Med. J. Cairo Univ., Vol. 78, No. 1, March: 177-182, 2010 www.medicaljournalofcairouniversity.com Rapid Diagnostic Test for Streptococcal Throat Infection in Egyptian Children MOHAMED SEDKI, M.D.*; HASSAN SALAMA, M.D.*; EMAD SALAMA. M.D.*; NAGWA ABDALLA, M.D.* and HOAYDA EZZ, M.D.** The Departments of Pediatric, National Research Centre* and Clinical Pathology, National Research Centre**. Abstract Background: Acute streptococcal pharyngitis represents a high prevalence in developing countries responsible of morbidity and mortality. Difficulty of prompt diagnosis is responsible for either inadequate therapy and subsequent rheumatic heart disease and renal failure, or abuse of antibi- otics. Group AB hemolytic streptococcus (GABHS) detection by rapid tests is useful due to its rapidity and relative low cost. However sensitivity and specificity remain debatable. In Egypt, suspicion about its accuracy remains an important obstacle for mass utilization. The objective of this study was to evaluate the accuracy of a GABHS rapid antigen detection test kit, in comparison with oropharynx swab culture. Methods: Children aged 3 to 15 years with clinical diag- noses of non treated acute pharyngitis were recruited at public emergency health centers in a rural region eastern Cairo, with 95 patients, subjected to oropharyngeal swabs for rapid GABHS testing and conventional culture. Results: We observed sensitivity of 80.65%, specificity of 96.88%, a positive predictive value of 92.59%, a negative predictive value of 91.18% and a positive likelihood ratio for the rapid test used here, compared with throat culture. It was found a group of any 3 of fever, sore throat, dysphagia, cervical lymphadenopathy always present in false negative cases. Conclusions: The rapid test studied exhibited a good correlation with culture and is, therefore, of great use in clinical practice for detection of GABHS. Clinical picture has to be taken in consideration to increase the sensitivity of the test. Key Words: Streptococcal – Pharyngo-tonsillitis – Strepta- test – Culture. Introduction ACUTE pharyngitis (AP) is one of the commonest diagnoses in children. The group A streptococcus causing the widest range of disease in humans of all bacterial pathogens [1] , represents a high prev- alence in developing countries responsible, when Correspondence to: Dr. Mohamed Sedki, Department of Pediatrics, National Research Centre, Giza, Egypt. email: mohamed.sedky@57357.com inadequately treated, of morbidity and mortality [2,3] . The greatest burden is due to rheumatic heart disease, with a prevalence of at least 15.6 million cases, with 282,000 new cases and 233,000 deaths each year [4] . Viruses are responsible for >80% of acute pharyngitis, while Group A Streptococcus (GAS) accounts for 15% of them [5] . It is quite impossible to establish the etiology depending only on clinical features [6] . Subsequently, antibiotics are prescribed frequently and empirically despite all squeals of abuse [7,8] . Alternatively, and accord- ing to The current recommendations of: (the Amer- ican Academy of Pediatrics (AAP), the Centers for Disease Control and Prevention (CDC), the American Heart Association (AHA) and the Infec- tious Diseases Society of America (IDSA) to con- firm diagnosis of GABHS diagnosis by investiga- tory tests. On one side, conventional throat culture using blood agar necessitates a long time around 48h before confirming the diagnosis [9] . Associated to this, expenses and fallacies remain a handicap in rural areas. On the other side, immunologic techniques allow nowadays rapid antigen detection tests (RADT), of the specific streptococcal group A antigen from a simple throat swab on outpatient clinic basis [10] . However, results remain contra- dictory. GABHS rapid detection has passed through several eras from latex to immune assay in order to improve its sensitivity and specificity to be a reliable test. Depending on the revolutionary im- provement in rapid diagnostic tests based on radio- immunoassay, our target is to follow a new attitude to diagnose streptococcal pharyngitis without abuse antibiotics or laboratory investigation in order to prevent complications of GABHS. Material and Methods This prospective observational study was con- ducted in the period from 14 December 2006 to 7 March 2008. The study was conducted after the 177