Maria Aparecida da Silva Vieira

Early impact of 10-valent pneumococcal conjugate vaccine in childhood pneumonia hospitalizations using primary data from an active population-based surveillance

BACKGROUND In Brazil, 10-valent pneumococcal conjugate vaccine (PCV10) was introduced in 2010 in the childhood routine immunization program. We used primary data to evaluate the effect of PCV10 on the reduction of hospital admissions due to community-acquired pneumonia (CAP). METHODS Active population-based surveillance studies on pneumonia hospitalizations in children aged <36 months were conducted before and after PCV10 introduction in Central Brazil. The surveillances comprised all 17 pediatric hospitals of the study area, which provide assistance for public and private health insurances. Linear regression was performed to detect any trend in pneumonia monthly rates previously to vaccine introduction. PCV10 post-vaccination impact (Nov/2011 to Oct/2013) on clinical and X-Ray confirmed pneumonia was estimated as the relative and the absolute reduction (prevented burden) in pneumonia admission rates, taking as baseline the pre-vaccination period (May/2007 to Apr/2009). RESULTS Overall, males presented higher rates of pneumonia hospitalization, compared to females. The relative rate reduction for clinical and X-Ray confirmed pneumonia was 13.1%, and 25.4%, respectively for children aged 2-23 months. The highest prevented burden was observed in age-groups 2-11 months, respectively 853/100,000 (from 6788/100,000 to 5935/100,000), and 729/100,000 (from 2871/100,000 to 2142/100,000), for clinical and X-Ray confirmed pneumonia. CONCLUSIONS This study provides evidence for the impact of PCV10 in clinical and X-Ray confirmed pneumonia in routine vaccination program in Brazil, after 3 years of vaccine introduction. Extended follow-up studies should confirm the benefit of vaccination through herd effect given the high burden of pneumonia in our setting.

Direct Effect of 10-Valent Conjugate Pneumococcal Vaccination on Pneumococcal Carriage in Children Brazil

Background 10-valent conjugate pneumococcal vaccine/PCV10 was introduced in the Brazilian National Immunization Program along the year of 2010. We assessed the direct effectiveness of PCV10 vaccination in preventing nasopharyngeal/NP pneumococcal carriage in infants. Methods A cross-sectional population-based household survey was conducted in Goiania Brazil, from December/2010-February/2011 targeting children aged 7–11 m and 15–18 m. Participants were selected using a systematic sampling. NP swabs, demographic data, and vaccination status were collected from 1,287 children during home visits. Main outcome and exposure of interest were PCV10 vaccine-type carriage and dosing schedules (3p+0, 2p+0, and one catch-up dose), respectively. Pneumococcal carriage was defined by a positive culture and serotyping was performed by Quellung reaction. Rate ratio/RR was calculated as the ratio between the prevalence of vaccine-types carriage in children exposed to different schedules and unvaccinated for PCV10. Adjusted RR was estimated using Poisson regression. PCV10 effectiveness/VE on vaccine-type carriage was calculated as 1-RR*100. Results The prevalence of pneumococcal carriage was 41.0% (95%CI: 38.4–43.7). Serotypes covered by PCV10 and PCV13 were 35.2% and 53.0%, respectively. Vaccine serotypes 6B (11.6%), 23F (7.8%), 14 (6.8%), and 19F (6.6%) were the most frequently observed. After adjusted for confounders, children who had received 2p+0 or 3p+0 dosing schedule presented a significant reduction in pneumococcal vaccine-type carriage, with PCV10 VE equal to 35.9% (95%CI: 4.2–57.1; p = 0.030) and 44.0% (95%CI: 14.–63.5; p = 0.008), respectively, when compared with unvaccinated children. For children who received one catch-up dose, no significant VE was detected (p = 0.905). Conclusion PCV10 was associated with high protection against vaccine-type carriage with 2p+0 and 3p+0 doses for children vaccinated before the second semester of life. The continuous evaluation of carriage serotypes distribution is likely to be useful for evaluating the long-term effectiveness and impact of pneumococcal vaccination on serotypes reduction.

