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STREPTOCOCCAL INFECTION
Main statements
Group A streptococcus in 15-30% of cases is the etiological factor of acute
pharyngeal diseases.
At pharyngitis of possibly non-viral etiology (not accompanied by rhinitis,
conjunctivitis, cough or diarrhea) it is obligatory to perform bacteriological
evaluation of respiratory tract mucus.
Rapid diagnostic tests for revealing of group A streptococcus in pharyngeal swabs
have high sensitivity and specificity with conditions of precise performance of
investigation.
Main route of transmission of group A streptococcal infection in children is airborne.
The entrance routes for the bacteria at streptococcal toxic shock are damaged skin or
soft tissues.
Newborns acquire group A streptococcus prenatally or during delivery.
In the countries without scheduled prophylaxis against S. pneumonia, this bacterium
is the most common cause of sporadic cases of purulent meningitis in children older
than 6 months of age.
By mortality and frequency of severe complications, meningitis caused by S.
pneumonia overcomes meningitis caused by other bacteria.
Penicillin is recommended as first choice antibiotic at streptococcal
tonsillopharyngitis; at suspicion on group B streptococcal infection, ampicillin +
gentamycin are recommended; at pneumococcal infections – ampicillins and
cephalosporins.
Streptococcal infection is a group of diseases caused by streptococci of
different serogroups. Streptococcal infection is various in clinical presentation and
similar in epidemiological, pathogenetic, morphological and immunological
patterns.
Etiology. Streptococci are gram-positive spherical microorganisms from
family Lactobacillus. Depending on ability to cause erythrocyte haemolysis
streptococci are divided into β (can cause complete haemolysis), α (cause partial
haemolysis) and γ (do not cause haemolysis). Based on reaction of precipitation
streptococci are divided into several groups, which differ according to carbohydrate
contain of their membrane. Every group is named by Latin letters A, B, C, D, etc.
There are 21 these groups. From all the groups of streptococci the special place is
taken by group A, which includes S. рyogenes - β-hemolytic streptococcus. There
are 80 serovars of β-hemolytic streptococcus described, which are determined by
agglutination reaction with appropriate serum of immunized animals.
Epidemiology. Group A streptococci are constantly found in oropharynx of
healthy people; however, in only 15-20 % they can cause disease. Morbidity
depends on child’s age, climatic conditions, season, people overcrowding and
frequency of contacts with them.
The main route of transmission of group A streptococcal infection in children is
respiratory. Intensively of streptococci spread considerably increases at cough,
sneezing. Spread of streptococci is facilitated by presence of dust in the air, close
and long-term contact with sick person. Contact route is possible through toys and
surrounding items. Streptococcal infection can also be transmitted through food,
mainly with milk products.
For first year of age children the source of infection can be mother with breast
inflammation caused by group A streptococcus. Infants can also acquire
streptococcal infection from mother with inflammation of genitals, caused by group
B streptococcus, as it is known that this bacterium is one of flora component of
female genitals. Newborns acquire group B streptococcus by vertical way,
ascending or during delivery.
Bacterial transmission to newborns is increased with risk factors (prolonged
delivery, preterm delivery, rupture of amniotic vesicle). Frequency of group B
streptococcus transmission from infected mother to child is 50%. Newborn infection
can develop later after delivery as a result of nosocomial infection (from mucosa of
medical personnel, family members or other surrounding people). The highest
susceptibility to group B streptococcal infection is present in premature children
who received insufficient amount of anti-streptococcal antibodies through placenta.
Enterococci are widely spread as gastro-intestinal flora of human and animals.
E. faecalis is predominantly seen, which is detected in more than 90% of adults,
usually in high concentrations (approximately 107 colony-forming units per 1 gram
of stool). Almost 50 % of newborns are colonized with E. faecalis during the 1st
week of life. With age the process of colonization with E. faecium is slowed down,
and in adults enterococci are found in approximately 25 % of cases. The main area
of enterococcal presence is gastro-intestinal tract, but they can also be found in oral
secretions, dental deposits, in upper respiratory tract, on skin, in vagina.
