The impact of the SARS-CoV-2 pandemic on global influenza surveillance: Insights from 18 National Influenza Centers based on a survey conducted between November 2021 and March 2022.

Background: National Influenza Centers (NICs) have played a crucial role in the surveillance of SARS-CoV-2. The FluCov project, covering 22 countries, was initiated to monitor the impact of the SARS-CoV-2 pandemic on influenza activity. Methods: This project consisted of an epidemiological bulletin and NIC survey. The survey, designed to assess the impact of the pandemic on the influenza surveillance system, was shared with 36 NICs located across 22 countries. NICs were invited to reply between November 2021 and March 2022. Results: We received 18 responses from NICs in 14 countries. Most NICs (76%) indicated that the number of samples tested for influenza decreased. Yet, many NICs (60%) were able to increase their laboratory testing capacity and the "robustness" (e.g., number of sentinel sites) (59%) of their surveillance systems. In addition, sample sources (e.g., hospital or outpatient setting) shifted. All NICs reported a higher burden of work following the onset of the pandemic, with some NICs hiring additional staff or partial outsourcing to other institutes or departments. Many NICs anticipate the future integration of SARS-CoV-2 surveillance into the existing respiratory surveillance system. Discussion: The survey shows the profound impact of SARS-CoV-2 on national influenza surveillance in the first 27 months of the pandemic. Surveillance activities were temporarily disrupted, whilst priority was given to SARS-CoV-2. However, most NICs have shown rapid adaptive capacity underlining the importance of strong national influenza surveillance systems. These developments have the potential to benefit global respiratory surveillance in the years to come; however, questions about sustainability remain.

Hospital admissions with influenza and impact of age and comorbidities on severe clinical outcomes in Brazil and Mexico.

BACKGROUND: The risk of hospitalization or death after influenza infection is higher at the extremes of age and in individuals with comorbidities. We estimated the number of hospitalizations with influenza and characterized the cumulative risk of comorbidities and age on severe outcomes in Mexico and Brazil. METHODS: We used national hospital discharge data from Brazil (SIH/SUS) from 2010-2018 and Mexico (SAEH) from 2010-2017 to estimate the number of influenza admissions using ICD-10 discharge codes, stratified by age (0-4, 5-17, 18-49, 50-64, and ≥65 years). Duration of hospital stay, admission to the intensive care unit (ICU), and in-hospital case fatality rates (CFRs) defined the severe outcomes. Rates were compared between patients with or without pre-specified comorbidities and by age. RESULTS: A total of 327,572 admissions with influenza were recorded in Brazil and 20,613 in Mexico, with peaks period most years. In Brazil, the median hospital stay duration was 3.0 days (interquartile range, 2.0-5.0), ICU admission rate was 3.3% (95% CI, 3.2-3.3%), and in-hospital CFR was 4.6% (95% CI, 4.5-4.7). In Mexico, the median duration of stay was 5.0 days (interquartile range, 3.0-7.0), ICU admission rate was 1.8% (95% CI, 1.6-2.0%), and in-hospital CFR was 6.9% (95% CI, 6.5-7.2). In Brazil, ICU admission and in-hospital CFR were higher in adults aged ≥50 years and increased in the presence of comorbidities, especially cardiovascular disease. In Mexico, comorbidities increased the risk of ICU admission by 1.9 (95% CI, 1.0-3.5) and in-hospital CFR by 13.9 (95% CI, 8.4-22.9) in children 0-4 years. CONCLUSION: The SIH/SUS and SAEH databases can be used to estimate hospital admissions with influenza, and the disease severity. Age and comorbidities, especially cardiovascular disease, are cumulatively associated with more severe outcomes, with differences between countries. This association should be further analyzed in prospective surveillance studies designed to support influenza vaccination strategy decisions.

Vaccine complacency and dose distribution inequities limit the benefits of seasonal influenza vaccination, despite a positive trend in use.

