This plague you describe was known as the Antonine or Galen's plague (164-180). As you mentioned, this plague was probably brought back by from the Eastern frontier by Verus, serving as co-emperor with Marcus Aurelius.
Galen, the Greek physician from Pergamum, initially fled the plague, but was called back by the co-emperors to help control the plague. Most people (myself included) think it was a variant of small pox. Galen described a skin eruption occuring on the ninth day: sometimes dry and sometimes pustular. This does not sound like typhus or boubonic plague. A couple thousand people a day in Rome would die of this plague. Verus (and less likely, Aurelius) probably died from this plague.
Fortunately, we no longer suffer from smallpox. But it was the scourge of more recent history, too.
I feel that the impact of disease in the Ancient world has always been underestimated. This type of plague would have had a devastating impact on society. (Think about the impact of the Black Plague in Europe during the Middle Ages, for example. That plague killed at least a third of Europe's population. No one would write a serious history of the Middle Ages without at least a mention of the impact of the plague. Somehow, Ancient Roman history is frequently written without the slightest mention of the diseases that were so much a tragic part of everyday life in Ancient Rome.)
Plagues such as this would have caused immense depopulation and disruption in society. The Antonine plague and the later plague of Cyprian, also known as the Aurelian plague, (that lasted from 251 to 266 and killed Emperor Claudius Gothicus) could have resulted in the pressure for the Roman armies to recruit increasingly more barbarians into their diminishing ranks.
These plagues would haved caused food shortages due to the disruption of the food supply from the abandonment of farms to the breakdown of the means of transport. Undernourishment would only have made a population more vulnerable to the ravages of disease.
The plagues were excellent propaganda tools for the ruling elites. In Pagan Rome, the plagues could be seen as a result of the disruption of the Pax Deorum by the Christians. Later, in Chrisitan Rome, they could be seen as the result of the "wrath of a Christian [?] God."
In answer to your question, since Roman medicine did not adequately understand the cause (etiology) of these plagues, I doubt anything was done to prevent their spread except for isolation. (Remember, the simple concept such as handwashing in maternity wards wasn't widely accepted by Western medicine until the 19th century.)
At best, treatment would have been to reduce discomfort (palliative measures only)--narcotics and wine for pain, pleny of fluids, and blankets. At worst, use of bloodletting or cathartics would have hastened the poor victim's demise. Prayers and offerings would have had dubious benefits.
guy known as gaius