Last data update: Nov 04, 2024. (Total: 48056 publications since 2009)
Records 1-14 (of 14 Records) |
Query Trace: Carvalho MDG[original query] |
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Nasopharyngeal carriage of Streptococcus pneumoniae among children <5 years of age in Indonesia prior to pneumococcal conjugate vaccine introduction
Safari D , Daningrat WOD , Milucky JL , Khoeri MM , Paramaiswari WT , Tafroji W , Salsabila K , Winarti Y , Soebandrio A , Hadinegoro SR , Prayitno A , Childs L , Pimenta FC , Carvalho MDG , Pilishvili T . PLoS One 2024 19 (1) e0297041 Pneumococcal conjugate vaccines (PCVs) prevent nasopharyngeal colonization with vaccine serotypes of Streptococcus pneumoniae, leading to reduced transmission of pneumococci and stronger population-level impact of PCVs. In 2017 we conducted a cross-sectional pneumococcal carriage study in Indonesia among children aged <5 years before 13-valent PCV (PCV13) introduction. Nasopharyngeal swabs were collected during visits to community integrated health service posts at one peri-urban and one rural study site. Specimens were analyzed by culture, and isolates were serotyped using sequential multiplex polymerase chain and Quellung reaction. Antibiotic susceptibility was performed by broth microdilution method. We enrolled 1,007 children in Gunungkidul District, Yogyakarta (peri-urban) and 815 in Southwest Sumba, East Nusa Tenggara (rural). Pneumococcal carriage prevalence was 30.9% in Gunungkidul and 87.6% in Southwest Sumba (combined: 56.3%). PCV13 serotypes (VT) carriage was 15.0% in Gunungkidul and 52.6% in Southwest Sumba (combined: 31.8%). Among pneumococcal isolates identified, the most common VT were 6B (16.4%), 19F (15.8%), and 3 (4.6%) in Gunungkidul (N = 323) and 6B (17.6%), 19F (11.0%), and 23F (9.3%) in Southwest Sumba (N = 784). Factors associated with pneumococcal carriage were age (1-2 years adjusted odds ratio (aOR) 1.9, 95% CI 1.4-2.5; 3-4 years aOR 1.5, 95% CI 1.1-2.1; reference <1 year), other children <5 years old in the household (aOR 1.5, 95% CI 1.1-2.0), and presence of ≥1 respiratory illness symptom (aOR 1.8, 95% CI 1.4-2.2). Overall, 61.5% of the pneumococcal isolates were non-susceptible to ≥1 antibiotic class and 13.2% were multi-drug non-susceptible (MDNS) (non-susceptible to ≥3 classes of antibiotics). Among 602 VT isolates, 73.9% were non-susceptible and 19.9% were MDNS. These findings are critical to establish a pre-PCV13 carriage prevalence and demonstrate the complexity in evaluating the impact of PCV13 introduction in Indonesia given the wide variability in the carriage prevalence as shown by the two study sites. |
Long-term surveillance of invasive pneumococcal disease: The impact of 10-valent pneumococcal conjugate vaccine in the metropolitan region of Salvador, Brazil
Reis JN , Azevedo J , de Oliveira AML , Menezes APO , Pedrosa M , Dos Santos MS , Ribeiro LC , Freitas HF , Gouveia EL , Teles MB , Carvalho MDG , Reis MG , Nascimento-Carvalho C , Verani JR . Vaccine 2024 BACKGROUND: In 2010, Brazil introduced the ten-valent pneumococcal conjugate vaccine (PCV10) in the national infant immunization program. Limited data on the long-term impact of PCV10 are available from lower-middle-income settings. We examined invasive pneumococcal disease (IPD) in Salvador, Bahia, over 11 years. METHODS: Prospective laboratory-based surveillance for IPD was carried out in 9 hospitals in the metropolitan region of Salvador from 2008 to 2018. IPD was defined as Streptococcus pneumoniae cultured from a normally sterile site. Serotype was determined by multiplex polymerase chain reaction and/or Quellung reaction. Incidence rates per 100,000 inhabitants were calculated for overall, vaccine-type, and non-vaccine-type IPD using census data as the denominator. Incidence rate ratios (IRRs) were calculated to compare rates during the early (2010-2012), intermediate (2013-2015), and late (2016-2018) post-PCV10 periods in comparison to the pre-PCV10 period (2008-2009). RESULTS: