Clinical aspects of influenza A(H1N1)pdm09 cases reported during the pandemic in Brazil, 2009-2010

Usefulness of linked data for infectious disease events: a systematic review

Surveillance is a key public health function to enable early detection of infectious disease events and inform public health action. Data linkage may improve the depth of data for response to infectious disease events. This study aimed to describe the uses of linked data for infectious disease events. A systematic review was conducted using Pubmed, CINAHL and Web of Science. Studies were included if they used data linkage for an acute infectious disease event (e.g. outbreak of disease). We summarised the event, study aims and designs; data sets; linkage methods; outcomes reported; and benefits and limitations. Fifty-four studies were included. Uses of linkage for infectious disease events included assessment of severity of disease and risk factors; improved case finding and contact tracing; and vaccine uptake, safety and effectiveness. The ability to conduct larger scale population level studies was identified as a benefit, in particular for rarer exposures, risk factors or outcomes. Limitations included timeliness, data quality and inability to collect additional variables. This review demonstrated multiple uses of data linkage for infectious disease events. As infectious disease events occur without warning, there is a need to establish pre-approved protocols and the infrastructure for data-linkage to enhance information available during an event.

Factors associated with death due to severe acute respiratory syndrome caused by influenza: Brazilian population study

Introduction

Influenza infection is characterized by acute viral infection of high transmissibility. Worsening of the case can lead to the need for hospitalization, severe acute respiratory syndrome (SARS) and even death.

Method

This is a cross-sectional population-based study that used secondary database from the Brazilian Influenza Epidemiological Surveillance Information System. Only cases of adults with diagnosis of influenza by RT-PCR and case evolution recorded were included.

Results

We identified 2,273 adults with SARS by influenza, 343 of which had death as an outcome. The main risk factors for death were lack of hospitalization, not having cough and age, both with p<0.001. In addition, without asthma, having black skin color, not receiving flu vaccine, having brown skin color and not having a sore throat (p≤ 0.005) were risk factors too.

Conclusion

Factors associated with death due to SARS caused by influenza in Brazil, risk factors and protective factors to death were identified. It was evident that those who did not receive the flu vaccine presented twice the risk of unfavorable outcome, reinforcing the need to stimulate adherence to vaccination adhering and propose changes in public policies to make influenza vaccines available to the entire population, in order to prevent severe cases and unfavorable outcomes.

Viral detection profile in children with severe acute respiratory infection

Objectives

The role of viral co-detection in children with severe acute respiratory infection is not clear. We described the viral detection profile and its association with clinical characteristics in children admitted to the Pediatric Intensive Care Unit (PICU) during the 2009 influenza A(H1N1) pandemic.

Method

Longitudinal observational retrospective study, with patients aged 0–18 years, admitted to 11 PICUs in Rio de Janeiro, with suspected H1N1 infection, from June to November, 2009. The results of respiratory samples which were sent to the Laboratory of Fiocruz/RJ and clinical data extracted from specific forms were analyzed.

Results

Of 71 samples, 38% tested positive for H1N1 virus. Of the 63 samples tested for other viruses, 58 were positive: influenza H1N1 (43.1% of positive samples), rhinovirus/enterovirus (41.4%), respiratory syncytial vírus (12.1%), human metapneumovirus (12.1%), adenovirus (6.9%), and bocavirus (3.5%). Viral codetection occured in 22.4% of the cases. H1N1-positive patients were of a higher median age, had higher frequency of fever, cough and tachypnea, and decreased leukometry when compared to H1N1-negative patients. There was no difference in relation to severity outcomes (number of organic dysfunctions, use of mechanical ventilation or amines, hospital/PICU length of stay or death). Comparing the groups with mono-detection and co-dection of any virus, no difference was found regarding the association with any clinical variable.

Conclusions

Other viruses can be implicated in SARI in children. The role of viral codetection has not yet been completely elucidated.

Laboratory-confirmed deaths caused by influenza A (H1N1)pdm09 in the Santa Catarina State, Brazil, 2009-2014

INTRODUCTION

Little information is available on the evolution of influenza A (H1N1)pdm09-related mortality in Brazil.

METHODS

During the period 2009-2014, official epidemiological surveillance and mortality data were used to ascertain influenza-related deaths in the Santa Catarina State in Brazil.

RESULTS

The highest overall mortality rate (2.3 per 100,000) was observed in 2009. Pregnant women constituted the highest risk group (mortality rate 18.0 per 100,000). Following vaccination of high-risk groups, the rate reduced sharply but peaked again in 2012. It subsequently decreased, albeit more gradually.

CONCLUSIONS

Influenza A (H1N1)pdm09 mortality demonstrated a cyclic pattern, with two peaks followed by a gradual decrease.