Drug Resistance

Some Streptococcus pneumoniae (pneumococcus) are resistant to one or more antibiotics. Resistance can lead to treatment failures.

Latest data

CDC’s Antibiotic Resistance Threats in the United States, 2019 includes the latest national death and infection estimates that underscore the continued threat of antimicrobial resistance. The report identifies drug-resistant S. pneumoniae as a serious threat.

View the Streptococcus pneumoniae report.


Until 2000, pneumococcal infections caused 60,000 cases of invasive disease each year. According to Active Bacterial Core surveillance (ABCs) data, up to 40% of these infections were caused by pneumococcal bacteria that were resistant to at least one antibiotic. These numbers have decreased greatly following:

  • The introduction of pneumococcal conjugate vaccines (PCVs) for children
  • A change in definition of non-susceptibility (resistance) to penicillin in 2008
Timeline of CDC’s PCV recommendations
  • PCV7: 2000 in children
  • PCV13: 2010 in children; 2012 in adults with risk conditions; 2014 in adults 65 years or older
  • PCV15: 2021 in adults; 2022 in children
  • PCV20: 2021 in adults; 2023 in children

In 2019, ABCs estimated there were about 30,300 cases of invasive pneumococcal disease. Available data show that pneumococcal bacteria are resistant to one or more antibiotics in more than 30% of cases. How common drug-resistant Streptococcus pneumoniae (DRSP) is varies throughout the United States.

State and local health departments have reported outbreaks of DRSP in

  • Long-term care settings
  • Institutions for people living with HIV
  • Childcare centers


Before 2000, seven serotypes (6A, 6B, 9V, 14, 19A, 19F, and 23F) caused most DRSP in the United States. Rates of disease caused by these serotypes (except 19A) decreased after the introduction of PCV7, which does not include 19A.

Between 2000 and 2010, rates of disease and DRSP caused by serotype 19A increased. However, rates of disease caused by serotype 19A have greatly decreased since then due to use of PCV13 (includes 19A). No new serotype has emerged in its place.

The impact PCV15 and PCV20 will have on drug-resistant pneumococcal serotypes is yet to be determined.


DRSP is associated with increased costs compared to infections caused by non-resistant (susceptible) pneumococcus. This is because of

  • The need for more expensive antibiotics, new antibiotic drug development, and for surveillance to track resistance patterns
  • Repeat disease due to treatment failures
  • Educational requirements for patients, clinicians, and microbiologists

Risk Groups

People who attend or work at childcare centers are at increased risk for infection with DRSP. People with pneumococcal infections who recently used antibiotics are more likely to have a resistant infection than those who have not.


CDC funds ABCs, an active, laboratory- and population-based surveillance system in 10 states. All types of invasive pneumococcal disease (including DRSP) are included in the national public health surveillance system, National Notifiable Diseases Surveillance System (NNDSS). These surveillance data are used to estimate how many cases of invasive pneumococcal disease (including DRSP) occur each year in the United States.

Several private-sector systems also track DRSP.

Prevention: Challenges and Opportunities

There are several factors that create challenges for preventing emerging drug resistance of pneumococcus, including

  • Unnecessary use of antibiotics
  • Spread of resistant serotypes
  • Underuse of pneumococcal vaccines by adults recommended to receive them
  • Lack of adoption by some clinical laboratories of standard methods (NCCLS guidelines) for identifying and defining DRSP
  • Lack of vaccine availability to protect against all serotypes of pneumococcus

Improving appropriate antibiotic use and expanding use of vaccines may slow or reverse emerging drug resistance. Expanded use of recommended vaccines could also prevent more infections.