EPIDEMIOLOGY

Nurudeen Kallon Medical Microbiology

Epidemiology

Pharyngitis mainly affects young children with much greater frequency compared to the adult population. It is estimated that 15-30% of Pharyngitis cases among children in the cooler months are due to GAS. Only 10% of adult cases of Pharyngitis are due to GAS. The peak occurrence of bacterial and viral Pharyngitis occurs in the school-aged child aged 4-7 years. Pharyngitis, especially GAS infection, is rare in children younger than 3 years. Mycoplasma pneumoniae, Chlamydia pneumoniae and Arcanobacterium haemolyticus are other bacterial that causes Pharyngitis but these are rare. Antibiotics covering atypical pathogens should not routinely be used to treat Pharyngitis. Twefik TL (2005)

If a patient is presented with rhinorrhea, cough and hoarseness, doctors will usually test that patient for Group A Streptococcus. It has been shown that it is almost impossible to differentiate between Group A Streptococcus and Pharyngitis caused by viral infection. Rhinovirus and adenovirus are the most common etiological agents and each account for 6-20% of all cases of Pharyngitis, both viral and non-viral. A doctor may order a throat culture. Usually temperature checks are performed along with examinations of the throat, ears, nose, neck and lungs. Pharyngitis is common worldwide and is usually a disorder that affects children. Pharyngitis results in over 15 million hospital visits per year in the United State alone. Acute pharyngitis is the most common cause of a sore throat and is diagnosed in more than 1.9 million people a year in the United States Marx, John (2010). Pharyngitis is caused by numerous microorganisms. However, 90% of sore throats in adults and 60–75% of in children are caused by viruses. Streptococcus pyogene (b-hemolytic Group A Streptococcus) is the most common bacterial cause of acute pharyngitis. Dr. Neal R. Chamberlain (2009) Bacterial epidemiology is dominated by beta-haemolytic streptococci group A but other streptococcal groups notably group C and have been incriminated. Other responsible bacteria like Haemophilus spp., Staphylococcus spp. and Corynebacterium spp., are extremely rare but most probable. Mycoplasma pneumoniae and perhaps Chlamydia pneumoniae are probably found more frequently. Gehanno P, et al (1992). Although GABHS Pharyngitis is usually a self-limited entity, on average, a single episode in a child results in 1.9 days absence from school and a parent missing 1.8 days from work to care for the child. Pfoh E et al (2008) Children with GABHS Pharyngitis experience symptoms for an average of 4.5 days.

References:

· Bisno, AL. et. al. Practice guidelines for the diagnosis and management of group A streptococcal pharyngitis. 2002 · Cherry, CK, CW. Burt, and DA. Woodwell. National Ambulatory Care Survey, 1999. Advance data from vital and health statistics of the national center for health statistics, No. 322. July 17, 2001. · Gehanno P, Portier H, Longuet P. Current status on the epidemiology of acute pharyngitis and post-streptococcal syndromes. · Huffman, GB. Diagnosing Strep Throat: Are There Reliable Clues? American Family Physician. July 1, 2001 · Marx, John (2010). Rosen's emergency medicine: concepts and clinical practice (7th ed.). Philadelphia, Pennsylvania: Mosby/Elsevier. Chapter 30 · Pfoh E, Wessels MR, Goldmann D, Lee GM. Burden and economic cost of group A streptococcal pharyngitis. Pediatrics. Feb 2008;121(2):229-34. · Twefik TL, Al Garni M. Tonsillopharyngitis: Clinical highlights. J of Otolaryngology;34. 2005

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