I guess it might be nice to talk about something besides COVID-19, but diphtheria definitely is not nice. A couple of weeks ago the CDC issued a Level 1 travel alert for Vietnam due to an outbreak of diphtheria in the Central Highlands region. Level 1 is the lowest of 3 travel alert levels, just meaning to keep a watch on things if planning to travel there.
I'm hoping no one feels the need to travel abroad now with our current pandemic possibly ramping up again, but this notice does provide us with a good opportunity to review clinical signs and symptoms of diphtheria, a disease very few of us have seen.
Of course it is a vaccine-preventable disease, so immunization is our primary guard against becoming ill. Remember it is a toxin-mediated disease, with fatalities usually due to myocarditis or to neuritis causing paralysis. In addition to common findings of sore throat and low-grade fever, the characteristic gray pseudomembrane can form in the pharynx or nose and is a big clue for the disease if you know what you are looking for. Respiratory diphtheria is fairly contagious, leading to outbreaks. Antitoxin and antibiotic therapy are mainstays to prevent complications in infected individuals, and antibiotic treatment can reduce transmission to others. The CDC's Yellow Book has a concise summary of features.
Speaking of vaccines, please remember not to let our pandemic delay children being immunized!