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.