CAUSE REAL PROBLEMS. >>> WE LEARNED THE NEW HAMPSHIRE MAN WHO DIED FROM EASTERN EQUINE ENCEPHALITIS OR TRIPLE E WAS 41 YEARS OLD. STEVEN PERRY'S FAMILY TELLS US HE WAS HEALTHY ONE WEEK AND HEARTBREAKINGLY BRAIN DEAD THE NEXT. THANKS FOR JOINING US. I'M LISA HUGHES. >> I'M DAVID WADE. THIS IS THE STATE'S FIRST CONFIRMED HUMAN CASE OF TRIPLE E AND FIRST DEATH SINCE 2014. THE HAMPSTEAD, NEW HAMPSHIRE MAN HAD BEEN HOSPITALIZED WITH SEVERE CENTRAL NERVOUS SYSTEM DISEASE. MEMBERS OF THE COMMUNITY ARE NOW ON HEIGHTENED ALERT FOR MOSQUITOES. >> Reporter: DAVID AND LISA, I JUST SPOKE WITH THE MOTHER AND THE SISTER OF STEVEN PERRY. YOU SAID IT. HE IS 41. THEY WANT TO EMPHASIZE THIS IS A RARE VIRUS. BUT IT IS NOT TREATABLE SO PROTECTION IS VITAL. HIS FAMILY SAYS HE WAS FUNNY, SMART, AND DRIVEN. BUT IN ONE WEEK, EVERYTHING CHANGED. 41-YEAR-OLD STEVEN PERRY FROM NEW HAMPSHIRE WENT TO THE HOSPITAL WITH A BRAIN INFECTION AND DIED FROM EASTERN EQUINE ENCEPHALITIS OR TRIPLE E. >> THIS IS PRETTY SCARY. >> Reporter: IT'S A RARE VIRUS TRANSMITTED BY BITES FROM INFECTED MOSQUITOES. IT CAN ALSO CAUSE SEVERE BRAIN DAMAGE AND DEATH. >> UP TO A THIRD OF PEOPLE DIE AND MANY OF THE PEOPLE WHO RECOVER HAVE LIFELONG DISABILITIES. >> Reporter: WHILE HAMPSTEAD ALREADY MONITORS MOSQUITOES, DR. BENJAMIN CHANCE SAYS GRANITE STATE RESIDENTS SHOULD ASSUME THE THREAT IS EVERYWHERE. >> THE RISK FOR THE MOSQUITO TRANSMITTED INFECTIONS WE BELIEVE IS STATEWIDE. WE HAVE A SURVEILLANCE SYSTEM IN PLACE TO HELP IDENTIFY INFECTIONS OR MOSQUITO DETECTIONS WHEN WE TEST. BUT TESTING DOESN'T OCCUR STATEWIDE. >> Reporter: AVOID OUTDOORS AT DAWN AND DUSK. WEAR LONG SLEEVES AND PANTS, INSECT REPELLANT. AND REMOVE STANDING WATER FROM YOUR PROPERTY ARE SO IMPORTANT. IN MASSACHUSETTS, THE STATE WILL BEGIN SPRAYING TO KILL MOSQUITOES BY AIR, BY TRUCK, IN PLYMOUTH AND WORCESTER COUNTIES TONIGHT AFTER A MAN IN HIS 80s IN WORCESTER COUNTY BECAME THE FIRST PERSON WITH TRIPLE E IN THE COMMONWEALTH SINCE 2020. ACROSS THE REGION, THE MESSAGE IS NOT PANIC, JUST PROTECTION. >> DOESN'T FREAK ME OUT, BUT IT CONCERNS ME. >> Reporter: NEW HAMPSHIRE HEALTH OFFICIALS WANT TO EMPHASIZE THE RISK ARE THE TRIPLE E WILL NOT GO AWAY FOR A FEW MONTHS UNTIL THE FIRST FROST HAPPENS AND IT WIPES OUT THE MOSQUITO POPULATION SO STAY VIGILANT. LOUISA MOLLER, WBZ NEWS. >> THANK YOU. >>> NOW WHILE WEST MILE AND TRIPLE E ARE BOTH MOSQUITO BORN ILLNESSES THEY ARE VERY DIFFERENT. 80% OF PEOPLE INFECTED WITH WEST NILE WILL HAVE NO SYMPTOMS. THOSE WHO DO MAY EXPERIENCE A FEVER, HEADACHE, BODY ACHES OR NAUSEA. WEST NILE WAS JUST IN THE NEWS BECAUSE DR. ANTHONY FAUCI WAS HOSPITALIZED WITH IT BUT FEWER THAN 1% WILL DEVELOP A SEVERE ILLNESS. TRIPLE E IS MUCH MORE RARE AND MUCH MORE SERIOUS. HIGH FEVER, STIFF NECK AND A HEADACHE THAT MAY START THREE TO TEN DAYS AFTER A MOSQUITO BITE. THE MOST SERIOUS COMPLICATION IS INFLAMMATION AND SWELLING OF THE BRAIN. THE DISEASE PROGRESSES VERY QUICKLY AND THERE IS NO TREATMENT. >>> OUR WBZ NEXT WEATHER TEAM HAS AN EXCLUSIVE PARTNERSHIP WITH THE CENTERS FOR DISEASE CONTROL AND WITH JOHNS HOPKINS UNIVERSITY. OUR CHIEF METEOROLOGIST ERIC FISHER IS HERE WITH US. ERIC, I KNOW YOU HAVE THE NEWEST INFORMATION ABOUT THE AREAS RIGHT NOW THAT ARE AT HIGHEST RISK FOR TRIPLE E IN MASSACHUSETTS. >> REALLY FIND OUT WHEN THERE IS TESTING RIGHT? YOU HAVE TO CATCH CERTAIN MOSQUITOES. AND THOSE HAVE TO TEST. AND YOU GET A SENSE FOR WHERE THEY MIGHT BE LIVING. BUT WE HAVE THE DATA TO GIVE US AN IDEA OF WHERE THOSE AREAS ARE. SOME POCKETS TOWARD THE MERRIMAC VALLEY. IN NEW HAMPSHIRE, TOO. A LITTLE CLOSER LOOK. THERE HAS BEEN TESTING, WE KNOW THERE ARE MOSQUITOES THERE AND THE RISK IS HIGH. IT TENDS TO COME IN CYCLES. THE NEXT BIG OUTBREAK WAS FIVE YEARS AGO, SO THIS IS FAIRLY CLOSE TO THE LAST BIG ONE IN 2019. THOUGH THIS SUMMER HAS NOT BEEN NEARLY AS WET, WE HAVE A LOT OF STANDING WATER. LAST YEAR WAS ONE OF THE WETTEST ON RECORD. THIS IS THE FIFTH WETTEST ON RECORD. SITTING AT 22 IN BOSTON. A LOT OF THAT WAS BACK IN THE SPRING. IN THE WINTERTIME WHERE IT ISN'T EXACTLY COLD. THAT'S A BREEDING GROUND FOR MOSQUITOES. EVERY MONTH HAS BEEN WARMER THAN AVERAGE. CERTAINLY HAD CONDITIONS THAT ARE BIG HABITAT FOR MOSQUITOES. THE FIRST FROST IS WHAT WE