Group A streptococcal infection
Encyclopedia
The group A streptococcus bacterium (Streptococcus pyogenes
, or GAS) is a form of β-hemolytic Streptococcus
bacteria responsible for most cases of streptococcal illness. Other types (B, C, D, and G) may also cause infection. Several virulence factors contribute to the pathogenesis of GAS, such as M protein
, hemolysin
s, and extracellular enzymes.
(Note that some of these diseases can be caused by other infectious agents as well.)
of large joints, subcutaneous nodules, erythema marginatum
, and sydenham chorea (involuntary, purposeless movement). The most common clinical finding is a migratory arthritis involving multiple joints. Other indicators of GAS infection such as a DNAase or ASO serology test must confirm the GAS infection. Other minor Jones Criteria are fever, elevated ESR
and arthralgia
. Of the most serious complications is pancarditis, or inflammation of all three heart tissues. A fibrinous pericarditis
can develop with a classic friction rub that can be auscultated. This will give increasing pain upon reclining. Further endocarditis can develop with aseptic vegetations along the valve closure lines, particularly the mitral valve. Chronic rheumatic heart disease mostly affects the mitral valve
which can become thickened with calcification of the leaflets, often causing fusion of the commissures and chordae tendineae
. Other findings of ARF include erythema marginatum
(usually over the spine or other bony areas) and a red expanding rash on the trunk and extremities that recurs over weeks to months. Because of the different ways ARF presents itself, the disease may be difficult to diagnose. A neurological disorder, Sydenham chorea
, can occur months after an initial attack, causing jerky involuntary movements, muscle weakness, slurred speech, and personality changes. Initial episodes of ARF as well as recurrences can be prevented by treatment with appropriate antibiotics. It is important to distinguish ARF from rheumatic heart disease. ARF is an acute inflammatory reaction with pathognomonic Aschoff bodies histologically and RHD is a non-inflammatory sequelae of ARF.
; persons with suppressed immune systems; burn victims; elderly persons with cellulitis
, diabetes, blood vessel disease, or cancer
; and persons taking steroid
treatments or chemotherapy
. Intravenous drug users also are at high risk. GAS is an important cause of puerperal fever
worldwide, causing serious infection and, if not promptly diagnosed and treated, death in newly delivered mothers. Severe GAS disease may also occur in healthy persons with no known risk factors.
All severe GAS infections may lead to shock, multisystem organ failure, and death
. Early recognition and treatment are critical. Diagnostic tests include blood counts and urinalysis
as well as cultures of blood or fluid from a wound site.
Severe Group A streptococcal infections often occur sporadically but can be spread by person-to-person contact.
Close contacts of people affected by severe Group A streptococcal infections, defined as those who have had prolonged household contact in the week before the onset of illness, may be at increased risk of infection. This increased risk may be due to a combination of shared genetic susceptibility within the family, close contact with carriers, and the virulence of the Group A streptococcal strain that is involved.
Public Health
policies internationally reflect differing views of how the close contacts of people affected by severe Group A streptococcal infections should be treated. Health Canada
and the US CDC recommend close contacts see their doctor for full evaluation and may require antibiotics; current UK Health Protection Agency
guidance is that, for a number of reasons, close contacts should not receive antibiotics unless they are symptomatic but that they should receive information and advice to seek immediate medical attention if they develop symptoms.
s and obsessive compulsive disorder (OCD) hypothesized to be due to an autoimmune response to group A beta-hemolytic streptococcal infection (PANDAS) have been identified.
Streptococcus pyogenes
Streptococcus pyogenes is a spherical, Gram-positive bacterium that is the cause of group A streptococcal infections. S. pyogenes displays streptococcal group A antigen on its cell wall. S...
, or GAS) is a form of β-hemolytic Streptococcus
Streptococcus
Streptococcus is a genus of spherical Gram-positive bacteria belonging to the phylum Firmicutes and the lactic acid bacteria group. Cellular division occurs along a single axis in these bacteria, and thus they grow in chains or pairs, hence the name — from Greek στρεπτος streptos, meaning...
bacteria responsible for most cases of streptococcal illness. Other types (B, C, D, and G) may also cause infection. Several virulence factors contribute to the pathogenesis of GAS, such as M protein
M protein (Streptococcus)
M protein is a virulence factor that can be produced by certain species of Streptococcus.Viruses, parasites and bacteria are covered in protein and sugar molecules that help them gain entry into a host by counteracting the host's defences. One such molecule is the M protein produced by certain...
