The new cases occurred in seven counties, including one case in Sunflower County.
Two positive cases had been reported in Bolivar County prior to Monday's statement.
There have been 233 cases statewide in 2012, including five deaths.
This is the highest number of cases reported in one year in the state's history.
The total number of cases in 2012 has more than quadrupled from 2011's total of 52 cases.
Five deaths also occurred in 2011.
The MSDH only reports laboratory-confirmed cases to the public.
Symptoms of WNV infection are often mild and may include fever, headache, nausea, vomiting, a rash, muscle weakness or swollen lymph nodes.
In a small number of cases, infection can result in encephalitis or meningitis, which can lead to paralysis, coma or possibly death.
MSDH is currently working with city and county officials to help guide spraying efforts based on the location of cases.
The agency has developed and printed educational materials and door-hangers for mayors, boards of supervisors and other elected officials that are now being distributed locally through civic groups, churches and volunteer organizations.
The MSDH is also working with the Mississippi High School Athletics Association and the Mississippi Independent Schools Association in announcing public service messages at high school football games and other athletic events.
Peak season for WNV is July, August, and September in Mississippi, but mosquito-borne illnesses can occur year-round.
Mississippians should take appropriate precautions to reduce the risk of contracting WNV and other mosquito-borne illnesses
These precautions include: remove sources of standing water, especially after rainfall; install or repair screens on windows and doors; if exposed to mosquito-prone areas, wear protective clothing (such as long-sleeved shirts and pants) during peak times from dusk until dawn, and use repellents containing DEET, or Environmental Protection Agency (EPA) registered repellents for use on human skin.
Always read the manufacturer's directions carefully before putting on a repellent.
For more information on WNV and other mosquito-borne illnesses, a checklist to reduce the mosquito population in and around homes, and recommended mosquito repellents, visit the MSDH website at www.HealthyMS.com/westnile or call the WNV toll-free hotline from 8 a.m. until 5 p.m. Monday through Friday at 1-877-WST-NILE (1-877-978-6453).