Sukhman Athwal, Group 1Acute Pharyngitis Epidemiology.

The epidemiology of acute pharyngitis can be divided into the prevalence, causes, and control of the disease.

Acute pharyngitis is a common condition, occurring frequently in children and half as much in adults. In children the occurrence averages about 5 upper respiratory infections every year and one strep infection in 4 years. (Acerra JR, et al , 2009). Most adult cases of pharyngitis are limited to the infection itself and merely require supportive treatment. (Tasar A, et al , 2008) An estimated 12 million individuals are diagnosed with acute pharyngitis each year (Halsey E, 2009). GAS infection is diagnosed in about 15% percent of all presenting with a painful sore throat in accident and emergency rooms. (Acerra JR, et al , 2009)

Every year, GAS pharyngitis is approximated to occur in 616 million individuals worldwide. Out of this, the acute cases result in rheumatic heart disease in 6 million individuals (Halsey E, 2009). The incidence of acute pharyngitis is reported to be high internationally, mainly because of the higher rates of resistance of bacterial pharyngitis to antibiotics. (Acerra JR, et al , 2009)

In developed countries, including the UK, the consequences of untreated GAS pharyngitis, including acute rheumatic fever (ARF) and rheumatic heart disease (RHD), are now rare. However, in regions with limited resources, ARF and RHD are still significant causes of morbidity and mortality, with prevalence rates that range from 1 to 5 per 1000 school-aged children, leading to more than 400 000 deaths annually. (Carapetis JR, et al , 2005)

Acute pharyngitis usually occurs secondary to viral or bacterial infection. A less likely cause is a fungal infection (Swedo SE, et al , 1998) There are a number of microbial causes of acute pharyngitis (Prescott HP, et al , 2007). These are listed below ( this table has been pasted from wrongdiagnosis.com).

Viral:o Adenovirus types 1–7, 7a, 9, 14, 15, and 16o Epstein–Barr virus (EBV)o Influenza A, B: Usually associated with more severe

systemic complaintso Parainfluenza 1, 2, and 3o Enteroviruses: Coxsackie A and B and echoviruseso Measles, rubella, coronavirus, and cytomegaloviruso Herpes simplex virus (HSV)

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Sukhman Athwal, Group 1Acute Pharyngitis Epidemiology.

o Rhinovirus and respiratory syncytial virus (RSV): Not usually associated with pharyngeal inflammation

o HIV Bacterial:

o Streptococcus pyogenes (group A β-hemolytic streptococcus)

o Group C or G streptococcio Corynebacterium diphtheriae (diphtheria)o Corynebacterium hemolyticumo Neisseria gonorrhoeae and Neisseria meningitidiso Mycoplasma pneumoniae and Mycoplasma hominiso Chlamydia pneumoniae, Chlamydia psittacio Yersinia enterocoliticao Treponema pallidum (syphilis)o Oral anaerobes (Vincent angina)

Fungi: Candida species (oral thrush)

Of these, the most common bacterial cause of acute Pharyngitis is Streptococcus pyogenes (Group A strep – GAS). Streptococci are usually found in school age children, as is the 6 year old patient in this case. The most common viral causes of acute Pharyngitis are Adenoviruses, Epstein-Barr virus, and a few other respiratory viruses. (Brooks GF et a l , 2007) The patient has not presented with a runny nose or other cold symptoms, so the cause is unlikely to be of viral origin. Thus laboratory tests are necessary to determine if a bacterial infection is present, hence allowing the course of treatment to be determined. (If the infection is found not to be of bacterial origin, then antibiotics are not to be administered.) The etiologic pathogen is not seen in 50% of all cases, of pharyngitis,  although full bacteriological and virologic investigations are executed. Only GAS pharyngitis should be treated with antibiotics. (Tasar A, et al , 2008)

Other, less commonly occurring causes of acute pharyngitis include oral thrush, dry air, post-nasal drip and smoking.

To detect the presence of GAS, the tests required are a rapid strep test, and a throat culture. The rapid strep test is based on an antigen-antibody reaction and uses blood agar or another selective culture medium. This allows detecting of the presence of beta-Hemolytic Streptococcus groups A, C and G. (Brooks GF et a l , 2007)

These tests will ensure the control of the disease in this case, as they will allow accurate diagnosis and treatment. In other cases of acute pharyngitis, the control of the disease also relies on accurate diagnosis and treatment of the disease. However, as mentioned, in developing countries with limited resources, the prevalence rates are higher and

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this must be altered to control the disease so that further repercussions such as RHD and ARF can be limited.

References.

Acerra JR, and Aronson A, 2009, "Pharyngitis," eMedicine , Medscape, available at: http://emedicine.medscape.com/article/764304-overview , accessed on: 16/11/2010.

Brooks GF, Butel JS, Ornston LN, 2007, Medical Microbiology, 24 t h edition, McGraw Hill, USA.

Carapetis JR, Steer AC, Mulholland EK, and Weber M, 2005, The global burden of group A streptococcal diseases, Lancet Infect Dis , 685–694.

Halsey E, 2009, "Pharyngitis, Bacterial," eMedicine , Medscape available at: http://emedicine.medscape.com/article/225243-overview , accessed on: 16/11/2010.

Prescott LM, Harley JP, Klein DA, 2007, Microbiology, 7 t h edition, Wm.C. Brown Publishers, Oxford.

Swedo SE, Leonard HL, Garvey M, et al,1998, Paediatric autoimmune neuropsychiatric disorders associated with streptococcal infections: Clinical description of the first 50 cases, Am J Psychiatry.155:264–271.

Tasar A, Yanturali S, Topacoglu H, Ersoy G, Unverir P, Sarikaya S, 2008, CLINICAL EFFICACY OF DEXAMETHASONE FOR ACUTE EXUDATIVE PHARYNGITIS, Journal of emergency medicine, 35: 363-367.

http://www.wrongdiagnosis.com/a/acute_pharyngitis/intro.htm : web source, accessed on: 16/11/2010.

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