The importance of streptococcal infections and their prevention


 * streptococcal infections are among the most common bacterial infections
 * a large group of clinically diverse diseases
 * they are obligately pathogenic, facultatively pathogenic and saprophytic microorganisms
 * streptococci are classified according to the degree of hemolysis – α-hemolytic (complete hemolysis on agar) and β-hemolytic (marginal hemolysis), according to the serological differentiation of capsular antigen C into groups A and B

Content

 * 1Group A streptococcal infection
 * 1.1Complications of angina and scarlet fever
 * 1.1.1Rheumatic fever
 * 1.2Complications of streptococcal skin infections
 * 2Group B streptococcal infection
 * 2.1clinical picture
 * 2.2Prevention of group B streptococcal infections
 * 3Links
 * 3.1Source

Group A streptococcal infection

 * they are the cause of 90% of streptococcal infections
 * toxins - erythrogenic toxin, streptolysin O and S (haemolysis, toxic for myocardial fibers and hepatocytes), streptokinase (fibrinolysis), hyaluronidase (invasive factor of streptococci) etc.
 * Ig useful in diagnosis is formed against some - ASLO (antistreptolysin O) - they decrease in a few weeks after infection
 * cause various diseases - skin and mucous membrane damage, protracted seropurulent rhinitis in young children, scarlet fever, impetigo, tonsillopharyngitis

Complications of angina and scarlet fever

 * submandibular node colic, retrotonsillar, paratonsillar abscess, otitis, mastoitis, sinusitis
 * less often – bacteremia, metastatic foci – purulent arthritis, endocarditis, meningitis, brain abscess, osteomyelitis
 * without therapy – risk of late complications – rheumatic fever or glomerulonephritis

Rheumatic fever
More detailed information can be found on the Rheumatic fever page .


 * most often after group A streptococcus, 1-4 weeks after infection (in about 3% of those infected)
 * the course of the original infection may be inapparent
 * acute immunologically conditioned multisystemic inflammation
 * often affects the heart - chronic changes in the valves
 * main manifestations – migrating polyarthritis, carditis, subcutaneous nodules, erythema marginatum and Sydenham's chorea – st. Welcome, chorea minor (neurological disorder – unconscious untargeted rapid movements)
 * side symptoms - non-specific - fever, joint pain, increased CRP...
 * diagnosis - Jones criteria - history of streptococcal infection, presence of at least two manifest main or secondary symptoms
 * pathogenesis – hypersensitivity reaction, Ig against M-protein of streptococci cross-react with glycoproteins of heart muscle, joints, etc.
 * relapses

Complications of streptococcal skin infections

 * rarely septic complications, possibly also glomerulonephritis
 * rheumatic fever rarely
 * acute glomerulonephritis

Group B strep infection

 * are conditionally pathogenic, we distinguish types Ia, Ib, Ic, II and III
 * asymptomatic carriage is common - in the nasopharynx, vagina and rectum
 * it is in the vagina in 5-30% of women, more often with intrauterine contraception
 * transmission to the fetus can occur ascendingly during premature outflow of amniotic fluid
 * in the birth canal, there is a higher risk in protracted and instrumental births
 * colonization occurs in 60% of newborns of infected mothers, 1–2% become ill (information from Infectology by Havlík from 1990)
 * horizontal transmission – nosocomial – from another mother, child, staff
 * premature babies are exposed to a 15x higher risk

clinical picture

 * we distinguish two forms – early and late
 * early form - manifests itself by the 5th day of life (most often between 20 and 48 hours)
 * the onset is sudden
 * the child vomits, is cyanotic, often hypotonic, has tachycardia and respiratory disorders
 * respiratory insufficiency with pneumonia dominates the clinical picture
 * septic condition
 * late form - begins between the 7th day and the 4th month, manifests as purulent meningitis
 * symptoms – tachycardia, tachypnea, there may be convulsions, apnoeic pauses
 * pulsating fontanelle is a very late symptom, we cannot wait for it
 * with symptoms of sepsis - lumbar puncture
 * laboratory for sepsis - newborns have leukocytosis physiologically (even a shift to the left), but with sepsis they can also go into leukopenia (mostly unfavorable)
 * we can evaluate IT (immature total) - the ratio of immature neutrophils to all - if the value is above 0.2, we consider sepsis
 * CRP is rising late, we can't wait for it to start rising
 * thrombocytosis - a sign that they are recovering from sepsis
 * blood culture, swabs from everywhere, urine culture

Prevention of group B streptococcal infections

 * in the period between the 35th and 37th week, a culture examination of the lower third of the vagina should be performed
 * the samples are then placed in a transport medium and sent to the laboratory, the result should be available in 48 hours
 * it is not expedient to immediately treat a woman with a positive result with antibiotics, as the vagina can be repopulated soon after the end of therapy (in up to 70% of women)
 * the possibility of serious illness in the newborn will be reduced the most if antibiotics are given at the time of delivery
 * ATB of first choice is penicillin or ampicillin, if given at least 4 hours before birth, streptococcal colonization of the newborn is usually low and the risk of infection is small
 * 4 doses should be in time (so depending on the frequency of administration, we need to start sufficiently in advance)
 * if the mother is allergic to penicillin or ampicillin, clindamycin is given, or cephalosporins
 * it is important to report information about the result of the culture examination or its absence to the pediatrician who takes care of the newborn, who will decide accordingly on the procedure for monitoring the newborn after birth
 * newborns of these mothers require increased monitoring, even if the mother is properly treated during delivery, it is recommended to monitor the respiratory functions of the newborn for 48 hours after delivery, it is not safe to discharge the newborn home earlier than 72 hours after delivery

Source

 * BENEŠ, Jiří. Study materials  [online]. ©2008. [feeling. 8/13/2013]. http://www.jirben.wz.cz}}

Category :


 * Pediatrics
 * Infectious Medicine