E. faecalis is responsible for 80 - 90 % cases of infectious diseases caused by
enterococci, often due to activation of local flora of the patient. Direct transmission
from human to human is not an important route of enterococci transmission, though
outbreaks of this infection in newborn departments and intensive care units justify
the possibility of this way of transmission.
Asymptomatic pharyngeal carriage of groups C and G streptococci is observed
in approximately 5 % of children. Place of localization of these groups streptococci
is often the skin, gastro-intestinal tract, vagina. S. equisimilis can be cultured from
umbilicus of healthy newborns but it seldom causes a disease.
Approximately one third of healthy children culture S. pneumoniae,
pneumococcus, from nasopharynx and oropharynx. Carriage of some serotypes of
pneumococcus can continue several months, especially in early age children.
Transmission of pneumococci is performed by airborne way. Majority of
disease cases are episodic; nevertheless, epidemic outbreaks are described in close
collectives. Contagiosity of the sick person is decreased 24 hours after beginning of
effective antibacterial therapy.
Among immunocompetent children maximal amount of pneumococcal
infection cases is seen in children of the first 2 years of life. Breastfed infants have
considerably decreased risk of pneumococcal infection. Recurrent pneumococcal
meningitis is due to inborn or acquired damage of skull integrity, as well as
disturbances of development, head trauma and neurosurgery.
In immunocompromised patients high frequency of pneumococcal infection is
seen in all age groups. Some immunodeficient conditions lead to increased
susceptibility to localized and generalized pneumococcal diseases, recurrent course.
They include inborn and acquired immunodeficiencies (agammaglobulinemia,
hypogammaglobulinemia), as well as selective inability to respond to
polysaccharide antigens; complement system deficits (C3 - C9); inborn or surgical
removal of the spleen; malignant diseases (Hodgkin disease); nephrotic syndrome,
human immunodeficiency virus (HIV).
Inborn pneumococcal infection is seldom seen, but early sepsis (within 24
hours after birth) develops when the child is infected during passage through
maternal birth canal. Type specific antibodies passed from mother protect the child
during several first months of life.
Frequency of pneumococcal infection morbidity correlates with growth of
ARVI cases, which is most typical for winter and spring months.
Clinical manifestations.
Diseases caused by group A streptococci
Among group A streptococcal infections there are localized forms: tonsillitis,
rhinitis, pharyngitis, adenoiditis, otitis, sinusitis, laryngitis, bronchitis, pneumonia,
pyelitis, nephritis; and generalized forms: sepsis, meningitis, pleural empyema, etc.
Respiratory tract diseases. In 15-30% the cause of acute pharyngitis in
children is streptococcus. Incubational period is 1-3 days. Disease symptoms depend
on the age of the patient. Children under 6 months of age present with liquid
transparent nasal discharge, anorexia, irritability. Fever is often subfebrile.
Described symptoms are present during 1 week, more seldom during 2-4 weeks.
Children from 6 months till 3 years of life present with subfebrile fever,
nasopharyngitis, cervical lymphadenitis; nasal discharge can be purulent in
character. Often complications develop in form of otitis, sinusitis. Length of the
disease is 1-2 months.
Older age children present with symptoms of acute pharyngitis or tonsillitis.
Acute onset is typical with fever till 380-390С, vomiting. Children become flaccid,
anorexia, headache and abdominal pain appear. Tonsils and oropharyngeal mucosa
are brightly hyperemic, covered by purulent exudate, the uvula is edematous,
becomes bright red. Hyperemia is spreading to palate; petechiae appear. Cervical
lymphadenitis and sore throat are often observed. The disease course can be
different, from manifest to asymptomatic forms (diagnosis is confirmed by
increased titer of anti-streptococcal antibodies).
Streptococcal pharyngitis typically has seasonality (winter-spring) and age
predisposition (predominantly 15 years).
Skin involvement.
