: 2.20; 95% CI: (0.72, 7.48)]; however, the numbers were small with a high degree of uncertainty. None of the UAD-positive individuals died.

Conclusions

Pneumococcal lower respiratory tract infection (LRTI), as detected by positive UAD, occurred in patients hospitalized with COVID-19. Moreover, pneumococcal LRTI was more common in those with more serious COVID-19 outcomes. Future studies should assess how pneumococcus and SARS-CoV-2 interact to influence COVID-19 severity in hospitalized patients.

A Pandemic Lesson for Global Lung Diseases: Exacerbations Are Preventable

A dramatic global reduction in the incidence of common seasonal respiratory viral infections has resulted from measures to limit the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the pandemic. This has been accompanied by falls reaching 50% internationally in the incidence of acute exacerbations of preexisting chronic respiratory diseases that include asthma, chronic obstructive pulmonary disease, and cystic fibrosis. At the same time, the incidence of acute bacterial pneumonia and sepsis has fallen steeply worldwide. Such findings demonstrate the profound impact of common respiratory viruses on the course of these global illnesses. Reduced transmission of common respiratory bacterial pathogens and their interactions with viruses appear also as central factors. This review summarizes pandemic changes in exacerbation rates of asthma, chronic obstructive pulmonary disease, cystic fibrosis, and pneumonia. We draw attention to the substantial body of knowledge about respiratory virus infections in these conditions, and that it has not yet translated into clinical practice. Now that the large scale of benefits that could be gained by managing these pathogens is unmistakable, we suggest that the field merits substantial academic and industrial investment. We consider how pandemic-inspired measures for prevention and treatment of common infections should become a cornerstone for managing respiratory diseases.

Pathogen- and Type-Specific Changes in Invasive Bacterial Disease Epidemiology during the First Year of the COVID-19 Pandemic in The Netherlands

COVID-19 control measures have resulted in a decline in invasive bacterial disease caused by Neisseria meningitidis (IMD), Streptococcus pneumoniae (IPD), and Haemophilus influenzae (Hi-D). These species comprise different serogroups and serotypes that impact transmissibility and virulence. We evaluated type- and pathogen-specific changes in invasive bacterial disease epidemiology in the Netherlands during the first year of the SARS-CoV-2 pandemic. Cases were based on nationwide surveillance for five bacterial species with either respiratory (IMD, IPD, Hi-D) or non-respiratory (controls) transmission routes and were compared from the pre-COVID period (April 2015−March 2020) to the first COVID-19 year (April 2020−March 2021). IMD, IPD, and Hi-D cases decreased by 78%, 67%, and 35%, respectively, in the first COVID-19 year compared to the pre-COVID period, although effects differed per age group. Serogroup B-IMD declined by 61%, while serogroup W and Y-IMD decreased >90%. IPD caused by serotypes 7F, 15A, 12F, 33F, and 8 showed the most pronounced decline (≥76%). In contrast to an overall decrease in Hi-D cases, vaccine-preventable serotype b (Hib) increased by 51%. COVID-19 control measures had pathogen- and type-specific effects related to invasive infections. Continued surveillance is critical to monitor potential rebound effects once restriction measures are lifted and transmission is resumed.

Increase in invasive disease caused by Haemophilus influenzae b, the Netherlands, 2020 to 2021

The incidence of most respiratory-transmitted diseases decreased during the COVID-19 pandemic as a result of containment measures. In contrast, in the Netherlands we noted an increase in invasive disease caused by Haemophilus influenzae b (Hib) (from < 0.3/100,000 before 2019 to 0.39 and 0.33/100,000 in 2020 and 2021) in vaccinated and unvaccinated age groups. We did not find a change in vaccine effectiveness against Hib invasive disease (effectiveness > 90%). We discuss factors that may have contributed to this rise.