Pre-PCV10, overall IPD incidence among all ages was 2.48/100,000. After PCV10 introduction, incidence initially increased (early post-PCV10 IRR 3.80, 95% CI 1.18-1.99) and then declined to 0.38/100,000 late post-PCV10 (IRR 0.15; 95% CI 0.09-0.26). The greatest reductions in the late post-PCV10 period were observed in children aged ≤2 years, with no cases (IRR not calculated) and those ≥60 years (IRR 0.11, 95% CI 0.03-0.48). Late post-PCV10, significant reductions were observed for both PCV10 serotypes (IRR 0.02; 95% CI 0.0-0.15) and non-PCV10 serotypes (IRR 0.27; 95%CI 0.14-0.53). Non-PCV10 serotypes 15B, 12F, 3, 17F, and 19A became predominant late post-PCV10 without a significant increase in serotype-specific IPD incidence compared to pre-PCV10. CONCLUSION: Significant declines in IPD, including among adults not eligible for vaccination, suggest direct and indirect protection up to nine years after PCV10 introduction, without evidence of significant replacement disease. Continued surveillance is needed to monitor changes in non-vaccine serotypes and inform decisions about introducing higher valent PCVs. |
Nasopharyngeal colonization by Streptococcus pneumoniae in children and adults before the introduction of the 10-valent conjugate vaccine, Paraguay
Chamorro G , Kawabata A , Carvalho MDG , Pimenta FC , Lessa FC , Torres C , Lerea MJ , León ME . PLoS One 2023 18 (2) e0280722 Streptococcus pneumoniae is a cause of invasive diseases such as pneumonia, meningitis, and other serious infections among children and adults in Paraguay. This study was conducted to establish S. pneumoniae baseline prevalence, serotype distribution, and antibiotic resistance patterns in healthy children aged 2 to 59 months and adults ≥60 years of age prior to the introduction of PCV10 in the national childhood immunization program in Paraguay. Between April and July 2012, a total of 1444 nasopharyngeal swabs were collected, 718 from children aged 2 to 59 months and 726 from adults ≥60 years of age. The pneumococcal isolation, serotyping, and antibiotic susceptibility testing were performed using standard tests. Pneumococcal colonization prevalence was 34.1% (245/718) in children and 3.3% (24/726) in adults. The most frequent pneumococcal vaccine-types (VT) detected in the children were 6B (42/245), 19F (32/245), 14 (17/245), and 23F (20/245). Carriage prevalence with PCV10 serotypes was 50.6% (124/245) and PCV13 was 59.5% (146/245). Among colonized adults, prevalence of PCV10 and PCV13 serotypes were 29.1% (7/24) and 41.6% (10/24), respectively. Colonized children were more likely to share a bedroom, have a history of respiratory infection or pneumococcal infection compared to non-colonized children. no associations were found in adults. However, no significant associations were found in children and neither in adults. Vaccine-type pneumococcal colonization was highly prevalent in children and rare in adults in Paraguay prior to vaccine introduction, supporting the introduction of PCV10 in the country in 2012. These data will be useful to evaluate the impact of PCV introduction in the country. |
High prevalence of vaccine-type infections among children with pneumococcal pneumonia and effusion after 13-valent pneumococcal conjugate vaccine introduction in the Dominican Republic
Ahmed SS , Lessa FC , Coradin H , Sánchez J , Carvalho MDG , Soda E , Peña C , Fernández J , Cedano D , Whitney CG , Feris-Iglesias J . J Infect Dis 2021 224 S228-s236 BACKGROUND: In 2013, the Dominican Republic introduced 13-valent pneumococcal conjugate vaccine (PCV13) using a 3-dose schedule (at 2, 4 and 12 months of age). We evaluated the impact of PCV13 on serotypes causing pneumococcal pneumonia with pleural effusion. METHODS: Surveillance data after PCV13 introduction (July 2014 to June 2016) were compared with data before PCV13 introduction (July 2009 to June 2011). Cases were defined as radiologic evidence of pneumonia with pleural effusion in a child aged <15 years. Pneumococcus was detected in pleural fluid