DIPTHERIA - THE DISEASE

1.  Information on Diptheria
   1. Pediatric Reference (detailed)http://emedicine.medscape.com/article/963334-overview 
   2. World Health Organization (simple)http://www.who.int/mediacentre/factsheets/fs089/en/ 
   3. Emergency Medicine Reference (detailed)http://emedicine.medscape.com/article/782051-overview 
   4. Mayo Clinic Information (basic)http://www.mayoclinic.com/health/diphtheria/DS00495 
2. What is diptheria?
3. How is it transmitted? How can it be prevented? Spread primarily occurs via contact with airborne respiratory droplets, direct contact with respiratory secretions of symptomatic individuals, or contact with exudate from infected skin lesions. Asymptomatic respiratory carriers are important in transmission.
4. What are its symptoms? What is its clinical significance? In the classic description of diphtheria, the primary focus of infection is the tonsils or pharynx in more then 90% of patients; the nose and larynx are the next most common sites. After an average incubation period of 2-4 days, local signs and symptoms of inflammation develop. Fever is rarely higher than 39°C.
5. How is it treated? Is it a chronic or acute condition? Prognosis depends on the virulence of the organism (with the gravis strain usually accounting for the most severe disease), the age and immunization status of the patient, the site of involvement, and the speed with which antitoxin is administered. For patients in whom disease is recognized on day 1 and therapy is promptly initiated, the mortality rate is approximately 1%. If appropriate treatment is withheld until day 4, the mortality rate rises to 20%. Antitoxin is administered once at an empiric dose based on the degree of toxicity, site and size of the membrane, and duration of illness. Most authorities prefer the intravenous route, with infusion over 30-60 minutes. Antitoxin is probably of no value for local manifestations of cutaneous diphtheria, but its use is prudent because toxic sequelae can occur. Commercially available immunoglobulin preparations for intravenous use contain antibodies to diphtheria toxin; their use for therapy of diphtheria is not proved or approved. Antitoxin is not recommended for asymptomatic carriers.
6. What are its severe complications? How often do they occur? Death due to mechanical airway obstruction or cardiac involvement with circulatory collapse occurs in at least 10% of patients with respiratory tract diphtheria. Note that there are various forms of diptheria - classical cutaneous, non respiratory mucocutaneous, and respiratory. 
7. What is the rate of infection?
8. What are risk factors for infection? Who is most at risk? Residual indigenous cases have been concentrated among incompletely vaccinated or unvaccinated persons of low socioeconomic status. Overcrowding, poor health, substandard living conditions, incomplete immunization, and immunocompromised states facilitate susceptibility to diphtheria and are risk factors associated with transmission of this disease.
9. What is its prevalence & incidence? And where? Incidence range from 0.5 - 1 per 100,000 population in Armenia, Estonia, Lithuania and Uzbekistan, to 27 - 32 per 100,000 in Russia and Tajikistan. Case fatality rates range from 2-3% in Russia and Ukraine, to 6-10% in Armenia, Kazakhstan, Moldova and Latvia, and to 17-23% in Azerbaijan, Georgia and Turkmenistan.