Health authorities believe vaporizers and e-cigarettes have left dozens of Texans hospitalized.

A total of 51 people in Texas have developed symptoms of severe lung illness after vaping, according to data posted Friday by the Texas Department of State Health Services.

Cases are most frequent in north and southeast Texas, accounting for 44 cases together. Remaining cases number in the single digits across other regions of the state.

Data from the Texas Department of State Health Services. Region defined by DSHS designated Public Health Regions. No cases were reported in the Panhandle region.

The total accounts for 10% of the 530 cases reported nationwide. The sudden outbreak of hospitalizations has triggered investigations from the Centers for Disease Control, Food and Drug Administration and local health authorities. In response, federal authorities plan to ban the sale of non-tobacco-flavored e-cigarettes said to be popular among youth consumers.

Texas health officials are also investigating an additional 21 cases, attempting to confirm that symptoms and substance use patterns match those of the 51 confirmed cases.

Symptoms include difficulty breathing, shortness of breath and coughing. DSHS says patients have also experienced nausea, vomiting and diarrhea.

Researchers are still unsure of the specific cause of the illnesses. However, many believe oils inhaled from vaporizer products can cause lung inflammation, making it harder to breathe. Others suspect vitamin E acetate used in vaping solutions may be to blame. Complicating the search for a cause is the proliferation of illicit and counterfeit vaporizers used to inhale tetrahydrocannabinol, or THC, the active ingredient that gives marijuana its high.

The sheer number of different vaporizer products – legal or illegal – has given investigators a complex problem to work though.

"Nobody really knows what exactly is in all of these products," Texas State Health Services commissioner Dr. John William Hellerstedt told the Texas Standard.

Until more is known, health authorities have advised people – especially youth and pregnant women – to avoid using vaporizers and e-cigarettes.

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