Emergence of Streptococcus pneumoniae serotype 19A (Spn19A) in the pediatric population in Bogotá, Colombia as the main cause of invasive pneumococcal disease after the introduction of PCV10

Invasive pneumococcal disease in Latin America and the Caribbean: Serotype distribution, disease burden, and impact of vaccination. A systematic review and meta-analysis

BACKGROUND

Invasive pneumococcal diseases (IPD) are associated with high morbidity, mortality, and health costs worldwide, particularly in Latin America and the Caribbean (LAC). Surveillance about the distribution of serotypes causing IPD and the impact of pneumococcal vaccination is an important epidemiological tool to monitor disease activity trends, inform public health decision-making, and implement relevant prevention and control measures.

OBJECTIVES

To estimate the serotype distribution for IPD and the related disease burden in LAC before, during, and after implementing the pneumococcal vaccine immunization program in LAC.

METHODS

Systematic literature review following Cochrane methods of studies from LAC. We evaluated the impact of the pneumococcal vaccine on hospitalization and death during or after hospitalizations due to pneumococcal disease and serotype-specific disease over time. We also analyzed the incidence of serotyped IPD in pneumococcal conjugate vaccine PCV10 and PCV13. The protocol was registered in PROSPERO (ID: CRD42023392097).

RESULTS

155 epidemiological studies were screened and provided epidemiological data on IPD. Meta-analysis of invasive diseases in children <5 years old found that 57%-65% of causative serotypes were included in PCV10 and 66%-84% in PCV13. After PCV introduction, vaccine serotypes declined in IPD, and the emergence of non-vaccine serotypes varied by country.

CONCLUSIONS

Pneumococcal conjugate vaccines significantly reduced IPD and shifted serotype distribution in Latin America and the Caribbean. PCV10/PCV13 covered 57-84% of serotypes in children under 5, with marked decline in PCV serotypes post-vaccination. Continuous surveillance remains crucial for monitoring evolving serotypes and informing public health action.

Serotype distribution, clinical characteristics, and antimicrobial resistance of pediatric invasive pneumococcal disease in Colombia during PCV10 mass vaccination (2017-2022)

Introduction

Invasive Pneumococcal Disease (IPD) causes significant morbidity and mortality in children under 5 y. Colombia introduced PCV10 vaccination in 2012, and the Neumocolombia network has been monitoring IPD in pediatric patients since 2008.

Materials and methods

This study is a secondary analysis of a prospective cohort involving pediatric patients with IPD admitted to 17 hospitals in Colombia, from January 1st, 2017, to December 31st, 2022. We present data on serotypes (Spn), clinical characteristics, and resistance patterns.

Results

We report 530 patients, 215 (40.5%) were younger than 24 months. Among these, 344 cases (64.7%) presented with pneumonia, 95 (17.9%) with primary bacteremia, 53 (10%) with meningitis, 6 (1.1%) had pneumonia and meningitis, and 32 (6%) had other IPD diagnosis. The median hospital stay was 12 days (RIQ 8-14 days), and 268 (50.6%) were admitted to the ICU, of whom 60 (11.3%) died. Serotyping was performed in 298 (56.1%). The most frequent serotypes were Spn19A (51.3%), Spn6C (7.7%), Spn3 (6.7%), Spn6A (3.6%), and Spn14 (3.6%). Of 495 (93%) isolates with known susceptibility, 46 (9.2%) were meningeal (M) and 449 (90.7%) non-meningeal (NM). Among M isolates, 41.3% showed resistance to penicillin, and 21.7% decreased susceptibility to ceftriaxone. For NM isolates, 28.2% had decreased susceptibility to penicilin, and 24.2% decreased susceptibility to ceftriaxone. Spn19A showed the highest resistant to penicillin at 47% and was linked to multiresistance.

Conclusion

The prevalence of PCV10-included serotypes decreased, while serotypes 19A and 6C increased, with Spn19A being associated with multiresistance. These findings had played a crucial role in the decision made by Colombia to modify its immunization schedule by switching to PCV13 in July 2022.