The most common form of skin damage at streptococcal infection is pyodermia
(impetigo). The disease begins with vesicular rash on the skin. Vesicular contain
rapidly becomes purulent, vesicles are covered by thick crusts. Patients often
complain on itching and pain. Regional lymph nodes are quite often enlarged.
General symptoms are often absent.
Sometimes bullous form of streptodermia (streptococcal impetigo) can
develop. At this form round form bullas appear on the skin; they rapidly grow on
periphery, become plain and not tensed. Their covers are easily broken and erosions
appear with remnants of the bulla along the borders. Development of bullous form
of streptodermia is often connected to joining of staphylococcal infection.
Erysipelas is one of the forms of streptococcal infection characterized by
serous-exudative skin and subcutaneous fatty tissue damage, which is accompanied
by intoxication and lymphangitis.
By character of inflammatory process there are bullous and erythematous
forms of erysipelas. The disease begins acutely with chills and fever. At the place of
inflammation bright hyperemia at first appears in the form of macula, which rapidly
grows in size. Borders are scalloped, indurated. Regional lymph nodes are enlarged
and tender. Intoxication symptoms are prominent. At bullous form of erysipelas
bullas filled with serous-purulent exudates appear on the areas of damaged skin.
In newborn children erysipelas is often localized in the area of umbilicus. The
process is spreading downwards during 1-2 days and rapidly involves lower
extremities, buttocks, back. Skin hyperemia is less prominent than in older children;
inflammatory border is not distinct. Intoxication increases and septicopyemia
develops. Mortality is very high.
Perinatal dermatosis is the disease which is hard to diagnose and which is
often misdiagnosed as fungal infection. Clinically it presents in infants with itching,
pain and often proctitis.
Vulvovaginitis of streptococcal etiology is a common cause of itching,
discharge, dysuria and pain at walking. Early age girls are often affected, more
seldom – school age girls.
Scarlet fever. The course of scarlet fever consists of 4 periods: incubational,
prodromal, rash period and recovery.
Incubational period is between several hours and 7 days.
Prodromal period is the length between disease onset and appearance of rash. It
is usually very short, from several hours till 1-2 days. Main symptoms of this period
are intoxication and tonsillitis. Intoxication presents with fever, headache, malaise,
vomiting. Sore throat restricted hyperemia of oropharyngeal mucosa and soft palate
enanthema appear.
Typical symptom of scarlet fever is rash. Exanthema at scarlet fever is usually
small pointed, presents with roseolas 1-2 mm in diameter, situated close to each
other on hyperemic background skin. The rash is spreading to neck, upper part of
thorax, than to trunk and extremities within several hours. The rash color during the
first day is bright red, by the 3-4th day it becomes pale till light-pink color. In some
patients the rash is almost invisible on the 2-3rd day of the disease. Skin hyperemia,
typical for scarlet fever in past years, currently can be seen 1-2 days or be absent
completely. Predominant localization of the rash is the following: flexor surfaces of
extremities, anterior and lateral surfaces of the neck, lateral sides of thorax and
abdomen, inner surface of thighs and natural skin folds. The rash is mo re abundant
on these areas, bright, remains for longer time. At scarlet fever small petechiae often
appear on the skin. Sometimes they form hemorrhagic lines (Pastia symptom),
which can remain for some time after rash disappearance and can be one of
additional signs of scarlet fever in later terms.
Besides typical rash at scarlet fever small papulous or miliar rash can be
observed, in form of small vesicles situated predominantly on skin of abdomen and
inner surface of the thighs. White dermographism is typical for scarlet fever. During
the first 3-4 days of the disease it has long latent period and short evident; after 4-5 th
day of the disease it has short latent and long evident period.
The face appearance is typical for acute period of scarlet fever: paleness of
nasolabial triangle is exacerbated by redness of cheeks and strawberry lips. This
symptom is called Filatov’s mask. The skin in majority of the patients is dry. On the
2-3rd week of the disease skin desquamation appears. Typical for scarlet fever is
scaled desquamation which begins from palms and soles, appears in form of small
fissures around nail borders and spreads further to all fingers, palms and soles. On
extremities the skin is desquamated by larger scales, on trunk by small scales.
