CDC alerts doctors to watch for rare bacterial infection that's killing one in SIX people and appearing with unusual symptoms

Health officials have warned doctors to be on the lookout for a rare bacterial infection that kills one in six sufferers. 

The CDC issued an alert Thursday to doctors about increased cases of a form a type of meningitis-causing strain that is rising rapidly in the US. 

The agency found that there have already been 143 infections caused by the bacteria Neisseria meningitidis subgroup Y ST-1466 - 80 percent more than this time last year. 

This form is different than more common types, which usually causes stiff neck and high fever and kill one in 10 people. 

Instead, this rapidly increasing strain leads to blood infections and stiff or achy joints elsewhere on the body, which doctors have been warned to watch out for. 

Neisseria meningitidis can be spread from person to person through saliva and respiratory secretions, such as from kissing, coughing, sneezing, or living in close contact with others who are infected. 

Last year, 422 illnesses from Neisseria meningitidis were reported in the US, the highest since 2014. 

There are four subgroups of meningococcal bacteria that circulate in the US: B, C, W, and Y. The CDC said that ST-1466 is in subgroup Y. 

About 65 percent of cases have been in adults ages 30 to 60, the majority of whom were black (63 percent).

Another 15 percent were patients with HIV, which has been shown to increase the risk of meningococcal disease. 

The agency said that at least 17 patients died.  

Meningococcal disease typically manifests as meningitis, an inflammation of protective membranes covering the brain and spinal cord.

Symptoms include high fever, severe headache, stiff neck, nausea, vomiting, trouble concentrating, seizures, sleepiness, sensitivity to light, or lack of appetite.

Meningitis is responsible for about 150 to 300 deaths per year in the US.  

However, the CDC urged doctors to look out for unusual symptoms, such as blood infections and joint pain. 

The agency warned that symptoms can escalate within hours, and quick treatment with antibiotics is essential. 

There are also vaccines to protect against meningococcal disease, which officials recommend for children ages 11 to 12. 

Protection fades, so a booster is typically given at age 16. 

Officials also urge people with compromised immune systems, such as HIV, to get a booster every three to five years. 

The CDC's alert comes after five people in Virginia died from this form of meningococcal disease in September.