Streptococcus pneumoniae serotype 19A in hospitalized children with invasive pneumococcal disease after the introduction of conjugated vaccines in Lima, Peru

BACKGROUND

The Pneumococcal conjugate vaccine (PCV) has decreased cases of invasive pneumococcal disease (IPD) worldwide. However, the impact of PCVs introduction may be affected by the serotype distribution in a specific context.

METHODS

Cross-sectional multicenter passive surveillance study of IPD cases in pediatric patients hospitalized in Lima, Peru between 2016 and 2019 (after PCV13 introduction) to determine the serotype distribution and antimicrobial resistance of Streptococcus pneumoniae. Serotyping was performed by a sequential multiplex PCR and confirmed by whole genome sequencing.

RESULTS

Eighty-five S. pneumoniae isolates were recovered (4.07/100,000 among children <60 months of age). Serotype 19A was the most common (49.4%). Children infected with serotype 19A in comparison with children infected with other serotypes were younger, had a lower rate of meningitis and higher rates of pneumonia, complicated pneumonia and antimicrobial resistance; 28.6% of patients with serotype 19A have received at least one dose of PCV13 vs. 62.8% of patients with other serotypes. Using MIC-breakpoints, 81.2% (56/69) of non-meningitis strains and 31.2% (5/16) of meningitis strains were susceptible to penicillin; 18.8% (3/16) of meningitis strains had intermediate resistance to ceftriaxone. Resistance to azithromycin was 78.8% (67/85). Serotype 19A frequency increased over time in the same study population, from 4.2% (4/96) in 2006-2008, to 8.6% (5/58) in 2009-2011, to 49.4% (42/85) in the current study (2016-2019) (p < 0.001).

CONCLUSIONS

After PCV13 introduction in Peru, serotype 19A remains the most prevalent; however, the vaccination coverage is still not optimal. Therefore, additonal surveillance studies are needed to determine the remaining IPD burden.

Cytokine profile in patients with acute bacterial meningitis

BACKGROUND

Bacterial meningitis is a life-threatening disease with high mortality and common long-term sequelae. The inflammatory response in the subarachnoid space, modulated by different cytokines, plays a major role in the pathogenesis of acute central nervous system infections. We aimed to examine correlations of interleukin (IL)-6, IL-8, IL-10, IL-12(p40), and tumor necrosis factor (TNF)-α levels with disease severity, complications, and outcome in patients with acute bacterial meningitis.

METHODS

The study involved 30 patients with bacterial meningitis/meningoencephalitis admitted to the University Hospital St. George, Plovdiv over a period of 4 years. Patients were selected based on clinical presentation and laboratory abnormalities, consistent with a neuroinfection. Enzyme-linked immunosorbent assay was used to measure the studied cytokines in both cerebrospinal fluid (CSF) and serum in parallel. For microbiological diagnosis multiplex, polymerase chain reaction, and CSF culture were used.

RESULTS

In patients with acute bacterial meningitis CSF levels of IL-6, IL-8, IL-10, and TNF-α are significantly increased than in serum. CSF TNF-α, CSF IL-8, and CSF IL-10 had a moderate negative correlation to CSF glucose. It was found that serum IL-8 is significantly elevated in patients who experienced neurological complications, have severe clinical course, and in deceased patients. CSF IL-10 is increased only in patients with severe acute bacterial meningitis.

CONCLUSION

Among patients with acute bacterial meningitis serum IL-8 could delineate these with increased risk of neurological complications, severe clinical course, and fatal outcome. Serum IL-8 and CSF IL-10 could be used as indicators of disease severity.

Pneumococcal carriage, serotype distribution, and antimicrobial susceptibility in Papua New Guinean children vaccinated with PCV10 or PCV13 in a head-to-head trial

BACKGROUND

Children in Papua New Guinea (PNG) are at high risk of pneumococcal infections. We investigated pneumococcal carriage rates, serotype distribution, and antimicrobial susceptibility in PNG children after vaccination with 10-valent or 13-valent pneumococcal conjugate vaccines (PCV10; PCV13).

