rifampin, any flouroquinolone, and at least one of the injectable second-line, anti-TB drugs (i.e.,
capreomycin, kanamycin, and amikacin). Some clues that the patient may harbor drug-
resistant TB include prior treatment of latent or active TB (51), exposure to a person with
known resistant TB, and possibly, travel abroad. XDR-TB has been identified in at least
41 countries (44), including the United States. Soberingly, an analysis of TB patients in
California from 1993–2006 revealed 424 were infected with MDR TB, 18 of whom were infected
with XDR-TB (52). Consultation with a specialist experienced in TB management is
recommended if the diagnosis of MDR or XDR-TB is suspected.
S. pneumoniaeis a common cause of life-threatening bacterial pneumonia worldwide, and
the commonest cause in the United States (43). The presence of known risk factors such as
chronic lung disease, HIV, and asplenia should increase the suspicion of pneumococcal
disease, but their absence does exclude the diagnosis since pneumococcal pneumonia is also
common in previously healthy people. Penicillin-resistantS. pneumoniae(PSRP) is increasingly
problematic worldwide with an overall prevalence in the United States of approximately 21%
(53). Treatment options of PRSP infections include a respiratory fluoroquinolone or an
advanced macrolide plus a beta-lactam antibiotic (such as cefotaxime, ceftriaxone, ampicillin-
sulbactam, or ertapenem). Vancomycin should also be considered for CNS involvement or
severe infections (54).
The CDC estimates that within the United States, 8000–18,000 persons are hospitalized
each year with Legionnaires disease, 20% of whom have recently traveled (55).L. pneumophila
has been documented as a cause of severe pneumonia among travelers using whirlpool spas
on cruise ships (56). In one outbreak involving 50 cruise ship passengers, the risk of acquiring
Legionnaire’s disease increased by 64% for every hour spent in the whirlpool (56). The
diagnosis ofL. pneumophilacan be difficult and respiratory specimens must be cultured
on selective media (57). Urine antigen testing can provide a more rapid diagnosis of
L. pneumophila serogroup 1 (which comprises 80% of L. pneumophiliaisolates) with a
sensitivity of 80% and specificity>99% (57). Recommended treatment of severe Legionnaire’s
disease includes azithromycin or a respiratory fluoroquinolone for at least 10 daysrifampin
300 mg IV.
It is helpful to recall that no matter what time of the year it is, somewhere around the
globe there is an active influenza epidemic. With this thought in mind, a good travel history
can be essential to help determine the likelihood of influenza in the returned traveler.
Epidemic influenza varies in seasonality based on the geographic region, with outbreaks
typically occurring in the northern hemisphere from December through April, in the southern
hemisphere from May through September, and in tropical regions year long. Focal outbreaks
have also been documented among returning travelers and their contacts (58). Complicated
influenza disease may be anticipated in patients with advanced age, respiratory comorbidity,
and compromised immunity. It has also been suggested that those taking trips>30 days and
those who travel to visit family/friends are at greater risk as well (41). Although the northern
and southern hemisphere influenza vaccines differ somewhat in their viral component
composition, there are currently no recommendations for travelers to obtain the local influenza
vaccine upon arrival to their destination (59). The diagnosis of influenza is based on a
compatible clinical presentation during the appropriate season (abrupt onset, high fevers,
myalgias, and respiratory symptoms), isolation or detection of virus, and/or serology.
Antiviral therapies with the neuraminidase inhibitors (oseltamivir, zanamavir) have
documented efficacy against influenza A and B. Because of increasing rates of resistance,
the CDC recommends against the use of amantadine and rimantadine for the treatment or
prophylaxis of influenza (60). If after several days of improvement, signs of relapse arise (new
fever, cough, sputum production, new infiltrate on chest radiography), consideration should
be given for a potential secondary bacterial pneumonia with organisms, such asStaphylococcus
aureus or S. pneumoniae, and initiation of appropriate antibiotics.
Other less common respiratory infections among travelers include hantaviral pulmonary
syndrome (HPS),Pseudomonas pseudomalleiinfection (melioidosis), plague, histoplasmosis and
atypical manifestations of malaria, typhoid fever, leptospirosis, rickettsial diseases as well as
some protozoal (amebiasis), and helminthic (schistosomiasis, fascioliasis) infections (48). In
1993, an outbreak of the first described HPS cases within the United States occured (61).
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