WEST NILE VIRUS
NOTE: This report was prepared in late August 2002, for the most current statistics on West Nile virus, please go to the CDC website.The West Nile virus, a flavivirus related to dengue fever and yellow fever, is a new epidemic in the U.S. The virus causes encephalitis (West Nile encephalitis) and is similar to a disease that occurs in the Orient, called Japanese encephalitis. It is believed that the West Nile virus has been in the U.S. since 1999, with the first outbreak occurring in and around the city of New York. It is transmitted by mosquitoes, which get the virus primarily from infected birds. Finding of dead birds is a sign that West Nile virus may have infected an area. The largest outbreak of West Nile encephalitis this year has occurred in Louisiana, illustrating the rapid spread of the infection zone, due to bird migration (see CDC Table). This virus is now a permanent feature of the Western Hemisphere. While work progresses towards finding a vaccine against the disease or an effective treatment, the main method of control will be to limit mosquito populations. The U.S. government has earmarked several million dollars in emergency funds for pesticide spraying of mosquito areas. Mosquito control was the key method for reducing the incidence of yellow fever, which had been a major disease in the Western Hemisphere a century ago.
Even for those who live in areas where this virus has been found, the risk of being exposed by any individual mosquito bite remains remote. Further, only about 1% of those infected by the virus experience a severe disease; those at risk for serious encephalitis are mainly the elderly (over 50 years of age, particularly those already in poor health). Of those who experience the most severe form of the disease, some will die from it; the death rate has been about 5% during this first year.
Typical symptoms of the disease are body aches, occasionally with skin rash and swollen lymph glands. These symptoms will clear up in a few days in the mild cases. More severe infection may be marked by headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, and paralysis, typical signs of encephalitis of various causes. There is not a specific medical treatment, but palliative care is given for the severe disease, from which about 95% of patients are expected to recover.
Some people who are concerned that they are infected with the disease will seek out herbal remedies. At this time, there are no proven effective herbal therapies and it is doubtful that there will be proof of such effectiveness in the near future. However, herbs have been applied to encephalitis cases in China, and for treatment of viral diseases, including yellow fever. Therefore, if one wished to make use of Chinese herbs for a suspected or known case of West Nile virus infection, herbs with antiviral properties and herbs reputed helpful in encephalitis would be used.
In the book Modern Study and Application of Chinese Materia Medica, some herbs are listed for treatment of arboviruses (these are viruses that are transmitted by insects, which would include Dengue fever, yellow fever, and West Nile virus). The herbs listed that are readily available and known to have broad spectrum anti-viral effects are isatis (root and leaf) and hu-chang (huzhang). Herbs used in treatment of encephalitis symptoms include three groups of herbs; namely those that: clear heat (to reduce fever); calm internal wind (to reduce tremors, convulsions, stiffness, and muscle weakness); and open the orifices (to prevent or treat stupor, disorientation, and coma). Fever reducing herbs include raw rehmannia, moutan, coptis, and scute; wind calming herbs include uncaria, gastrodia, and silkworm; orifice opening herb therapies include acorus and borneol.
August 2002