Fundamentals of Microbiology by Jeffrey C. Pommerville

Author:Jeffrey C. Pommerville [Pommerville, Jeffrey C.]
Language: eng
Format: epub, pdf
Publisher: Jones & Bartlett Learning
Published: 2013-01-09T06:00:00+00:00

Other Respiratory Viruses Also Produce Pneumonia

A few other viruses can cause LRT infections in adults.

SARS. Severe acute respiratory syndrome (SARS) was first reported in southeastern China in spring 2003, and quickly spread through Southeast Asia and to 29 countries. It is an example of how fast an emerging disease can spread (TEXTBOOK CASE 15).

Scientists at the CDC and other laboratories identified in SARS patients a previously unrecognized coronavirus, which they named the SARS coronavirus (SARS-CoV). Being a member of the Coronaviridae, it is a nonsegmented +ssRNA virus with helical symmetry and a spiked envelope (FIGURE 15.7)

SARS-CoV can be spread through close person-to-person contact by touching one’s eyes, nose, or mouth after contact with the skin of someone with SARS. Spreading also comes from contact with objects contaminated through coughing or sneezing with infectious droplets by a SARS-infected individual. Whether SARS can spread through the air or in other ways remains to be discovered. Bats are the reservoir of SARS-CoV.

Reservoir:

The location or organism where pathogens exist and maintain their ability for infection.

Many people remain asymptomatic after contacting SARS-CoV. However, in affected individuals, moderate URT illness may occur and include fever, headache, an overall feeling of discomfort, and body aches. After 2 to 7 days, SARS patients may develop a dry cough and have trouble breathing. In those patients progressing to a severe LRT illness, pneumonia develops with insufficient oxygen reaching the blood. In 10% to 20% of cases, patients require mechanical ventilation.

Because this was a newly emerging disease that has not reappeared, treatment options remain unclear.

Hantavirus Pulmonary Syndrome. In the autumn of 1992, the El Niño oscillation of the ocean-atmosphere system caused heavy precipitation in the Four Corners region of the United States (New Mexico, Arizona, Colorado, and Utah), resulting in the increased growth of berries, seeds, and nuts in the spring of 1993. The increased food supply brought an explosion in the rodent population in this area. Then, a cluster of sudden and unexplained deaths in previously healthy young adults occurred in rural New Mexico and the Four Corners region. The CDC identified a hantavirus, now called Sin Nombre virus (SNV), as the infectious agent and termed the pulmonary disease hantavirus pulmonary syndrome (HPS). HPS has been identified in 31 states with more than 50% of reported cases outside the Four Corners region. Between 1993 and 2011, there have been more than 550 HPS cases reported in the United States. In September 2012, nine confirmed cases of HPS were reported in people who recently visited Yosemite National Park.

Textbook CASE 15

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