, hemolysin
Hemolysin
Hemolysins are exotoxins produced by bacteria that cause lysis of red blood cells in vitro. Visualization of hemolysis of red blood cells in agar plates facilitates the categorization of some pathogenic bacteria such as Streptococcus and Staphylococcus...
s, and extracellular enzymes.
Types of infection
Infections are largely categorized by the location of infection:- bacteremiaBacteremiaBacteremia is the presence of bacteria in the blood. The blood is normally a sterile environment, so the detection of bacteria in the blood is always abnormal....
– bloodstream - impetigoImpetigoImpetigo is a highly contagious bacterial skin infection most common among pre-school children. People who play close contact sports such as rugby, American football and wrestling are also susceptible, regardless of age. Impetigo is not as common in adults. The name derives from the Latin impetere...
, cellulitisCellulitisCellulitis is a diffuse inflammation of connective tissue with severe inflammation of dermal and subcutaneous layers of the skin. Cellulitis can be caused by normal skin flora or by exogenous bacteria, and often occurs where the skin has previously been broken: cracks in the skin, cuts, blisters,...
, and erysipelasErysipelasErysipelas is an acute streptococcus bacterial infection of the deep epidermis with lymphatic spread.-Risk factors:...
– skinSkin-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
and underlying tissues - focal infectionFocal infectionFocal infection theory is the idea that a local infection affecting a small area of the body can lead to subsequent infections or symptoms in other parts of the body due either to the spread of the infectious agent itself or toxins produced from it....
s – limited to a particular site. BacteremiaBacteremiaBacteremia is the presence of bacteria in the blood. The blood is normally a sterile environment, so the detection of bacteria in the blood is always abnormal....
can be associated with these infections, but it is not always present. Treatment depends on the specific clinical findings. Types include:- pneumoniaPneumoniaPneumonia is an inflammatory condition of the lung—especially affecting the microscopic air sacs —associated with fever, chest symptoms, and a lack of air space on a chest X-ray. Pneumonia is typically caused by an infection but there are a number of other causes...
– pulmonary alveolusPulmonary alveolusAn alveolus is an anatomical structure that has the form of a hollow cavity. Found in the lung parenchyma, the pulmonary alveoli are the dead ends of the respiratory tree, which outcrop from either alveolar sacs or alveolar ducts, which are both sites of gas exchange with the blood as well... - tonsillitisTonsillitisTonsillitis is an inflammation of the tonsils most commonly caused by viral or bacterial infection. Symptoms of tonsillitis include sore throat and fever. While no treatment has been found to shorten the duration of viral tonsillitis, bacterial causes are treatable with antibiotics...
– tonsilTonsilPalatine tonsils, occasionally called the faucial tonsils, are the tonsils that can be seen on the left and right sides at the back of the throat....
s - septic arthritisSeptic arthritisSeptic arthritis is the purulent invasion of a joint by an infectious agent which produces arthritis. People with artificial joints are more at risk than the general population but have slightly different symptoms, are infected with different organisms and require different treatment. Septic...
– jointJointA joint is the location at which two or more bones make contact. They are constructed to allow movement and provide mechanical support, and are classified structurally and functionally.-Classification:...
s - osteomyelitisOsteomyelitisOsteomyelitis simply means an infection of the bone or bone marrow...
– boneBoneBones are rigid organs that constitute part of the endoskeleton of vertebrates. They support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue...
s - peritonitisPeritonitisPeritonitis is an inflammation of the peritoneum, the serous membrane that lines part of the abdominal cavity and viscera. Peritonitis may be localised or generalised, and may result from infection or from a non-infectious process.-Abdominal pain and tenderness:The main manifestations of...
