什么是新生儿肝炎？

　　新生儿肝炎是一种炎症性肝病，通常发生于一至两个月后出生的婴幼儿。大约20%的婴儿出现新生儿肝炎病毒感染，造成肝脏发炎。无论是出生前就通过自己的母亲，或出生后不久感染 病毒，都可造成新生儿肝炎。而病毒会造成婴幼儿感染，包括巨细胞病毒，风疹(麻疹)，和甲肝、乙肝和丙肝。在剩下的80%的患婴中，他们的肝炎出现是没有特定原因的，但许多专家怀疑病毒还是难辞其咎。

　　新生儿肝炎是怎样的症状？

　　一个患有肝炎的新生儿通常有黄疸(黄色眼睛和皮肤)，一般在一至两个月年龄出现。 黄疸在胆汁流向肝脏，而肝脏发生阻断因炎症或胆管梗阻时出现。由于胆汁是一个极为重要的消化和脂肪吸收的脂溶性维生素，所以一个有新生儿肝炎的孩子可能不长不胖或不能正常成长。婴儿也可能会有肝脾肿大的现象。

　　如何为新生儿肝炎诊断？

　　诊断新生儿肝炎最初是基于血液测试，以确定可能的病毒感染导致的疾病。万一没有识别到病毒，那么就需要执行活肝组织检查。这就涉及到去除一小块肝，在显微镜下借助一种特殊的注射器做检查。

　　活组织切片检查结果往往显示，每组四个或五个肝细胞一起形成较大的细胞，虽然这些大细胞继续发挥作用，但这些大细胞的活动效率要比正常肝细胞低。这种类型的新生儿肝炎有时被称为巨细胞肝炎。

　　新生儿肝炎的症状类似于与另一婴儿肝病——称为胆道闭锁。然而新生儿胆道闭锁症中胆管逐步被破坏的原因我们还了解甚少。尽管一个婴儿患有胆道闭锁症的同时也伴有黄疸与肝部肿大，但还是会正常生长并且脾脏不出现炎症。除了这些症状外，肝组织活检及血液测试都需要用来区分胆道闭锁症及新生儿肝炎。

　　什么是新生儿肝炎并发症？

　　新生儿肝炎所致风疹或巨细胞病毒有可能发展一种脑感染，可能导致智力迟钝或脑瘫。这些婴儿其中的许多也将因为肝病破坏引起的永久性的肝细胞损伤，导致疤痕(肝硬化)。

　　多数婴儿巨细胞病毒性肝炎将会痊愈，很少或者根本没有疤痕。对肝脏来说，随着胆汁流动的改善，它的成长也会逐渐正常。然而，大约20%的婴儿因为受到肝炎的影响，将继续以发展为慢性(进行性)肝病和肝硬化。这些儿童的肝脏将会因为疤痕而变硬，而且六个月以下大的婴儿的黄疸会不消退，最终符合这些症状的婴儿将需要进行肝脏移植。

　　小儿慢性肝炎新生儿由于缺乏胆汁将无法消化脂肪，吸收脂溶性维生素(A，D和E及K)，并且伴有肝细胞损伤。缺乏维生素D会导致骨质疏松与软骨发育不良(佝偻病)。缺乏维生素A会影响正常生长和视力。维生素K缺乏会有易青紫及出血倾向，而缺乏维生素E会导致婴儿协调性变差。由于胆汁负责消除在体内的许多毒素，所以新生儿慢性肝炎也有可能导致血液中积聚毒素，从而导致瘙痒，皮疹和过敏。

　　如何为新生儿肝炎治疗？

　　目前尚无治疗新生儿肝炎的特效药， 许多婴儿常使用一些药物改善胆汁分泌，维生素补充剂也是经常会在处方中出现的，含有脂肪的奶粉也更容易被身体消化。

　　新生儿肝炎会传染给别人吗？

　　新生儿肝炎所引起的巨细胞病毒、风疹或病毒性肝炎可能传染给前来与婴儿保持密切接触的人。这些受感染的婴儿不要接触孕妇，因为这样的话孕妇可能把病毒传染给胎儿。

原文：

Neonatal Hepatitis

What is neonatal hepatitis?

