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BackgroundPneumococcal colonization is a precursor to pneumonia, and pneumococcal conjugate vaccines (PCV) can decrease vaccine-type (VT) colonization. Pneumococcal colonization studies are traditionally done among healthy children in the community; however, VT colonization prevalence may differ between these children and those with pneumonia. We assessed overall and VT pneumococcal colonization and factors associated with colonization among children with and without pneumonia after Mozambique introduced 10-valent PCV (PCV10) in 2013.MethodsWe used data from ongoing pneumonia surveillance in children aged <5 years and from cross-sectional nasopharyngeal colonization surveys conducted in October 2014 –April 2015 and October 2015 –May 2016. Pneumonia was defined using WHO standard criteria for radiologically confirmed pneumonia. Children with pneumonia enrolled from January 2014 –April 2016 were compared to children without pneumonia enrolled from the cross-sectional surveys. Clinical data and nasopharyngeal (NP) swabs were collected from each child. NP specimens were cultured for pneumococci, and culture-negative specimens from children with pneumonia underwent polymerase chain reaction (PCR).ResultsOf 778 and 927 children with and without pneumonia, 97.4% and 27.0% were exposed to antibiotics before swab collection, respectively. Based on culture, pneumococcal colonization was 45.1% for children with and 84.5% for children without pneumonia (P<0.001); VT pneumococcal colonization was 18.6% for children with and 23.4% for children without pneumonia (P = 0.02). The addition of PCR in children with pneumonia increased overall and VT-pneumococcal colonization to 79.2% and 31.1%, respectively. In multivariable analysis including PCR results, pneumonia was associated with VT pneumococcal colonization (adjusted OR: 1.4, 95%CI: 1.10–1.78).ConclusionVaccine-type pneumococcal colonization remains common among children with and without pneumonia post-PCV10 introduction in Mozambique. In a population of children with high antibiotic exposure, the use of PCR for culture-negative NP swabs can improve assessment of pneumococcal colonization and circulating serotypes.

We identified risk factors for any emm type group A streptococcal (GAS) colonization while investigating an invasive emm26.3 GAS outbreak among people experiencing homelessness in Alaska. Risk factors included upper extremity skin breakdown, sleeping outdoors, sharing blankets, and infrequent tooth brushing. Our results may help guide control efforts in future outbreaks.

Using population-based surveillance data, we quantified the secondary invasive group A Streptococcus disease risk among household contacts. The disease risk in the 30 days postexposure to an index-case patient was highest among individuals aged ≥65 years, versus the annual background incidence of all ages.

BACKGROUND: Most countries use 3-dose pneumococcal conjugate vaccine (PCV) schedules; a 4dose (3 primary and 1 booster) schedule is licensed for US infants. We evaluated the invasive pneumococcal disease (IPD) breakthrough infection incidence in children receiving 2 vs 3 primary PCV doses with and without booster doses (2 1 1 vs 3 1 1; 2 1 0 vs 3 1 0). METHODS:We used 2001-2016 Active Bacterial Core surveillance data to identify breakthrough infections (vaccine-type IPD in children receiving $1 7-valent pneumococcal conjugate vaccine [PCV7] or 13-valent pneumococcal conjugate vaccine [PCV13] dose) among children aged ,5 years. We estimated schedule-specific IPD incidence rates (IRs) per 100 000 personyears and compared incidence by schedule (2 1 1 vs 3 1 1; 2 1 0 vs 3 1 0) using rate differences (RDs) and incidence rate ratios. RESULTS:We identified 71 PCV7 and 49 PCV13 breakthrough infections among children receiving a schedule of interest. PCV13 breakthrough infection rates were higher in children aged ,1 year receiving the 2 1 0 (IR: 7.8) vs 3 1 0 (IR: 0.6) schedule (incidence rate ratio: 12.9; 95% confidence interval: 4.1-40.4); PCV7 results were similar. Differences in PCV13 breakthrough infection rates by schedule in children aged ,