– peritoneumPeritoneumThe peritoneum is the serous membrane that forms the lining of the abdominal cavity or the coelom — it covers most of the intra-abdominal organs — in amniotes and some invertebrates... - meningitisMeningitisMeningitis is inflammation of the protective membranes covering the brain and spinal cord, known collectively as the meninges. The inflammation may be caused by infection with viruses, bacteria, or other microorganisms, and less commonly by certain drugs...
– meningesMeningesThe meninges is the system of membranes which envelopes the central nervous system. The meninges consist of three layers: the dura mater, the arachnoid mater, and the pia mater. The primary function of the meninges and of the cerebrospinal fluid is to protect the central nervous system.-Dura... - vaginitisVaginitisVaginitis is an inflammation of the vagina. It can result in discharge, itching and pain, and is often associated with an irritation or infection of the vulva. It is usually due to infection. The three main kinds of vaginitis are bacterial vaginosis , vaginal candidiasis, and trichomoniasis. A...
– vaginaVaginaThe vagina is a fibromuscular tubular tract leading from the uterus to the exterior of the body in female placental mammals and marsupials, or to the cloaca in female birds, monotremes, and some reptiles. Female insects and other invertebrates also have a vagina, which is the terminal part of the...
(more common in pre-pubescent girls)
- pneumonia
- necrotizing fasciitisNecrotizing fasciitisNecrotizing fasciitis , commonly known as flesh-eating disease or Flesh-eating bacteria syndrome, is a rare infection of the deeper layers of skin and subcutaneous tissues, easily spreading across the fascial plane within the subcutaneous tissue.Necrotizing fasciitis is a quickly progressing and...
– skinSkin-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
, fasciaFasciaA fascia is a layer of fibrous tissue that permeates the human body. A fascia is a connective tissue that surrounds muscles, groups of muscles, blood vessels, and nerves, binding those structures together in much the same manner as plastic wrap can be used to hold the contents of sandwiches...
and muscleMuscleMuscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to... - scarlet feverScarlet feverScarlet fever is a disease caused by exotoxin released by Streptococcus pyogenes. Once a major cause of death, it is now effectively treated with antibiotics...
– upper body - sinusitisSinusitisSinusitis is inflammation of the paranasal sinuses, which may be due to infection, allergy, or autoimmune issues. Most cases are due to a viral infection and resolve over the course of 10 days...
– sinuses. - strep throatStrep throatStreptococcal pharyngitis, streptococcal tonsillitis, or streptococcal sore throat is a type of pharyngitis caused by a group A streptococcal infection. It affects the pharynx including the tonsils and possibly the larynx. Common symptoms include fever, sore throat, and enlarged lymph nodes...
– pharynxPharynxThe human pharynx is the part of the throat situated immediately posterior to the mouth and nasal cavity, and anterior to the esophagus and larynx. The human pharynx is conventionally divided into three sections: the nasopharynx , the oropharynx , and the laryngopharynx... - toxic shock syndromeToxic shock syndromeToxic shock syndrome is a potentially fatal illness caused by a bacterial toxin. Different bacterial toxins may cause toxic shock syndrome, depending on the situation. The causative bacteria include Staphylococcus aureus and Streptococcus pyogenes...
– multiple systems
(Note that some of these diseases can be caused by other infectious agents as well.)
Acute rheumatic fever
Acute rheumatic fever (ARF) is a complication of respiratory infections caused by GAS. The M-protein generates antibodies that cross-react with autoantigens on interstitial connective tissue, particularly of the endocardium and synovium, that can lead to significant clinical illness. Although common in developing countries, ARF is rare in the United States, possibly secondary to improved antibiotic treatment, with small isolated outbreaks reported only occasionally. It is most common among children between 5–15 years old and occurs 1–3 weeks after an untreated GAS pharyngitis. ARF is often clinically diagnosed based on Jones Criteria, which include: pancarditis, migratory polyarthritisPolyarthritis
Polyarthritis is any type of arthritis which involves 5 or more joints simultaneously. It is usually associated with autoimmune conditions.Polyarthritis may be experienced at any age and is not gender specific.-Causes:...
of large joints, subcutaneous nodules, erythema marginatum
Erythema marginatum
Erythema marginatum is described as the presence of pink rings on the trunk and inner surfaces of the limbs which come and go for as long as several months. It is found primarily on extensor surfaces....
