Dr. Frederick Howell tries to recruit Kimble to help out in his clinic. Kimble tries to refuse saying he is wanted for murder. Dr. Howell's answer is: "I don't care if you're the Mad Bomber!" This is a reference to George Peter Metesky aka "The Mad Bomber", who planted more than 30 bombs in New York City in the 1940s and 1950s.
Meningococcus is a term for Neisseria Meningitidis, a strain of bacteria that left unchecked will inflame the membrane surrounding the brain and spinal cord. This membrane is called the meninges and its inflammation is called meningitis, hence the term meningococcus meningitis that Dr. Howell uses to indicate the focus of his research.
This is the fifth and final appearance Rodolfo Hoyos Jr. makes in the series and the fifth of seven appearances he makes on screen with David Janssen, the last two appearances occurring in Operation: Deadhead (1971) and Elegy for a Cop (1975), respectively.