The flu is a far greater threat than anything carried by people crossing the southern border

The death on Christmas eve of a Guatemalan child housed in a border detention facility from influenza B underscores the danger that the flu can pose in certain situations, and raises important concerns about the threat of influenza at border facilities.

This 8-year old child was misdiagnosed with a common cold and was not even tested for influenza. He exhibited a 104-degree Fahrenheit fever that, while common with many childhood viral illnesses, is not usually the case with the common cold. In my opinion, this fever coupled with travel history and housing status should have prompted consideration of influenza given that the Northern Hemisphere is in the midst of flu season.

Currently, the United States is experiencing widespread flu activity in many states and more than a dozen pediatric deaths have occurred so far. Thankfully, early indicators suggest that this season will not be as severe as the last due to a vaccine well-matched to the dominant strain in most of the country. But we must continue to take the threat seriously.

Southern border states California, Arizona and New Mexico are all reporting widespread flu activity and as the season progresses to its traditional peak in February, we can expect most states to be experiencing widespread flu cases.

The border facilities themselves, as their population expands and changes, could represent a mechanism by which influenza could spread among those who are housed or work there. Any location that serves as an environment for extensive human interaction — whether a school, a camp, or a border facility — gives microbes, especially those that spread through the respiratory route, an opportunity to spread amongst the population. This was evident in the adenovirus outbreak at the University of Maryland, the low-vaccination status fueled chickenpox outbreak at a North Carolina school, and cruise ship related noro-virus outbreaks.

Another factor that plays a role in the risk of influenza in these facilities is the health status of those who are housed there. It is unclear what proportion are vaccinated against influenza, what their nutritional status is, and what their hydration status is. All these elements impact one’s resilience against the flu. It is also not well known how these facilities mitigate the threat of influenza: are vaccinations being administered, how are symptomatic individuals handled (isolation), what hygienic measures are in place, what is the availability of symptomatic relief medications such as ibuprofen and acetaminophen, and how easy is it see a health-care provider and be tested and treated for influenza?

The U.S. Customs and Border Patrol has been increasing medical screenings (which are now mandatory for children) and is being assisted by the U.S. Public Health Service and Coast Guard in the wake of increased numbers of individuals being housed. Diagnoses such as influenza, pneumonia, and gastrointestinal illnesses have been made and some migrants have been hospitalized.

The border facilities as locations of mass housing, just like a camp or school, will be important to survey for respiratory illnesses such as influenza and should be a place in which interventions such as vaccination are routinely performed.

Influenza will remain a threat to those in and at the border facilities throughout the flu season, but influenza emanating from these border facilities poses no substantial threat to the general public. The U.S. is already experiencing widespread flu activity and, as I have argued before, the disease threat from indigenous and ordinary travel-related infections is far greater than infections carried by people crossing the southern border.

Influenza is one of the most important infectious disease threats the we face, and vigilance against it in all settings is warranted.

Amesh Adalja, M.D., is a senior scholar at the Johns Hopkins Center for Health Security. Follow him on Twitter at @AmeshAA.