Parts of the US have reported record numbers of West Nile virus infections, with experts warning that warming temperatures and flooding driven by climate change is heightening the risk of Americans contracting the debilitating disease.

Cases of West Nile virus have been reported in every US state except Hawaii so far this year, leading to deaths in Georgia, surging numbers of patients in Pennsylvania and record numbers of infections in Massachusetts.

Texas is also set for an unusually large number of cases of the mosquito-borne virus this year, with Kristy Murray, a vice-chair of research at Baylor College of Medicine in Houston, reporting “a really big year” in terms of the number of patients presenting with the disease.

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“We started getting two or three patients in a week around June, which was very early,” she said. “I thought ‘oh my gosh I don’t remember it ever being this intense.’ We have this worrisome trend where we are seeing bigger and bigger increases in this virus. It seems like we are getting very big outbreaks every other year.”

West Nile virus first appeared in the US in 1999, with 62 reported cases in New York. Last year 2,097 cases and 146 deaths were reported nationally, according to the Centers for Disease Control and Prevention (CDC), with this year on track to match or surpass this mark, with 1,976 recorded cases so far. The virus surges during the warm summer months and infections can take a month or so to be logged with the CDC.

Infections in particular years go up or down due a variety of factors – in 2003 nearly 10,000 cases were reported – but research has suggested that West Nile virus risks becoming broadly more prevalent as the climate changes. Mosquitoes that carry the disease multiply in pools of standing water and thrive in warm temperatures – conditions fueled by climate change, which is bringing heat and heavier downpours in areas of the US.

“A lot of it is driven by climate,” said Murray, who added that Hurricane Harvey, which dropped more than 20 trillion gallons of water on the Houston area when it tore through Texas last year, aided mosquito spread. “We are seeing a lot of activity in Houston and the longer trend is making me nervous.”

After a short incubation period following a bite from an infected mosquito, a person with West Nile virus may experience fever, headache and swollen lymph glands. In some cases this can worsen to a potentially deadly inflammation of the brain, a condition called encephalitis, or into meningitis.

A paper authored by Murray last year found the virus is also linked to brain damage. “A simple mosquito bite can be a life-changing event,” she said. “I’ve seen a patient in his 20s who had paralysis and was in rehab for weeks. Another family near Austin had a 13-year-old who was completely healthy and then died after a bite. It can affect anyone.”

There is no vaccine for West Nile virus and drugs can only manage the condition, meaning the CDC urges a focus on prevention such as using insect repellent, wearing long-sleeved shirts and getting rid of pools of water that accumulate outside houses.

A CDC spokeswoman said it “remains unclear exactly how climate change may affect the distribution and timing of existing infectious disease” but said research was ongoing.

“Climate does play a role, although West Nile activity does go up and down,” said Gregory Ebel, an expert in infectious diseases at Colorado State University. “It’s one of the drivers along with healthcare, poverty, lack of infrastructure and just generally how we live our lives with irrigation and sewers.

“We don’t have good drugs to treat the virus and we don’t have a vaccine. The underlying issue is the same as the spread of dengue and zika – the way we inhabit the planet and interact with each other is making things worse. I don’t know how you deal with that. It’s a problem of humanity, really.”