DIPHTHERIA

Diphtheria — is an upper respiratory tract illness characterized by sore throat, low fever, and an adherent membrane (a pseudomembrane) on the tonsils, pharynx, and/or nasal cavity. A milder form of diphtheria can be restricted to the skin. Diphtheria is an infectious disease caused by the bacterium Corynebacterium diphtheriae, also called the “Kleb-Loffler Baciilllus. This disease primarily affects the mucous membranes of the respiratory tract (respiratory diphtheria), although it may also affect the skin (cutaneous diphtheria) and lining tissues in the ear, eye, and the genital areas.

Diphtheria causes the progressive deterioration of myelin sheaths in the central and peripheral nervous system leading to degenerating motor control and loss of sensation. Diphtheria is a contagious disease spread by direct physical contact or breathing the aerosolized secretions of infected individuals.

Signs and Symptoms:
The onset of disease is usually gradual. Symptoms include fatigue, fever, a mild sore throat and problems swallowing. Children infected have symptoms that include nausea, vomiting, chills, and a high fever, although some do not show symptoms until the infection has progressed further. In 10% of cases, patients experience neck swelling, informally referred to as "bull neck." These cases are associated with a higher risk of death.

In addition to symptoms at the site of infection (sore throat), the patient may experience more generalized symptoms, such as listlessness, pallor, and fast heart rate. These symptoms are caused by the toxin released by the bacterium. Low blood pressure may develop in these patients. Longer-term effects of the diphtheria toxin include cardiomyopathy and peripheral neuropathy (sensory type).

The cutaneous form of diphtheria is often a secondary infection of a preexisting skin disease. Signs of cutaneous diphtheria infection develop an average of seven days after the appearance of the primary skin disease.

Mode of Transmission:
Diphtheria is transmitted to close contacts via airborne respiratory droplets or by direct contact with nasopharyngeal secretions or skin lesions. Rarely, it can be spread by objects contaminated by an infected person. Overcrowding and poor living conditions can further contribute to the spread of diphtheria.

INCUBATION Period:
The respiratory form has an incubation period of 2–6 days; occasionally, longer, if clinical symptoms finally results in one who has been healthy carrier of the nasal type.

PERIOD OF COMMUNICABILITY:
Variable, rarely more than 2-4 weeks in untreated patients or 1-2 days in treated patients.

DIAGNOSTIC LABORATORIES:
1. Nose and Throat Swab – culture of nose and throat in all types. Swabs are streaked on fresh pai’s Loeffler’s serum agar, bloodtellurite or tinsdale media and examined after 8-24 hours of incubation.
2. Virulence Test – direct smear properly stained will frequently reveal the typical gram-positive organism.
3. Schick Test – an intradermal injection of dilute diphtheria toxin, will show a positive reaction in individuals without immunity, and hence, susceptible to diphtheria. Within 48-72 hours a positive reaction reveals itself as a local circumscribed area of redness, usually 1-3cm in diameter, but occasionally larger.
4. Moloney Test – to determine hypersensitivity to diphtheria toxoid; it is performed by injecting intradermally 0.1cc of fluid toxoid. If positive, an area of erythema will develop within 24 hours of injection.

Treatment:
Diphtheria is a serious illness. Doctors treat it immediately and aggressively with these medications:
 An antitoxin. After doctors confirm that a person has diphtheria, the infected child or adult receives a special antitoxin. The antitoxin neutralizes the diphtheria toxin already circulating in your body. The antitoxin is injected into a vein (intravenously) or into a muscle (intramuscular injection). But first, doctors may perform skin allergy tests to make sure that the infected person doesn't have an allergy to the antitoxin. People who are allergic must first be desensitized to the antitoxin. Doctors accomplish this by initially giving small doses of the antitoxin and then gradually increasing the dosage.
 Antibiotics. Diphtheria is also treated with antibiotics, such as Penicillin G Potassium, 100,000 mg/kg/day in 4 doses or Erythromycin, 40 mg/kg in 4 doses, orally for 7-10days. Antibiotics help kill bacteria in the body, clearing up infections. Antibiotics reduce to just a few days the length of time that a person with diphtheria is contagious.

Prevention:
The prevention of diphtheria is best achieved through universal immunization with diphtheria toxoid-containing vaccines. Immunization for infants and children consists of five DTaP vaccinations generally given at ages 2, 4, and 6 months, with the fourth dose being administered between 15-18 months, and the fifth dose at ages 4-6 years. At age 11-12 years, children should receive a single Tdap vaccination if they have completed the recommended childhood vaccination schedule. Because immunity wanes over time, subsequent booster immunization is required every 10 years thereafter to maintain protective antibody levels.

NURSING INTERVENTIONS:
1. Rest – confined to bed at least 2 weeks, no privileges.
2. Care of the nose and throat – it must be kept clean, prevent dryness and excoriation caused by discharges from the lesions.
3. Ice Collar – to reduce pain of the sore throat.
4. Diet – when there is sore throat, soft food is easily swallowed than fluid. Fruit juices help to maintain alkalinity of the blood.