Molecular epidemiology of coagulase-negative Staphylococcus carriage in neonates admitted to an intensive care unit in Brazil

BackgroundNasal colonization with coagulase-negative Staphylococcus (CoNS) has been described as a risk factor for subsequent systemic infection. In this study, we evaluated the genetic profile of CoNS isolates colonizing the nares of children admitted to a neonatal intensive care unit (NICU).MethodsWe assessed CoNS carriage at admittance and discharge among newborns admitted to a NICU from July 2007 through May 2008 in one of the major municipalities of Brazil. Isolates were screened on mannitol salt agar and tryptic soy broth and tested for susceptibility to antimicrobials using the disc diffusion method. Polymerase chain reaction (PCR) was used to determine the species, the presence of the mecA gene, and to perform SCCmec typing. S. epidermidis and S. haemolyticus isolated from the same child at both admission and discharge were characterized by PFGE.ResultsAmong 429 neonates admitted to the NICU, 392 (91.4%) had nasal swabs collected at both admission and discharge. The incidence of CoNS during the hospitalization period was 55.9% (95% confidence interval [CI]: 50.9-60.7). The most frequently isolated species were S. haemolyticus (38.3%) and S.epidermidis (38.0%). Multidrug resistance (MDR) was detected in 2.2% and 29.9% of the CoNS isolates, respectively at admittance and discharge (p = 0.053). The mecA gene was more prevalent among strains isolated at discharge (83.6%) than those isolated at admission (60%); overall, SCCmec type I was isolated most frequently. The length of hospitalization was associated with colonization by MDR isolates (p < 0.005). Great genetic diversity was observed among S. epidermidis and S. haemolyticus.ConclusionsNICU represents an environment of risk for colonization by MDR CoNS. Neonates admitted to the NICU can become a reservoir of CoNS strains with the potential to spread MDR strains into the community.

Methicillin-resistant Staphylococcus aureus nasal carriage in neonates and children attending a pediatric outpatient clinics in Brazil

BACKGROUND In Latin America, few studies have been carried out on methicillin-resistant Staphylococcus aureus carriage in the pediatric population. We conducted a survey of nasal S. aureus carriage in neonates and in children attending the pediatric outpatient clinics in a large Brazilian city with high antimicrobial consumption. METHODS Pernasal swabs of neonates were collected upon admission and at discharge in four neonatal intensive care units and of children less than five years of age during outpatient visits. Methicillin-resistant S. aureus isolates were characterized for antibiotic susceptibility, mec gene presence, pulsed-field gel electrophoresis, spa type, SCCmec-type, multilocus sequence type, and presence of Panton-Valentine leukocidin genes. RESULTS S. aureus was carried by 9.1% and 20.1% of the 701 neonates and of 2034 children attending the outpatient clinics, respectively; methicillin-resistant S. aureus carriage was detected in 0.6% and 0.2%, of the these populations, respectively. Healthcare-associated methicillin-resistant S. aureus strains found in neonates from neonatal intensive care units and outpatients were genetically related to the Brazilian (SCCmec-III, ST239) and to the Pediatric (SCCmec-IV, ST5) clones. Community-associated methicillin-resistant S. aureus was only detected in outpatients. None of the methicillin-resistant S. aureus strains contained the Panton-Valentine leukocidin gene. Methicillin-resistant S. aureus strains related to the Brazilian clone showed multidrug resistance pattern. CONCLUSIONS Despite the high antibiotic pressure in our area, and the cross transmission of the healthcare-associated methicillin-resistant S. aureus clones between neonatal intensive care units and outpatients, the prevalence of methicillin-resistant S. aureus carriage is still low in our setting.

Vaccination Coverage and Compliance with Three Recommended Schedules of 10-Valent Pneumococcal Conjugate Vaccine during the First Year of Its Introduction in Brazil: A Cross-Sectional Study

Pneumococcal 10-valent conjugate vaccine (PCV10) was introduced to Brazil’s National Immunization Program (NIP) in 2010. During the first year of vaccine introduction three schedules were used to deal with age at initiation of PCV for catch-up purposes: 3 primary doses + 1 booster (for children aged ≤6 months), a catch-up schedule of 2 doses + 1 booster (7-11 months), and a catch-up schedule of a single dose (12-15 months). The purpose of this study was to assess the magnitude and associated risk factors for under-vaccination or lack of on time vaccination six to eight months after PCV10 introduction. A household survey was conducted in the municipality of Goiania with 1,237 children, who were retroactively classified into one of three age groups, as a factor of the child’s age relatively to 30 days after PCV10 introduction. Socioeconomic characteristics and vaccination dates were obtained during home interviews. Vaccination coverage was defined as the percentage of children who completed the recommended number of doses. Compliance with recommended schedules was defined as the percentage of children who received all valid doses at the NIP recommended time interval. Adjusted prevalence ratios (PR) of variables independently associated with coverage and compliance were estimated by log binomial regression. Coverage of DTP-Hib was used for comparison purposes. Overall, vaccination coverage was 54.6% (95% CI 52.1-57.7%), lower than DTP-Hib coverage (93.0%; 95% CI 91.5-94.3%). Compliance with recommended schedules was 16.8% (95% CI: 14.7-18.6%). Children 7-11 months old had lower coverage (40.7%) and compliance (6.3%) compared to children aged 12-15 months (coverage: 88.8%; compliance: 35.6%) and ≤6 months old (coverage: 54%; compliance: 18.8%). Having private health insurance was associated with higher PCV10 coverage (PR=1.25; 95% CI: 1.06-1.47, p=0.007), and compliance (PR=1.09; 95% CI: 1.02-1.16, p=0.015). Although PCV10 coverage rapidly increased shortly after vaccination introduction, it was not matched by compliance with recommended schedules. Public initiatives should target compliance of PCV10 because of the burden of pneumococcal diseases on childhood morbidity and mortality.