METHODS

Infants (N = 262) were randomized to receive 3 doses of PCV10 or PCV13 at 1-2-3 months of age, followed by pneumococcal polysaccharide vaccination (PPV) or no PPV at 9 months of age. Nasopharyngeal swabs (NPS) collected at ages 1, 4, 9, 10, 23 and 24 months were cultured using standard bacteriological procedures. Morphologically distinct Streptococcus pneumoniae colonies were serotyped by the Quellung reaction. Antimicrobial susceptibility was determined by Kirby-Bauer disc diffusion and minimum inhibitory concentration (MIC).

RESULTS

S. pneumoniae was isolated from 883/1063 NPS collected at 1-23 months of age, including 820 serotypeable (64 different serotypes) and 144 non-serotypeable isolates. At age 23 months, 93.6% (95%CI 86.6-97.6%) of PCV10 recipients and 88.6% (95%CI 80.1-94.4%) of PCV13 recipients were pneumococcal carriers, with higher carriage of PCV10 serotypes by PCV10 recipients (19.8%, 95%CI 12.2-29.5) than PCV13 recipients (9.3%, 95%CI 4.1-17.3) (p = 0.049). There were no other statistically significant differences between PCV10 and PCV13 recipients and children receiving PPV or no PPV. Nearly half (45.6%) of carried pneumococci were non-susceptible to penicillin based on the meningitis breakpoint (MIC ≥ 0.12 µg/mL), but resistance was rare (1.1%) using the non-meningitis cut-off (MIC ≥ 8 µg/mL). Non-susceptibility to trimethoprim-sulfamethoxazole (SXT) was common: 23.2% of isolates showed intermediate resistance (MIC 1/19-2/38 µg/mL) and 16.9% full resistance (MIC ≥ 4/76 µg/mL). PCV serotypes 14 and 19A were commonly non-susceptible to both penicillin (14, 97%; 19A, 70%) and SXT (14, 97%; 19A, 87%).

CONCLUSION

Even after PCV10 or PCV13 vaccination, children living in a high-risk setting such as PNG continue to experience high levels of pneumococcal colonization, including carriage of highly antimicrobial-resistant PCV serotypes. The study is registered with ClinicalTrials.gov (CTN NCT01619462).

Comparison of the epidemiology of invasive pneumococcal disease between Australia and New Zealand in 2017-2021: an observational study based on surveillance data

Background

The Australian immunisation schedule uses 13-valent pneumococcal conjugate vaccine (PCV13), while New Zealand (NZ) changed from PCV13 to 10-valent PCV (PCV10) in 2017. In NZ, cases of serotype 19A (not in PCV10) have been increasing since 2017. We compared invasive pneumococcal disease (IPD) epidemiology between Australia and NZ in 2017-2021.

Methods

We collated IPD notification data from national surveillance systems. Between Australia and NZ, we compared IPD incidence rates and assessed the proportion of serotype 19A, and stratified for ethnicity and age.

Findings

Between 2017 and 2021, the crude IPD incidence per 100,000 in Australia ranged from 4.3 to 8.4, and ranged from 6.9 to 11.4 in NZ. The highest age-adjusted IPD rates were observed in Australian Indigenous people (range: 27.3-35.5) followed by NZ Māori/Pacific peoples (range 19.7-30.4). For children <2 years, ethnicity-adjusted IPD rates were similar between Australia and NZ in 2017-2020. In 2021, however, the ethnicity-adjusted incidence in children <2 years was higher in NZ (30.2; 95% CI 21.1-39.4) than in Australia (23.3 95% CI: 19.5-27.1) (p < 0.01). In Australia, the proportion of serotype 19A remained 5%, whereas in NZ serotype 19A increased from 11.5% to 29.5% with the largest increase in children <2 years and 2-4 years.

