A child who was hospitalized with measles in Texas has died, state health officials said this week. It marks the first death in the state's latest outbreak — the largest such outbreak in close to 30 years — which has left more than 140 people infected.

The number of people with measles in Texas increased to 146 in an outbreak that led this week to the death of an unvaccinated school-aged child, health officials said Friday.

Texas' measles outbreak is up to 90 cases. Here's what you need to know about the virus, vaccination and boosters.