2. 4 QUESTIONS
• How should a GAS pharyngitis is diagnosed?
• Who needs to take the test?
• What test should be used?
• What is the treatment?
2
3. EPIDEMIOLOGY
• Strep throat is caused by Group A Streptococcus (GAS)
• GAS is the most common cause of bacterial pharyngitis in children,
accounts for 15-30% of all cases pharyngitis in children from 5-15 years.
• Children < 3 years old: only 1 – 10% => one of reason why we don’t need
to take routine Strep test.
19/03/2019 3
5. CLINICAL FEATURES
• Scarlet fever: erythematous, finely papular rash which
characteristically starts in the groin and neck, axilla and then spreads
to the trunk and extremities, followed by desquamation. Strawberry
tongue.
19/03/2019 5
6. CLINICAL FEATURES
• Children < 3 years: : only 0 – 10%
• Symptoms are non specific with: low grade fever ( < 38 C), runny
nose, nasal congestion, tender anterior lymph nodes.
19/03/2019 6
7. CLINICAL FEATURES
• GAS are very contagious. Generally, people spread the bacteria to
others through:
• Respiratory droplets
• Direct contact
• GAS pharyngitis naturally self limiting
• Resolve spontaneously in 3-4 days with or without antibiotics.*
• Complication?
19/03/2019 7
8. COMPLICATION of
Strep pharyngitis?
• Nonsuppurative:
• Acute rheumatic fever => important reason for treatment
• Poststreptococcal glomerulonephritis
=> Can not be prevented by treating GAS
• Suppurative:
• Otitis media
• Sinusitis
• Peritonsillar abscess
• Bacteremia
19/03/2019 8
9. 1. How should a GAS Pharyngitis be
diagnosed?
Clinical diagnosis
• CENTOR criteria; viral pharyngitis vs bacterial
Laboratory diagnosis
• Throat culture
• Rapid streptococcal antigen tests (RSAT)
• Molecular assay for GAS
19/03/2019 9
10. How should a GAS Pharyngitis be
diagnosed?
• Viral pharyngitis vs bacterial pharyngitis: overlap symptoms
• Lack of fever + rhinorrhea, conjunctivitis, cough, hoarseness, anterior
stomatitis, ulcerative vesicles, diarrhea => suggest a more viral pharyngitis
19/03/2019 10
11. How should a GAS Pharyngitis be
diagnosed?
• CENTOR Criteria => none perform well in children. In some cases these scoring
systems can help to identify children at low risk for GAS and therefore reduce
the need for further testing.
• in pt with 3 points, only 32% positive and in pt with 4 points - 56%
• 50% -65% of patients who present with 3-4 clinical criteria=> test negative
• In pt with 0-1 point only 7-12% pt were positive 11
12. How should a GAS Pharyngitis be
diagnosed?
• Broad overlap between the signs and symptoms of streptococcal and non-
streptococcal (usually viral) pharyngitis => identify GAS on the basis of clinical
alone is generally poor (IDSA).
12
Clinical Practice Guideline for the Diagnosis and Management of Group A Streptococcal Pharyngitis: 2012 Update by the Infectious Diseases Society of
America
Group A streptococcal (GAS) pharyngitis: A practical guide to diagnosis and treatment ( Canadian Paediatric Society
13. How should a GAS Pharyngitis be
diagnosed?
IDSA: Infectious Disease Society of America
13
Clinical Practice Guideline for the Diagnosis and Management of Group A Streptococcal Pharyngitis: 2012 Update by the Infectious Diseases Society of
America
14. 2. Who NEEDS to test?
• Evidence of acute tonsillopharyngitis
(erythema, edema, and/or exudates)
or Scarlet fever rash and absence of
multiple signs and symptoms of viral infections.
• Exposure to an individual with GAS at home
or school or a high prevalence of GAS infections
in the community (outbreak…)
and symptoms of GAS pharyngitis
• Suspected acute rheumatic fever (ARF) or poststreptococcal
glomerulonephritis.
