VIENNA — An Austrian commission following up on claims that doctors deliberately infected patients with malaria to treat others with syphilis says hundreds of people, including orphans in a psychiatric hospital, might have been infected.

The commission started work last year following accusations by former patients who were orphaned children on a psychiatric and neurological ward run by the city of Vienna. Lawyer Johannes Oehlboeck, who represents some of them, said Friday that several believe they were used as “carriers” for the malaria parasite to keep it alive until it could be injected into syphilis patients, in a medical therapy once thought to be effective.

Malaria is a potentially fatal disease caused by parasites and usually spread to people by infected mosquitoes. Most deaths occur in children under 5.

Commission head Gernot Heiss said Friday that ongoing investigations of the 1951-1969 period show that 230 people, including some children on the ward, were injected with the parasite, all between 1955 and 1960.

The injections normally caused two weeks of fever as high as 42 Celsius, nearly 108 Fahrenheit, as well as sudden fever attacks that continued for up to two decades. In an email, Heiss said that none of those known to have been infected so far died from malaria.

The fever caused by malaria was meant to kill the syphilis. The commission has so far examined 5,140 medical histories and Heiss said it expects to end its work next year with a ruling on whether the practices reflected modern medical standards of the time.

Heiss said that malaria therapy was “recognized and practiced worldwide” until the early 1960s. He did not comment on the suspicions by the clients of Oehlboeck, the Vienna lawyer.

In 1927, Austrian psychiatrist Julius Wagner-Jauregg received the Nobel Prize in medicine for using malaria to treat people with a severe form of syphilis that infects the brain and can cause delusions, psychosis and paralysis. Doctors in Britain and the U.S. also used the treatment, sometimes using mosquitoes to infect their patients.

In subsequent years, there were ethical concerns about using malaria to treat patients with mental health problems. The later introduction of penicillin to treat infections and other therapies ultimately made the malaria treatment obsolete.