Pennsylvania health officials reported Tuesday that the state’s measles outbreak has reached 792 cases, an increase of 25 since Sept. 18, with infections now recorded across 39 counties.
How serious is the outbreak?
There have been 155 hospitalizations, meaning roughly one in five reported cases has required hospital care. Four deaths have been designated as measles associated. Measles is one of the most contagious diseases known, capable of spreading to most susceptible people in a shared space and remaining infectious in the air for up to two hours after an infected person leaves.
What about the four deaths?
County coroners and the state have not fully aligned. Coroners determined that two deaths were caused by measles, that one appeared to have been, and that one was not. This kind of discrepancy is normal rather than suspicious. A state health department tracks measles associated deaths for surveillance purposes, which captures deaths occurring in infected individuals, while a coroner makes a specific cause determination for an individual. The two categories are built to answer different questions and will not always produce the same number.
Four cases were in vaccinated people. What does that mean?
Less than it appears. Four breakthrough infections among 792 cases is what public health officials expect from a vaccine that is effective but not absolute. Two doses provide an estimated 97 percent protection, which means a small number of vaccinated people can still contract measles, generally with milder illness and reduced transmission. In an outbreak this size, the striking figure is not the four but the 788. If the vaccine were failing, the ratio would look entirely different.
Who faces the greatest risk?
Infants under 12 months, who are too young for a first dose, along with pregnant women, people with weakened immune systems and anyone unvaccinated. Complications include pneumonia and encephalitis, and measles can suppress immune function for months afterward, leaving survivors more vulnerable to other infections.
What should people in Pennsylvania do?
Check vaccination records. Anyone unsure whether they received two doses can ask a physician or consult state immunization records. Adults vaccinated as children generally do not need a booster, though those vaccinated between 1963 and 1968 may have received an older formulation and should ask a doctor. Anyone in an affected county with symptoms should call ahead before visiting a clinic rather than arriving unannounced, since measles spreads readily in waiting rooms.
What are the symptoms?
High fever, cough, runny nose and red eyes appear first, followed several days later by a rash that typically begins at the hairline and spreads downward. A person is contagious for roughly four days before the rash appears, which is why the Pennsylvania measles outbreak has spread across so many counties before detection.
Why is this happening now?
Measles was declared eliminated in the United States in 2000, meaning it no longer spread continuously within the country. Outbreaks since then have begun with imported cases reaching communities with lower vaccination coverage. Sustained transmission on this scale indicates coverage has fallen below the threshold required to prevent spread, which is roughly 95 percent for a population.
Where can updates be found?
The Pennsylvania Department of Health publishes case counts as they are confirmed. The figures in this article reflect Tuesday’s update and will change. Anyone with specific medical questions should consult a physician rather than relying on news coverage.
