The CDC is monitoring two recent outbreaks of meningococcal disease at Princeton University and the University of California, Santa Barbara. In anticipation of the holiday travel season, the CDC issued an outbreak status update and advice to reduce the risk of spreading the disease.
Meningococcal disease is caused by the bacteria neisseria meningitidis and it is also sometimes called meningococcus. There are two serious forms of meningococcal disease—meningitis and septicemia. Meningitis is an infection of the protective membranes covering the brain and spinal cord, which is known as the meninges. Septicemia is an infection of the blood stream, which causes bleeding in the skin and organs. Septicemia gives rise to complications from meningococcal disease that are not neurologic.
Fewer than 1,000 cases occur each year in the United States. In 2012, about 500 cases were reported. This shows a marked improvement over the late 1990s and early 2000s when there were close to 3,000 cases of meningococcal disease a year. Very few cases occur as part of an outbreak relative to the total number of cases in the U.S. But typically there are a couple of meningococcal disease outbreaks every year.
Reports of this disease are more common in the winter months. Cases occur in all age groups. Meningococcal disease can strike otherwise healthy individuals.
Meningococcal disease can be devastating. Even with antibiotic treatment, people die in about 10 to 15 percent of cases of meningococcal disease. About 15 percent of survivors have long term disabilities such as loss of limbs, deafness, nervous system problems, or brain damage.
Early recognition and early treatment of meningococcal disease is key to reduce the long-term consequences. However, it is often difficult to diagnose meningococcal disease because often the first signs and symptoms are similar to the flu. Signs and symptoms of meningococcal disease include rapid onset of high fever, headache, and stiff neck. The headache presents as among the worst headaches that the person has had. The stiff neck prevents an infected person from moving their neck. For example, an infected people cannot touch their chins to their chests. Other symptoms include nausea, vomiting, increased sensitivity to light, confusion, exhaustion, and sometimes a rash.
Every case of meningococcal disease requires a public health response by local and state health officials. Meningococcal disease is highly recognized so cases are reported quickly to health departments. Health officials follow up with patients to determine with whom they have come into close contact. Then they recommend preventive antibiotics to close contacts.
Vaccination is the best way to prevent meningococcal disease when it is a vaccine preventable strain. There are several serogroups or strains of these bacteria. The most common ones circulating in the U.S. are serogroups B, C and Y. The U.S. has approved vaccines to help protect against serogroups C, Y, A and W. These vaccines are recommended for all adolescents with the first dose preferably given at 11 to 12 years old, and a second dose at 16. The U.S. has not approved a vaccine to protect against serogroup B, which is the cause of the cases at Princeton University and UC Santa Barbara. That is because there have been challenges making serogroup B vaccine. The serogroup B target capsule looks like an antigen we actually have in our bodies, so it does not provoke an immune response.
Fortunately, meningococcal bacteria are harder to spread than viruses that cause diseases, like the flu or respiratory viruses, and they do not live long outside the body. These bacteria are not spread by casual contact like being in the same room with somebody who is sick or carrying the bacteria or handling items that they touched. They are spread through the exchange of respiratory secretions. The organisms spread through close contact, such as household contact or French kissing. For example, roommates, who spend a lot of time together, are potential close contacts of a case of meningococcal disease. Hand washing and covering coughs or sneezes reduce the risk of transmission.
At any given time, about 10 percent of people, not just in outbreaks, but all over in the United States, carry these bacteria in the back of their nose or throat and do not ever develop symptoms. This is known as being a carrier. Once a person becomes a carrier, he or she develop immunity and the bacteria disappear from their nose and throat, and they are no longer a carrier. Rarely, does the bacteria invade the blood stream. Since the bacteria can spread through carriers, most cases of meningococcal disease appear to be random and are not directly linked to each other. Even in the case of an outbreak, the cases often do not occur among close contacts. Rather, the cases occur in an organization or community.