Background In July 2016, invasive infections caused by a rare subtype of group A Streptococcus (iGAS; subtype emm26.3) were detected among the estimated 700–1000 homeless persons in Anchorage, Alaska. An increase in case numbers of emm26.3 iGAS was detected in October, including one death. We implemented a mass antibiotic intervention at homeless service facilities in Anchorage to prevent further cases of emm26.3 iGAS.Methods We defined cases as the isolation of emm26.3 GAS from a normally sterile body site, or nonsterile sites in the case of necrotizing fasciitis or toxic shock syndrome. We identified cases through routine laboratory-based surveillance and conducted antimicrobial susceptibility testing on all invasive isolates. From February 13–18, 2017, we evaluated persons accessing homeless services at six facilities in Anchorage and offered a single oral dose of 1 gram of azithromycin for iGAS prophylaxis. We concurrently collected oropharyngeal (OP) and wound swab specimens on a subset of participants. The swab collection was repeated at the same locations 4 weeks after the intervention. Swabs were cultured for GAS and emm-typed.ResultsFrom October 1, 2016 through February 18, 2017, we detected 31 cases among homeless persons. All emm26.3 iGAS isolates were erythromycin susceptible. We evaluated 484 persons at homeless services facilities and provided azithromycin to 394 (81%). Of 289 swab participants, 9 (3.1%) had baseline emm26.3 OP colonization. Of participants with wounds, 3/71 (4.2%) had emm26.3 wound colonization. At follow-up, 3/298 (1.0%) participants had emm26.3 OP colonization and 1/63 (1.6%) had emm26.3 wound colonization (P-value for change in any colonization = 0.05). Colonization by other emm-types, primarily erythromycin non-susceptible emm11, was 5.1% at baseline and 5.0% at follow-up. In the 6 weeks post-intervention, we detected 1 case among homeless persons (0.2 cases/week post- vs. 1.6 cases/week pre-intervention, P = 0.01 for change).Conclusion We reached a substantial proportion of the Anchorage homeless population with an antibiotic intervention to prevent iGAS. While possible that the outbreak was waning, the intervention was temporally associated with reduced case counts and colonization prevalence.Disclosures All authors: No reported disclosures.

Background Burkina Faso, a country in Africa’s meningitis belt, introduced 13-valent pneumococcal conjugate vaccine (PCV13) in October 2013, with 3 primary doses given at 8, 12 and 16 weeks of age. To assess whether the new PCV13 program controlled pneumococcal carriage, we evaluated overall and serotype-specific colonization among children and adults during the first 3 years after introduction. Methods We conducted 2 population-based, cross-sectional, age-stratified surveys in 2015 and 2017 in the city of Bobo-Dioulasso. We used standardized questionnaires to collect sociodemographic, epidemiologic, and vaccination data. Consenting eligible participants provided nasopharyngeal (all ages) and oropharyngeal (≥5 years only) swab specimens. Swab specimens were plated onto blood agar either directly (2015) or after broth enrichment (2017). Pneumococci were serotyped by conventional multiplex polymerase chain reaction. We assessed vaccine effect by comparing the proportion of vaccine-type (VT) carriage among colonized individuals from a published baseline survey (2008) with each post-PCV survey. Results We recruited 992 (2015) and 1005 (2017) participants. Among children aged &lt;5 years, 42.8% (2015) and 74.0% (2017) received ≥2 PCV13 doses. Among pneumococcal carriers aged &lt;1 year, VT carriage declined from 55.8% in 2008 to 36.9% in 2017 (difference, 18.9%; 95% confidence interval, 1.9%–35.9%; P = .03); among carriers aged 1–4 years, VT carriage declined from 55.3% to 31.8% (difference, 23.5%; 6.8%–40.2%; P = .004); and among participants aged ≥5 years, no significant change was observed. Conclusion Within 3 years of PCV13 implementation in Burkina Faso, we documented substantial reductions in the percentage of pneumococcal carriers with a VT among children aged &lt;5 years, but not among persons aged ≥5 years. More time, a change in the PCV13 schedule, or both, may be needed to better control pneumococcal carriage in this setting.