Impact of Rapid Molecular Detection of Respiratory Viruses on Clinical Outcomes and Patient Management

Trends of respiratory viruses and factors associated with severe acute respiratory infection in patients presenting at a university hospital: a 6-year retrospective study across the COVID-19 pandemic

Background

The COVID-19 pandemic significantly disrupted the epidemiology of respiratory viruses, altering seasonal patterns and reducing circulation. While recovery trends have been observed, factors associated with severe acute respiratory infections (SARIs) during pre- and post-pandemic periods remain underexplored in middle-income countries.

Objective

This study aimed to analyze the trends in respiratory virus circulation and identify factors associated with SARI in patients attending a tertiary care university hospital in western Mexico over a six-year period spanning the pre-pandemic, pandemic, and post-pandemic phases.

Methods

A retrospective study was conducted using data from 19,088 symptomatic patients tested for respiratory viruses between 2018 and 2024. Viral trends were analyzed through interrupted time series (ITS) modeling, incorporating locally estimated scatterplot smoothing (LOESS) and raw positivity rates. Additionally, ITS analysis was performed to evaluate temporal changes in SARI proportions across different phases of the pandemic. Multivariate logistic regression models were applied to determine independent risk factors for SARI across different time periods.

Results

During the pandemic (2020-2021), respiratory virus positivity rates significantly declined, particularly for influenza, which experienced a sharp reduction but rebounded post-2022. Respiratory syncytial virus (RSV) demonstrated a delayed resurgence, whereas other respiratory viruses exhibited heterogeneous rebound patterns. ITS modeling of SARI proportions revealed a significant pre-pandemic increasing trend, followed by a slower rise during the pandemic, and a sharp post-pandemic drop in early 2022, before resuming an upward trajectory. Among older adults (>65 years), a marked increase in SARI was observed at the beginning of the pandemic, while younger groups showed more stable patterns. Logistic regression identified advanced age, male sex, cardiovascular disease, obesity, and immunosuppression as major risk factors for SARI, while vaccination consistently showed a protective effect across all periods and subgroups.

Conclusion

The COVID-19 pandemic induced persistent shifts in respiratory virus circulation, disrupting seasonal dynamics and modifying the burden of SARI. The findings underscore the importance of continuous surveillance, targeted vaccination programs, and early diagnostics to mitigate severe outcomes. These results highlight the need for adaptive public health strategies in middle-income countries to address evolving respiratory disease threats.

Impact of molecular diagnostic techniques on the acute respiratory infection sentinel surveillance program, Antioquia, Colombia, 2022

Objectives

Surveillance of acute respiratory infection (ARI) informs vaccination, preventive, and management decisions. In many countries, immunofluorescence is the cornerstone for ARI surveillance. We aimed to determine the effect of adding multiplex polymerase chain reaction (mPCR) to conventional surveillance in ARI.

Methods

Respiratory samples from patients with influenza-like illness (ILI) and severe acute respiratory infection (SARI) were tested by a conventional approach [direct immunofluorescence (DIF) and SARS-CoV-2 PCR, and a subset of samples underwent routine testing]. Negative specimens were tested by multiplex PCR (mPCR), and remain negative samples were sequenced. Descriptive, multivariable regression analyses were conducted.

Results

Between March and June 2022, 299 patients were enrolled. Pathogens were detected in 43.8% of samples (131/299) tested by the conventional approach. Of the 168 negatives after the conventional approach, 157 (93.4%) were positive by mPCR, increasing the detection rate to 96.3% (288/299). With the conventional approach, the most frequent pathogen was respiratory syncytial virus (50.3%, 66/131), whereas with mPCR it was Haemophilus influenzae (37.5%, 63/168). mPCR significantly improved pathogen detection in ARI surveillance (Adjusted Incidence Rate Ratios 4.22 95% IC 4.22-5.85).

Conclusion

Adding mPCR to respiratory surveillance conventionally based on DIF significantly enhanced virus and bacteria detection. mPCR should be considered for routine ARI surveillance.

Management of pneumonia in critically ill patients

Severe pneumonia is associated with high mortality (short and long term), as well as pulmonary and extrapulmonary complications. Appropriate diagnosis and early initiation of adequate antimicrobial treatment for severe pneumonia are crucial in improving survival among critically ill patients. Identifying the underlying causative pathogen is also critical for antimicrobial stewardship. However, establishing an etiological diagnosis is challenging in most patients, especially in those with chronic underlying disease; those who received previous antibiotic treatment; and those treated with mechanical ventilation. Furthermore, as antimicrobial therapy must be empiric, national and international guidelines recommend initial antimicrobial treatment according to the location's epidemiology; for patients admitted to the intensive care unit, specific recommendations on disease management are available. Adherence to pneumonia guidelines is associated with better outcomes in severe pneumonia. Yet, the continuing and necessary research on severe pneumonia is expansive, inviting different perspectives on host immunological responses, assessment of illness severity, microbial causes, risk factors for multidrug resistant pathogens, diagnostic tests, and therapeutic options.

Missed opportunities to use rapid influenza testing and severity assessment to avoid hospital admission: A cohort study from an East London District General Hospital

Annual outbreaks of seasonal influenza cause a substantial health burden. The aim of this study was to compare patient demographic/clinical data in two influenza patient groups presenting to hospital; those requiring O2 or critical care admission and those requiring less intensive treatment. The study was conducted from 1 December 2017 until 1 April 2019 at a district general hospital in East London. Patient demographic and clinical information was collected for all patients who had tested influenza positive by near-patient testing. χ2 test was used for categorical variables to see if there were significant differences for those admitted and the Wilcoxon rank-sum test to compare the length of inpatient stay. Of 127 patients, 56 (44.1%) required oxygen or critical care. There were significant increases in National Early Warning Score (NEWS) observations (P %3C .001), Charlson comorbidity index (P = .049), length of inpatient stay (P %3C .001), and a strong association with increasing age (P = .066) when the more intensive treatment group was compared with the less intensive treatment group. A total of 13 (18.3%) of 71 patients not requiring oxygen or critical care were not admitted to the hospital. Following rapid influenza testing, NEWS scores, comorbidities, and age should be incorporated into a decision tool in Accident and Emergency to aid hospital admission or discharge decisions.

SAA and CRP are potential indicators in distinction and severity assessment for children with influenza

PURPOSE

The clinical values of C-reactive protein (CRP) and serum amyloid A (SAA) to distinguish non-severe from severe influenza in children are rarely reported.

METHODS

Baseline characteristics and laboratory results were collected and analyzed. Receiver operating characteristic (ROC) curve analysis was used for combined detection of indicators for children with influenza, and scatter-dot plots were used to compare the differences between non-severe and severe influenza.

RESULTS

Children with influenza B had more bronchitis and pneumonia (P < 0.05) and children with influenza A had more other serious symptoms (P = 0.015). Lymphocyte count, neutrophil count, neutrophil-to-lymphocyte ratio (NLR), CRP, and SAA performed differently among children with influenza A and B. Joint detection of SAA and other indicators could better separate healthy children from children with influenza than single indicator detection. The CRP and SAA levels of children with severe influenza B infection and SAA levels of children with severe influenza A infection were significantly elevated compared with children with non-severe influenza (P < 0.05).

CONCLUSIONS

SAA and CRP could be potential indicators in distinction and severity assessment for children with influenza; however, age should be taken into account when using them in children with influenza B.