In general, the CDC defines an outbreak of meningococcal disease as three or more cases in three months that cannot be connected to each other. Most outbreaks of this disease are self-limited and no more than three or four cases occur. When cases continue to occur over several months, intervention is required to reduce the length of the outbreak. In an outbreak caused by serogroup C or Y meningococcal disease, the CDC would recommend the quadrivalent meningococcal vaccine to prevent additional cases. Many universities have very high coverage with the licensed and recommended vaccine that protects against serogroup C and Y. Thus, the CDC has started to see fewer cases of serogroup C and Y meningococcal disease and more cases of serogroup B disease. Until very recently, there was no available and broadly effective serogroup B vaccine that could be used to reduce the length of a serogroup B outbreak in the United States. However, there is now a vaccine that was recently licensed for use in Europe and Australia, but not in the United States.
Novartis, the company that makes the serogroup B meningococcal vaccine, has completed phase II clinical studies in the United States. After careful review of requirements for licensure, existing vaccination schedules, and feedback from public health experts, the company has decided to advance a meningococcal vaccine that helps protect against five serogroups (A, B, C, Y, and W) into late stage development. This vaccine would cover the most common serogroups that cause meningococcal disease circulating in the United States. The exact timeline for approval in the United States depends on many factors.
The CDC is open to recommending this vaccine during outbreaks of serogroup B meningococcal disease. Each outbreak is unique and requires a rigorous assessment before use of this vaccine can be considered. Expanding access for use of an investigational vaccine such as this requires careful review of the particular circumstances of the outbreak and making sure the vaccine can be safely administered and ensuring the appropriate systems are in place for safety follow-up after the vaccination campaign. Importing vaccine that is not approved in the U.S. even when licensed is a complex process that takes time.
Dr. Amanda Cohn, a pediatrician and an expert in meningococcal disease at the CDC, said that Princeton University and UC Santa Barbara are experiencing outbreaks of serogroup B meningococcal disease. There have not been any fatalities from the outbreaks, but there have been some very serious cases.
The CDC and the New Jersey Department of Health (NJDOH), Princeton University officials, and local health authorities have been working closely together since the first case of meningococcal disease was reported in association with Princeton University in March 2013. At the request of the NJDOH, the CDC reviewed the eight cases of meningococcal disease that occurred among Princeton University students and visitors since March 2013. All of these cases were caused by serogroup B meningococcal bacteria. The number of cases and lack of direct connection among the cases at Princeton indicate that this is an outbreak.
Cases have continued to occur over several months at Princeton. Given that cases have occurred during two school years, it is anticipated that there will be more cases. This requires intervention to reduce the length of the outbreak. The CDC and the FDA have determined that the unique pattern of disease in the Princeton outbreak including the high rate of cases that have occurred and the long period of time over which they have occurred warrants access to this serogroup B vaccine for that high-risk population. Partners are working to organize serogroup B vaccine campaigns at Princeton University as quickly as possible. Approval is being sought from various health agencies and the university. Special labels are being developed. The vaccine has to be sent via climate controlled shipping from Europe. Dr. Cohn stated that the vaccine campaign should begin shortly after Thanksgiving break once everything is in place.
The CDC is continuing to work with local and state partners to closely monitor the UC Santa Barbara situation. If cases continue to occur, the CDC will determine the best course of action.
In the meantime, the CDC stressed the importance of knowing the signs and symptoms of meningococcal disease and the need to seek prompt care if concerned. If anyone is connected to either of the universities develops a fever, headache, or rash he or she should seek medical attention. Dr. Cohn clarified that there is no need to change family members and communities' contact with students from these universities as they travel home for the holidays. The CDC does not recommend curtailing social interactions or canceling travel plans as a preventive measure to prevent cases of meningococcal disease. The CDC sent out a health alert to providers and state and local health departments, to increase awareness for providers to consider meningococcal disease in their differential diagnosis, if a student from one of these two universities presents with symptoms.
See the CDC Press Briefing Transcript
See the CDC Serogroup B Meningococcal Vaccine Questions and Answers Report
See also Medical Law Perspectives, January 2013 Report: Vaccines: An Ounce of Prevention May Lead to a Pound of Injury