Respiratory illness refers to any acute illness that affects the respiratory system such as the common cold, flu or influenza, to more serious illnesses such as SARS, MERS, or the 2019/2020 Coronavirus outbreak in Wuhan, China.
Respiratory illness or infection can be upper respiratory or lower respiratory depending on which part of the respiratory system the illness or infection affects.
Upper respiratory infection is more common than lower respiratory infection.
[Viral pathogens are the most common cause of respiratory infection in travelers; causative agents include rhinoviruses, respiratory syncytial virus, influenza virus, parainfluenza virus, human metapneumovirus, measles, mumps, adenovirus, and coronaviruses.
Bacterial pathogens are less common than viral but can include Streptococcus pneumoniae, Mycoplasma pneumoniae, Haemophilus influenzae, and Chlamydophila pneumoniae. Coxiella burnetii and Legionella pneumophila can cause outbreaks and sporadic cases of respiratory illness. Bacterial sinusitis, bronchitis, or pneumonia may also occur secondarily after a viral respiratory infection.
Outbreaks may occur following common-source exposures in hotels, on cruise ships, or among tour groups. A few pathogens have been associated with outbreaks in travelers, including influenza virus, L. pneumophila, and Histoplasma capsulatum. The peak influenza season in the temperate Northern Hemisphere is December through February. In the temperate Southern Hemisphere, peak influenza season runs from June through August. There is no peak season for influenza in tropical climates; the risk of infection is present 12 months of the year. Exposure to an infected person traveling from another hemisphere, such as on a cruise ship or on a package tour, can lead to influenza outbreak at any time or place.
Most respiratory infections, especially those of the upper respiratory tract, are mild and not incapacitating. Upper respiratory tract infections often cause rhinorrhea or pharyngitis. Lower respiratory tract infections, particularly pneumonia, can be more severe. Lower respiratory tract infections are more likely than upper respiratory tract infections to cause fever, dyspnea, or chest pain. Cough is often present in either upper or lower respiratory tract infections. People with influenza commonly have acute onset of fever, myalgia, headache, and cough. Consider pulmonary embolism in the differential diagnosis of travelers who present with dyspnea, cough, or pleurisy and fever, especially those who have recently been on long car or plane rides (see Chapter 8, Deep Vein Thrombosis & Pulmonary Embolism).
Identifying a specific etiologic agent, especially in the absence of pneumonia or serious disease, is not always clinically necessary. If indicated, the following methods of diagnosis can be used:
- Molecular methods are available to detect a number of respiratory viruses, including influenza virus, parainfluenza virus, adenovirus, human metapneumovirus, and respiratory syncytial virus, and for certain nonviral pathogens.
- Rapid tests are also available to detect some pathogens such as respiratory syncytial virus, influenza virus, L. pneumophila, Histoplasma capsulatum, and group A Streptococcus.
- Microbiologic culturing of sputum and blood, although insensitive, can help identify a causative respiratory pathogen.
- Special consideration should be given to diagnosing patients with suspected MERS (www.cdc.gov/coronavirus/mers/interim-guidance.html) or avian influenza (www.cdc.gov/flu/avianflu/healthprofessionals.htm).
Travelers with respiratory infections are usually managed similarly to nontravelers, although travelers with progressive or severe illness should be evaluated for illnesses specific to their travel destinations and exposure history.
Vaccines are available to prevent a number of respiratory diseases, including influenza, S. pneumoniae infection, H. influenzae type B infection (in young children), pertussis, diphtheria, varicella, and measles. Unless contraindicated, travelers should be vaccinated against influenza and be up-to-date on other routine immunizations. Preventing respiratory illness while traveling may not be possible, but common-sense preventive measures include the following:
- Minimizing close contact with people who are coughing and sneezing
- Frequent handwashing, either with soap and water or alcohol-based hand sanitizers (containing ≥60% alcohol) when soap and water are not available
- Using a vasoconstricting nasal spray immediately before air travel if the traveler has a preexisting eustachian tube dysfunction, which may help lessen the likelihood of otitis or barotrauma
Appropriate infection control measures should be u