For more than 30 years, almost every summer, the god of death will come to this small village on the rugged highlands of Yunnan Province as scheduled. When a peasant woman named Li Linmei carried a basket of mushrooms and walked through the small road in Wangjia Village, and saw a new white curtain hanging in front of a small bungalow, she would know that someone in the village had been “towed” away.
Wangjiacun is a small village in the east of Dali, Yunnan. It takes about an hour’s drive from downtown Dali. Every year, when the monsoon and monsoon rain arrive here at the end of June, people of different ages in the village will mysteriously die one after another.
No one knows who the “murderer” is.
The only doctor in the village, Li Guanghui, walked out of the mourning hall with a pale face. He frowned and said to himself: “Who will die next?”
The mysterious murderer
Happened in the Wang’s house Similar death cases in the village and surrounding areas are all referred to as “sudden deaths of unknown cause in Yunnan”. Since 1978, there have been more than 400 deaths and dozens of non-fatal heart disease cases in the local area, which have been classified as “sudden death syndrome of unknown cause”.
Like a curse, these “unexplained” sudden deaths are always concentrated outbreaks, and the villagers die one after another without warning. Therefore, when the first dead person appears in the village, it often triggers panic among other villagers.
However, no one knows the true face of the “murderer”. Li Linmei, who is in her 50s, remembers that since the late 1970s, many experts came from Kunming and even Beijing during the rainy season to get into this village at an altitude of about 2,000 meters. These city people with glasses would frown, scribble on the notebook, and then leave one after another.
In June 2005, Zeng Guang, the chief epidemiologist of the Chinese Center for Disease Control and Prevention, led his team to Dali, Yunnan. They and local experts in Yunnan Province started a five-year follow-up work. In the first step, he predicted that these villages with sudden death symptoms, including Wangjiacun, conducted a life assessment.
Prior to this, Huang Wenli, deputy director of the Yunnan Provincial Endemic Disease Prevention and Control Institute, led another team to cast a big net. Since 2002, Huang Wenli has compiled a long list of risk factors for this disease, including enterovirus infection, drinking mountain water, alcoholism, and eating vegetable oil and mushrooms.
“But no evidence can persuade everyone.” Liu Jikai said. He is the chief pharmacist of the Kunming Institute of Botany, Chinese Academy of Sciences, and participated in the five-year investigation and evidence collection.
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In order to catch the culprit, people try their best. At first, local experts in Yunnan tended to attribute the cause of death to Keshan disease. On this rugged highland in northern Yunnan,r/>
Some sturdy mice were selected and placed in experimental cages. The extract was divided into different doses and fed to these mice as food.
Unexpectedly, within 24 hours, the mice died one after another, regardless of the amount swallowed. Before their deaths, they all had a strange symptom: like epilepsy, they were constantly shaking, edema, and small intestinal bleeding. It turns out that small white mushrooms are poisonous.
Next, Liu Jikai will purify and separate all the extracts. Spectroscopy technology has also been put into use. Liu Jikai used an electron mass spectrometer to break up the molecules of this compound, and used nuclear magnetic resonance imaging in spectroscopy to strip out three “strange” amino acids.
“All three are poisonous.” Liu Jikai said. He can almost determine who is the “ghost” who visits Yunnan villages every year.
Chase off the murderer
Not everyone agrees with this statement, such as Li Guanghui. He insisted that the contamination of mountain streams with toxic substances or pathogens is the main cause of this sudden death syndrome. “The vast majority of cases have drunk dirty water.” Villagers in this area like to drink the natural water in the mountains, although in the eyes of experts, this water has a strange taste.
Liu Jikai also confirmed that not all the sudden deaths have eaten this small white mushroom. Researchers of the investigation team noticed that the heavy metal element barium seemed to play a role in the death process. It can cause arrhythmia.
In 2006, the investigation team collected blood samples from the deceased and their families in two villages where mass sudden deaths occurred. Many people have excessive barium levels, and one of the dead has reached a very high level. In another group of sudden death, high levels of barium were detected in the blood, urine, hair and local water of the deceased.
Until now, Li Linmei and some villagers, who often put mushrooms in bamboo baskets, were unwilling to believe that it was the small white mushroom that caused the sudden death. In these small villages in Yunnan highlands, wild mushrooms are an important source of income for them. The mushroom picking season is generally in July and August every year, “almost people in the village go to pick mushrooms.”