Permanent symptom of scarlet fever is tonsillitis. The oropharyngeal mucosal
hyperemia has typical appearance. Restricted hyperemia is situated along anterior
palate arches, the basis of uvula and along the line between soft and hard palate. In
some patients on the background of hyperemia enanthema appears which looks like
pointed hemorrhages.
Tonsillitis at scarlet fever can be catarrhal, follicular, lacunar and necrotic.
Tonsillitis is accompanied as a rule by throat pain. Regional submandibular
lymphadenitis is typical.
At scarlet fever typical changes of the tongue are seen. On the first day of the
disease it has white covering, since the 2nd till 4-5th days it gradually clears. Its clean
surface becomes bright purple, enlarged papillas appear. During the following days
purple color of the tongue becomes pale gradually, but “”papillary” appearance is
still present during 2-3 weeks. Oropharyngeal mucosa hyperemia usually subsides
by 6-7th day. Regional lymphadenitis usually disappears by 4-5th day of the disease.
Skin changes disappear in some definite pattern. At first hyperemic skin
background disappears and the rash becomes pale; later the rash disappears almost
simultaneously on the skin of back and thorax but still remains in the places of its
predominant localization. Face hyperemia starts to disappear since the 2-3 rd day of
the disease; nevertheless, pale nasolabial triangle can remain till 6-7 th day of the
disease. Pastia symptom disappears at the end of the 1st – beginning of the 2nd week.
Cardiovascular involvement is typical for scarlet fever. At primary period pulse
acceleration and blood pressure increase are seen. 4-5 days later the pulse is
decelerated, quite often arrhythmia, decreased blood pressure, widening of heart
borders and systolic murmur at the apex are observed. Accent or splitting of the 2nd
tone on pulmonary artery is heard. These changes of cardiovascular system are first
of all caused by imbalance of vegetative nervous system but not by direct heart
damage.
Cardiovascular, musculoskeletal and lymphatic infections. Group A β-
hemolytic streptococcus is responsible for some percentage of cases of endocarditis,
myocarditis, pericarditis, phlebitis. Group A β-hemolytic streptococcus is the second
most common bacterial cause of muscle and skeletal infections and lymphadenitis
after S. aureus. One of the complications of group A β-hemolytic streptococcus is
necrotizing fasciitis.
PANDAS. PANDAS is the abbreviation for “pediatric autoimmune
neuropsychiatric disorders associated with streptococcal infection”. It is
characterized by ticks, involuntary movements, Tourette syndrome, motion
hyperactivity, emotional instability, absent-mindedness, attention deficit, falling
asleep disorder. The most commonly PANDAS develops during the first 3 months
but it can also appear within 12 months after episode of streptococcal infection.
Diagnostic criteria of one of the most severe streptococcal diseases,
streptococcal toxic shock syndrome, are presented in the following table.
Diagnostic criteria of streptococcal toxic shock syndrome
Clinical criteria
Arterial hypotension + two or more symptoms Kidney damage Coagulopathy Liver damage Adult-type RDS Generalized erythematous rash Soft tissue necrosis
Confirmed case: clinical criteria + positive group A streptococcus culture from organism media which are normally sterile.
Probable case: clinical criteria + positive group A streptococcus culture from organism media which are normally non-sterile.
Diseases caused by group B streptococci
Diseases caused by group B streptococci are mostly seen in newborns and early
age children.
In newborns there are two variants of streptococcal infection course, which are
based on epidemiological characteristics, clinical particularities and terms of clinical
symptoms appearance. Early streptococcal infection develops during the first 7 days
of life and is often connected to disease in pregnant or delivering woman
(chorioamnionitis, prolonged period after amniotic membranes rupture, premature
delivery). In majority of cases the newborns develop symptoms during the first 24
hours from birth. Main clinical manifestations of early streptococcal disease are
sepsis (50% of cases), pneumonia (30%) and meningitis (15%). In some patients
non-specific symptoms are revealed: hypothermia or fever, restlessness, sleepiness,
apnea, bradycardia. For pneumonia it is typical to have cyanosis, apnea, tachypnea,
typical changes on X-ray.