by either culture or polymerase chain reaction, and serotyping was performed. The Ministry of Health's PCV13 uptake data for 2014-2016 were obtained. RESULTS: The prevalence of pneumococcus among cases was similar before and after PCV13 introduction (56.4% and 52.8%, respectively). The proportion of pneumococcal cases caused by vaccine serotypes was 86% for children <2 years old both before and PCV13 introduction. Compared with before PCV13, serotype 14 accounted for a smaller (28% vs 13%, respectively; P = .02) and serotype 1 for a larger (23% vs 37%; P = .09) proportion of pneumococcal cases after PCV13 introduction. National uptake for the first, second, and third PCV13 doses was 94%, 81%, and 28%, respectively, in 2014 and 75%, 61%, and 26% in 2015. DISCUSSION: While the decrease in pneumococcal pneumonia with pleural effusion caused by serotype 14 may reflect an early effect of PCV13 implementation, other vaccine serotypes, including serotype 1, are not well controlled. Better PCV13 coverage for all 3 doses is needed. |
Impact of 13-valent pneumococcal conjugate vaccine on nasopharyngeal carriage rates of Streptococcus pneumoniae in a rural community in the Dominican Republic
Dunn MG , Lessa FC , Sánchez J , Cordero R , Feris-Iglesias J , Cedano D , Carvalho MDG , Fernández J , Feemster KA . J Infect Dis 2021 224 S237-s247 BACKGROUND: Invasive pneumococcal disease (IPD) leads to thousands of pediatric deaths annually. Pneumococcal colonization precedes IPD. In 2013, the Dominican Republic introduced the 13-valent pneumococcal conjugate vaccine (PCV13) into its routine infant immunization program, with doses at ages 2, 4, and 12 months. Prevalence of pneumococcal nasopharyngeal colonization was evaluated post-PCV13 introduction. METHODS: A prospective cohort study of 125 children aged 2-35 months was conducted in a rural Dominican Republic community November 2016 through July 2017. Nasopharyngeal swabs and clinical and vaccination data were collected at enrollment and 4-6 months later. Serotypes included in PCV13 were defined as vaccine-type. Colonization rates and serotype distribution were compared at baseline and follow-up, and the association between colonization and vaccination status among the entire cohort was evaluated at each time point. RESULTS: Of 125 children enrolled, 118 (94%) completed follow-up. Overall and vaccine-type pneumococcal colonization rates were 62% and 25%, respectively, at baseline and 60% and 28% at follow-up. Among children age-eligible for 3 doses, 50% and 51% were fully vaccinated at baseline and follow-up, respectively. At baseline assessment, children up-to-date for age for PCV13 were less likely to be colonized with vaccine-type pneumococci than children not up-to-date, and the same was found for fully vaccinated children (3 doses) compared to those not fully vaccinated (odds ratios [ORs], 0.38 [95% confidence interval {CI}, .18-.79], and 0.14 [95% CI, .04-.45], respectively). The same associations were not found at follow-up assessment. CONCLUSIONS: Three years post -PCV13 introduction, vaccine-type colonization rates remained high. Low vaccination coverage for 3 PCV13 doses may have contributed. The protective effect of PCV13 on vaccine-type carriage suggests an increase in PCV13 coverage could lead to substantial declines in pneumococcal vaccine-type carriage. |
Nonpneumococcal Strains Recently Recovered from Carriage Specimens and Expressing Capsular Serotypes Highly Related or Identical to Pneumococcal Serotypes 2, 4, 9A, 13, and 23A
