Israel Medical Association Journal

Background: Group A Streptococcus (GAS) is the predominant bacterial pathogen of pharyngitis in children. However, distinguishing GAS from viral pharyngitis is sometimes difficult. Unnecessary antibiotic use contributes to unwanted side effects, such as allergic reactions and diarrhea. It also may increase antibiotic resistance. 

Objectives: To evaluate the effect of a machine learning algorithm on the clinical evaluation of bacterial pharyngitis in children.

Methods: We assessed 54 children aged 2–17 years who presented to a primary healthcare clinic with a sore throat and fever over 38°C from 1 November 2021 to 30 April 2022. All children were tested with a streptococcal rapid antigen detection test (RADT). If negative, a throat culture was performed. Children with a positive RADT or throat culture were considered GAS-positive and treated antibiotically for 10 days, as per guidelines. Children with negative RADT tests throat cultures were considered positive for viral pharyngitis. The children were allocated into two groups: Group A streptococcal pharyngitis (GAS-P) (n=36) and viral pharyngitis (n=18). All patients underwent a McIsaac score evaluation. A linear support vector machine algorithm was used for classification.

Results: The machine learning algorithm resulted in a positive predictive value of 80.6 % (27 of 36) for GAS-P infection. The false discovery rates for GAS-P infection were 19.4 % (7 of 36).

Conclusions: Applying the machine-learning strategy resulted in a high positive predictive value for the detection of streptococcal pharyngitis and can contribute as a medical decision aid in the diagnosis and treatment of GAS-P.

Background: Erythema nodosum (EN) is the most common type of panniculitis, commonly secondary to infectious diseases.

Objectives: To elucidate the causative factors and the clinical presentation of patients with EN (2004–2014) and to compare their data to those reported in a previous study.

Methods: A retrospective study was conducted of all patients diagnosed with EN who were hospitalized at Soroka University Medical Center (2004–2014). The clinical, demographic, and laboratory characteristics of the patients were compared to those in a cohort of patients diagnosed with EN from 1973–1982.

Results: The study comprised 45 patients with a diagnosis of EN. The most common symptoms of patients hospitalized with EN were arthritis or arthralgia (27% of patients). Patients with EN, compared to those reported in 1987, has significantly lower rates of fever (18% vs. 62% P < 0.001), streptococcal infection (16% vs. 44%, P = 0.003), and joint involvement (27% vs. 66%, P < 0.001). In addition, fewer patients had idiopathic causes of EN (9% vs. 32%, P = 0.006).

Conclusions: In the past decades, clinical, epidemiological, and etiological changes have occurred in EN patients. The lowering in rate of fever, streptococcal infection, and joint involvement in patients with EN are probably explained by improvements in socioeconomic conditions. The significantly decreasing rate of idiopathic causes of EN is possibly due to the greater diagnostic accuracy of modern medicine. The results of the present study demonstrate the impact of improvements in socioeconomic conditions and access to healthcare on disease presentation.

Background: Food-borne pharyngitis outbreaks causing substantial morbidity have been documented.

Objectives: To investigate an outbreak of food-borne Streptococcus beta hemolyticus group A pharyngitis among employees of a high-tech company.

Methods: We received a report on an unusually high rate of morbidity among employees of a company in September 2003. The Tel Aviv District Health Office conducted an epidemiological investigation of the outbreak.

Results: Among the 278 people who attended a company party, 83 people became ill. The overall attack rate was 29.8%. Information was available on 174 of 193 employees and family members who attended the party and worked in the Tel Aviv district. Forty-six of them became ill (attack rate 26.4%). The secondary attack rate was 3.8%. Most cases developed symptoms 24–48 hours following the event. Seven cases had throat cultures positive for Streptococcus beta hemolyticus group A. Three items were significantly associated with becoming sick: spring chicken (odds ratio 2.26, 95% confidence interval 1.11–4.63, P = 0.02), vegetable salad (OR[1] 2.88 95%CI[2] 1.40–5.94, P = 0.003) and corn (OR 7.73, 95%CI 3.18–18.80, P < 0.001). Eating corn remained significantly associated with pharyngitis after controlling for other food items consumed.

Conclusions: We describe the epidemiological investigation of a large food-borne outbreak of Streptococcus beta hemolyticus group A pharyngitis most probably transmitted by corn. No previous publication has implicated corn. Food handlers and the public should be aware that they can transmit diseases to others.. Physicians should be aware that streptococcal pharyngitis could be a food-borne disease and that outbreaks in a non-confined setting may be easily missed.

Contamination of food with streptococci could present with unusual outbreaks that may be difficult to recognize in the early stages. This is demonstrated in a large food-borne outbreak of streptococcal pharyngitis that occurred in 2003 in a factory in Israel. The outbreak was reported to the public health services on July 2 and an epidemiologic investigation was initiated. Cases and controls were interviewed and throat swabs taken. An estimated 212 cases occurred within the first 4 days, the peak occurring on the second day. There was a wave of secondary cases during an additional 11 days. The early signs were of a respiratory illness including sore throat, weakness and fever, with high absenteeism rates suggesting a respiratory illness. As part of a case-control study, cases and controls were interviewed and throat swabs taken. Illness was significantly associated with consumption of egg-mayonnaise salad (odds ratio 4.2, 95% confidence interval 1.4–12.6), suggesting an incubation period of 12–96 hours. The initial respiratory signs of food-borne streptococcal pharyngitis outbreaks could delay the identification of the vehicle of transmission. This could be particularly problematic in the event of deliberate contamination.

Background: Acute pharyngitis in children is one of the most frequent illnesses for which primary care physicians are consulted. It is caused more frequently by viruses than by bacteria, but it is difficult to differentiate the causative agent by clinical signs alone. Group A Streptococcus accounts for 30% of children with a sore throat, and only in these cases is antibiotic therapy definitely indicated. However, the frequency and symptomatology of streptococcal pharyngitis in adults is not well established.

Objectives: To examine the clinical features that could distinguish sore throat caused by b-hemolytic group A Streptococcus in adults.

Methods: Patients aged over 16 years old (n=207) who presented with a sore throat to community clinics were examined and throat cultures were taken. The microbiologic confirmation of Group A Streptococcus was correlated with symptoms and clinical signs by univariate analysis.

Results: About 24% of the patients with positive cultures were younger individuals. Chills, absence of cough, pain in swallowing, absence of rhinitis, headache, vomiting, tonsillar exudate, oral malodor, fever >38°C and sweats had high sensitivity but low specificity for streptococcal pharyngitis. Univariate analysis suggested that chills and pharyngeal exudate had the greatest predictive value for streptococcal pharyngitis (P = 0.044, odds ratio 2.45; P = 0.001, OR[1] 5.49, respectively). When compared with a published scoring method (Centor criteria), large inconsistencies were found.

Conclusion: Our adult population had a relatively high prevalence of group A Streptococcus, and their presentation differed from that of pediatric patients. In primary care, a throat swab culture is not necessary in adults with a low score (0–1 points).