What is the laboratory diagnosis of diphtheria?
diphtheriae in a lab culture of material from the throat membrane confirms the diagnosis. Doctors can also take a tissue sample from an infected wound and have it tested in a lab to check for the type of diphtheria that affects the skin (cutaneous diphtheria).
What are the differential diagnosis of diphtheria?
Differentiating diphtheria from other diseases Infectious mononucleosis due to EBV. Group A streptococci pharyngitis. Epiglottitis due to Hemophilus influenza type b. Viral pharyngitis due to influenza, HSV or adenovirus.
What is the diagnostic clinical feature of a diphtheria infection?
In addition to respiratory symptoms, absorption and dissemination of diphtheria toxin can lead to toxin damage of the heart (myocarditis), nervous system, and kidneys. The onset of symptoms is typically gradual; the most common presenting symptoms are sore throat, malaise, cervical lymphadenopathy, and low-grade fever.
How is Corynebacterium diphtheriae identified in the lab?
The clinical diagnosis of diphtheria requires bacteriologic laboratory confirmation of toxigenic C diphtheriae in throat or lesion cultures. For primary isolation, a variety of media may be used: Loeffler agar, Mueller-Miller tellurite agar, or Tinsdale tellurite agar.
Why is early laboratory diagnosis of diphtheria important?
Early, accurate diagnosis is imperative since delay in specific therapy may result in death. The microbiologic diagnosis of the disease, the identification of contacts and carriers, and the appropriate clinical management of these patients are therefore crucial.
What causes bull neck?
A combination of cervical adenopathy and swollen mucosa imparts a “bull’s neck” appearance to many of the infected patients; this is shown in the image below. The most frequent cause of death is airway obstruction or suffocation following aspiration of the pseudomembrane.
Is Corynebacterium diphtheriae gram-positive?
C. diphtheriae is a pleomorphic, club-shaped, Gram positive bacillus that is catalase positive, non-motile, non-spore forming, and non-acid fast. On Gram stain, the organisms are typically described as having a “picket fence” or “Chinese character” morphology (image 3).
What is the clinical hallmark of diphtheria?
The hallmark of respiratory diphtheria is a pseudomembrane that appears within 2–3 days of illness over the mucous lining of the tonsils, pharynx, larynx, or nares and that can extend into the trachea.
What tests are used to detect Toxigenicity?
Elek’s test or the Elek plate test is an in vitro test of virulence performed on specimens of Corynebacterium diphtheriae, the bacteria that causes diphtheria. It is used to test for toxigenicity of C. diphtheriae strains. The test uses immunodiffusion.
What tests are used to detect Toxigenicity in diphtheria?
Elek’s test or the Elek plate test is an in vitro test of virulence performed on specimens of Corynebacterium diphtheriae, the bacteria that causes diphtheria. It is used to test for toxigenicity of C. diphtheriae strains.
What is pseudomembrane in diphtheria?
Within two to three days, the dead tissue forms a thick, gray coating that can build up in the throat or nose. Medical experts call this thick, gray coating a “pseudomembrane.” It can cover tissues in the nose, tonsils, voice box, and throat, making it very hard to breathe and swallow.
Is Corynebacterium beta hemolytic?
Arcanobacterium haemolyticum (formerly known as Corynebacterium haemolyticum) is the causative agent of sore throat and also causes skin and soft tissue infections in diabetes patients. A. haemolyticum is a Gram-positive, catalase-negative, β-haemolytic bacillus.
Which test is performed in Corynebacterium?
What is the clinical examination for leprosy?
Clinical examination is intended to find out if the patient has any skin or nerve lesion. The most important is the definite sensory deficit in the skin lesions which if present confirms the diagnosis of leprosy.
How is diphtheria diagnosed and treated?
Diagnosis and Treatment. Doctors usually decide if a person has diphtheria by looking for common signs and symptoms. They can use a swab from the back of the throat and test it for the bacteria that cause diphtheria. A doctor can also take a sample from a skin lesion (like a sore) and try and grow the bacteria to be sure a patient has diphtheria.
What are the recent developments in the workup of diphtheria?
Recent developments have focused upon methods for detection of the lethal and potent exotoxin produced by the causative organism, C. diphtheriae; this detection is the definitive test for the microbiologic diagnosis of diphtheria.
How are samples obtained for the diagnosis of respiratory diphtheria?
In cases of suspected respiratory diphtheria, samples should be obtained from the throat or nasopharynx (or both). In cases of cutaneous disease, samples should be obtained from any wound or skin lesions. If present, membranous material should also be examined. In addition, care should be taken to obtain material beneath the membrane [ 7 ].