Group A streptococcal tonsillopharyngitis in children and adolescents: Clinical features and diagnosis ( Uptodate)
Clinical Practice Guideline for the Diagnosis and Management of Group A Streptococcal Pharyngitis: 2012 Update by the Infectious Diseases Society of
America; American Association of Pediatric;
15. Who DOES NOT NEED the test?
15
Clinical Practice Guideline for the Diagnosis and Management of Group A Streptococcal Pharyngitis: 2012 Update by the Infectious Diseases Society of
America
American Academy of Pediatrics. Group A streptococcal infections. In: Red Book: 2021-2024 Report of the Committee on Infectious Diseases
16. 3. Which test CAN be used?
• Rapid streptococcal antigen tests (RSAT) – Rapid Strep test
• Throat culture
• Molecular assay for GAS ( PCR …)
• GAS serology
19/03/2019 16
17. Rapid streptococcal antigen tests
(RSAT)
• specificity of ≥95 % and a sensitivity that varies between 60 and 80 %
for GAS
positive RADT is useful in establishing the diagnosis of GAS pharyngitis,
but a negative RADT does not rule out GAS; back-up throat culture should
be performed in children and adolescents with a negative RADT
19/03/2019 17
20. Molecular assay for GAS ( PCR …)
GAS serology
19/03/2019 20
• GAS serology:
• confirm previous infection in patients who are being evaluated for ARF or
poststreptococcal glomerulonephritis.
• not helpful with acute pharyngitis.
21. Which test SHOULD be used?
21
Clinical Practice Guideline for the Diagnosis and Management of Group A Streptococcal Pharyngitis: 2012 Update by the Infectious Diseases Society of
America
American Academy of Pediatrics. Group A streptococcal infections. In: Red Book: 2021-2024 Report of the Committee on Infectious Diseases
22. COLLECTING AN APPROPRIATE
SPECIMEN IS VERY IMPORTANT
• Avoid touching the tongue and lips
• Swab from the exudate and both tonsils
and the posterior pharynx.
22
23. Whom to treat ?
• Empiric treatment is not recommended.
• recommend antibiotic treatment for any patient with symptomatic
pharyngitis or tonsillopharyngitis who has a positive rapid antigen test or
culture for group A Streptococcus (GAS)
• If clinical suspicion for GAS pharyngitis is high, it is reasonable to start
antibiotic treatment while test results are pending.
23
24. ANTIBIOTIC TREATMENT
24
“Clinical Practice Guideline for the Diagnosis and Management of Group A Streptococcal Pharyngitis: 2012 Update by the Infectious Diseases Society of
America”
“American Academy of Pediatrics. Group A streptococcal infections. In: Red Book: 2021-2024 Report of the Committee on Infectious Diseases”
“2014 AHA/ACC guideline for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart
Association Task Force on Practice Guidelines.”
25. 10 days vs 5-7 days ?
• enhance the rate of GAS eradication from the oropharynx.
• in 433 patients (age ≥6)
• Clinical cure rates were similar between groups (89.6 versus 93.8 percent
• bacterial eradication rates were lower in the 5-day treatment group (80.4 versus 90.7
percent
25
“ BMJ 2019;367:l5337 |doi:10.1136/bmj.l5337”
26. PENICILLIN ALLERGY
• First-generation cephalosporin such as cephalexin
Mild, non-IgE-mediated reactions to penicillin (maculopapular rash beginning days into
therapy)
• Second- or third-generation cephalosporin such as cefuroxime, cefdinir, or cefpodoxime.
Mild, possibly IgE-mediated reactions (eg, urticaria or angioedema but NOT
anaphylaxis)
• Macrolide, such as azithromycin
History of severe angioedema and/or anaphylaxis
• 10-day course of clindamycin.
Macrolide-resistant GAS who cannot tolerate cephalosporins
26
“Treatment and prevention of streptococcal pharyngitis in adults and children (Uptodate)”
27. FOLLOW UP TEST AFTER TREATING
• Patients with a history of acute rheumatic fever
• Patients who acquired infection during an outbreak of acute rheumatic
fever or poststreptococcal glomerulonephritis
• Patients who acquired infection during a cluster of cases in their household
or other close-contact setting
• Symptomatic patients
27
28. If the follow up test is positive?
• an antibiotic that has greater beta-lactamase effect than the one used
for the initial treatment course
• Penicillin/ amoxicillin was used for initial treatment => use either amoxicillin-
clavulanate or a first-generation cephalosporin (cephalexin)
• if a first-generation cephalosporin was used, we select a later-generation
cephalosporin. ( 2nd or 3rd )
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29. Take Away Points
• Do not 100% rely on the clinical diagnosis for GAS pharyngitis in children.