Gertz RE Jr , Pimenta FC , Chochua S , Larson S , Venero AK , Bigogo G , Milucky J , Carvalho MDG , Beall B . mBio 2021 12 (3) The polysaccharide capsule is a key virulence factor of Streptococcus pneumoniae There are numerous epidemiologically important pneumococcal capsular serotypes, and recent findings have demonstrated that several of them are commonly found among nonpathogenic commensal species. Here, we describe 9 nonpneumococcal strains carrying close homologs of pneumococcal capsular biosynthetic (cps) loci that were discovered during recent pneumococcal carriage studies of adults in the United States and Kenya. Two distinct Streptococcus infantis strains cross-reactive with pneumococcal serotype 4 and carrying cps4-like capsular biosynthetic (cps) loci were recovered. Opsonophagocytic killing assays employing rabbit antisera raised against S. infantis US67cps4 revealed serotype 4-specific killing of both pneumococcal and nonpneumococcal strains. An S. infantis strain and two Streptococcus oralis strains, all carrying cps9A-like loci, were cross-reactive with pneumococcal serogroup 9 strains in immunodiffusion assays. Antiserum raised against S. infantis US64cps9A specifically promoted killing of serotype 9A and 9V pneumococcal strains as well as S. oralis serotype 9A strains. Serotype-specific PCR of oropharyngeal specimens from a recent adult carriage study in the United States indicated that such nonpneumococcal strains were much more common in this population than serotype 4 and serogroup 9 pneumococci. We also describe S. oralis and S. infantis strains expressing serotypes identical or highly related to serotypes 2, 13, and 23A. This study has expanded the known overlap of pneumococcal capsular serotypes with related commensal species. The frequent occurrence of nonpneumococcal strains in the upper respiratory tract that share vaccine and nonvaccine capsular serotypes with pneumococci could affect population immunity to circulating pneumococcal strains.IMPORTANCE The distributions and frequencies of individual pneumococcal capsular serotypes among nonpneumococcal strains in the upper respiratory tract are unknown and potentially affect pneumococcal serotype distributions among the population and immunity to circulating pneumococcal strains. Repeated demonstration that these nonpneumococcal strains expressing so-called pneumococcal serotypes are readily recovered from current carriage specimens is likely to be relevant to pneumococcal epidemiology, niche biology, and even to potential strategies of employing commensal live vaccines. Here, we describe multiple distinct nonpneumococcal counterparts for each of the pneumococcal conjugate vaccine (PCV) serotypes 4 and 9V. Additional data from contemporary commensal isolates expressing serotypes 2, 13, and 23A further demonstrate the ubiquity of such strains. Increased focus upon this serological overlap between S. pneumoniae and its close relatives may eventually prove that most, or possibly all, pneumococcal serotypes have counterparts expressed by the common upper respiratory tract commensal species Streptococcus mitis, Streptococcus oralis, and Streptococcus infantis. |
New pneumococcal serotype 15D
Pimenta F , Moiane B , Gertz RE Jr , Chochua S , Snippes Vagnone PM , Lynfield R , Sigaúque B , Carvalho MDG , Beall B . J Clin Microbiol 2021 59 (5) The pneumococcal serogroup 15 comprises 4 capsular polysaccharide serotypes (15A, 15B, 15C, 15F) that collectively account for an impactful disease burden (1,2).…. |
Indirect effects of 10-valent pneumococcal conjugate vaccine against adult pneumococcal pneumonia in rural western Kenya
Bigogo GM , Audi A , Auko J , Aol GO , Ochieng BJ , Odiembo H , Odoyo A , Widdowson MA , Onyango C , Borgdorff MW , Feikin DR , Carvalho MDG , Whitney CG , Verani JR . Clin Infect Dis 2019 69 (12) 2177-2184 BACKGROUND: Data on pneumococcal conjugate vaccine (PCV) indirect effects in low-income countries with high HIV burden are limited. We examined adult pneumococcal pneumonia incidence before and after 10-valent PCV introduction in Kenya in 2011. METHODS: From 1/1/2008 to 12/31/2016, we conducted surveillance for acute respiratory infection (ARI) among ~12,000 adults (>/=18 years) in western Kenya, where HIV prevalence ~17%. ARI cases (cough or difficulty breathing or chest pain, plus temperature >/=38.0 C or oxygen saturation <90%) presenting to a clinic underwent blood culture and pneumococcal urine antigen testing (UAT). We calculated ARI incidence