Diphtheria: An Overview of the Infectious Threat

It is an infectious disease caused by a bacteria called Corynebacterium diphteriae.

Cause

Diphtheria is a highly contagious infectious disease, spread through respiratory droplets (from coughs or sneezes) of infected people. It can also be spread through infected objects or food (such as contaminated milk).

The infection of this bacterium is located preferably in the nose and throat. The throat infection produces gray or black, hard and fibrous pseudomembranes characteristic of the disease that can cause the obstruction of the airway (produce asphyxia). In some cases the bacteria can infect the skin.

The toxins released by the bacteria can also cause significant damage to the heart or nervous system.

Routine vaccination with the DTaP vaccine has made diphtheria an almost non-existent disease in our environment.

Risk factors for its spread are overcrowding, poor hygiene, and non-vaccination.

Symptoms

Symptoms appear 2 to 5 days after being in contact with the bacteria.

The infection causes a sore throat (sometimes very severe), pain when swallowing (odynophagia), hoarseness, barking or metallic cough, stridor (due to obstruction of the airways by a pseudomembrane), and shortness of breath. In the most severe cases, it can completely obstruct the airway, preventing the entry of air and causing asphyxia and respiratory arrest.

In addition, the child may have a watery or bloody nasal discharge, excessive drooling (it is an important warning sign because it means that the airway is closing), high fever and skin lesions.

Treatment

Treatment should be given immediately when the disease is suspected. Diphtheria toxin is given by intramuscular injection and antibiotics such as penicillin or erythromycin.

Depending on the severity of the disease, admission to a hospital may be necessary.

If the breathing difficulty in the child is very severe, it should be helped to breathe by means of mechanical ventilation.

The mortality rate is 10% and recovery from the disease is very slow.

The main complications of diphtheria are inflammation of the heart muscle (myocarditis) and the nervous system, causing temporary paralysis.

Anyone who has been in contact with an infected person should be vaccinated or given a booster dose against diphtheria. Protective immunity only lasts 10 years after the last dose. For this reason, adults should get a booster shot for tetanus and diphtheria every 10 years (Td).