Patients with meningitis often present with non-specific symptoms or
symptoms resembling pneumonia and sepsis; more specific signs of CNS
involvement are often absent.
Late streptococcal diseases develop during 7-90 days of child’s life and more
often are presented with bacteremia (in 45-60 %) and meningitis (25-35 %). Local
infections (of bones, skin and soft tissue, urinary tract, lungs) develop somewhat
later (in 20 %). As a rule, children who develop diseases later usually have milder
course and mortality frequency at these forms is not higher than 2-3 %.
Enterococcosis. Majority of cases of infectious diseases caused by enterococci
are observed in people with damage of physiological barriers (gastro-intestinal tract,
skin, urinary tract). Other factors predisposing to the disease are prolonged
hospitalization, wide usage of antibiotics, compromised immune system. In
newborns these microbes are often causes of sepsis, and in older children and adults
they cause bacteremia, intra-abdominal abscesses and urinary tract infections.
Up till 10 % of all cases of bacteremia and sepsis in newborns are caused by E.
faecalis. Diseases caused by E. faecalis are seldom seen, but outbreaks are
registered among newborns.
There are 2 variants of enterococcal sepsis in newborns. The disease with early
beginning (within 7 days after birth) is similar to early septicemia caused by
streptococci B, but it has milder course. Infection with early onset is mostly seen
term-born babies. Infection with late onset (after 7 days f life) is mostly seen at the
presence of risk factors: profound prematurity, presence of intra-vessel catheter,
necrotic enterocolitis, performance of surgery. At this form the course is more severe
with apnea, bradycardia and respiratory distress. Besides, septicopyemia can
develop. Mortality at early-onset sepsis is about 6 %, at late-onset about 15 %; in
most of the cases it is connected to development of necrotic enterocolitis.
Enterococci are seldom the cause of meningitis in newborns, usually as a
complication of septicemia. Besides, infection spread through defects of neutral
tube, neuroenteral cysts at submeningeal injections, through ventricular shunt at
hydrocephalus is possible.
Enterococcal bacteremia in older age children is most often hospital-acquired.
Factors promoting development of the infection are the flowing: presence of central
venous catheter, surgery on gastro-intestinal tract, immunodeficient conditions,
cardiovascular.
Age of the patients at “home-acquired” infection is less than at “hospital-
acquired” and in the first case it is usually less than 1 year of life. As well as in
adults, in children quite often polymicrobial bacteremia is seen.
Enterococci in children are the rare cause of urinary infections; nevertheless,
they are responsible for almost 15% of nosocomial infections of these organs.
Presence of urinary catheter is the main risk factor for hospital-acquired urinary
tract infections. Enterococci can also cause intra-abdominal abscesses at intestinal
perforation. Unlike adults, in whom enterococci cause up to 15 % of all
endocarditis, in children these bacteria seldom affect heart.
Diseases caused by group C and G streptococci.
Spectrum of diseases caused by group C and G streptococci is the same as for
S. pyogenes. In children they cause more often infections of respiratory system, in
particular pharyngitis. Real frequency of streptococcal C and G pharyngitis is hard
to evaluate, as asymptomatic colonization of these microbes takes place. However,
there are proves of their role in etiology of pharyngitis. Clinical presentation of
pharyngitis caused by streptococci of group С, G and S. pyogenes is similar.
Cases of pneumonia caused by group C streptococci are described. This disease
is accompanied as a rule by formation of abscess, development of empyema and
bacteremia. In spite of massive antibacterial therapy, inflammation disappearance
occurs slowly; permanent fever longer than 7 days is observed. Among other
diseases at streptococcal group C infection, cases of epiglottitis and sinusitis are
described.
