Surveillance for Severe Acute Respiratory Infections in Southern Arizona, 2010–2014

Zimy Wansaula; Sonja J. Olsen; Mariana G. Casal; Catherine Golenko; Laura M. Erhart; Peter Kammerer; Natalie Whitfield; Orion Z. McCotter


Influenza Resp Viruses. 2016;10(3):161-169. 

In This Article

Abstract and Introduction


Background The Binational Border Infectious Disease Surveillance program began surveillance for severe acute respiratory infections (SARI) on the US–Mexico border in 2009. Here, we describe patients in Southern Arizona.

Methods Patients admitted to five acute care hospitals that met the SARI case definition (temperature ≥37·8°C or reported fever or chills with history of cough, sore throat, or shortness of breath in a hospitalized person) were enrolled. Staff completed a standard form and collected a nasopharyngeal swab which was tested for selected respiratory viruses by reverse transcription polymerase chain reaction.

Results From October 2010–September 2014, we enrolled 332 SARI patients. Fifty-two percent were male and 48% were white non-Hispanic. The median age was 63 years (47% ≥65 years and 5·2% <5 years). During hospitalization, 51 of 230 (22%) patients required intubation, 120 of 297 (40%) were admitted to intensive care unit, and 28 of 278 (10%) died. Influenza vaccination was 56%. Of 309 cases tested, 49 (16%) were positive for influenza viruses, 25 (8·1%) for human metapneumovirus, 20 (6·5%) for parainfluenza viruses, 16 (5·2%) for coronavirus, 11 (3·6%) for respiratory syncytial virus, 10 (3·2%) for rhinovirus, 4 (1·3%) for rhinovirus/enterovirus, 3 (1·0%) for enteroviruses, and 3 (1·0%) for adenovirus. Among the 49 influenza-positive specimens, 76% were influenza A (19 H3N2, 17 H1N1pdm09, and 1 not subtyped), and 24% were influenza B.

Conclusion Influenza viruses were a frequent cause of SARI in hospitalized patients in Southern Arizona. Monitoring respiratory illness in border populations will help better understand the etiologies. Improving influenza vaccination coverage may help prevent some SARI cases.


The 2009 influenza pandemic highlighted the need for more global data on severe influenza disease, and the World Health Organization recommended Member States conduct surveillance for hospitalized severe acute respiratory infection (SARI) in addition to surveillance for influenza-like illness (ILI) in outpatients.[1] As a result, SARI surveillance is now conducted in many countries around the world; however, it is only conducted in limited settings in the United States. The pandemic also highlighted the importance of having surveillance on the US–Mexico border, as the first cases of influenza A(H1N1)pdm09 virus infection were detected in southern California.[2,3]

The Arizona Department of Health Services (ADHS) has conducted statewide influenza surveillance since 1997. Surveillance indicators include monitoring ILI among ambulatory patients, tracking laboratory-confirmed cases, monitoring ILI in schools, and testing and subtyping influenza viruses in specimens submitted to the Arizona State Public Health Laboratory. Laboratory-confirmed cases of respiratory syncytial virus (RSV) infections are also monitored. However, epidemiological data on influenza hospitalizations has been limited, and there is no established statewide surveillance for respiratory viral infections beyond influenza and RSV. In 2010, Arizona began conducting SARI surveillance as part of Centers for Disease Control and Prevention (CDC) Binational Border Infectious Disease Surveillance (BIDS) program with the aim of describing the patterns of disease in a highly fluid border region. Here, we report SARI surveillance data in Arizona from 2010 to 2014.