Molecular epidemiological investigation to determine the source of a fatal case of serotype 22F pneumococcal meningitis

A childs death due to pneumococcal meningitis after contracting the disease in an after-school programme prompted an investigation to assess nasopharyngeal (NP) carriage among her contacts. The serotype of the meningitis case isolate was determined, together with the serotypes of the NP specimens of contacts, comprising the case patients brother, the case patients after-school programme contacts and the brothers day-care centre (DCC) contacts. NP swabs from 155 children and 69 adults were obtained. Real-time PCR and conventional multiplex PCR (CM-PCR) assays were used to detect pneumococcal carriage and determine serotypes. Broth-enriched culture of NP specimens followed by pneumococcal isolation and Quellung-based serotyping were also performed. DNA extracts prepared from cerebrospinal fluid of the index case and from the NP strain isolated from the brother and from one attendee of the brothers DCC were subjected to genotyping. Pneumococcal carriage assessed by real-time PCR and culture was 49.6 and 36.6%, respectively (P<0.05). Twenty-three serotypes were detected using CM-PCR, with serotypes 6A/6B, 14, 19F, 6C/6D, 22F/22A, 23F and 11A/11D being the most frequent. All eight serotype 22F/22A NP specimens recovered were from children attending the brothers DCC. The meningitis case isolate and the NP carriage isolate from the patients brother were both serotype 22F and shared the same new multilocus sequence type (ST6403) with the attendee of the brothers DCC. CM-PCR proved to be useful for assessing carriage serotype distribution in a setting of high-risk pneumococcal transmission. The causal serotype appeared to be linked to the brother of the case patient and attendees of his DCC.

Single-dose varicella vaccine effectiveness in Brazil: A case-control study

BACKGROUND Varicella vaccine was introduced into the Brazilian Immunization Program in October 2013, as a single-dose schedule administered at 15 months of age. Its effectiveness had not yet been assessed in the country. METHODS A matched case-control study was carried out in São Paulo and Goiânia (Southeast and Midwest regions, respectively), Brazil. Suspected cases, were identified through a prospective surveillance established in the study sites. All cases had specimens from skin lesion collected for molecular laboratory testing. Cases were confirmed by either clinical or PCR of skin lesions and classified as mild, moderate, and severe disease. Two neighborhood controls were selected for each case. Cases and controls were aged 15-32 months and interviewed at home. Evidence of prior vaccination was obtained from vaccination cards. Univariate and multivariate logistic regression models were used, and odds ratio and its respective 95% confidence intervals were estimated. Vaccine effectiveness was estimated by comparing de odds of having received varicella vaccine among cases and controls. RESULTS A total of 168 cases and 301 controls were enrolled. Moderate and severe illness, was found in 33.3% and 9.9% of the cases. Effectiveness of a single dose varicella vaccine was 86% (95%CI 72-92%) against disease of any severity and 93% (95%CI 82-97%) against moderate and severe disease. Out of 168 cases, 81.8% had positive PCR results for wild-type strains, and 22.0% were breakthrough varicella cases. Breakthrough cases were milder compared to non-breakthrough cases (p < .001). CONCLUSIONS Effectiveness of single dose varicella vaccine in Brazil is comparable to that in other countries where breakthrough varicella cases have also been found to occur. The goal of the varicella vaccination program, along with disease burden and affordability should be taken into consideration when considering the adoption of a second dose of varicella vaccine into national immunization programs.

Perfil Epidemiológico das Parturientes Atendidas em uma Maternidade de Alto Risco de Goiânia-GO

Resumo: o estudo objetivou descrever as caracteristicas das parturientes e recem-nascidos (RN) atendidos em hospital universitario de Goiânia. Os dados foram obtidos dos prontuarios, de janeiro a julho/2012. Foram incluidas 296 parturientes. A morbidade materna mais frequente foi infeccao do trato urinario. Aproximadamente 34% RNs nasceram prematuros; observou- se 72,0% de cesarianas, percentual superior a recomendacao da Organizacao Mundial de Saude. Palavras-chave: Gravidez de alto risco. Partos cesareos. Morbidades Maternas. Estudo epidemiologico.