22.3 Viral infections of the respiratory tract  (Page 6/16)

MERS was first reported in Saudi Arabia in 2013. Although some infected individuals will be asymptomatic or have mild cold-like symptoms, most will develop a high fever, aches, cough and a severe respiratory infection that can progress to pneumonia. As of 2015, over 1,300 people in 27 countries have been infected. About 500 people have died. There are no specific treatments for either MERS or SARS. In addition, no vaccines are currently available. Several recombinant vaccines, however, are being developed.

Viral respiratory diseases causing skin rashes

Measles, rubella (German measles), and chickenpox are three important viral diseases often associated with skin rashes. However, their symptoms are systemic, and because their portal of entry is the respiratory tract, they can be considered respiratory infections.

Measles (rubeola)

The measles virus (MeV) causes the highly contagious disease measles , also known as rubeola, which is a major cause of childhood mortality worldwide. Although vaccination efforts have greatly reduced the incidence of measles in much of the world, epidemics are still common in unvaccinated populations in certain countries. Centers for Disease Control and Prevention. “Global Health - Measles, Rubella, and CRS, Eliminating Measles, Rubella&Congenital Rubella Syndrome (CRS) Worldwide.” 2015. http://www.cdc.gov/globalhealth/measles/. Accessed July 7, 2016.

The measles virus is a single-stranded, negative-strand RNA virus and, like the influenza virus, it possesses an envelope with spikes of embedded hemagglutinin. The infection is spread by direct contact with infectious secretions or inhalation of airborne droplets spread by breathing, coughing, or sneezing. Measles is initially characterized by a high fever, conjunctivitis, and a sore throat. The virus then moves systemically through the bloodstream and causes a characteristic rash. The measles rash initially forms on the face and later spreads to the extremities. The red, raised macular rash will eventually become confluent and can last for several days. At the same time, extremely high fevers (higher than 40.6 °C [105 °F]) can occur. Another diagnostic sign of measles infections is Koplik’s spots , white spots that form on the inner lining of inflamed cheek tissues ( [link] ).

Although measles is usually self-limiting, it can lead to pneumonia, encephalitis , and death. In addition, the inhibition of immune system cells by the measles virus predisposes patients to secondary infections. In severe infections with highly virulent strains, measles fatality rates can be as high as 10% to 15%. There were more than 145,000 measles deaths (mostly young children) worldwide in 2013. World Health Organization. “Measles Factsheet.” 2016. http://www.who.int/mediacentre/factsheets/fs286/en/. Accessed July 7, 2016.