Streptococci of group С and G can affect skin and soft tissues. They can also
cause inflammation of bone and muscle tissue, including purulent arthritis. These
forms are mostly seen in adults with prolonged course of the disease. In pediatrics
there are rare cases of arthritis. These microbes rarely cause sepsis of newborns.
Group G streptococci in 2.2 % of cases can be etiological factors for neonatal
infection. As well as at group streptococcal infection, risk factor is prematurity.
Clinical presentation might not differ from infection caused by group B streptococci
with early onset and includes respiratory distress syndrome, hypotension, asphyxia,
bradycardia and DIC syndrome.
Endocarditis, bacteremia, central nervous system infections (especially brain
abscess) can be caused by group C and G streptococci but they are seldom seen in
children, mainly at immunodeficient conditions. Brain abscess can complicate
sinusitis in immunocompetent children as well.
Group C and G streptococci can also cause postinfectious glomerulonephritis
and reactive arthritis in rare cases.
Pneumococcal infection. The most common diseases caused by pneumococci
are the following: acute otitis media, bronchitis, pneumonia and bacteremia.
Besides, pneumococci are common causes of meningitis, sinusitis and
conjunctivitis. For these infections pneumococcus is the leading etiological factor.
Less common diseases caused by pneumococci are soft tissue infections, cheek and
periorbital paniculitis, erysipeloid, abscesses, as well as purulent arthritis,
osteomyelitis, primary peritonitis, salpingitis and endocarditis.
Manifestations of pneumococcal infection are similar to those at other purulent
diseases. Pneumococcal disease of respiratory tract is often preceded by acute
respiratory viral infection. Pneumococcal pneumonia is characterized by sudden
onset, chills, fever, thoracic pains, headache, tachypnea, weakness, sputum
discharge with reddish color. Physical and X-ray signs justify presence of
pulmonary lobar infiltration. Clinical presentation spectrum can vary in children of
different age. The disease can present with moderate non-specific respiratory
changes at which cough can be at the beginning of the disease or can be absent. In
early age children fever, vomiting, abdominal distention and pain can prevail and
resemble appendicitis. In patients with involvement of upper lobe of the lungs neck
stiffness can be present, which resembles meningitis.
The most typical X-ray sign of pneumococcal pneumonia is consolidation of
pulmonary tissue, but in early age children bronchopneumonia with chaotic foci of
consolidation is more often seen. X-ray examination can also reveal pleural
exudates, pneumatocele and lung abscess.
Pneumococcal bacteremia in patients with sickle cell disease, with inborn
asplenia (or after splenectomy), with HIV infection is characterized by rapid
progression of fulminant forms with acute onset, progressing DIC syndrome and
death during 24-48 hours, which resembles Waterhouse-Friderichsen syndrome. S.
pneumoniae causes majority of infections in patients after splenectomy.
Cystic damage of gingivae in children with pneumococcal bacteremia is
described. Rare complications of pneumococcal infection are hemolytic-uremic
syndrome and acute necrosis of skeletal muscles.
In the countries where prophylactic vaccination against S. pneumoniae is not
performed, this causative agent is the most common cause of sporadic purulent
meningitis among children from 6 months of age. S. pneumoniae penetrates into
brain meninges by hematogenous route or due to trauma with damage of scull bones
from middle ear or from nasal sinuses. In majority of the patients the disease
develops gradually with non-specific symptoms first: fever, anorexia, vomiting,
sleepiness, malaise, irritability. Neurological symptoms are usually prominent and
appear 1-2 days after disease onset. They include sleepiness, delirium, positive signs
of Brudsinski and Kernig, paresis of cranial nerves. Approximately 25 % of children
develop seizures. Complications of pneumococcal meningitis are deafness (up to
50% of patients), epilepsy, learning difficulties, psychic disorders, residual pareses
and paralyses. According to mortality and frequency of severe complications
meningitis caused by pneumococci prevail over meningitis caused by other bacteria
(Haemophilus influenzae type B, Neisseria meningitidis).
