Diphtheria is a disease that has worldwide distribution. Nonetheless, it is uncommon in Thailand. There were 18 cases of diphtheria in 2019, with the majority in the south, such as Satun, Songkhla, and Pattani provinces. In neighboring countries such as Myanmar, there was an outbreak of diphtheria among the migrant population 3-4 years ago. Furthermore, globally, periodic flare-ups of the disease occur due to children not being fully vaccinated according to national guidelines. Although diphtheria is uncommon, it can cause severe illnesses.
Corynebacterium diphtheriae bacteria is the causative agent which spreads through nasal mucus, saliva, and respiratory secretions. An untreated patient can infect up to 6-7 other persons. The infection results in respiratory symptoms, and some may also have skin lesions; in severe cases, myocarditis, renal failure, and death may ensue.
Symptoms
Patients become symptomatic 2 and 5 days after the initial infection and usually present with mild symptoms of low-grade fevers, muscle aches, and sore throats. In the early stages, the patient will present with pharyngeal injection and swollen lymph glands, followed by hoarseness and increasing difficulty breathing. With continuing infection, patches of grey-white debris, called pseudomembrane resulting from bacterial toxins damaging normal tissue will form, tightly adhered to the throat or respiratory tract linings in the back of the nasal cavity or windpipe. Scraping on the patch will lead to bleeding. An experienced doctor can make a diagnosis based on the appearance of the pseudomembrane alone.
In severe cases, the pseudomembrane may obstruct the airway, causing death. In addition to the respiratory system, the toxin may disseminate via the bloodstream to cause irregular heartbeats (Arrhythmia), heart inflammation (Myocarditis) as well as inflammation of the peripheral nerves (Neuritis).
Treatment
Antibiotics and diphtheria antitoxin are the mainstays of treatments with favorable responses in most patients. Moreover, doctors will also monitor the patient’s close contact for symptom development or provide prophylactic treatment to prevent the development of diphtheria.
Prevention
For prevention, vaccination can significantly lower the risk of getting diphtheria. Before immunization became available, the disease was an endemic public health issue with several large outbreaks. With increasing population diphtheria vaccination coverage, the incidents of this disease gradually fade away. However, childhood diphtheria vaccination cannot confer lifelong protection. In Thailand, every adult should get a booster shot every ten years. Children should receive the diphtheria vaccination at ages 2, 4, 6, and 18 months, 4-6 years, and 11-12 years.
