The number of reported coronavirus deaths in long-term care facilities has more than doubled to 5,670 since last week, according to state health data gathered by NBC News, driven by huge increases in hard-hit states like New York, where more than 2 percent of nursing home residents have died of the virus.

The death count is based on data from 29 state health departments and includes nursing homes, assisted living and other long-term care facilities. An NBC News investigation published last week found 2,246 deaths associated with long-term care facilities in 24 states.

There are now 3,466 long-term care facilities in 39 states with known coronavirus infections, according to state data – nearly 1,000 more facilities than state officials reported to NBC News last week.

The federal government does not track nursing home residents who have died from the virus, or the numbers of facilities that have had outbreaks, despite the high mortality rate among those who are elderly and have underlying health conditions. Some high-population states like Florida have refused to disclose such information and access to testing is highly limited in many states, which means the actual number of COVID-19 deaths in long-term care facilities is likely significantly higher.

By far the largest increase in nursing home deaths was in New York state, where the death count soared from 1,330 last week to 3,060, as of Wednesday, according to a state health spokeswoman. That means that 2.3 percent of the estimated 131,000 New York residents who live in nursing homes and assisted living facilities have died from the coronavirus so far.

In New Jersey, the coronavirus has spread to more than 95 percent of the state’s 375 long-term care facilities, according to state health officials. Within the last eight days, the number of nursing homes deaths has risen nearly five-fold in New Jersey, from 128 to 625 deaths, state health officials said.

Massachusetts has also been hit hard, with 444 nursing home deaths in 214 facilities. The state did not provide data on the number of deaths when NBC News conducted its first tally last Friday.