PRESIDENT BIDEN WHEN THE NONSPEAKING PERSON WAS CUT OFF. >>> DR. ANTHONY FAUCI, THE MAN WHO HELPED GUIDE THE UNITED STATES THROUGH THE COVID-19 PANDEMIC, IS RECOVERING FROM A DIFFERENT SERIOUS ILLNESS, WEST NILE VIRUS. FAUCI TOLD CBS NEWS HE WAS HOSPITALIZED ABOUT TWO WEEKS AGO. HE RETURNED HOME LATE LAST WEEK. THE 83-YEAR-OLD SAID HE LIKELY CONTRACTED THE VIRUS AFTER BEING BITTEN BY A MOSQUITO IN HIS BACKYARD. FAUCI IS EXPECTED TO MAKE A FULL RECOVERY. SO WHAT IS WEST NILE VIRUS? THE CDC SAYS IT'S THE MOST COMMON MOSQUITO-BORNE DISEASE IN THE UNITED STATES. SO FAR THIS YEAR THERE HAVE BEEN MORE THAN 200 CASES REPORTED ACROSS 31 STATES. THERE ARE NO VACCINES TO PREVENT IT, NOR MEDICINES TO TREAT IT. CBS NEWS MEDICAL CONTRIBUTOR DR. CELINE GOUNDER JOINS US NOW FOR ME. SHE'S ALSO EDITOR-AT-LARGE FOR PUBLIC HEALTH AT KFF. IF DR. ANTHONY FAUCI CAN GET IT, HOW CONCERNED SHOULD PEOPLE BE THAT THEY MIGHT GET THIS VIRUS? >> WELL, THIS IS, IN FACT, THE MOST COMMON MOSQUITO-BORNE DISEASE IN THE UNITED STATES. MANY CASES GO UNDER THE RADAR BECAUSE THEY'RE ASYMPTOMATIC. REMEMBER WE COVID WE TALKED ABOUT ASYMPTOMATIC. NOT EVERYBODY DEVELOPS SYMPTOMS. THE VAST MAJORITY OF THESE CASES ARE ASYMPTOMATIC. THE PEOPLE WHO ARE LIKELY TO DEVELOP SYMPTOMS ARE OLDER PEOPLE, PEOPLE WHO ARE IMMUNOCOMPROMISED, AND PREGNANT WOMEN ARE ALSO AT RISK BECAUSE REMEMBER, PREGNANCY IS A PERIOD OF IMMUNOCOMPROMISE. IT'S HOW YOU ARE ABLE TO CARRY THE BABY WITHOUT YOUR IMMUNE SYSTEM REJECTING IT. >> SO IF YOU ARE SYMPTOMATIC, WHAT SHOULD YOU LOOK FOR AND HOW BAD CAN IT GET? >> YOU CAN GET FLU-LIKE SYMPTOMS, 5, HEADACHE, MUSCLE PAGES, FEELING FLU-LIKE AND FATIGUED. MORE SEVERE SYMPTOMS, IF YOU DEVELOP A RASH, STIFF NECK, THE HEADACHE, ESPECIALLY IF IT'S NOT GETTING BETTER, CAN BE A SIGN OF MENINGITIS OR ENCEPHALITIS. SO THOSE WOULD BE RED FLAGS, REASONS TO BE GOING IN TO SEE A HEALTHCARE PROVIDER. >> LET ME ASK YOU ABOUT EASTERN EQUINE ENCEPHALITIS. WHAT IS THAT AND THEY'RE SPRAYING FOR, THAT RIGHT? TELL US WHAT THAT IS AND THEN WE'LL FIND IT OUT WHAT THEY'RE DOING ABOUT IT. >> SO THIS IS A VERY RARE, FORTUNATELY, VERY RARE MOSQUITO -BORNE INFECTION. THE LAST TIME I SAW A CASE WAS 20 YEARS AGO IN MASSACHUSETTS, BUT IT IS A HORRIBLE INFECTION. WHEN PEOPLE ACQUIRE EEE, VERY FEW GET AWAY WITHOUT LONG TERM COMPLICATIONS. THEY MAY HAVE SEIZURES LONG TERM, COGNITIVE ISSUES AND THERE'S A PRETTY HIGH MORTALITY RATE FROM EEE AS WELL. >> ENCEPHALITIS AFFECTS THE BRAIN. IS THAT RIGHT? >> THAT AFFECTS THE BRAIN. SO BOTH WEST NILE AND EEE IS CAUSE BRAIN INFECTIONS, WHICH IS A VERY SEVERE MANIFESTATION OF THE DISEASE. >> BECAUSE IT'S SO SERIOUS IS WHY THEY'RE SPRAYING FOR IT, NOT BECAUSE IT'S SO PREVALENT. >> BECAUSE IT IS SO SERIOUS. WE'RE SEEING BIG PICTURE A RISE IN MOSQUITO-BORNE DISEASES ACROSS THE UNITED STATES AND THIS IS DRIVEN BY CLIMATE CHANGE, WETTER CLIMATES, HUMIDITY, AND WE'RE SEEING AN INCREASE IN THE RANGE OF MOSQUITOES AS A RESULT. SO IT'S NOT JUST WEST NILE AND EEE THEY'RE SPRAYING FOR. THERE ARE OTHER INFECTIONS LIKE DENGUE, FOR EXAMPLE, IN FLORIDA AND PUERTO RICO WE'RE SEEING ACROSS THE COUNTRY. >> WHAT CAN THOSE OF US IN THE BACKYARD DO TO PROTECT FROM THIS OTHER THAN JUST STAYING INSIDE, MY PREFERENCE? >> LOOK, WE ALL HAVE TO GO ABOUT OUR DAILY LIVES. WE SHOULD BE ABLE TO SPEND SOME TIME OUTDOORS, PARTICULARLY WHEN THE WEATHER IS NICE, BUT IF YOU HAVE STANDING WATER IN YOUR BACKYARD, DRAIN THAT, IF YOU CAN IF AT ALL POSSIBLE, BECAUSE THAT'S WHERE MOSQUITOES BREED. SOME OF THE OTHER MEASURES YOU CAN TAKE TO REDUCE YOUR RISK WOULD INCLUDE WEARING LONG SLEEVES, LONG PANTS TO GUARD AGAINST BITES, USING MOSQUITO REPELLANTS AND, OF COURSE, YOUR HEALTH DEPARTMENT IS THERE TO INSPECT AREAS WHERE THEY THINK THERE MIGHT BE MOSQUITOES BREEDING AND THEY