Interpretation

Despite higher risks in Indigenous populations in Australia compared to all other groups, the overall IPD rate in NZ is increasing, particularly among children. The numbers and proportions of IPD due to serotype 19A are increasing in NZ especially in children. These data support the NZ decision from December 2022 to change to PCV13.

Funding

This research received no specific funding.

Chronic medical conditions associated with invasive pneumococcal diseases in inpatients in teaching hospitals in São Paulo city: Estimating antimicrobial susceptibility and serotype-coverage of pneumococcal vaccines

BACKGROUND

Chronic conditions increase the risk of invasive pneumococcal diseases (IPD). Pneumococcal vaccination remarkably reduced IPD morbimortality in vulnerable populations. In Brazil, pneumococcal vaccines are included in the National Immunization Program (PNI): PCV10 for < 2 years-old, and PPV23 for high risk-patients aged ≥ 2 years and institutionalized ≥ 60 years. PCV13 is available in private clinics and recommended in the PNI for individuals with certain underlying conditions.

METHODS

A retrospective study was performed using clinical data from all inpatients from five hospitals with IPD from 2016 to 2018 and the corresponding data on serotype and antimicrobial-non-susceptibility of pneumococcus. Vaccine-serotype-coverage was estimated. Patients were classified according to presence of comorbidities: healthy, without comorbidities; at-risk, included immunocompetent persons with specific medical conditions; high-risk, with immunocompromising conditions and others RESULTS: 406 IPD cases were evaluated. Among 324 cases with information on medical conditions, children < 5 years were mostly healthy (55.9%), while presence of comorbidity prevailed in adults ≥ 18 years old (> 82.0%). Presence of ≥1 risk condition was reported in ≥ 34.8% of adults. High-risk conditions were more frequent than at-risk in all age groups. Among high-risk comorbidity (n = 211), cancer (28%), HIV/AIDS (25.7%) and hematological diseases (24.5%) were the most frequent. Among at-risk conditions (n = 89), asthma (16.5%) and diabetes (8.1%) were the most frequent. Among 404 isolates, 42.9% belonged to five serotypes: 19A (14.1%), 3 (8.7%), 6C (7.7%), 4 and 8 (6.2% each); 19A and 6C expressed antimicrobial-non-susceptibility. The vaccine-serotype-coverage was: PCV10, 19.1%, PCV13, 43.8%; PCV15, 47.8%; PCV20, 62.9%; PCV21, 65.8%, and PPV23, 67.3%. Information on hospital outcome was available for 283 patients, of which 28.6% died. Mortality was 54.2% for those with meningitis.

CONCLUSION

Vaccine with expanded valence of serotypes is necessary to offer broad prevention to IPD. The present data contribute to pneumococcal vaccination public health policies for vulnerable patients, mainly those with comorbidity and the elderly.

A cost-effectiveness analysis of pneumococcal conjugate vaccines in infants and herd protection in older adults in Colombia

BACKGROUND

Pneumococcal diseases have a clinical and economic impact on the population. Until this year, a 10-valent pneumococcal vaccine (PCV10) used to be applied in Colombia, which does not contain serotypes 19A, 3, and 6A, the most prevalent in the country. Therefore, we aimed to assess the cost-effectiveness of the shift to the 13-valent pneumococcal vaccine (PCV13).

RESEARCH DESIGN AND METHODS

A decision model was used for newborns in Colombia between 2022-2025 and adults over 65 years. The time horizon was life expectancy. Outcomes are Invasive Pneumococcal Diseases (IPD), Community-Acquired Pneumonia (CAP), Acute Otitis Media (AOM), their sequelae, Life Gained Years (LYGs), and herd effect in older adults.

RESULTS

PCV10 covers 4.27% of serotypes in the country, while PCV13 covers 64.4%. PCV13 would avoid in children 796 cases of IPD, 19,365 of CAP, 1,399 deaths, and generate 44,204 additional LYGs, as well as 9,101 cases of AOM, 13 cases of neuromotor disability and 428 cochlear implants versus PCV10. In older adults, PCV13 would avoid 993 cases of IPD and 17,245 of CAP, versus PCV10. PCV13 saves $51.4 million. The decision model shows robustness in the sensitivity analysis.

