Neuromuscular complications of hepatitis A virus infection and vaccines.

The hepatitis A virus (HAV) infects millions of people worldwide every year. Case histories report on various acute neuropathy syndromes in the context of acute HAV infection, but any causal link has not been established. Epidemiological data also cast doubt on the importance of HAV as a trigger for Guillain-Barré syndrome. The virtual absence of a chronic HAV-infected state likely explains the rare occurrence of extrahepatic immune-mediated diseases, including an absence of chronic autoimmune neuromuscular disorders. Several vaccines against HAV provide effective protection against natural infection. Isolated case histories report on an unconvincing association between HAV vaccination and neuropathy. Medical and epidemiological data show insufficient evidence to support a causal relationship between HAV vaccines and neuropathy syndromes. Aluminum hydroxide, a HAV vaccine adjuvant, is considered a trigger of the macrophagic myofasciitis syndrome. This review concludes that it seems unnecessary to routinely consider HAV infection or vaccination as triggers of neuromuscular diseases.