CONCORD, N.H. (AP) — Gov. John Lynch on Friday declared that a public health threat exists in nearly four dozen New Hampshire communities where mosquito batches have tested positive for West Nile virus.

The declaration allows the communities to take measures, including spraying, to decrease the threat to public health.

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Earlier this week New Hampshire health officials reported the first human case of West Nile virus in two years. The Manchester adult is recovering from the virus, health officials said.

Spraying began Thursday in Manchester — one of 45 communities named by Lynch as being at risk. Most of the communities are in the seacoast region and from Manchester south.

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Health Commissioner Nicholas Toumpas told Lynch West Nile activity this year has increased significantly in the Northeast.

The infected mosquitoes were found in the following cities and towns: Amherst, Atkinson, Auburn, Bedford, Brentwood, Candia, Chester, Danville, Derry, East Kingston, Epping, Exeter, Fremont, Goffstown, Greenland, Hampstead, Hampton, Hampton Falls, Hollis, Hooksett, Hudson, Kensington, Kingston, Litchfield, Londonderry, Manchester, Merrimack, Nashua, New Castle, Newfields, Newington, Newmarket, Newton, North Hampton, Pelham, Plaistow, Portsmouth, Raymond, Rye, Salem, Sandown, Seabrook, South Hampton, Stratham and Windham.

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Copyright 2012 The Associated Press.