Ima, encontrei seu texto e acho que esse "messa" deve ser gíria para doença de Lyme. Veja:

Pregnant Lyme-disease patients cannot be treated with the first-choice antibiotic, ***doxycycline*** (see below), as it is potentially harmful for the fetus. Instead, erythromycin is usually given; it is less effective against the disease but harmless for the fetus.[51]

In later stages, the bacteria disseminate throughout the body and may cross the blood-brain barrier, making the infection more difficult to treat. Late diagnosed Lyme ***is treated with oral or IV antibiotics***, frequently ceftriaxone for a minimum of four weeks. Minocycline is also indicated for neuroborreliosis for its ability to cross the blood-brain barrier.[98]
http://en.wikipedia.org/wiki/Lyme_disease

Parece-me tratar-se da bactéria que causa a doença de Lyme.