, and sydenham chorea (involuntary, purposeless movement). The most common clinical finding is a migratory arthritis involving multiple joints. Other indicators of GAS infection such as a DNAase or ASO serology test must confirm the GAS infection. Other minor Jones Criteria are fever, elevated ESR
Erythrocyte sedimentation rate
The erythrocyte sedimentation rate , also called a sedimentation rate or Biernacki Reaction, is the rate at which red blood cells sediment in a period of 1 hour...
and arthralgia
Arthralgia
Arthralgia literally means joint pain; it is a symptom of injury, infection, illnesses or an allergic reaction to medication....
. Of the most serious complications is pancarditis, or inflammation of all three heart tissues. A fibrinous pericarditis
Pericarditis
Pericarditis is an inflammation of the pericardium . A characteristic chest pain is often present.The causes of pericarditis are varied, including viral infections of the pericardium, idiopathic causes, uremic pericarditis, bacterial infections of the precardium Pericarditis is an inflammation of...
can develop with a classic friction rub that can be auscultated. This will give increasing pain upon reclining. Further endocarditis can develop with aseptic vegetations along the valve closure lines, particularly the mitral valve. Chronic rheumatic heart disease mostly affects the mitral valve
Mitral valve
The mitral valve is a dual-flap valve in the heart that lies between the left atrium and the left ventricle...
which can become thickened with calcification of the leaflets, often causing fusion of the commissures and chordae tendineae
Chordae tendineae
The chordae tendineae, or heart strings, are cord-like tendons that connect the papillary muscles to the tricuspid valve and the mitral valve in the heart....
. Other findings of ARF include erythema marginatum
Erythema marginatum
Erythema marginatum is described as the presence of pink rings on the trunk and inner surfaces of the limbs which come and go for as long as several months. It is found primarily on extensor surfaces....
(usually over the spine or other bony areas) and a red expanding rash on the trunk and extremities that recurs over weeks to months. Because of the different ways ARF presents itself, the disease may be difficult to diagnose. A neurological disorder, Sydenham chorea
Chorea (disease)
Choreia is an abnormal involuntary movement disorder, one of a group of neurological disorders called dyskinesias. The term choreia is derived from the Greek word χορεία , see choreia , as the quick movements of the feet or hands are vaguely comparable to dancing or piano playing.The term...
, can occur months after an initial attack, causing jerky involuntary movements, muscle weakness, slurred speech, and personality changes. Initial episodes of ARF as well as recurrences can be prevented by treatment with appropriate antibiotics. It is important to distinguish ARF from rheumatic heart disease. ARF is an acute inflammatory reaction with pathognomonic Aschoff bodies histologically and RHD is a non-inflammatory sequelae of ARF.
Post-streptococcal glomerulonephritis
Post-streptococcal glomerulonephritis (PSGN) is an uncommon complication of either a strep throat or a streptococcal skin infection. It is classified as a type III hypersensitivity reaction. Symptoms of PSGN develop within 10 days following a strep throat or 3 weeks following a GAS skin infection. PSGN involves inflammation of the kidney. Symptoms include pale skin, lethargy, loss of appetite, headache and dull back pain. Clinical findings may include dark-colored urine, swelling of different parts of the body (edema), and high blood pressure. Treatment of PSGN consists of supportive care.Severe streptococcal infections
Some strains of group A streptococci (GAS) cause severe infection. Those at greatest risk include children with chickenpoxChickenpox
Chickenpox or chicken pox is a highly contagious illness caused by primary infection with varicella zoster virus . It usually starts with vesicular skin rash mainly on the body and head rather than at the periphery and becomes itchy, raw pockmarks, which mostly heal without scarring...
; persons with suppressed immune systems; burn victims; elderly persons with cellulitis
Cellulitis
Cellulitis is a diffuse inflammation of connective tissue with severe inflammation of dermal and subcutaneous layers of the skin. Cellulitis can be caused by normal skin flora or by exogenous bacteria, and often occurs where the skin has previously been broken: cracks in the skin, cuts, blisters,...