Instead use a Rapid Antigen Detection Test (RADT) and, if negative, a throat
culture for diagnosis.
• There is no indication to test children <3 years of age for GAS pharyngitis
with the RADT or strep culture unless there is a known household contact
with GAS.
• Antibiotics for streptococcal pharyngitis are primarily to prevent
rheumatic fever. A child may still develop post-streptococcal
glomerulonephritis after completing a course of antibiotics.
• Treat with a 10 days course of amoxicillin or cephalexin in non-
anaphylactic, penicillin-allergic patients. Clindamycin or azithromycin are
appropriate antibiotics in anaphylactic, penicillin-allergic patients.
19/03/2019 29
31. References
• “Red Book: 2021–2024 Report of the Committee on Infectious Diseases (32ND
EDITION); BOOK CHAPTER: Group A Streptococcal Infections; AAP.”
• “Clinical Practice Guideline for the Diagnosis and Management of Group A
Streptococcal Pharyngitis: 2012 Update by the Infectious Diseases Society of
America”
• “American Academy of Pediatrics. Group A streptococcal infections. In: Red Book:
2021-2024 Report of the Committee on Infectious Diseases”
• “2014 AHA/ACC guideline for the management of patients with valvular heart
disease: a report of the American College of Cardiology/American Heart
Association Task Force on Practice Guidelines.”
• “Group A streptococcal (GAS) pharyngitis: A practical guide to diagnosis and
treatment; Canadian Paediatric Society”
• “Group A streptococcal tonsillopharyngitis in children and adolescents: Clinical
features and diagnosis ( Uptodate) “
19/03/2019 31
32. When can patient come back to work or
school?
• 1 full day ( at least 24h) of treatment and afebrile ( elimination rate is 80 - 90%)
32
33. Tonsillectomy ?
• We suggest tonsillectomy (with or without adenoidectomy) as an
option for children with recurrent throat infection who are severely
affected:
• ≥7 episodes in one year,
• ≥5 episodes in each of two years,
• ≥3 episodes in each of three years.
19/03/2019 33
34. Bonus: Adjunctive treatment
• Supportive care (rest, adequate fluid intake, avoidance of respiratory
irritants, soft diet).
• Hand hygiene is a key measure for preventing spread to others
• After patient has been on antibiotics for 24-48 hours, replace the old
toothbrush.
• Aspirin should be avoided in children (strong, moderate).
• Adjunctive therapy with a corticosteroid is not recommended (weak,
moderate).
19/03/2019 34
35. References
• “Red Book: 2021–2024 Report of the Committee on Infectious Diseases (32ND
EDITION); BOOK CHAPTER: Group A Streptococcal Infections; AAP.”
• “Clinical Practice Guideline for the Diagnosis and Management of Group A
Streptococcal Pharyngitis: 2012 Update by the Infectious Diseases Society of
America”
• “American Academy of Pediatrics. Group A streptococcal infections. In: Red Book:
2021-2024 Report of the Committee on Infectious Diseases”
• “2014 AHA/ACC guideline for the management of patients with valvular heart
disease: a report of the American College of Cardiology/American Heart
Association Task Force on Practice Guidelines.”
• “Group A streptococcal (GAS) pharyngitis: A practical guide to diagnosis and
treatment; Canadian Paediatric Society”
• “Group A streptococcal tonsillopharyngitis in children and adolescents: Clinical
features and diagnosis ( Uptodate) “
19/03/2019 35
36. PREVENTION
• Patients with a history of acute rheumatic fever —high risk for recurrent
rheumatic fever and the development of chronic valvular heart disease with any
subsequent GAS infection => recommend long-term antibiotic prophylaxis.
• Chronic GAS carriers — Antibiotic treatment is not routinely recommended for
chronic carriers
19/03/2019 36
37. Postexposure prophylaxis
• Testing and treatment of asymptomatic persons who have been
exposed to a patient with group A Streptococcus (GAS) pharyngitis
are not routinely recommended, except for patients with:
• a history of acute rheumatic fever, during outbreaks of acute rheumatic fever
and/or poststreptococcal glomerulonephritis,
• or when GAS infections are recurring in households or other close-contact
settings.