CONCLUSION

PCV13 is a cost-saving strategy versus PCV10 to avoid pneumococcal diseases.

Invasive Pneumococcal Disease Characterization in Adults and Subgroups aged < 60 years and ≥ 60 years in Bogota, Colombia

•

The clinical burden of IPD is high in the elderly and adults with comorbidities

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IPD placed a high burden on healthcare resources in the adult population

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The most common types causing IPD in adults were similar to those found in children

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Policy makers should consider pneumococcal vaccination for populations at risk

Background

Methods

Results

Conclusions

Epidemiological characteristics and serotype distribution of culture-confirmed pediatric pneumococcal pneumonia before and after PCV 10 introduction, a multicenter study in Bogota, Colombia, 2008-2019

BACKGROUND

Pneumococcal conjugate vaccines (PCVs) have decreased pneumonia in children. Colombia introduced mass vaccination with PCV10 in 2012.

METHODS

Cases of pneumococcal pneumonia from 10 hospitals were included. Two periods were compared: pre-PCV10: 2008-2011 and post-PCV10: 2014-2019. The objective was to compare epidemiological and clinical characteristics before and after PCV10 vaccination.

RESULTS

A total of 370 cases were included. Serotypes 1 (15, 11.2%) and 14 (33, 24.6%) were the most frequent in the pre-PCV10 period, with only 4 (3%) cases of serotype 19A and 1 case (0.7%) serotype 3. From the pre-PCV10 period to the post-PCV10 period, cases of serotypes 1 (6, 3.1%) and 14 (1, 7.8%) decreased, while cases of serotypes 19A (58, 30.2%), serotype 3 (32, 16.7%) and 6A (7, 3.6%) increased (p < 0.001); complicated pneumonia (CP) increased significantly (13.4% to 31.8%) (p < 0.001); hospitalizations increased from 8 (5.5-15) to 12 (7-22) days (p < 0.001); and the frequency of PICU admission increased from 32.8% to 51.6% (p = 0.001). The use of ampicillin-sulbactam (0.7% to 24%) and ceftriaxone/clindamycin (0.7% to 5.7%) increased in the post-PCV10 period. The duration of empirical antibiotic treatment was 7 (4-11) days in the pre-PCV10 period and increased to 10 (6-17) days (p < 0.001) in the post-PCV10 period. Lethality showed a slight nonsignificant increase (7.5% vs. 9.9%; p = 0.57) in the post-PCV10 period.

CONCLUSIONS

PCV10 significantly decreased cases of serotypes 1 and 14, with an increase in cases of serotypes 19A, 3 and 6A, which were the predominant serotypes and had greater severity (e.g., admission to the PICU, CP and more resistance, with an increase in the use of broad-spectrum antibiotics and longer hospitalization) and subsequently included in PCV13. Current data support national and regional evidence on the importance of replacing PCV10 with a higher valence that includes 19A, such as PCV13, with the aim of reducing circulation, particularly of this serotype.

Changes in the incidence of acute bacterial meningitis caused by Streptococcus pneumoniae and the implications of serotype replacement in children in Colombia after mass vaccination with PCV10

INTRODUCTION

Acute bacterial meningitis (ABM) is a public health problem. The disease has reemerged after the introduction of pneumococcal conjugate vaccines (PCVs) due to an increase in serotypes that are not covered. The objective was to determine the changes in the disease incidence before and after the introduction of the 10-valent vaccine (PCV10) in Colombia.

METHODS

This multicenter study was conducted in 17 hospitals in Colombia. Data were collected from January 2008 to December 2019 in 10 hospitals in Bogotá and from January 2017 to December 2019 in seven hospitals in Cali, Medellín and Cartagena. The data were grouped into three periods: 2008-2011, 2012-2015, and 2016-2019.