, diabetes, blood vessel disease, or cancer
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
; and persons taking steroid
Steroid
A steroid is a type of organic compound that contains a characteristic arrangement of four cycloalkane rings that are joined to each other. Examples of steroids include the dietary fat cholesterol, the sex hormones estradiol and testosterone, and the anti-inflammatory drug dexamethasone.The core...
treatments or chemotherapy
Chemotherapy
Chemotherapy is the treatment of cancer with an antineoplastic drug or with a combination of such drugs into a standardized treatment regimen....
. Intravenous drug users also are at high risk. GAS is an important cause of puerperal fever
Puerperal fever
Puerperal fever or childbed fever, is a bacterial infection contracted by women during childbirth or miscarriage. It can develop into puerperal sepsis, which is a serious form of septicaemia. If untreated, it is often fatal....
worldwide, causing serious infection and, if not promptly diagnosed and treated, death in newly delivered mothers. Severe GAS disease may also occur in healthy persons with no known risk factors.
All severe GAS infections may lead to shock, multisystem organ failure, and death
Death
Death is the permanent termination of the biological functions that sustain a living organism. Phenomena which commonly bring about death include old age, predation, malnutrition, disease, and accidents or trauma resulting in terminal injury....
. Early recognition and treatment are critical. Diagnostic tests include blood counts and urinalysis
Urinalysis
A urinalysis , also known as Routine and Microscopy , is an array of tests performed on urine, and one of the most common methods of medical diagnosis...
as well as cultures of blood or fluid from a wound site.
Severe Group A streptococcal infections often occur sporadically but can be spread by person-to-person contact.
Close contacts of people affected by severe Group A streptococcal infections, defined as those who have had prolonged household contact in the week before the onset of illness, may be at increased risk of infection. This increased risk may be due to a combination of shared genetic susceptibility within the family, close contact with carriers, and the virulence of the Group A streptococcal strain that is involved.
Public Health
Public health
Public health is "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals" . It is concerned with threats to health based on population health...
policies internationally reflect differing views of how the close contacts of people affected by severe Group A streptococcal infections should be treated. Health Canada
Health Canada
Health Canada is the department of the government of Canada with responsibility for national public health.The current Minister of Health is Leona Aglukkaq, a Conservative Member of Parliament appointed to the position by Prime Minister Stephen Harper.-Branches, regions and agencies:Health Canada...
and the US CDC recommend close contacts see their doctor for full evaluation and may require antibiotics; current UK Health Protection Agency
Health Protection Agency
The Health Protection Agency, or, in Welsh, Yr Asiantaeth Diogelu Iechyd is a statutory corporation. It is an independent UK organisation that was set up by the government in 2003 to protect the public from threats to their health from infectious diseases and environmental hazards...
guidance is that, for a number of reasons, close contacts should not receive antibiotics unless they are symptomatic but that they should receive information and advice to seek immediate medical attention if they develop symptoms.
Treatment
Once group A streptococcus is documented as the cause of infection, treatment with penicillin should be started. Erythromycin or another macrolide can be used in patients who are allergic to penicillin. Treatment with ampicillin/sulbactam is appropriate if deep oropharyngeal abscesses are present. In cases of streptococcal toxic shock syndrome, treatment consists of penicillin and clindamycin, given with intravenous immunoglobulin.Relation with tics and OCD
In recent years, subsets of children with acute, rapid-onset of tic disorderTic disorder
Tic disorders are defined in the Diagnostic and Statistical Manual of Mental Disorders based on type and duration of tics...
s and obsessive compulsive disorder (OCD) hypothesized to be due to an autoimmune response to group A beta-hemolytic streptococcal infection (PANDAS) have been identified.
External links
- Group A streptococcal infection at National Institutes of HealthNational Institutes of HealthThe National Institutes of Health are an agency of the United States Department of Health and Human Services and are the primary agency of the United States government responsible for biomedical and health-related research. Its science and engineering counterpart is the National Science Foundation...
- Group A streptococcal infections - Frequently Asked Questions at UK Health Protection AgencyHealth Protection AgencyThe Health Protection Agency, or, in Welsh, Yr Asiantaeth Diogelu Iechyd is a statutory corporation. It is an independent UK organisation that was set up by the government in 2003 to protect the public from threats to their health from infectious diseases and environmental hazards...