Officials said pertussis spreads through coughing or close contact, with symptoms appearing up to 21 days after exposure and often worsening from cold-like signs into severe coughing fits.
Families are urged to keep vaccinations current, keep sick children home and seek medical advice; infants, pregnant women and caregivers of infants may need preventive antibiotics.
If today's vaccine can't stop transmission, are we facing endless whooping cough outbreaks?
Could a new nasal spray vaccine finally end the threat of the '100-day cough' for good?
Since vaccinated adults can be silent carriers, how can we truly shield newborns from whooping cough?