Diseases caused by viridans streptococci. Viridans group streptococci include
multiple varieties of α-hemolytic streptococci. They belong to normal flora of oral
cavity but are the most common causes of bacterial endocarditis. They can also
cause abdominal and brain abscesses.
Laboratory diagnosis.
Laboratory confirmation of streptococcal etiology of acute pharyngitis is
necessary, as there are no clear criteria of differential diagnosis between
streptococcal pharyngitis and pharyngitis of other, first of all viral etiology.
Differentiation of group A streptococcus from other streptococci is performed by
bacteriological method (material is mucus from posterior pharyngeal wall and
tonsils) with further confirmation by methods of latex agglutination, precipitation
and immune fluorescence. Currently rapid diagnostic tests are appraised which have
high sensitivity and specificity. Correctly performed express test reveals group A
streptococcus from pharyngeal swab and does not require further bacteriological
investigations; latter are indicated at negative results of express tests.
For confirmation of the diseases caused by group B streptococcus,
pneumococcus, the bacteria is cultured from biologic material which is normally
sterile: from blood, CSF, pleural cavity. For detection of causative agent PCR
method is used.
Treatment.
Antibacterial therapy is indicated for all forms of scarlet fever. It is due to the
fact that even after mild cases of the disease complications can develop. Early
antibacterial therapy allows decrease bacteria load on child’s organism and
consequently avoid the risk of complications. First choice drugs at mild and
moderate forms of group A streptococcal infection are oral penicillins
(aminopenicillins) and macrolides. Antibacterial course at scarlet fever is 10-14
days. Late complications at scarlet fever can be caused by short course of
antibacterial therapy or by reinfection.
First choice antibiotic at scarlet fever is recommended to be penicillin V or
penicillin G. patients with increased sensitivity to penicillin should be treated with
cephalosporins of 1-2-3 generation (cefuroxime, cefpodoxime) or macrolides
(azythromycin, roxithromycin, erythromycin, clarithromycin), aminopenicillins
(amoxicillin). Oral route of therapy is preferable. At severe forms of the disease
antibiotics are given parentherally. The drugs of choice in these situations can be
cephalosporins of 1, 2 or 3 generation (cefazolin, cefuroxime, ceftriaxone,
cefotaxime), vancomycin, aminopenicillins.
The patient with scarlet fever must be done urinalysis on the 3, 7 and 14 th days
of the disease, complete blood count on 7-14 th days, throat swab for streptococcus at
14th day. If indicated, ECG should be done, consultations of cardiologist,
nephrologists and ENT are provided.
First-choice therapy at suspicion on group B streptococcal infection should
consist of ampicillin in combination with gentamycin. This regimen covers a large
spectrum of neonatal pathogens and this combination is synergetic both in vitro and
in vivo for lysis of group B streptococci. Dosage of ampicillin at meningitis is 300
mg/kg of body weight, gentamycin is 5-7 mg/kg of body weight. At all other forms
of infection dosage of ampicillin is 150 mg/kg of body weight. Dosage of penicillin
G at meningitis is 400-500 thousand units/kg of body weight at other localization of
infection till 200-300 thousand units/kg of body weight. Length of antibacterial
therapy is 14-28 days. Alternative therapy of group B streptococcal infection can be
1st-2nd generation cephalosporins, vancomycin, imipenem.
At normal immune status of microorganism not severe localized infections
caused by enterococci can be treated by ampicillin or amoxicillin. If β-lactamase
activity is detected in enterococci, antibiotics containing β-lactamase inhibitors are
used (clavulanic acid, sulbactam, tasobactam). Majority of strains are sensitive to
nitrofuranes and these drugs can be an alternative for aminopenicillins at the
treatment of not-complicated urinary tract infections.
