Microbial Diseases Of The Cardiovascular and Lymphatic Systems |
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The growth of microorganisms in blood is called sepsis. Signs include lymphangitis (inflamed lymph vessels).
Lymphangitis
Sepsis usually results from a focus of infection in the body.
Gram-negative sepsis can lead to septic shock, characterized by decreased blood pressure. Endotoxin causes the symptoms.
Antibiotic-resistant enterococci and group B streptococci cause gram-positive sepsis.
Puerperal sepsis begins as a focal infection of the uterus following childbirth or abortion; it can progress to peritonitis or septicemia.
Streptococcus pyogenes is the most frequent cause.
Oliver Wendell Holmes and Ignaz Semmelweiss demonstrated that puerperal sepsis was transmitted by the hands and instruments of midwives and physicians.
Puerperal sepsis is now uncommon because of modern hygienic techniques and antibiotics.
The inner layer of the heart is the endocardium.
Subacute bacterial endocarditis is usually caused by alpha-hemolytic streptococci, but may also be caused by staphylococci or enterococci.
The infection arises from a focus of infection, such as a tooth extraction.
Preexisting heart abnormalities are predisposing factors.
Signs include fever, anemia and heart murmur.
If untreated, the condition is fatal within a few months.
Subacute Bacterial Endocarditis
Acute bacterial endocarditis is usually caused by Staphylococcus aureus (or Streptococcus pyogenes).
The bacteria cause rapid destruction of heart valves and is frequently fatal within days or weeks.
Laboratory diagnosis is based on isolation and identification.
Streptococci can also cause pericarditis, inflammation of the pericardium.
Rheumatic Fever
Rheumatic fever is an autoimmune complication of streptococcal infections.
Rheumatic fever is expressed as arthritis or inflammation of the heart. It can result in permanent heart damage.
Antibodies against group A ß-hemolytic streptococci react with streptococcal antigens deposited in joints or heart valves or cross-react with the heart muscle.
Rheumatic fever can follow a streptococcal infection, such as streptococcal sore throat. Streptococci might not be present at the time of rheumatic fever.
Prompt treatment of streptococcal infections can reduce the incidence of rheumatic fever.
Because the organism has remained sensitive to penicillin it is administered as a preventive measure against subsequent streptococcal infections to people who are at risk (people who have had an incidence of rheumatic fever).
A Nodule Caused by Rheumatic Fever
