CARACAS, Venezuela (AP) -- At least 38 Warao Indians have died in remote villages in Venezuela, and medical experts suspect an outbreak of rabies spread by bites from vampire bats.
Warao Indian women grieve over the body of Elbia Rivas, who died from an unidentified illness August 3.
Laboratory investigations have yet to confirm the cause, but the symptoms point to rabies, according to two researchers from the University of California at Berkeley and other medical experts.
The two UC Berkeley researchers -- the husband-and-wife team of anthropologist Charles Briggs and public health specialist Dr. Clara Mantini-Briggs -- said the symptoms include fever, body pains, tingling in the feet followed by progressive paralysis, and an extreme fear of water. Victims tend to have convulsions and grow rigid before death.
Dr. Charles Rupprecht, chief of the rabies program at the Centers for Disease Control and Prevention in Atlanta, agreed with their preliminary diagnosis.
"The history and clinical signs are compatible with rabies," Rupprecht told The Associated Press on Friday. "Prevention is straightforward: Prevent bites and vaccinate those at risk of bites."
Venezuelan health officials are investigating the outbreak and plan to distribute mosquito nets to prevent bat bites and send a medical boat to provide treatment in remote villages on the Orinoco River delta, Indigenous Peoples Minister Nicia Maldonado said Thursday, according to the state-run Bolivarian News Agency.
Outbreaks of rabies spread by vampire bats are a problem in various tropical areas of South America, including Brazil and Peru, Rupprecht said.
He said researchers suspect that in some cases environmental degradation -- including mining, logging or dam construction projects -- may also be contributing to rabies outbreaks.
"Vampire bats are very adaptable," Rupprecht said. And when their roosts are disrupted or their normal prey grow scarce, "Homo sapiens is a pretty easy meal."
More study is needed to confirm through blood or other samples from victims that it is the rabies virus in Venezuela, researchers say.
At least 38 Warao Indians have died since June 2007, and at least 16 have died in the past two months, according to a report the Berkeley researchers and indigenous leaders provided to Venezuelan officials this week.
One village, Mukuboina, lost eight of its roughly 80 inhabitants -- all of them children, Briggs said. All victims throughout the area died within two to seven days from the onset of symptoms, he said.
During a study trip Briggs and Mantini-Briggs made through 30 villages in the river delta, relatives said the victims had been bitten by bats. The couple have worked among the Warao in Delta Amacuro state for years and were invited by indigenous leaders to study the outbreak.
"It's a monster illness," said Tirso Gomez, a Warao traditional healer who said the indigenous group of more than 35,000 people has never experienced anything similar.
Mantini-Briggs, a Venezuelan former health official, said she was surprised to find many Warao villages now have cats -- a new development. "The Waraos told us it was because there were too many bats that were biting the children," she said.
Another tropical medicine expert, Dr. Daniel Bausch of Tulane University in New Orleans, agreed the symptoms and accounts suggest rabies transmitted by bats, and if confirmed, "probably a vaccination campaign would be in order."
The researchers have begun taking precautions. Mantini-Briggs said she started to wonder about her own health Friday while talking with biologist Omar Linares, a bat expert at Simon Bolivar University.
She remembered there was blood on her sheet after sleeping in a hammock in a Warao village two weeks ago. Initially she had dismissed it as an unimportant insect bite or something else, but she remembered her finger hurting that morning and that she saw two small red dots there.
Confirming it must have been a bat bite, Linares suggested she get rabies shots immediately."I'm sure a bat bit me," she said. "I remembered and said 'I'm going to get vaccinated.' "