At generalized infections, including neonatal sepsis, endocarditis and
meningitis, therapy usually starts with combination of ampicillin and
aminoglycosides. As etiotropic therapy at enterococcosis vancomycin can also be
used but only in combination with aminoglycosides, as its action alone is only
bacteriostatic. Treatment of infections caused by highly resistant to aminoglycosides
strains is problematic, due to absence of bactericidal action of vancomycin. As a
result, even after prolonged therapy recurrence of the infection can be seen,
particularly, of endocarditis. In these cases high doses of penicillin can be used (till
500-700 thousand units /kg of body weight).
In cases when bacteremia is caused by presence of catheter, it is necessary to
remove the catheter. In patients with endocarditis caused by resistant to
aminoglycosides strains, valve replacement can be required. Reserve drugs at severe
forms of enterococcal infection are linezolids in dosage 10 mg/kg of body weight
every 8 hours.
At mild and moderate pneumococcal infections, including acute otitis,
treatment can be performed by oral forms of penicillin, amoxicillin, cephalosporins
of 1-2 generation, erythromycin or other macrolides. Amoxicillin is currently the
drug of choice at pneumococcal infection in outpatient conditions in dosage 40
mg/kg of body weight 3 times per day during 10 days.
For the treatment of pneumococcal meningitis ceftriaxone is used in dosage
100 mg/kg/day in 1-2 injections, cefotaxime in dosage 200-400 mg/kg of body
weight in 3-4 injections, vancomycin 60 mg/kg/day in 4 injections. Length of
therapy is minimum 14 days. At the absence of positive dynamics or at antibiotic
resistance of pneumococcal strain it is necessary to perform CSF examination
during 48 hours for determination of therapy efficacy.
At sever forms of pneumococcal infection it is recommended to use
amoxicillin/clavulanate, ampicillin/sulbactam, cephalosporins of 2-4 generations in
combination with aminoglycosides, as well as lincomycin, clindamycin, imipenem,
rifampin, vancomycin.
Questions for self-control
1. Characteristics of streptococci of different groups.2. Epidemiology of streptococcal infection.3. Pathogenesis of diseases of streptococcal etiology.4. Streptococcal skin damage (pyodermia, erysipelas, perinatal dermatosis).5. Scarlet fever.6. Streptococcal toxic shock syndrome.7. Diseases caused by group B streptococcus.8. Diseases caused by group C and G streptococcus.9. Laboratory diagnosis of streptococcal infection.10. Treatment of streptococcal infection.
Tests for self-control
1. What diseases are most commonly caused by Str. pyogenes:А. Skin infectionsВ. OsteomyelitisС. CellulitisD. Endocarditis Е. Arthritis2. What diseases are most commonly caused by enterococcus:А. Skin infectionsВ. PneumoniaС. CellulitisD. Neonatal sepsis Е. Arthritis3. What diseases are more commonly caused by Str. pneumoniae:А. Skin infections В. Osteomyelitis С. Cellulitis D. Pneumonia Е. Arthritis 4. At which age the morbidity of group A streptococcal infection is the lowest:А. 0-1 year
В. 1-3 years С. 3-7 yearsD. 7-12 years Е. Adults 5. What is the main way of group B streptococcus transmission for children:А. Airborne В. Fecal-oral С. Parentheral D. Vertical Е. All the answers are correct 6. What rash is typical for scarlet fever:А. Large macular В. Small pointed С. Vesicular D. Macular-papular Е. Hemorrhagic-necrotic 7. Which symptom of scarlet fever is obligatory:А. Rash В. Fever С. Tonsillitis D. Lymphadenitis Е. “Strawberry” tongue 8. Possible complications of pneumococcal meningitis:А. Deafness В. Epilepsy С. Psychiatric disturbances D. Pareses, paralyses Е. All the answers are correct9. Laboratory methods of diagnosis of streptococcal infection:А. Bacteriological В. Latex agglutination С. Precipitation D. PCR Е. All the answers are correct10. At which forms of scarlet fever is antibacterial therapy indicated:А. Severe В. Septic С. Moderate and severe D. With complications Е. At all forms
Test answers
1-А; 2-D; 3-D; 4-А; 5-D; 6-В; 7-С; 8-Е; 9-Е; 10-Е.
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