References:
- Global Infectious Diseases and Epidemiology Online Network: Infectious Diseases of the Philippines, 2013 eBook Edition, ISBN 978-1-61755-582-4, by Stephen Berger. Accessed here.
| Agent | BACTERIUM. Corynebacterium diphtheriae, a facultative gram-positive bacillus |
| Reservoir | Human |
| Vector | None |
| Vehicle | Droplet Contact Dairy products Clothing |
| Incubation Period | 2 to 5 days (As early or late as 1 to 10 days) |
| Diagnostic Tests | Culture on special media Advise laboratory when this diagnosis is suspected |
| Typical Adult Therapy | Respiratory isolation. Equine antitoxin 1,000 units/kg IM. Erythromycin 10 mg/kg QID X 10d |
| Typical Pediatric Therapy | Diphtheria antitoxin Diphtheria DTP DT DTaP Td |
| Clinical Hints | Pharyngeal membrane with cervical edema and lymphadenopathy; or punched out skin ulcers with membrane; myocarditis or neuropathy (foot/wrist drop) appears weeks later. |
| Synonyms | Corynebacterium diphtheriae, Difteri, Difteria, Difterie, Difterite, Diphterie |
WHO Case Definition for Surveillance
Clinical description
- An illness of the upper respiratory tract characterized by laryngitis or pharyngitis or tonsillitis, and adherent membranes of tonsils, pharynx and/or nose
Laboratory criteria for diagnosis
- Isolation of Corynebacterium diphtheriae from a clinical specimen.
- Note: A rise in serum antibody (fourfold or greater) is of interest only if both serum samples were obtained before administration of diphtheria toxoid or antitoxin. This is not usually the case in surveillance, where serological diagnosis of diphtheria is thus unlikely to be an issue.
Case classification
- Suspected: Not applicable.
- Probable: A case that meets the clinical description.
- Confirmed: A probable case that is laboratory confirmed or linked epidemiologically to a laboratory confirmed case.
Note: Persons with positive C. diphtheriae cultures who do not meet the clinical description (i.e. asymptomatic carriers) should not be reported as probable or confirmed diphtheria cases.
Faucal Diphtheria
Following an incubation period of 2 to 5 days (7 days after primary skin infection for cutaneous diphtheria), the patient presents with nonspecific symptom which may include fever and chills, malaise, sore throat, hoarseness or dysphagia, cervical edema and lymphadenopathy, rhinorrhea (mucopurulent or blood-tinged), cough, stridor, wheezing, nausea and vomiting and headache.
- Respiratory diphtheria may progress rapidly to respiratory arrest from airway obstruction by a tracheobronchial pseudomembrane.
- Tachycardia, pallor, and foul breath may be present.
- The pseudomembrane is generally firm, adherent, thick, fibrinous and of a gray-brown color.
- It may occur over the palate, pharynx, epiglottis, larynx, or trachea • occasionally extending into the tracheobronchial tree.
- The area may bleed if disturbed.
- Marked edema of the tonsils, uvula, submandibular region and anterior neck (“bull neck) may be observed and may be associated with thick speech, stridor, anterior cervical lymphadenopathy, and petechial hemorrhages.
Cutaneous Diphtheria
Cutaneous diphtheria is associated with a history of a break in the skin, followed by pain, tenderness, erythema, or exudate.
- Lesions appear as punched-out ulcers with dirty gray membranes at their margins.
- Genital ulcers may be misdiagnosed as venereal disease.
Complications
Cardiac Complications
Cardiovascular signs ensue 1 to 2 weeks following the initial illness.
- Myocarditis occurs in as many as two thirds of patients, and approximately 20% develop cardiac dysfunction.
- Circulatory collapse, heart failure, atrioventricular blocks and arrhythmias may occur.
- Endocarditis and mycotic aneurysms also have been reported, typically in intravenous drug users.
Neurological Complications
Approximately 70% of patients with severe infection develop neuropathy, neuritis or motor paralysis 2 to 8 weeks following initial illness.
- Clinical and cerebrospinal fluid findings at this stage are indistinguishable from those Guillain-Barre syndrome.
- Potentially fatal paralysis of the diaphragm may ensue.
- Paralysis typically resolves completely with resolution of infection.
The neurological manifestations of diphtheria include:
- Hypesthesia and paralysis of the soft palate
- Weakness of the posterior pharyngeal, laryngeal, and facial nerves, resulting in a “nasal tone” to the voice, difficulty in swallowing, and occasionally aspiration
- Cranial neuropathies, typically during the fifth week, leading to oculomotor and ciliary paralysis (strabismus, blurred vision, and loss of accommodation)
- Symmetric polyneuropathy beginning within 10 days to 3 months after infection, and manifest as motor deficit with diminished deep tendon reflexes
- Proximal muscle weakness of the extremities progressing distally (or distal weakness progressing proximally).