Diphtheria is a life-threatening infection of the upper respiratory airways caused by the bacterial pathogen Corynebacterium diphtheria. Transmission of infection is common during the spring and winter months . The spread of infection is by means of droplet infection through the upper respiratory tract during the first 2 to 5 days of infection . Diphtheria is currently rare in developed nations, its effective eradication was accomplished by the radical immunization of the pediatric age group against this type of infection.
The signs and symptoms typically presents within the first 2 to 5 days from infection. The symptomatology of the disease includes the following:
Patients can be easily diagnosed clinically with the aid of a detailed medical history and the demonstration of the throat signs like the pseudomembrane formation and the neck adenopathy. A throat swab can be performed for culture and sensitivity purposes where a specialized culture media is used to grow Corynebacterium diptheriae. In cases of cutaneous diphtheria, a skin sample is biopsied and processed to demonstrate the infecting bacillus in culture. Diphtheria which complicates to myocarditis can be assessed using serum troponin I levels to determine its severity .
Diphtheria is a potentially fatal disease that warrants immediate medical care and treatment. Patients are promptly given diphtheria antitoxins intravenously or intramuscularly to neutralize the circulating diphtheria toxin in the body. Due care and diligence must be observed in the introduction of the antitoxin because this can cause a life-threatening hypersensitivity reaction among susceptible patients. Antibiotics like penicillin and erythromycin are also being used in the treatment of diphtheria infections . The antibiotic therapy clears up the bacterial load of the infections and shortens its infective stage.
The international mortality rate for all forms of diphtheria is 5% to 10%. Mortality increases beyond 20% among children below 5 years or age and adults beyond 40 years of age. Toxigenic forms of the diphtheria bacteria are associated with increased mortality and morbidity among patients. Regions of the world with high immunization patterns have lower mortality ratings than those with low immunization coverage. Diphtheria in its aggressive bacteremia phase may carry a poorer prognosis and could reach a mortality rate of up to 40% .
Diphtheria is brought about by the gram positive aerobic bacillus Corynebacterium diphtheria. The aerobic bacterium propagates near the surface of the throat’s mucous membrane. The pathogen can be spread via airborne droplet through sneezing and coughing. There are less common ways of diphtheria transmission like the inadvertent contact with personal belongings and household items (i.e. towels, toys, and tissue papers).
In the United States, diphtheria occured in at least 200,000 patients annually before the advent of the vaccination in the 1920’s . Effective preventive measures and mass immunizations have eradicated the disease, and limited the incidence of diphtheria infections to 1,000 cases per annum at the maximum. Sporadic occurrence of diphtheria has been noted among the Native American population, alcoholics, homeless people, and those in the low socioeconomic group . In the international arena, the World Health Organizations has continually regarded diphtheria as a public health threat in the poor and developing nations.
Large epidemics were recorded in the Russian federation and the Baltic states during the periods 1990 to 1995. Moreover, diphtheria outbreaks in small pockets were documented in the regions of the sub-Saharan Africa, France, and India . After the development of the vaccine, mortality rate of diphtheria in United States has gone down to 1 case per 100 million population. There is no sexual and racial predilection to the diphtheria infection.
When the diphtheria bacillus attaches to the airway mucosal epithelium, the local endosomes consequently release exotoxins that cause a localized inflammation. This process causes cell destruction and necrosis of the epithelium. Toxins may be carried hematologically or lymphatically to distant sites and organs in the advent of the cell destruction. The diphtheria toxin may affect the myocardium, the nervous system, and the kidneys. The toxigenic strains of the diphtheria bacteria are the most insidious and invasive in terms of organ afflictions and complications.
The most effective way in preventing diphtheria is by active immunization during childhood. The protection developed from the initial immunization will fade in time and would render the host susceptible to diphtheria infection once again. Booster shots when the child reaches 12 years old and every 10 years henceforth will essentially boost the immune system against the diphtheria infection. Early detection and treatment is paramount in shortening its clinical course and preventing its spread and transmission.
Diphtheria is a serious infection of the upper airways which usually involves the mucous membrane of throat and nose. The hallmark sign of diphtheria is the pseudomembrane formation at the back of the throat accompanied by symptoms of sore throat, fever, and weakness. Primary diphtheria is easily controlled by antibacterial therapy while complicated cases may cause damage to the kidneys, heart and the nervous system .
The diphtheria infection is caused by the toxigenic type and the non-toxigenic type of Corynebacterium diphtheria.
Patients suffering from diphtheria typically present with a pseudomembrane formation over the throat and tonsils with bilateral lymph node enlargement. Cutaneous diphtheria presents as ulcers with a grayish membrane. Constitutional signs of fever and chills can also be present.
The diagnosis of diphtheria is done with the use of a detailed medical history and the careful physical examination of the throat. Culture and sensitivity of the bacteria taken from throat swabs and skin ulcer scrapings may also elucidate the infecting bacteria.
Treatment and follow-up
Patients with diphtheria are injected with diphtheria antitoxin and given penicillin and erythromycin antibiotics to control the disease. Primary prevention with the use of active immunization with diphtheria is the best way to control the spread of the illness.