Florida health officials confirmed 10 new Zika infections on Friday, the largest number of infections found on a single day and a sign of the United States’ faltering response to a looming crisis.

One doctor's mission to understand Zika virus in Brazil – in pictures Read more

There are now nearly 1,000 people infected with the virus in Washington DC and the 50 states, 246 of them in Florida, and 2,026 infections in American territories, according to the Centers for Disease Control and Prevention (CDC).

Those totals include 537 pregnant women, 43 of whom live in Florida. The state has also seen its first case of an infant born with microcephaly, the fifth case of the birth defect related to the virus in the US.

The US has not recorded any cases of transmission by mosquito in the 50 states, though the insects are spreading the virus in Puerto Rico, the Virgin Islands and American Samoa. People on the mainland have instead become infected while traveling abroad, through sexual transmission and in one case in a laboratory.

Even without mosquitoes, the virus has steadily drifted north through the spring and summer. All but five states – Alaska, Idaho, Wyoming and North and South Dakota – has reported an infection. It has also started to appear in northern cities: Cincinnati reported its first case this week, New York City health officials reported 233 cases, mostly in people who had travelled to the Dominican Republic, and Washington state reached double digits.

“This is not the time to play politics,” Barack Obama said on Friday in a speech addressing the virus, referring to the Senate’s inability to pass funding to combat Zika.

“When there are emergencies, when there are public health emergencies, when we know that we have the chance to prevent serious tragedies in the lives of families and protect the health and safety of our populations, and particularly our children, then those politics need to be set aside.”

The president and the CDC have requested $1.9bn to prevent, study and combat the virus, but have been blocked by the Republican-controlled Congress.

“We can issue precautions for travel to areas that have Zika,” Obama said. “We can give people guidelines in terms of how to deal with it if they get infected. But this is actually something that we could reduce the risks if Congress does the right thing and allocates the dollars.”

Obama urged calm in his warning to Congress and the public, saying: “The good news is that for the most part, Zika is not a type of disease like Ebola, where it’s life-threatening.”

The CDC has confirmed that the virus causes birth defects such as abnormally small heads and brain damage, but much about it remains unknown. Health officials have warned pregnant women should not to travel to Puerto Rico or other regions where mosquito transmission is high, and that men who have travelled to such areas should use condoms or abstain from sex for six months.

“To tell people not to have sex until we get back to you is not a very satisfying recommendation,” Anne Schuchat, a CDC deputy director, told Reuters. “We would like to have some more understanding of the sexual risk.”

Zika generally causes no symptoms in 80% of healthy adults, and mild symptoms – fever, joint pain, red eyes and rash, lasting a week to 10 days – in the remaining 20%. But it appears to devastate a growing fetus, with a confirmed link to microcephaly, and suspected links to eye problems, hearing loss and other brain disorders.

Newly presented research suggests that some symptoms, including seizures and serious joint problems, do not appear for months after birth.

Scientists are struggling to track the virus, which resembles yellow fever and dengue and can be found in regions where the latter is common. They believe it lasts about a week in blood and two weeks in urine. Some studies have shown it can last for months in semen.

States have had motley responses to the virus, largely based on internal politics and what the CDC is able to grant them. Gulf states with dense, poor neighborhoods, such as Texas and Mississippi, are particularly at risk, rife with stagnant water pooling in abandoned homes, landfills and potholed roads. On a tour through Houston, Dr Peter Hotez showed the Associated Press what he called a “Zika heaven” of mosquito breeding grounds.

In Florida, governor Rick Scott used emergency powers to authorize $26.2m in funding to combat mosquitos and prevent the spread of the virus. Officials there and around the US hope to use larvicide, traps and nets to prevent the insects from surging with the warm weather. Officials in states like Illinois are bracing for budget fights after cuts to state services and school programs.

In Maryland and Ohio, officials have urged people to take care over the holiday weekend by wearing long-sleeved shirts and pants, emptying out any standing water and applying insect repellent after sunscreen. In Hawaii, officials are preparing to spray homes as they did to combat a recent outbreak of dengue fever.

The CDC has started research despite its lack of funding.

“We are going out on a limb, but we have to,” the National Institute of Allergy and Infectious Diseases director, Anthony Fauci, said earlier this week. “We can’t say we’re going to wait until we get all the money.”