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The International Circumpolar Surveillance System for population-based surveillance of invasive pneumococcal disease 1999–2003

Abstract number: 1134_02_221

Bruce M., Cottle T., Parks D., Deeks S.L., Tam T., Lovgren M., Jette L., Kristinsson K.G., Sigmundsdottir G., Brinklov Jensen K., Lovoll O., Nuorti P., Herva E., Koch A., Hennessy T., Parkinson A.J.

Background:

The International Circumpolar Surveillance (ICS) Project is a population-based surveillance network for invasive bacterial disease in the US Arctic, Alaska (AK), Northern Canada (N Can), Greenland (GN), Iceland (IC), Norway (Nor) and Finland (Fin). Among circumpolar countries, the 7-valent conjugate vaccine (pcv7) has been used for routine infant immunization in AK since 2001 and in selected areas in N Can since 2002.

Methods:

We defined a case of invasive pneumococcal disease (IPD) as illness in a surveillance area resident with isolation of Streptococcus pneumoniae from a normally-sterile site. We analysed data on IPD from AK and N Can (Jan 1999–Dec 2003), and from GN, IC, Nor, Fin (Jan 2000–Dec 2003) to determine: 1) Common clinical syndromes, 2) Rates of disease by country, 3) Serotype distribution and 4) Antimicrobial susceptibility patterns.

Results:

A total of 7196 cases of laboratory-confirmed IPD were reported from AK (547), N Can (195), GN (38), IC (183), Nor (3664), and Fin (2569). Case-fatality ratios varied from 5.0–22.0%. Pneumonia (46%), septicemia (28%), and meningitis (8%) were the most common clinical presentations. Rates of IPD in aboriginals in AK and N Can were 42 and 38 cases per 100,000 persons, respectively. Rates of IPD in children <2 years of age and persons >2 years of age ranged from 35–144 and 8–24 cases per 100,000 persons, respectively. In AK, the rate of IPD in children <2 with pcv7 serotypes declined by 85% after routine vaccination; from 137 in 1999–2000 to 21 in 2001–2003 (p < 0.001). Rates of non-pcv7 serotypes in AK increased from 26 in 1999–2000 to 49 in 2001–2003 in children <2 years of age (p = 06). Overall, 89% of isolates from persons >2 years of age were serotypes contained in the 23-valent polysaccharide vaccine. The proportion of isolates fully-resistant to penicillin varied by country from <1% in Fin to 7.5% in AK.

Conclusions:

Rates of IPD are high in aboriginals and children <2 years of age residing in Arctic countries. After introduction of pcv7 in AK, rates of disease in children <2 years of age with pcv7 serotypes rapidly declined; however, increasing rates of non pcv7 serotypes are concerning and merit further surveillance. Continued surveillance is needed to determine the impact of pcv7 in AK and areas of N Can. High IPD rates in children <2 warrant consideration of pcv7 use in other circumpolar countries.

Session Details

Date: 01/08/2007
Time: 00:00-00:00
Session name: XXIst ISTH Congress
Subject:
Location: Oxford, UK
Presentation type:
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