New Jersey has recorded its first two confirmed cases of West Nile virus for 2025, state health officials announced this week.
An Atlantic County child tested positive for the disease, with symptoms reported the third week of July, according to an announcement from the New Jersey Department of Health.
A Middlesex County adult also tested positive for the disease, with symptoms reported the first week of August, the agency said.
Both patients were discharged from hospitals and are recovering at home.
Four other suspected West Nile virus cases in the state are also under investigation, officials said.
The agency also reported a blood donor in Sussex County tested positive for the virus but showed no symptoms.
West Nile is most commonly spread by mosquito bites and the virus is the leading cause of mosquito-borne disease in the United States, according to the Centers for Disease Control and Prevention.
Most West Nile virus cases occur between mid-August and mid-September, and 14 human cases are typically reported in a year statewide, according to the health department. Figures soared last year, when New Jersey recorded 41 human cases, including eight deaths.
The current number of human infections in New Jersey is lower than last year, but experts are seeing high levels of the virus circulating in mosquitoes, according to Acting New Jersey Health Commissioner Jeff Brown.
This year in New Jersey, mosquitoes carrying the virus were first detected in April, which is much earlier than expected, officials said. West Nile has been detected in all 21 counties, with the highest levels recorded in Bergen, Middlesex, Union, Essex and Hudson counties.
"As mosquito season can last into early November, depending on weather conditions, bite prevention will be essential in protecting yourself and your family against mosquito-borne diseases like West Nile virus in the remaining summer weeks and into the fall," Brown said.
While there is no treatment for West Nile, it can be prevented by avoiding mosquito bites and reducing mosquito populations.
Most of those infected show no symptoms or attribute mild symptoms to other causes, while others may develop a fever, headaches, body aches, joint pain, vomiting, diarrhea or rash, according to health officials.
Older people and those with weakened immune systems are more likely to develop serious cases that affect the central nervous system and result in hospitalization or, in some cases, death.
Recovery from severe cases can take several weeks to months and some effects may be permanent.
In a typical year, more than 1,200 people develop severe illness from the virus nationwide and more than 120 die, according to the CDC.