Epidemeologia

New Mexico Epidemiology

November 25, 2011

Volume 2011, Number 11

Invasive Pneumococcal Disease,
New Mexico, 2006–2010

Invasive pneumococcal disease (IPD) is caused by the
bacteria Streptococcus pneumoniae and is considered
invasive when bacteria are isolated from a normally
sterile body site, such as blood or cerebrospinal fluid.1
According to the World Health Organization,pneumo-
coccal disease is a public health concern for children
and adults worldwide. In the U.S., the estimate of IPD
between 2006 and 2009 was approximately 14.1 cases
per 100,000 population per year. The estimated na-
tional death rate from IPD between 2006 –2009 was
1.6 deaths per 100,000 population per year. Surveil-
lance for IPD is conducted through the Active Bacte-
rial CoreSurveillance (ABCs) program, a 10-site net-
work collaboration with the Centers for Disease Con-
trol and Prevention (CDC).2, 3

In 2004, New Mexico began participating in the Active
Bacterial Core Surveillance (ABCs) program, a com-
ponent of the national Emerging Infections Program
(EIP). Through the program, NM conducts surveil-
lance for cases of IPD as well as four other invasive
bacterialpathogens. When IPD is diagnosed in a New
Mexico resident, a review of the medical chart is con-
ducted by an NM EIP Surveillance Officer using a
standardized case report form. S. pneumoniae isolates
are sent to the NM Department of Health (NMDOH)
Scientific Laboratory Division (SLD), state public
health lab where they are sub-cultured, logged, and
shipped to the CDC, or a CDC contractlaboratory for
further testing, including serotype and antimicrobial
susceptibility testing. CDC uses the information to cal-
culate national estimates of IPD, summaries of trends
in antimicrobial resistance of S. pneumoniae, and sero-
type information for vaccine development.1,3

Risk of infection with IPD is greater among certain
ages and racial/ethnic groups. Persons at higher risk of
IPDinfection included the elderly (aged>65 years),
and children aged less than two years. Risk is in-
creased in children or adults attending or working in
day care centers, immunocompromised individuals,

Lisa Onischuk, BS,MT(ASCP), Scientific
Laboratory Division, Megin Nichols, DVM, MPH,
Joseph Bareta, MS, Epidemiology and Response
Division, New Mexico Department of Health
and those who areBlack or American Indian/Alaskan
Native (AIAN).1 The AIAN population has histori-
cally experienced higher rates of disease, including
IPD, compared to the White U.S. population.4 Risk of
infection with drug resistant S. pneumoniae is in-
creased among persons who have recently completed
antimicrobial therapy.1,9 Vaccination is the only avail-
able tool in preventing pneumococcal disease,espe-
cially among high risk groups, and developing antim-
icrobial resistance highlights the need for use of effec-
tive vaccines.2,5

Pneumococcal conjugate vaccine, targeting seven
pneumococcal serotypes was licensed in the United
States for children on February 17, 2000. After the
introduction of the PCV7 vaccine, a decrease in IPD
occurred among vaccinated children, as well as unvac-cinated children and adults nationally. Indirect (herd)
immunity is thought to result from the reduced naso-
pharyngeal carriage in vaccinated children, therefore
preventing transmission to unvaccinated children and
adults.6

In February 2010, a new vaccine for children which
targets 13 pneumococcal serotypes (PCV13) became
available. The recommended vaccination series in-
cludes dosesat ages 2, 4, 6, and 12-15 months, with a
recommended single supplemental dose available to
all children aged 14-59 months. The PCV13 vaccine
consists of the serotypes in PCV7 plus six additional
serotypes. In NM between 2006 and 2010, 649 (46%)
cases of IPD occurred from strains that are exclusive to
the new PCV13 vaccine. The introduction of PCV13 is
anticipated to decrease the burden...