Pneumonic plague is one of the three plague types that can be contracted when exposure to the bacteria Yersinia pestis occurs. Without treatment, it is fatal to almost all people who get it and treatment is best begun within 24 hours of exposure in order to improve survival rates. This form of plague is rare, but it does occasionally crop up in human populations, as it did in August of 2009 in China.
There are a couple of ways that exposure to Y. pestis may cause pneumonic plague. People infected in the lymph nodes (bubonic plague) or blood (septicemia plague) may have the bacteria move to their lungs. They thus develop secondary pneumonic plague and can pass the plague by breathing around others. Alternately, close exposure to the breathing of an animal (and there are many rodents who either are infected or carry pests that can be infected) could cause pneumonic plague. Most disease specialists stress that exposure must be extremely close, and cases of pneumonic plague are often associated with extensive handling of animals.
The main symptoms of pneumonic plague emerge within one to three days after exposure and include significant cough, which may involve coughing up mucus that is bloody. Pneumonia develops soon after, and other symptoms like fever, headache, chills, and persistent weakness are also present. The development of pneumonia is greatly significant though, and typically explains why pneumonic plague can be so dangerous. The aggressive pneumonia quickly inhibits breathing and results in failure of the respiratory system.
Pneumonic plague is curable especially when it is identified in its early stages. There are several types of antibiotics that fight Y. pestis effectively, but in most cases treatment is most favorable if the illness is diagnosed within 24 hours of emergence. Later diagnosis creates a decline in survival rate, whereas early diagnosis tends to have a near 100% cure rate.
There is effective treatment for exposure to a person with this form of plague. Antibiotic treatment can be used to prevent developing the condition, and this may be one of the best methods for controlling spread of the plague. Though typically this form of the plague is rare, once it begins to be passed from person to person, contagion rate is higher. However, when this plague is identified, anyone exposed could be protected with a week’s course of antibiotics.
Plague of any form is undoubtedly frightening, and it may not be the first thing that occurs to diagnosticians due to its rarity. It probably makes sense for most people to know the symptoms of the major plagues that can occur from Y. pestis exposure. Yet it is also important to realize emergence of plague in large-scale form is uncommon.
