(Reuters) -The U.S. Centers for Disease Control and Prevention issued an advisory on Thursday alerting healthcare providers about an increase in invasive meningococcal disease and urging them to ensure necessary vaccinations against the deadly disease.

Meningococcal disease, caused by the bacterium Neisseria meningitidis, is a serious bacterial infection that commonly affects the brain, spinal cord and bloodstream.

As of Monday, 143 cases had been reported, compared with 81 cases this time last year, the CDC said. There were 422 cases recorded last year, the highest annual number since 2014.

The increase in infections is mainly attributable to a particular bacterial strain in the meningococcal bacteria group Y.

An infection with this strain had disproportionately affected people aged 30–60 years, African American people, and people with HIV, the agency said, urging healthcare providers to have a "heightened suspicion" for meningococcal disease among these populations.

The agency also warned that patients may present with bloodstream or joint infection and without symptoms typical of meningitis, which include fever, headache, and stiff neck.

Four of the six meningococcal bacteria groups - A, B, C, W, X, and Y - circulate in the United States, according to the CDC, with vaccines available against all except the X group.

In October, the U.S. Food and Drug Administration approved Pfizer's vaccine Penbraya, the first shot to protect against five meningococcal bacteria groups.

Pfizer currently sells two vaccines to protect against the disease, with Trumenba targeting the B group and Nimenrix protecting against the other four bacteria groups.

(Reporting by Mariam Sunny in Bengaluru; Editing by Devika Syamnath and Alan Barona)