美疾控中心公布阿拉巴马州9例不明肝炎儿童病例调查结果
The entrance to the U.S. Centers for Disease Control and Prevention is seen, April 19, 2022, in Atlanta. /CFP
美国疾病控制与预防中心（CDC）日前公布了阿拉巴马州报告的9例不明原因肝炎儿童迄今为止最详细的调查结果，并认为腺病毒感染可能是导致健康儿童肝损伤的一个未被充分认识的因素，但仍需要进一步调查。
此前，阿拉巴马州报告了9名严重肝炎患儿，年龄从2岁到6岁不等，其中三名儿童肝功能衰竭，两名需要进行肝移植。
根据美国CDC的数据，所有9名患儿的腺病毒检测都呈阳性，并没有任何一名儿童感染过新冠。这些儿童在感染前没有任何健康问题，而且肝炎病毒检测没有呈阳性。
这些病例中，有5名儿童是在去年秋天确诊的；去年11月至今年2月期间，阿拉巴马州又发现了4例病例；2月以后，没有发现新增病例。
Nine young children from Alabama affected by a mysterious hepatitis (inflammation of the liver) all tested positive for a common pathogen called adenovirus 41, a study by U.S. Centers for Disease Control and Prevention (CDC) said Friday.
The children, who ranged in age from about one to six years old and were all previously healthy, are among around 170 cases across 11 countries as of April 21, according to the World Health Organization. Another state, Wisconsin, is investigating a death.
CDC's new paper is specifically about the cluster in Alabama, even as investigations continue nationwide.
"At this time, we believe adenovirus may be the cause for these reported cases, but other potential environmental and situational factors are still being investigated," the CDC said in a statement that accompanied the study.
Adenovirus 41 is known to cause gastroenteritis in children, but "it is not usually known as a cause of hepatitis in otherwise healthy children," the agency said.
However, an investigation had ruled out other common exposures, including COVID-19; hepatitis viruses A, B, and C (the most common causes of hepatitis in the U.S.); autoimmune hepatitis and Wilson disease.
The nine Alabama cases occurred between October 2021 and February 2022. Three experienced acute liver failure, two of whom required liver transplants.
"All patients have recovered or are recovering, including the two transplant recipients," the paper said.
Six tested positive for Epstein-Barr Virus but did not have antibodies, which implies an earlier infection, not active.
Before hospitalization, most of the children experienced vomiting and diarrhea, while some experienced upper respiratory symptoms. During hospitalization, most had yellowing eyes and yellowing skin (jaundice), and enlarged livers.
Last week, the CDC issued a health alert to notify doctors and public health authorities to be on the lookout for similar cases.
Wisconsin is investigating four cases, including two children who had severe outcomes, one who needed a liver transplant and one fatality. Cases have also been reported in Illinois and elsewhere.
CDC recommends children stay up to date on their vaccinations and that parents and caregivers practice preventive actions such as hand hygiene, avoiding people who are sick, covering coughs and sneezes, and avoiding touching the eyes, nose or mouth.
Adenoviruses are commonly spread by close personal contact, respiratory droplets and surfaces. There are more than 50 types of adenoviruses, which most commonly cause the cold, but also many other diseases.