RESULTS

Of the 706 cases of invasive pneumococcal disease, 81 (11.4%) corresponded to meningitis. The relative incidence in Bogotá in the first period was 0.6 per 100,000 patients ≤ 5 years, decreased to 0.4 per 100,000 patients ≤ 5 years in the second period and increased in the third period to 0.7 per 100,000 patients ≤ 5 years. Serotypes covered by PCV10 decreased from 75 to 9.1%, with Spn19A (31.8%) and Spn34 (13.6%) emerging in the third period. Increased resistance to penicillin (13 to 37%) and to ceftriaxone (5.9 to 16%) was due to the emergence of multidrug-resistant Spn19A. The total mortality rate was 23.5% and increased from 12 to 33%.

CONCLUSIONS

ABM due to pneumococcus has high morbidity and mortality rates. Reemergence of the disease has been observed due to the inclusion of polymerase chain reaction (PCR) for diagnosis and replacement of circulating serotypes after the introduction of PCV10, with an increase in Spn19A, which causes death and exhibits antimicrobial resistance. Continued surveillance is needed.

Guía de práctica clínica para el manejo de la neumonía adquirida en la comunidad

La neumonía sigue siendo una de las principales causas de consulta y de hospitalización a la que, además de su un alto impacto en términos de morbilidad y mortalidad, se suma la actual problemática de resistencia a los antimicrobianos, por lo que establecer directrices que permitan su adecuado diagnóstico y tratamiento es de gran importancia para obtener mejores desenlaces clínicos y promover un uso racional de antibióticos en estos pacientes. La presente guía de práctica clínica (GPC) contiene recomendaciones basadas en la evidencia para el diagnóstico y tratamiento de la neumonía adquirida en la comunidad en adultos, las cuales fueron realizadas mediante el proceso de adaptación de GPC basadas en la evidencia para el contexto colombiano.

Sentinel surveillance for bacterial pneumonia and meningitis in children under the age of 5 in a tertiary pediatric hospital in Colombia - 2016

Introduction:

Bacterial pneumonia and meningitis are vaccine-preventable diseases. Sentinel surveillance provides relevant information about their behavior.

Objective:

To present the data from sentinel surveillance carried out at the Fundación HOMI, Fundación Hospital Pediátrico La Misericordia in 2016.

Materials and methods:

We conducted a descriptive study from January 1 to December 31, 2016, on the daily surveillance of patients under 5 years of age diagnosed with pneumonia or bacterial meningitis according to PAHO's definitions. We identified the microorganisms using the automated VITEK^TM 2 system. Bacterial isolates were sent to the Microbiology Group at the Colombian Instituto Nacional de Salud for confirmation, serotyping, phenotypic, and genotypic characterization. Antimicrobial susceptibility profiles were established.

Results:

From 1,343 suspected cases of bacterial pneumonia, 654 (48.7%) were probable, 84% had complete Hib vaccination schedules, and 87% had complete pneumococcal vaccination schedules for age. Blood culture was taken in 619 (94.6%) and 41 (6.6%) were positive while S. pneumoniae was isolated in 17 (41%) of them. The most frequent serotype was 19A in five cases (29.4%), and four 19A serotypes were associated with the reference isolate ST320. The incidence rate of probable bacterial pneumonia was 7.3 cases/100 hospitalized patients, and lethality was 2.1%. As for bacterial meningitis, 22 suspected cases were reported, 12 (54%) were probable, four (33%) were confirmed: two by Escherichia coli and two by group C N. meningitidis. The incidence of probable bacterial meningitis was 0.14 cases/100 hospitalized patients.

Conclusion:

Streptococcus pneumoniae serotypes 19A and 3 were the most frequent cause of pneumonia. Spn19A is related to the multi-resistant clone ST320. Strengthening and continuing this strategy will allow understanding the impact of vaccination.

Invasive pneumococcal disease burden in hospitalized adults in Bogota, Colombia

Background

The incidence of invasive pneumococcal disease (IPD) varies depending on a number of factors, including vaccine uptake, in both children and adults, the geographic location, and local serotype prevalence. There are limited data about the burden of Streptococcus pneumoniae (Spn), serotype distribution, and clinical characteristics of adults hospitalized due to IPD in Colombia. The objectives of this study included assessment of Spn serotype distribution, clinical characteristics, mortality, ICU admission, and the need for mechanical ventilation.