19/03/2019 37
38. DIFFERENTIAL DIAGNOSIS
Bacterial infections
• Group C and G
streptococci
• Neisseria gonorrhoeae
• Diphtheria
• Mycoplasma
pneumoniae
Viral infections
• Infectious
mononucleosis
• Herpes simplex virus
• Influenza
• Adenovirus
• Enteroviruses ( Cox A)
38
39. Why do patients with GAS need to
treat?
• Prevent suppurative complications and acute rheumatic fever (ARF)
• Prevent disease transmission, particularly if the patient is a contact of
someone with a history of ARF
• Reduce duration and severity of symptoms
19/03/2019 39
40. DIAGNOSIS CRITERIA
• The diagnosis of GAS pharyngitis is supported by:
• a positive microbiologic test (throat culture, rapid antigen detection test
[RADT], or molecular point-of-care test [POC] for GAS)
PLUS
• patient with symptoms of GAS pharyngitis and absence of multiple signs and
symptoms of viral infections (eg, rhinorrhea, conjunctivitis, cough,
hoarseness, anterior stomatitis, discrete ulcerative lesions or vesicles,
diarrhea).
19/03/2019 40
42. Why do patients with GAS need to
treat?
• Prevent suppurative complications and acute rheumatic fever (ARF)
• Prevention of spread to others, particularly if the patient is a contact
of someone with a history of ARF
• antibiotic use appears to eliminate GAS from the oropharynx in about 80 to 90 percent of cases after 24 hours of therapy
• Reduce duration and severity of symptoms
19/03/2019 42
Editor's Notes
We can have a better understand about this disease
At the end of the topic, we will be able to know: how should a GAS pharyngitis is established? Who needs to take the test? What test should be used? And What is the treatment?
[‚epɪdiːmɪ'ɒlədʒɪ]
['pælətl] [pɪ'tɪːkɪə]
But none of these symtoms are specific for strep pharyngitis.
/æk'silə/ one of the characteristic symptoms is strawberry tongue.
Like we have mentioned before. It makes the diagnosis of GAS becomes a challenger.
Spon tei ni es li.
What happens if we don’t treat Strep pharyngitis?
What happen if pt is not treates?
Most of guidelines recomment that we use Rapid strep test or throat culture to confirm the diagnosis
Why do we need to treat => making the prevention of complications becomes the key goal of care.
['sʌpjəreɪtɪv
bak·tuh·ree·mee·uh can devide in 2 groups: it containts:
With these complications we can prevent with the treatment
A desease can be diagnosed base on clinical and laboratory, some of disease like otititis media, hand foot mouth disease, we can make the diagnosis base on clinical signs and symptoms but some of disaes we need laboraty test to help us confirm the diagnosis like HBV; HAV …
How can we know this pt has viral or bacterial pharyngitis, and do we have any scoring system or criteria to help us ?
Lesions ['lɪːʒn]
How can we know is this a bacterial or viral pharyngitis?
Pt with viral pharyngitis usually have the same symptoms with
Unfortunately, the symptoms of viral pharyngitis vs bacterial
however, a lack of fever and the presence of rhinorrhea, cough, conjunctivitis, stomatitis, oral ulcers, and viral exanthem suggest a more viral etiology.
It seems like base on clinical only is not good enough to diagnosis.
We can not make the diagnosis alone with these symptoms, but how about any scoring system, any criteria ?
Do we have any scoring system to help us in the clinical diagnosis like we have scoring system for hypothyroidism on children? To help us make a diagnosis.
3-14 years old with 64,789
Analysis of data collected from 206,870 patients 3 years and above who presented with a painful throat, we tried to find how many percent of patients testing positive for GAS pharyngitis according to Centor and McIsaac scores
Based on the result from this analysis: inf pt with 3 points, only 32% are positive and in pt with 4poins it is 56% and 50% -65% of patients who present with all of the clinical criteria in a particular tool will test negative for GAS on throat culture, this meants a viral pharyngitis.