Neonatal hepatitis is an inflammation of the liver that occurs in early infancy, usually one to two months after birth. About 20 per cent of infants who develop neonatal hepatitis were infected with a virus causing inflammation of the liver either before birth through their mother, or shortly after birth. Viruses which can cause neonatal hepatitis in infants include cytomegalovirus, rubella (measles), and hepatitis A, B and C. In the remaining 80 per cent of affected infants, no specific cause can be identified, but many experts suspect a virus is to blame.

What are the symptoms of neonatal hepatitis?

An infant with neonatal hepatitis usually has jaundice (yellow eyes and skin) that appears at one to two months of age. Jaundice occurs when the flow of bile from the liver is blocked due to an inflammation or obstruction of the bile ducts. Since bile is essential in the digestion of fats and absorption of fat soluble vitamins, a child with neonatal hepatitis may fail to gain weight and grow normally. The infant will also have an enlarged liver and spleen.

How is neonatal hepatitis diagnosed?

The diagnosis of neonatal hepatitis is initially based on blood tests aimed at identifying possible viral infections leading to the disease. In cases where no virus is identified, a liver biopsy is performed. This involves the removal of a small piece of the liver using a special syringe for examination under a microscope.

Biopsy results will often show that groups of four or five liver cells have joined together to form larger cells. Although these large cells continue to function, they do so at a lesser rate than normal liver cells. This type of neonatal hepatitis is sometimes called giant cell hepatitis.

The symptoms of neonatal hepatitis are similar to those associated with another infant liver disease called biliary atresia. In infants with biliary atresia however, bile ducts are progressively destroyed for reasons that are poorly understood. Although an infant with biliary atresia is also jaundiced with an enlarged liver, there is generally normal growth and the spleen is not inflamed. In addition to symptoms, a liver biopsy and blood tests are needed to distinguish biliary atresia from neonatal hepatitis.

What complications are associated with neonatal hepatitis?

Infants with neonatal hepatitis caused by rubella or cytomegalovirus are at risk of developing an infection of the brain that could lead to mental retardation or cerebral palsy. Many of these infants will also have permanent liver disease due to the destruction of liver cells and the resulting scarring (cirrhosis).

The majority of infants with giant cell hepatitis will recover with little or no scarring to the liver. Their growth pattern will also normalize as bile flow improves. However, about 20 per cent of affected infants will go on to develop chronic (ongoing) liver disease and cirrhosis. In these children, the liver becomes very hard due to scarring, and the jaundice does not dissipate by six months of age. Infants who reach this point in the disease eventually require a liver transplant.

Infants with chronic neonatal hepatitis will not be able to digest fats and absorb fat soluble vitamins (A, D, E and K) as a result of insufficient bile flow and the damage caused to liver cells. The lack of vitamin D will lead to poor bone and cartilage development (rickets). A deficiency in vitamin A may affect normal growth and vision. Vitamin K deficiency is associated with easy bruising and a tendency to bleed, whereas the lack of vitamin E results in poor coordination. Since bile is responsible for the elimination of many toxins in the body, chronic neonatal hepatitis can also lead to a buildup of toxins in the blood which in turn may result in itching, skin eruptions and irritability.

How is neonatal hepatitis treated?

There is no specific treatment for neonatal hepatitis. Vitamin supplements are usually prescribed and many infants are given medications which improve bile flow. Formulas containing fats more easily digested by the body are also given.

Can neonatal hepatitis be spread to others?

Infants with neonatal hepatitis caused by the cytomegalovirus, rubella or viral hepatitis may transmit the infection to others who come in close contact with them. These infected infants should not come into contact with pregnant women because of the possibility that the woman could transmit the virus to her unborn child.

　　原文刊登于加拿大肝脏基金会，39健康网独家翻译，未经允许，不得转载。