An outbreak of measles in the South Plains of Texas is continuing to grow, with the number of cases doubling in less than a week. At least 48 cases were identified with symptom onset within the last three weeks,

Additional measles cases "are likely to occur" as an outbreak of the virus grows, the Texas Department of State Health Services said in its latest update.

At least 49 cases have been confirmed. Health officials — who are scrambling to get a handle on the vaccine-preventable outbreak — suspect 200 to 300 people may be infected.