The number of positive cases of dengue fever associated with the Big Island outbreak has been slowly mounting and hit 167 Monday.

The latest initial onset of the disease was Dec. 13, and three people are potentially still infectious, the Department of Health reported Monday. The earliest known case had an initial onset date of Sept. 11.

Of the 167, 34 are children. Eighteen are visitors.

The Health Department has ruled out 659 reported potential cases based on negative test results or because the cases do not meet the criteria for locally acquired dengue. One case of dengue fever on the Big Island and one on Oahu were imported from Asia.

Symptoms include high fever, headache, nausea, red rash, muscle aches, and bone and joint pain.

Anyone who suspects he or she might have dengue is urged to seek medical care as some cases can become severe. All testing is done by a state laboratory and is free to the patient.

The mosquito-borne virus cannot be passed on from human to human. The Health Department continues to spray and treat areas for mosquitoes connected to confirmed cases of dengue, as well as at nearby public facilities.

South Kona continues to be a high-risk area for potential dengue infection. Pahoa, Milolii and North Kona are considered moderate-risk areas, and a smattering of other areas are said to have some risk, including Hilo, Mountain View, Waikoloa Village, Kawaihae, Kalaoa and Ocean View.