In pt with 0-1 point only 7-12% pt were positive => In some cases these scoring systems can help to identify children at low risk for GAS and therefore reduce the need for further testing.
generally test for GAS pharyngitis in patients with ≥3 Centor criteria (some practitioners use a threshold of ≥2). Patients with Centor criteria <3 are unlikely to have GAS pharyngitis and generally do not need testing [68-70]. Because the Centor criteria are neither sensitive nor specific for the diagnosis of streptococcal pharyngitis, use of these criteria should not replace testing for GAS and should not be used as the determinant of the need for antibiotic therapy.
use of these criteria should not replace testing for GAS.
While there exist several prediction tools designed to aid in the clinical diagnosis of GAS pharyngitis, such as the Centor and McIsaac Criteria, none perform well in children
y. However, the signs and symptoms of streptococcal and nonstreptococcal pharyngitis overlap too broadly for diagnosis to be made with the requisite diagnostic precision on the basis of clinical grounds alone.
50% -65% of patients who present with all of the clinical criteria in a particular tool will test negative for GAS on throat culture, indicating a viral etiology
generally test for GAS pharyngitis in patients with ≥3 Centor criteria (some practitioners use a threshold of ≥2). Patients with Centor criteria <3 are unlikely to have GAS pharyngitis and generally do not need testing [68-70]. Because the Centor criteria are neither sensitive nor specific for the diagnosis of streptococcal pharyngitis, use of these criteria should not replace testing for GAS and should not be used as the determinant of the need for antibiotic therapy.
While there exist several prediction tools designed to aid in the clinical diagnosis of GAS pharyngitis, such as the Centor and McIsaac Criteria, none perform well in children
y. However, the signs and symptoms of streptococcal and nonstreptococcal pharyngitis overlap too broadly for diagnosis to be made with the requisite diagnostic precision on the basis of clinical grounds alone.
65% of patients who present with all of the clinical criteria in a particular tool will test negative for GAS on throat culture, indicating a viral etiology
Based on these evidence
Reliably
Pt with symptoms of pharyngitis and isolated viral symptoms => do the test.
prevent identification of GAS carriers with viral respiratory infection, we avoid microbiologic testing for GAS in children and adolescents with multiple manifestations strongly suggestive of viral illness (eg, rhinorrhea, conjunctivitis, cough, hoarseness, anterior stomatitis, discrete ulcerative lesions or vesicles, diarrhea). In a retrospective study of >60,000 children and adolescents (age 3 to 21 years) who were tested for GAS in a national network of retail clinics, the prevalence of GAS positivity was 28 percent among those with ≥1 feature of viral illness [27]. The prevalence of GAS positivity decreased with increasing numbers of viral features.
Suspected acute rheumatic fever (ARF) or poststreptococcal glomerulonephritis. generally test for GAS pharyngitis in patients with ≥3 Centor criteria (some practitioners use a threshold of ≥2). Patients with Centor criteria <3 are unlikely to have GAS pharyngitis and generally do not need testing [68-70]. Because the Centor criteria are neither sensitive nor specific for the diagnosis of streptococcal pharyngitis, use of these criteria should not replace testing for GAS and should not be used as the determinant of the need for antibiotic therapy.
2. Do not take the test on pt contact with GAS and asymptomatic.
Many studies have shown that clinical scoring systems can be useful in predicting the likelihood of streptococcal infection [19, 20, 22, 49] but that laboratory confirmation is essential in making a precise diagnosis because physicians often greatly overestimate the probability that GAS is the cause of pharyngitis Because of the general increase in rates of resistance to antibiotics, antimicrobial therapy should be prescribed only for proven episodes of GAS pharyngitis
With the information from abovw:
< 3: the prevalence of GAS pharyngitis is significantly lower for children <3 years of age, ranging from 10% to 14%, and if a corresponding rise in ASO is required, the prevalence can be as low as 0%–6% [61, 62]. Thus, diagnostic testing for GAS pharyngitis is not routinely indicated in children <3 years of age Reports of ARF in children <3 years of age are very rare [17, 64–68]. Of 541 new cases of ARF reported from Salt Lake City, Utah, only 5% involved individuals <5 years of age. This is thought to be because it may take repeated exposures to GAS or priming of the immune system before there is an immune response to streptococcal pharyngitis that can lead to rheumatic fever [70]. The low prevalence of GAS pharyngitis and the low risk of developing ARF in children <3 years of age limits the usefulness of diagnostic testing in this age group
if a child is <3 years of age and there is household contact with a school-aged sibling with documented streptococcal pharyngitis, then it is reasonable to consider testing the child if the child is symptomatic. The likelihood of the spread of infection in a family is as high as 25% if the index subject has symptomatic pharyngitis
The reason I put this title is that we have a lot of test to confirm the diagnosis but it is not easy to choose 1 onf them
[ə'seɪ]
[sɪ'rɑlədʒɪ /-'rɒ-]
enzyme or acid extraction of antigen from throat swabs
Is this an accuracy test for Strep pharyngitis?
