Risk of Non-Travel-Related Malaria to the General Public Remains Low

TRENTON, NJ – The New Jersey Departments of Health (NJDOH) and Environmental Protection (NJDEP) are investigating a case of malaria in a resident of Morris County with no international travel history. NJDOH is working closely with the U.S. Centers for Disease Control and Prevention (CDC) to investigate potential sources of infection; it is possible the resident was infected with malaria in New Jersey.

If confirmed, this would be the first known locally acquired case of malaria in New Jersey since 1998*. Although the Anopheles mosquitoes that transmit malaria are present in New Jersey, the risk of locally acquired malaria remains low.

“While risk to the general public is low, it’s important to take the necessary precautions to prevent locally acquired malaria in New Jersey. The most effective ways are to prevent mosquito bites in the first place and to ensure early diagnosis and treatment of malaria in returning travelers,” said Acting Health Commissioner Jeff Brown. “Anyone traveling to countries with widespread malaria should take appropriate steps to prevent malaria while traveling and monitor for symptoms.”

“I urge the public to continue taking steps to eliminate standing water around their properties, which will go a long way to reducing the risk of mosquito breeding,” Environmental Protection Commissioner Shawn M. LaTourette said. “As the summer winds down, taking this simple but necessary step will help ensure quality of life and protect public health.”

Malaria is a mosquito-borne disease caused by a parasite transmitted by certain mosquitoes and is widespread in many tropical and subtropical countries. Malaria typically causes fever, chills, headache, muscle aches, and fatigue. It can also cause nausea, vomiting, and diarrhea. In most cases, infected persons develop symptoms 7-30 days after exposure. Malaria can be cured with prescription antimalarial drugs, but it can be life-threatening if it is not diagnosed and treated quickly.

There are about 100 travel-associated cases of malaria reported in New Jersey each year. Locally acquired malaria typically occurs when a mosquito bites a person infected with travel-associated malaria, acquiring the parasite, and then bites another person, passing the infection. Successful treatment of individuals confirmed to have malaria significantly reduces or eliminates the risk of further transmission.

Summer and early fall months are peak times for other mosquito-borne diseases in New Jersey, including West Nile virus and Eastern equine encephalitis. The best way to prevent all mosquito-borne diseases is to:

• Prevent mosquito bites by using EPA-registered insect repellant and wearing long-sleeved shirts, pants, and socks while spending time outdoors.
• Reduce mosquito populations by eliminating standing water around properties. Mosquito-proof your yard by removing and reducing places where mosquitoes can breed by removing or covering sources of standing water such as birdbaths, pools, tires, and other places where water may collect.
• Protect yourself while travelling to countries where malaria or other travel-associated diseases (e.g., dengue, chikungunya) are common. Review travel notices for your destination and contact a health care provider before travel to discuss if medications or vaccines are recommended. After returning home, travelers should take extra precautions to avoid mosquito bites for three weeks to reduce the risk of New Jersey mosquitoes becoming infected and potentially spreading the infection to others.

The New Jersey State Mosquito Control Commission and NJDEP Office of Mosquito Control Coordination are working closely with the Morris County Mosquito Control Division, NJDOH, and the CDC in an attempt to minimize risks to the public through support of local mosquito control needs.

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*Correction (Posted August 21, 2025): An earlier version misstated the year. The correct year of the last known locally acquired case of malaria in New Jersey is 1998, not 1991.