and adjusted for healthcare seeking using data from household visits. The proportion of ARI cases with pneumococcus detected among those with complete testing (blood culture and UAT) was multiplied by adjusted ARI incidence to estimate pneumococcal pneumonia incidence. RESULTS: Pre-PCV (2008-2010), crude and adjusted ARI incidence were 3.14 and 5.30/100 person-years-observation (pyo), respectively. Among ARI cases, 39.0% (340/872) had both blood culture and UAT; 21.2% (72/340) had pneumococcus detected, yielding baseline pneumococcal pneumonia incidence of 1.12/100 pyo (95% confidence interval [CI] 1.0-1.3). In each post-PCV year (2012-2016), pneumococcal pneumonia incidence was significantly lower than baseline; with incidence rate ratios (IRR) of 0.53 (95%CI 0.31-0.61) in 2012 and 0.13 (95%CI 0.09-0.17) in 2016. Similar declines were observed in HIV-infected (IRR 0.13, 95%CI 0.08-0.22), and HIV-uninfected (IRR 0.10, 95%CI 0.05-0.20). CONCLUSIONS: Adult pneumococcal pneumonia declined in western Kenya following 10-valent PCV introduction, likely reflecting vaccine indirect effects. Evidence of herd protection is critical for guiding PCV policy decisions in resource-constrained areas. |
Streptococcus mitis Expressing Pneumococcal Serotype 1 Capsule.
Lessa FC , Milucky J , Rouphael NG , Bennett NM , Talbot HK , Harrison LH , Farley MM , Walston J , Pimenta F , Gertz RE , Rajam G , Carvalho MDG , Beall B , Whitney CG . Sci Rep 2018 8 (1) 17959 Streptococcus pneumoniae's polysaccharide capsule is an important virulence factor; vaccine-induced immunity to specific capsular polysaccharide effectively prevents disease. Serotype 1 S. pneumoniae is rarely found in healthy persons, but is highly invasive and a common cause of meningitis outbreaks and invasive disease outside of the United States. Here we show that genes for polysaccharide capsule similar to those expressed by pneumococci were commonly detected by polymerase chain reaction among upper respiratory tract samples from older US adults not carrying pneumococci. Serotype 1-specific genes were predominantly detected. In five oropharyngeal samples tested, serotype 1 gene belonging to S. mitis expressed capsules immunologically indistinct from pneumococcal capsules. Whole genome sequencing revealed three distinct S. mitis clones, each representing a cps1 operon highly similar to the pneumococcal cps1 reference operon. These findings raise important questions about the contribution of commensal streptococci to natural immunity against pneumococci, a leading cause of mortality worldwide. |
Early declines in vaccine type pneumococcal carriage in children less than 5 years old after introduction of 10-valent pneumococcal conjugate vaccine in Mozambique
Sigauque B , Moiane B , Massora S , Pimenta F , Verani JR , Mucavele H , Chauque A , Quinto L , Dos Santos RT , Carvalho MDG , Whitney CG , Lessa FC . Pediatr Infect Dis J 2018 37 (10) 1054-1060 BACKGROUND: Pneumococcal carriage is a precursor of invasive pneumococcal disease. Mozambique introduced 10-valent pneumococcal conjugate vaccine (PCV10) in April 2013, using a 3-dose schedule without a booster. We evaluated PCV10 impact on pneumococcal carriage and colonization density by HIV status. METHODS: We conducted 2 cross-sectional surveys (pre and post PCV10 introduction) among children 6 weeks to 59 months old. Participants included HIV-infected children presenting for routine care at outpatient clinics and a random sample of HIV-uninfected children from the community. We collected demographic data, vaccination history and nasopharyngeal swabs. Swabs were cultured and isolates serotyped by Quellung. We selected serotypes 11A, 19A and 19F for bacterial density analyses. We compared vaccine-type (VT) carriage prevalence from the pre-PCV10 with the post-PCV10 period by HIV status. FINDINGS: Prevalence of VT carriage declined from 35.9% (110/306) pre already defined in the background. It should be pre-PCV (PCV) to 20.7% (36/174 fully vaccinated) post PCV (P < 0.001) in