Border Infectious Disease Surveillance - Influenza
and Other Respiratory Infections
Viral and bacterial respiratory
infections are a major cause of morbidity and mortality worldwide. In the US, influenza
and other respiratory viral
to more than 400,000 hospitalizations in individuals younger than 18 years of
age every year. International organizations such as the World Health
Organization and the Pan-American
Health Organization recognize the
importance that surveillance of influenza-like illness (ILI) and severe acute
respiratory infection (SARI) play in protecting the public from epidemics and
pandemics of influenza and other respiratory infections. After the 2009
influenza pandemic, US-Mexico surveillance systems were designed to monitor the
burden of respiratory infections in the highly mobile communities that live,
play, and work in the Southern border of the US.
Severe Acute Respiratory Infection
Since 2009, the Imperial County Public
Health Department has conducted year-round enhanced surveillance of SARI at two
acute-care hospitals: El Centro Regional Medical Center and Pioneers Memorial
Hospital. Recently, a hospital in Mexicali, Baja
California has been added as a sentinel site for SARI. Specimens collected at
these sites are tested for viral and
bacterial respiratory pathogens at the Naval Health Research Center (NHRC) laboratory
in San Diego, CA.
For the 2016-17 influenza season, 332
samples were collected and tested from SARI patients. Information collected about the
respiratory pathogens circulating in Imperial County through SARI surveillance
helps public health officials understand the burden of disease in the area, and
can be helpful in designing prevention and intervention methods.
Influenza-Like Illness (ILI)
are defined as those
that present with fever ≥
100°F, and either sore throat or cough; or any cause of pneumonia. BIDS enrolls ILI patients at the community
clinic San Ysidro Health near the Tijuana border. Nasopharyngeal swabs are collected for influenza rapid tests and further tested for molecular
identification of respiratory pathogens.
For the 2015-16 and 2016-17 influenza
seasons, 361 ILI samples were processed by BIDS. The information collected from
test results and case report forms filled out can help inform public health
campaigns, alert of outbreaks, and report the tendencies of disease spread on
the US-Mexico border region.