The Centers for Disease Control and Prevention (CDC) reported on Thursday that the number of tuberculosis cases in the United States slightly rose last year for the first in more than two decades.

According to CDC’s Morbidity and Mortality Weekly Report, there were 9,563 new cases of TB diagnosed last year, a rise from 9,406 cases reported on 2014. That translates to 157 more cases, about three cases per 100,000 people. Even though the rate was nearly three times higher 20 years ago, it has been stalled at three since 2013.

The CDC recently reported that the number of tuberculosis cases in the U.S. rose last year for the first in 23 years. Credit: NBC

“It’s always concerning when we see progress stall, especially when there are proven interventions to prevent a disease,” Dr. Tom Frieden, director of the CDC, said in a statement.

The CDC report states the causes are unclear and the data need further evaluation if the reasons behind the trend are to be identified. But one of the factors is likely to be a reduction in prevention efforts nationwide.

TB in the U.S.

Tuberculosis is usually caused by the bacterium Mycobacterium and it is spread when people with active infections spit, sneeze, cough or even speak. But in the U.S., most of the cases of TB do not occur for transmission. It has mostly been diagnosed in individuals with reactivation of latent TB who were born outside of the country but have been residing in the United States for five years or less.

The CDC’s National Tuberculosis Surveillance System reports that TB incidence in foreign-born individuals is about 13 times that of U.S.-born people (15.1 versus 1.2 cases per 100,000).

More than half of cases reported in 2015 were grouped in four states: California, Florida, New York and Texas. This last one saw 1,334 cases in 2015, which was 5% more than the previous year. South Carolina experienced a 32 percent increase year over year, with 104 cases in 2015.

On the other hand, the top five countries of origin for foreign-born individuals were Mexico, the Philippines, India, Vietnam and China, accounting for close to 57% of all cases in foreign-born people.

TB over time

Tuberculosis, which is caused by bacteria that usually attack the lungs, once was a major cause of death and illness, and in the late 1800s killed one out of every seven people living in the United States and Europe.

The development of antibiotics and public health efforts succeeded in treating infections and tracking down those they infected.

Even though it had been thought to have been under control before, TB flared during the 1980’s and 1990’s because of the AIDS epidemic, mostly because those with weakened immune systems such as those with HIV/AIDS are at greatest risk of getting the disease.

During the 1st decade of the new millennium, it had fallen back. But still today as many as 13 million Americans have latent TB, meaning the bacteria live in their lungs but aren’t causing any illness.

Source: Washington Post