HIV-uninfected and from 34.8% (144/414) to 19.7% (27/137 fully vaccinated) (P = 0.002) in HIV-infected children. Colonization prevalence for the 3 serotypes (3, 6A, 19A) included in the 13-valent PCV but not in PCV10 increased from 12.4% (38/306) to 20.7% (36/174 fully vaccinated) (P = 0.009) among HIV- uninfected children, mainly driven by 19A; no significant increase was observed in HIV-infected children. VT carriage among unvaccinated children decreased by 30% (P = 0.005) in HIV-infected children, with no significant declines observed in HIV-uninfected children. CONCLUSION: Declines in VT carriage were observed in both HIV-uninfected and HIV-infected children after PCV10 introduction with an early signal of herd effect especially in HIV-infected children. Ongoing monitoring of increases in 19A carriage and disease is necessary. |
Pneumococcal carriage and serotype distribution among children with and without pneumonia in Mozambique, 2014-2016
Adebanjo T , Lessa FC , Mucavele H , Moiane B , Chauque A , Pimenta F , Massora S , Carvalho MDG , Whitney CG , Sigauque B . PLoS One 2018 13 (6) e0199363 BACKGROUND: Pneumococcal 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. METHODS: We 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). RESULTS: Of 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). CONCLUSION: Vaccine-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. |
Nasopharyngeal carriage of Streptococcus pneumoniae among HIV-infected and -uninfected children <5 years of age before introduction of pneumococcal conjugate vaccine in Mozambique
Verani JR , Massora S , Acacio S , Dos Santos RT , Vubil D , Pimenta F , Moura I , Whitney CG , Costa MH , Macete E , Matsinhe MB , Carvalho MDG , Sigauque B . PLoS One 2018 13 (2) e0191113 Nasopharyngeal carriage is a precursor for pneumococcal disease and can be useful for evaluating pneumococcal conjugate vaccine (PCV) impact. We studied pre-PCV pneumococcal carriage among HIV-infected and -uninfected children in Mozambique. Between October 2012 and March 2013, we enrolled HIV-infected children age <5 years presenting for routine care at seven HIV clinics in 3 sites, including Maputo (urban-south), Nampula (urban-north), and Manhica (rural-south). We also enrolled a random sample of HIV-uninfected children <5 years old from a demographic surveillance site in Manhica. A single nasopharyngeal swab was obtained and cultured following enrichment in Todd Hewitt broth with yeast extract and rabbit serum. Pneumococcal isolates were serotyped by Quellung reaction and multiplex polymerase chain reaction. Factors associated with pneumococcal carriage were examined using logistic regression. Overall pneumococcal carriage prevalence was 80.5% (585/727), with similar prevalences among HIV-infected (81.5%, 339/416) and HIV-uninfected (79.1%, 246/311) children, and across age strata. Among HIV-infected, after adjusting for recent antibiotic use and hospitalization, there was no significant association between study site and colonization: Maputo (74.8%, 92/123), Nampula (83.7%, 82/98), Manhica (84.6%, 165/195). Among HIV-uninfected, report of having been born to an HIV-infected mother was not associated with colonization. Among 601 pneumococcal isolates from 585 children, serotypes 19F (13.5%), 23F (13.1%), 6A (9.2%), 6B (6.2%) and 19A (5.2%) were most common. The proportion of serotypes included in the 10- and 13-valent vaccines was 44.9% and 61.7%, respectively, with no significant differences by HIV status or age group. Overall 36.9% (n = 268) of children were colonized with a PCV10 serotype and 49.7% (n = 361) with a PCV13 serotype. Pneumococcal carriage was common, with little variation by geographic region, age, or HIV status. PCV10 was introduced in April 2013; ongoing carriage studies will examine the benefits of PCV10 among HIV-infected and-uninfected children. |
Invasive bacterial disease trends and characterization of group B streptococcal isolates among young infants in southern Mozambique, 2001-2015.
