Thirteen people have died after contracting infections from tick bites in east China's Shandong Province, provincial health authorities said Friday.

The 13 people are among the 182 reported cases of human granulocytic anaplasmosis (HGA) since May 2008, when the provincial Center for Disease Control (CDC) started monitoring the disease. Many of the patients were bitten by hard ticks, according to a statement from Shandong's health department.

Twenty-six cases of HGA, including six deaths, were reported in coastal Penglai City.

Shandong is educating the public about the disease and training doctors for the disease's treatment, it said.

Shandong's health department said in a statement earlier Friday seven people were killed by the disease. It later corrected that number to 13 in a second statement.

The statement came after several deaths from tick bites were reported in central China's Henan Province and attracted nationwide attention.

Henan's CDC said Wednesday 18 people in the province had died of the disease. The victims were among 557 reported cases of suspected HGA since May 2007. Most of the cases were found in Xinyang's Shangcheng and Guangshan counties and Shihe and Pingqiao districts.

Three experts have been sent by the Ministry of Health to look into the outbreak in Shangcheng County of Henan.

Wang Shiwen and Ding Fan with the Chinese Center for Disease Control and Prevention and Wang Guiqiang with Peking University First Hospital arrived at the county.

"It is still difficult to pinpoint the pathogen of the disease since it may be caused by a new virus," said Wang Shiwen.

HGA reduces white blood cell and platelet counts in the blood, leading to organ failure and death. The disease can cause people to feel nauseous and have a fever.

"The disease was, in many cases, misdiagnosed as cold, so many patients were not treated properly at first," said Cui Ning, doctor at the infectious diseases ward of the No.154 hospital of the People's Liberation Army.

The disease is curable if treated quickly and most people infected are between ages 40 to 70.