Chapter 2The Pre-Travel ConsultationSelf-Treatable Conditions
Respiratory infection is a leading cause of seeking medical care in returning travelers and has been reported to occur in up to 20% of all travelers. Thus, respiratory infections may be almost as common as travelers’ diarrhea. Upper respiratory infection is more common than lower respiratory infection. In general, the types of respiratory infections that affect travelers are similar to those in nontravelers, and exotic causes are rare.
Viral pathogens are the most common cause of respiratory infection in travelers; causative agents include coronavirus, adenovirus, rhinovirus, influenza virus, parainfluenza virus, human metapneumovirus, and respiratory syncytial virus. Bacterial pathogens are less common but include Streptococcus pneumoniae, Mycoplasma pneumoniae, Haemophilus influenzae, Chlamydophila pneumoniae, and Legionella species. Viral pathogens may set the stage for subsequent bacterial sinusitis or bronchitis.
RISK FOR TRAVELERS
Outbreaks are usually associated with common exposure in hotels and cruise ships or among tour groups. A few pathogens have been associated with outbreaks in travelers, including influenza virus, L. pneumophila, severe acute respiratory syndrome (SARS) coronavirus, and Histoplasma capsulatum. The peak influenza season in the temperate Northern Hemisphere is December through February. In the temperate Southern Hemisphere, the peak influenza season is June through August. Travelers to tropical zones are at risk all year. Exposure to an infected person from another hemisphere, such as on a cruise ship or package tour, can lead to an outbreak of influenza at any time or place.
Air-pressure changes during ascent and descent of aircraft can facilitate the development of sinusitis and otitis media. Intermingling of large numbers of people in airports, travel hubs, transport vehicles, cruise ships, and hotels can also facilitate transmission. Direct airborne transmission aboard aircraft is unusual because of frequent air recirculation and filtration, although sporadic cases of SARS, influenza, tuberculosis, and other diseases have occurred in modern aircraft. Transmission of infection may occur between passengers who are seated near one another, usually through direct contact or droplets.
The air quality at many travel destinations may not be optimal, and exposure to sulfur dioxide, nitrogen dioxide, carbon monoxide, ozone, and particulate matter is associated with a number of health risks, including respiratory tract inflammation, exacerbations of asthma and chronic obstructive pulmonary disease, impaired lung function, bronchitis, and pneumonia. Certain travelers have a higher risk for respiratory tract infection, including children, the elderly, and people with comorbid pulmonary conditions, such as asthma and chronic obstructive pulmonary disease (COPD).
The risk for tuberculosis among travelers is low (see Chapter 3, Tuberculosis).
Identifying a specific etiologic agent, especially in the absence of pneumonia, is often difficult and not clinically necessary. If indicated, the following methods of diagnosis can be used:
- Molecular methods are available to diagnose a number of respiratory viruses, including influenza virus, parainfluenza virus, adenovirus, human metapneumovirus, and respiratory syncytial virus, and for certain nonviral pathogens, such as L. pneumophila.
- Rapid tests are also available to detect group A streptococcal pharyngitis.
- Microbiologic culturing of sputum and blood, although insensitive, can help identify a causative respiratory pathogen in people with pneumonia.
Most respiratory tract infections, especially those of the upper respiratory tract, are mild and not incapacitating. Lower respiratory tract infections, particularly pneumonia, can be more severe. People with influenza commonly have acute onset of fever, myalgia, headache, and cough. Travelers with a viral upper respiratory infection may have persistent symptoms and should consider the possibility of subsequent bacterial sinusitis or bronchitis with symptoms that worsen after 1 week.
Affected travelers 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. Most respiratory infections in travelers are due to viruses, are mild, and do not require specific treatment or antibiotics. No systematic study of travelers with respiratory infections who self-treat has been reported. Self-treatment with antibiotics during travel can be considered for upper respiratory infections that worsen after 7 days of symptoms, particularly if specific symptoms of sinusitis or bronchitis are present. A respiratory-spectrum fluoroquinolone such as levofloxacin or a macrolide such as azithromycin may be prescribed to the traveler for this purpose before travel.
The rate of influenza among travelers is not known. The difficulty in self-diagnosing influenza makes it problematic to decide whether to provide travelers with a self-treatment dose of a neuraminidase inhibitor. This practice should probably be limited to travelers with a specific underlying condition that may predispose them to severe influenza.
Specific situations that may require medical intervention include the following:
- Pharyngitis without rhinorrhea, cough, or other symptoms that may indicate infection with group A streptococcus.
- Sudden onset of cough, chest pain, and fever that may indicate pneumonia, resulting in a situation where the traveler may be sick enough to seek medical care right away.
- Travelers with underlying medical conditions, such as asthma, pulmonary disease, or heart disease, who may need to seek medical care earlier than otherwise healthy travelers.
PREVENTIVE MEASURES FOR TRAVELERS
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. 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 cleaners (containing at least 60% alcohol).
- Using a vasoconstricting nasal spray immediately before air travel, if the traveler has a preexisting eustachian tube dysfunction.
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