A muscle cramp is also known as charley horse. It is a strong, painful contraction of legs or that comes on suddenly and lasts from a few seconds. It often occurs in the legs. The causes of muscle cramps are because of decreased amounts of minerals like calcium and magnesium, especially in the later months of pregnancy and Exposure to cold temperatures. Quinine is very effective in preventing muscle cramps.
Altogether, 806 of the 836 samples were collected during spring migration in bird observatories, which is usually where the birds first land when they arrive in the country from the sea; the other 30 were collected during midsummer. However, virus infection during the previous year in northern Europe cannot be excluded. Detection of viable SINV in the migrating birds would be the ultimate proof for their involvement in distributing SINV, but that remains to be shown.