Amanda+Aryee

** The patient is a 6 year old male who had been in good health with no significant medical problems. In late September he presented to his paediatrician’s office with a complaint of sore throat, fever, headache, and swollen glands in his neck for the past 36 h. On physical examination (PE), he had fever of 38ºC, a red posterior pharynx, yellowish exudate on his tonsils, and multiple, enlarged, tender cervical lymph nodes. **   ** Infectious Agents of Acute Pharyngitis ** The symptoms described in the case study are appear to describe acute pharyngitis, which is the painful inflammation of the pharynx and surrounding lymphoid tissue, this is because the boys symptoms seem relatively severe and long lasting (36 h). Most acute infections (40%-80%) are cause by viruses. Other causes are bacterial, fungal (although not generally noted as a routinely causative agent) and irritants such as chemicals and pollutants. The following shows the range of different infectious agents that are causatives of acute pharyngitis; ** Bacteria ** // Arcanobacterium haemolyticum // —a much less common cause of pharyngitis seen in predominantly in teenagers and young adults // Corynebacterium diphtheriae // —rarely seen in the United States but it should be considered with an appropriate travel history to Africa, Asia/South Paciﬁc, South America, Haiti, Albania, and the former Soviet Republic countries // Mycoplasma pneumoniae // —a cause of pharyngitis in teenagers and young adults // Neisseria gonorrhoeae // —considered if suspecting child abuse Streptococci, groups C and G—a cause of self-limited pharyngitis in young adults // Streptococcus pyogenes // [group A strep (GAS)]—this is the most common bacterial cause of pharyngitis ** Viruses ** Adenovirus—causes pharyngitis, conjunctivitis, and acute respiratory disease Epstein-Barr virus—causes infectious mononucleosis, which is seen predominantly in the 15–25 year-old age group and frequently starts with pharyngitis Other respiratory viruses—rhinovirus, coronavirus, parainﬂuenza virus, inﬂuenza A and B viruses, coxsackievirus, cytomegalovirus Generally, during diagnostics in determining the causative agent of the infection, GAS being the most common cause is the expected tested for, along with groups being tested for if needs be. The two lab tests which will identify GAS are firstly the rapid strep test which detects GAS by detecting a carbohydrate (N-acetylglucosamin) which is unique to GAS. Secondly a throat culture is taken which will allow the organism to grow on an incubated blood agar plate. The rapid strep test has 95-100% specificity, however its sensitivity is not so high. It takes between 5- 10 minutes for a strep test to be completed, as compared to 48h for a culture to be completed. So where the strep test proves positive there is no need for further tests due its high specificity, however where the result is negative, further tests need to be taken due to its low sensitivity. The sample from the negative test is cultured on a blood agar plate, this incubated over night at 35-17 **°C ** 18-24h and for a further 24h. Where there is // Streptococcus pyogenes // present colonies will be seen. The type of hemolysis //Streptococcus pyogenes// presents, α, β or γ is can be determined by observing agar plates after the colony growth time has passed. The characteristics of α-hemolysis is the green colouration of the agar immediately surrounding the colony due to incomplete destruction of red blood cells, β cells have a clear area directly around them where complete lysis of red blood cells has occurred, γ hemolysis is where no hemolysis has occurred, so red blood cells remain and there is no change in the area surrounding the colonies. As Group A Strep is β hemolytic, so where the signs are shown, there is a diagnosis of it being the cause of acute pharyngitis. Where there is no sign of any of these sub-types, further testing is employed, A catlase test is was used. References: Boccazzi. A., Tonelli. P., Ceruti. R. 2000. Whats new in Streptococcal pharyngitis; International Journal of Antimicrobial Agents.
 * Acute Pharyngitis Case Study **