- A potentially deadly form of community acquired pneumonia
linked to adenovirus type 14 has emerged in the Pacific Northwest.
- First encountered in 2005 in Oregon, the viral pneumonia
frequently leads to hospitalization and has a 20 per cent fatality rate,
Paul Lewis, MD, of the Oregon State Public Health Department said at the
Infectious Diseases Society of America (IDSA) meeting [see: Lewis P, et
al: Adenovirus 14: a new cause of severe community-acquired pneumonia.
Infectious Diseases Society of America 45th Annual Meeting. 4-7 Oct 2007.
San Diego. Final Program and Abstracts. Abstract LB-5].
- "We recommend obtaining a viral culture in pneumonia
patients who lack a specific etiology, especially those with severe disease,"
said Dr Lewis. "If adenovirus 14 is detected, anticipate a stormy
course. We encourage an infectious disease consultation to discuss the
risks and benefits of any specific therapy that might be contemplated."
- Recognition of the adenoviral pneumonia began with 4
patients hospitalized simultaneously at a Portland hospital. Upon comparing
notes with physicians at area hospitals, Dr Lewis and colleagues "almost
fell out of our chairs because every hospital we called had recent severe
and fatal cases of adenovirus disease." Investigators followed up
the informal communication with a systematic review of all cases of adenovirus
disease identified by Oregon clinical laboratories from November 2006 to
April 2007. 6 months of active surveillance revealed what appeared to be
a winter-spring predominant adenovirus disease, as the number of reported
cases increased from January through April. Isolates from the sickest patients
were sent to the CDC (US Centers for Diseases Control and Prevention),
which found that almost all the cases involved adenovirus 14, a serotype
identified more than 50 years ago but rarely detected since then and never
in association with outbreaks.
- Dr Lewis and colleagues at the state health department
reviewed analyzed specimens dating back to 1993 and found a few cases of
adenoviral disease almost every year. Beginning in 2005, adenovirus 14
was the predominant serotype identified. Comparison of 31 patients with
adenovirus 14 disease and 14 patients with other adenovirus serotypes showed
that adenovirus 14 tended to infect older men (median age 52.9), and almost
half the cases involved smokers. Most strikingly, adenovirus 14 was associated
with a hospitalization odds ratio of 15.9 compared with other adenovirus
serotypes. The most common clinical features leading to diagnosis of adenovirus
14 disease were fever (about 80 per cent), tachypnea (75 to 80 per cent),
hypoxia (about 50 per cent), and hypotension (40 to 45 per cent). Chest
x-rays were abnormal in 23 of 24 cases. Radiographic progression was common,
including single-lobe disease to multilobe in 55 per cent of cases and
lobar disease to adult respiratory distress syndrome in 45 per cent.
- All patients received broad spectrum antibiotics. Dr
Lewis said 22 of the 31 patients with adenovirus 14 disease were hospitalized,
and 16 required ICU (intensive care unit) care. Median hospital and ICU
length of stay was 7 days. Of the patients treated in the ICU, 13 required
ventilatory support and 8 had severe hypotension requiring pressor drugs.
7 patients (22 per cent) died. Risk factors for death or ICU care were
a creatinine level greater than 1.2 mg/dL, lymphocyte count less than 100
microL, and coinfection with another pathogen. None of those factors remained
statistically significant in multivariate analysis.
- "This came out of nowhere in 2005 in Oregon,"
said Dr Lewis. Acknowledging that almost all of the cases have involved
severe illness, he agreed that the scope of the problem could be much larger
and involve a broader spectrum of illness severity.
- communicated by ProMED-mail
- The abundance of reports of avian and seasonal human
influenza virus infections has tended to obscure the fact that many other
viruses can be responsible for outbreaks of serious respiratory disease.
This report identifies human adenovirus 14 (classified as a member of the
_Human adenovirus B_ species) as the cause of an outbreak of serious disease
in the north western state of Oregon in the United States. Human adenovirus
14 has not previously been regularly associated with human respiratory
disease. It is perhaps too soon to designate human adenovirus 14-associated
pneumonia as an emerging disease rather than perhaps a co-factor in an
unusual disease situation. Nonetheless extended investigation and continued
surveillance are clearly warranted. - Mod.CP
- The state of Oregon, in the Pacific Northwest region
of the US, can be located on the map at http://geology.com/world/the-united-states-of-america-satellite-image.shtml.
- Patricia A. Doyle DVM, PhD Bus Admin, Tropical Agricultural Economics
Univ of West Indies Please visit my "Emerging Diseases" message board at:
- Also my new website: http://drpdoyle.tripod.com/
- Zhan le Devlesa tai sastimasa
- Go with God and in Good Health