Sustainable demand for seasonal influenza vaccines is a component of national security strategies for pandemic preparedness. However, the ongoing COVID-19 pandemic has revealed many weaknesses in the capacity of countries to design and execute sustainable vaccination programs. An influenza pandemic remains a global threat and yet there is no global monitoring system for assessing progress towards influenza vaccination coverage targets. The International Federation of Pharmaceutical Manufacturers and Associations' (IFPMA) Influenza Vaccine Supply International Task Force (IVS) developed a survey method in 2008 to estimate seasonal influenza vaccination coverage rates, which in turn serves as a crude estimate of pandemic preparedness. It provides evidence to guide expanded efforts for pandemic preparedness, specifically for increasing COVID-19 vaccine immunization levels. Furthermore, the results presented herein serve as a proxy for assessing the state of pandemic preparedness at a global and regional level. This paper adds data from 2018 and 2019 to the previous analyses. The current data show an upward or stable global trend in seasonal influenza vaccine dose distributed per 1,000 population with a 7% increase between 2017 and 2018 and 6% increase between 2018 and 2019. However, considerable regional inequities in access to vaccine persist. Three regions, Africa, the Middle-east, and Southeast Asia together account for 50% of the global population but only 6% of distributed seasonal influenza vaccine doses. This is an important finding in the context of the ongoing COVID-19 pandemic, as distribution of influenza vaccine doses in many ways reflects access to COVID-19 vaccines. Moreover, improving seasonal vaccine uptake rates is critical for optimizing the annual benefits by reducing the huge annual influenza-associated societal burdens and by providing protection to vulnerable individuals against serious complications from seasonal influenza infections.

Influenza vaccination situation in Middle-East and North Africa countries: Report of the 7th MENA Influenza Stakeholders Network (MENA-ISN).

BACKGROUND: The Middle East and North Africa (MENA) region faces a dual challenge with regard to influenza infection due to severe zoonotic influenza outbreaks episodes and the circulation of Northern Hemisphere human influenza viruses among pilgrims. METHODS: The MENA Influenza Stakeholder Network (MENA-ISN) was set-up with the aim of increasing seasonal influenza vaccination coverage by (i) enhancing evidence-based exchanges, and (ii) increasing awareness on the safety and benefits of seasonal vaccination. During the 7th MENA-ISN meeting, representatives from 8 countries presented their influenza surveillance, vaccination coverage and actions achieved and provided a list of country objectives for the upcoming 3 years. RESULTS: MENA-ISN countries share the goal to reduce influenza related morbidity and mortality. Participants admitted that lack of knowledge about influenza, its consequences in terms of morbidity, mortality and economy are the major barrier to attaining higher influenza vaccination coverage in their countries. The cost of the vaccine is another key barrier that could contribute to low vaccination coverage. Participants drew a list of strategic interventions to bridge gaps in the knowledge of influenza burden in this region. CONCLUSIONS: Participating countries concluded that despite an increase in vaccine uptake observed during the last few years, influenza vaccination coverage remains relatively low. Priority areas should be identified and action plans tailored to each country situation set-up to investigate the best way to move forward.

[Mortality related factors in patients requiring hospitalization for influenza like illness]. / Influenza benzeri hastalik nedeniyle hastaneye yatis gerektiren hastalarda mortaliteyle iliskili faktörler.

The knowledge about the viral etiologies causing respiratory disease in adults is limited. Viral respiratory diseases may lead deterioration in certain patient populations. The aim of this study was to determine the viral etiologies of influenza-like illness among patients requiring hospitalization and to document the risk factors for mortality. This prospective study was performed in one of the 7 centers in Turkey in the context of influenza surveillance by the Global Influenza Hospital Surveillance Network. A 35-bed Adult Emergency Service and 10-bed Acute Care Unit were screened for consequent recruitment of eligible patients daily, on weekdays only. ICD-10 codes in the electronic health records and direct patient encounters were used to screen for the following eligibility diagnoses: acute respiratory tract infection, asthma, heart failure, pneumonia, influenza, chronic obstructive lung disease, dyspnea/respiratory abnormality, respiratory symptoms, cough and fever. A total of 334 patients who were admitted with the eligible ICD-10 codes within the 24th and 48th hours were screened during the study period and of those eligible ones, 106 consented and were swabbed. Nasal or nasopharyngeal swabs were collected using Virocult (Medical Wire & Equipment, UK) and sent to the central laboratory in 1-3 days. Swabs were collected and specimens were introduced to real-time polymerase chain reaction based multiplex kits, as well as, ABI 7500 platform with CDC primers and probes. A total of 106 patients were swabbed. Hospital mortality was 12.2%. More than one fourth of the patients needed a sort of mechanical ventilation support and at least one organ failure developed in one third of the patients. One or more viral pathogens were detected in 56 (52.8%) of the swabbed patients, with influenza H3N2 being the most prevalent one. Having a lower body mass index (OR, 0.845, p= 0.034) was associated with mortality. Chronic lung diseases were shown to confer a survival advantage (OR, 0.127, p= 0.009). Community acquired viral respiratory infections might lead to significant compromise in adult patients. Prevention of malnutrition might result in better outcomes in patients who need acute admission. The survival advantage of those with chronic lung diseases warrants further investigation.