streptococcal infection


I- On a 2 types of pathology :

  • suppurative disease : by the germ itself (ex : abscess)
  • non-suppurative disease : by the germ toxin, syndrome post streptococcique (ex : Hriaa, glomérulonéphrite post streptococcique, erythema nodosum) with immunopathological mechanism.

II- Bactériologie :

  • On a 18 types of streptococci classified A->H and K>T. (the gangable streptococci)
  • In human pathology, the most common are Streptococcus : Streptococcus "the + virulent »-B-C-G.

III- Classification de LANCEFIELD :

  • Who said group streptococci and gangable nongroupables "PSK they don & rsquo; not C-peptide".
  • These secrete streptococci :

– Erythrogenic of toxins that are responsible for scarlet fever.
– O and S streptolysines responsible d & rsquo; hemolysis.
– Hyaluronidase which is a germ spreading factor.
– Streptokinase responsible & rsquo; fibrinolysis.
– A streptoNADase which cleaves the Coenzyme A.
– A depolymerized DNAase which the & rsquo; DNA.
– A proteinase which degrades certain proteins.

IV- serological diagnosis :

  • ASO "it n & rsquo; is not a certainty review SINCE & rsquo; there are false positives and false negatives".

V- Clinique :

  • strictly human reservoir : skin, nose / throat oral-genital sphere alimentary canal.
  • Frequency : streptococcal sepsis are less frequent than those Staphylococcus.
  • pathogenesis : A streptococci are the most common and the most virulent.
  • NB : we endocarditis in streptococcus SINCE & rsquo; there antigenic community between strep and valves and thus antibodies to germs will s & rsquo; address the valves.
  • The virulence of the germ depends :

– The ability of the germ to set.
– Resistance to & rsquo; immunity subject.
– The multiplication and dissemination (septic metastases).

WE- Sepsis streptococcal :

  • relatively rare except endocarditis are frequent.
  • Germ sensitive to penicillin.
  • Dissemination thrombophlébitique from & rsquo; d & rsquo a door; entrance is overt or latent and rarely lymph from & rsquo; lymphangitis.
  • Pote d & rsquo; entry : skin-oropharyngeal or dental (especially nongroupables)- Gastrointestinal Tract vesicular (D streptococcus)-uterus vaginal (GBS especially in neonatology).
  • NB :

+ If one has a streptococcal bacteremia D or nongroupables, the most common clinical consequence is the & rsquo; endocarditis (therefore asked either transthoracic echocardiography or transesophageal).
+ If bacteremia Bovis streptococcus or enterococcus imposes looking & rsquo; gastrointestinal injury (one seeks a door & rsquo; entry and at the same time we made a fibro / endoscopy to remove d & rsquo; other etiologies responsible for injury).

VII- Symptomatology :

A- Table bacteremia :

Demonstration of viable seed in the blood.

  • Chills, 39-40c ° fever, TIME, SPM (stade 1 or 2, soft -> recent).
  • cutaneous manifestations : exanthème scarlatiniforme (rare), closet érysipéloïde, vesicular rash pustular, purpura or petechial nouure.
  • articular manifestations : arthralgie, arthritis (serofibrinous or purulent).
  • Phlebitis of the lower limbs.
  • metastases : pulmonary pleura (pleurisy), hepatic (icterus, HPM, hepatic arrow, rarely abscess), musculoskeletal, muscle and peritoneal.

B- Table of & rsquo; erysipelas :

1- Definition :

– C & rsquo; is a dermo hypodermitis.
– Follows a focused infection that is due to streptococcus PYOGENES.
– C & rsquo; is a favored infection venolymphatic stasis, venous insufficiency, congenital or acquired lymphedema, trauma.
– The germ is another factor that is & rsquo; immunoallergie.
– For the & rsquo; erysipelas, there is often a recurrence (the disease is benign, which healed but relapse) and leaves no sequelae.
– The causative organism is susceptible to penicillin.
– Staphylococcal etiology isolated or associated with the streptococcus is possible.

2- Erysipelas of the face :

– sudden onset, chills, 39-40c ° fever, local pain, general malaise.
– A red infiltration, hot, indurated and painful that appears near the door & rsquo; entry.
– rhinitis, ear infection or a dental infection (butterfly wings lesions).
– The lesions are limited by a sharp boundary of peripheral bead, raised, peau de east recouverte vésicules en phlyctènes.
– The face is edematous with ADP.

3- Erysipelas of the lower limbs :

– C & rsquo; d & rsquo is a lesion location more frequently than the front, often in an elderly woman, an obese, venolymphatic with poor circulation but it can also be among the major sports.
– Porte d & rsquo; entry is represented by a trophic ulcer, the LEAP point, also research and especially impetigo.
– sudden onset, Table d & rsquo; a large red acute febrile leg,
painful, the lower limb is oedematous, tensioned warm skin shiny bright red indurated, sprinkled with petechiae, no peripheral bead.
– The pain is sharp pulsatile, exacerbated by the mobilization and ADP.
– You can see the & rsquo; erysipelas in d & rsquo; other locations : scalp, abdominogénitale region, buttocks, upper members (rare).

VIII- Complications :

  • Locoregional or systemic.
  • The spread of the germ or superinfection d & rsquo; other germs.

IX- Complementary exam :

  • FNS : hyperleucocytose.
  • VS élevée.
  • Blood culture.

X- serological diagnosis :


XI- Differential diagnosis :

  • Other sepsis : staphylococcal, BGN…etc.
  • For the & rsquo; erysipelas : malignant staphylococcal infection of the face.

XII- Treatment :

  • When it s & rsquo; d & rsquo acts; Streptococcus other than B, D enterococci and penicillin monotherapy enough (1-2M Ul/j).
  • When it s & rsquo; d & rsquo acts; Streptococcus B, D and enterococci (resistance problem), it will associate the penicillin with an aminoglycoside (GENTAMYCINE ou AMIKACINE).
  • Duration of treatment :

For the & rsquo; erysipelas : 10-15 days.
For sepsis : 15-20 days.