high specificity and limited sensitivity of the available tests, a positive RADT is useful in establishing the diagnosis of GAS pharyngitis, but a negative RADT does not rule out GAS; back-up throat culture should be performed in children and adolescents with a negative RADT
RADTs have a sensitivity of 70-90%, leading to some false negative results.5,6 Thus if the RADT result is negative, a strep culture should be sent with a follow-up plan, should the culture become positive. Antibiotics can be initially withheld, unless the patient is at high risk (immunosuppressed, medically complex) or has high-risk contacts.
What does it meant/ How does it affect to our treatment and management of patients?
Disadvantage:
Can not identify other bacteria that cause pharyngitis less commonly than GAS
Like on Tuesday we saw a test sult in which pt has Hemophilius influenza and GAS, in the real clinial practice sometimes we need to wait until 4-5days. And expenseive $270
Molecular assays are more likely than throat cultures to be positive in patients with both symptomatic and asymptomatic infection with GAS, as well as in GAS "carriers."
.GAS serology: However, such testing is not useful in the diagnosis of acute pharyngitis because antibody titers of the 2 most commonly used tests, antistreptolysin O (ASO) and antiDNase B, may not reach maximum levels until 3–8 weeks after acute GAS pharyngeal infection and may remain elevated for months even without active GAS infection it detects antibody when your immune system contact with TREP>
[məʊ'lekjələr /-kjʊlə
[sɪ'rɑlədʒɪ /-'rɒ-]
Titer
We see a pt, this pt is likely to have strep pharyngitis , when wating for throat culture
Amoxicillin is often preferred for young children because the taste of the amoxicillin suspension is more palatable than that of penicillin. In several randomized trials, standard-dose and once-daily dosing of amoxicillin appeared to have equivalent efficacy as oral penicillin [32-36].
The effect of 2 drugs is similar.
Palatable palatable ['pælətəbl]
symptoms typically improve within the first few days of treatment treating for 10 days appears to enhance the rate of GAS eradication from the oropharynx when compared with 5 or 7 days
One randomized trial directly compared a 5-day course of penicillin V with a 10-day course of penicillin V
Anaphylaxis ,ænəfi'læksis/
about 80 percent of patients with culture-proven group A streptococcal (GAS) pharyngitis clear the organism from the oropharynx within 24 hours of starting therapy
For patients who are asymptomatic at the end of a course of antibiotic therapy, a test of cure is typically not needed
For patients who have persistent or recurrent symptoms consistent with GAS pharyngitis after completing a course of antibiotic therapy, we generally repeat testing for GAS. Because chronic GAS carriage can occur after antibiotic therapy
For patients who test positive in these circumstances, we repeat a full 10-day course of therapy. We usually select an antibiotic that has greater beta-lactamase stability than the one used for the initial treatment course.
stə'bɪlətɪ]
Reye syndrome
Why I put this part before testing and diagnosis because it is related to the reason why we don’t need to do the test of some specific populations.
Because it is carrier.
Red and swollen tonsils
White patches or streaks of pus on the tonsils
Tiny, red spots on the roof of the mouth, called petechiae
Swollen lymph nodes in the front of the neck
Why I put this part before testing and diagnosis because it is related to the reason why we don’t need to do the test of some specific populations.
1. However, even without antibiotic therapy, symptoms typically resolve in about three to five days for most patients [13], making the prevention of complications a key goal of care.
2. The prevention of acute rheumatic fever is one of the main indications for antibiotic treatment
3. antibiotic use appears to eliminate GAS from the oropharynx in about 80 to 90 percent of cases after 24 hours of therapy [20,21]. When untreated, historic epidemiologic data suggest approximately 50 percent of patients with streptococcal pharyngitis will continue to harbor GAS in the oropharynx three to four weeks after symptom onset
