Here are some of the symptoms of the illness:
Among those 2 years old or older, the most common signs are high fever, headache and stiff neck. Other symptoms can include nausea, vomiting, discomfort looking at bright lights, confusion and sleepiness.
In newborns and small infants, classic symptoms are fever, headache and neck stiffness. However, some infants only appear inactive or irritable, or have vomiting and loss of appetite.
Symptoms can develop over several hours, or they can take one to two days. As the disease progresses, patients of any age may have seizures.