Viral burden in the brains of mice infected with WNV-FIN, Ita09 and 578/10.

<p>Mice were euthanized within 6 to 14 days upon reaching humane endpoints and viral burden was measured in terms of (<b>A</b>) RNA copies per gram of brain, and (<b>B</b>) TCID₅₀ per gram of brain. (<b>C</b>) Viral RNA copies per gram of brain in mice infected with WNV-FIN, Ita09 and 578/10, and euthanized on day 20 in the absence of clinical signs of disease. * <i>P</i> <0.05, ** <i>P</i> <0.01.