Sigauque B , Kobayashi M , Vubil D , Nhacolo A , Chauque A , Moaine B , Massora S , Mandomando I , Nhampossa T , Bassat Q , Pimenta F , Menendez C , Carvalho MDG , Macete E , Schrag SJ . PLoS One 2018 13 (1) e0191193 BACKGROUND: Maternal group B streptococcal (GBS) vaccines under development hold promise to prevent GBS disease in young infants. Sub-Saharan Africa has the highest estimated disease burden, although data on incidence and circulating strains are limited. We described invasive bacterial disease (IBD) trends among infants <90 days in rural Mozambique during 2001-2015, with a focus on GBS epidemiology and strain characteristics. METHODS: Community-level birth and mortality data were obtained from Manhica's demographic surveillance system. IBD cases were captured through ongoing surveillance at Manhica district hospital. Stored GBS isolates from cases underwent serotyping by multiplex PCR, antimicrobial susceptibility testing, and whole genome sequencing. RESULTS: There were 437 IBD cases, including 57 GBS cases. Significant declines in overall IBD, neonatal mortality, and stillbirth rates were observed (P<0.0001), but not for GBS (P = 0.17). In 2015, GBS was the leading cause of young infant IBD (2.7 per 1,000 live births). Among 35 GBS isolates available for testing, 31 (88.6%) were highly related serotype III isolates within multilocus sequence types (STs) 17 (68.6%) or 109 (20.0%). All seven ST109 isolates (21.9%) had elevated minimum inhibitory concentration (MIC) to penicillin (>/=0.12 mug/mL) associated with penicillin-binding protein (PBP) 2x substitution G398A. Epidemiologic and molecular data suggest this is a well-established clone. CONCLUSION: A notable young infant GBS disease burden persisted despite improvements in overall maternal and neonatal health. We report an established strain with pbp2x point mutation, a first-step mutation associated with reduced penicillin susceptibility within a well-known virulent lineage in rural Mozambique. Our findings further underscores the need for non-antibiotic GBS prevention strategies. |
Burden of invasive pneumococcal disease among children in rural Mozambique: 2001-2012
Sigauque B , Verani JR , Massora S , Vubil D , Quinto L , Acacio S , Mandomando I , Bassat Q , Nhampossa T , Pimenta F , Sacoor C , Carvalho MDG , Macete E , Alonso PL . PLoS One 2018 13 (1) e0190687 BACKGROUND: Invasive pneumococcal disease (IPD) is a major cause of illness and death among children worldwide. 10-valent pneumococcal conjugate vaccine (PCV10) was introduced as part of the Mozambican routine immunization program in April 2013. We characterized the IPD burden in a rural area of Mozambique before PCV introduction and estimated the potential impact of this intervention. METHODS: We conducted population-based surveillance for IPD, defined as S. pneumoniae isolated from blood or cerebrospinal fluid, among children <5 years old admitted to Manhica District Hospital, a referral hospital in a rural area with high prevalence of human immunodiciency virus infection. S. pneumoniae was identified using standard microbiologic methods and serotyped using sequential multiplex PCR or Quellung. IPD incidence was calculated among cases from a defined catchment area. RESULTS: From January 2001 through December 2012, we isolated 768 cases of IPD, 498 (65%) of which were bacteraemic pneumonia episodes. A total of 391 (51%) were from the catchment area, yielding IPD incidence rates of 479, 390 and 107 episodes per 100,000 children-years at risk among children <12, 12-23 and 24-<60 months old, respectively. The overall IPD incidence fluctuated and showed a downward trend over time. In these same age groups, in-hospital death occurred in 48 (17%), 26 (12%), and 21 (13%) of all IPD cases, respectively. Overall 90% (543/603) of IPD isolates were available for serotyping; of those, 65% were covered by PCV10 and 83% by PCV13. Among 77 hospital deaths associated with serotyped IPD, 49% and 69% were caused by isolates included in the PCV10 and PCV13, respectively. CONCLUSIONS: We describe very high rates of IPD among children in rural Mozambique that were declining before PCV introduction. Children <1 year old have the greatest incidence and case fatality; although the rates remain high among older groups as well. Most IPD episodes and many deaths among children <5 years old will likely be prevented through PCV10 introduction in Mozambique. |
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