Methods

This was an observational, retrospective, a citywide study conducted between 2012 and 2019 in Bogotá, Colombia. We analyzed reported positive cases of IPD from 55 hospitals in a governmental pneumococcal surveillance program. Pneumococcal strains were isolated in each hospital and typified in a centralized laboratory. This is a descriptive study stratified by age and subtypes of IPD obtained through the analysis of medical records.

Results

A total of 310 patients with IPD were included, of whom 45.5% were female. The leading cause of IPD was pneumonia (60%, 186/310), followed by meningitis. The most frequent serotypes isolated were 19A (13.87%, 43/310) and 3 (11.94%, 37/310). The overall hospital mortality rate was 30.3% (94/310). Moreover, 52.6% (163/310 patients) were admitted to the ICU, 45.5% (141/310) required invasive mechanical ventilation and 5.1% (16/310) non-invasive mechanical ventilation.

Conclusion

Pneumococcal pneumonia is the most prevalent cause of IPD, with serotypes 19A and 3 being the leading cause of IPD in Colombian adults. Mortality due to IPD in adults continues to be very high.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06769-2.

Laboratory-based surveillance in Latin America: attributes and limitations in evaluation of pneumococcal vaccine impact

Disease surveillance data are needed to monitor trends in disease activity, inform decision-making in public health and evaluate disease prevention/control measures. The Sistema Regional de Vacunas (SIREVA) supports laboratory-based surveillance of invasive pneumococcal disease (IPD) in Latin American countries, providing information on identification, distribution, and anti-microbial susceptibility of pneumococcal strains. We estimated the proportion of pneumococcal meningitis and sepsis/bacteremia cases captured by SIREVA, by comparing the number of SIREVA-reported isolates in Argentina, Brazil, Chile, Colombia, Ecuador and Mexico with the estimated expected number of cases based on regional estimates of disease incidence. In all six countries, the number of isolates reported by SIREVA was consistently lower than the number of cases expected, across all years with data available. The proportion of SIREVA-reported isolates was highest in Chile (43–83%) and lowest in Mexico (1.4–3.5%). Passive surveillance systems such as SIREVA are important tools for monitoring circulating strains that could be related to pneumococcal disease, but our results show that SIREVA is likely to underestimate pneumococcal disease incidence. This under-reporting will limit the precision of surveillance data in monitoring changes in the incidence of IPD after vaccine introduction, and this should be considered when assessing the impact of vaccination programs.

What is the context?

Infectious disease surveillance is an important epidemiological tool to monitor the health of a population.

Surveillence can be used to detect trends in disease activity and to trigger disease control measures.

In Latin America, the SIREVA surveillance system monitors occurrence of bacterial pneumonia, sepsis/bacteremia and meningitis.

However, passive surveillence systems may understimate disease occurrence.

What is new?

We compared the number of isolates of invasive pneumococcal disease (IPD), specifically meningitis and sepsis/bacteremia, in children aged <5 years reported in SIREVA data in six countries in Latin America with the expected number of cases based on regional estimates of IPD incidence.

Our results show that the number of isolates reported by SIREVA was consistently lower than the estimated number of cases, across all six countries and all the years available.

The percent difference between SIREVA-reported isolates and estimated number of cases was variable between countries, ranging from 43-83% in chile to 1.4-3.5% in Mexico.

What is the impact?

Passive surveillance systems such as SIREVA are important tools for monitoring disease incidence, but they are likely to underestimate pneumococcal disease occrruence.

This under-reporting will limit the precision of surveillance data in monitoring changes in disease incidence after vaccine introduction, and this needs to be considered when assessing vaccine impact.

Serotype distribution of invasive, non-invasive and carried Streptococcus pneumoniae in Malaysia: a meta-analysis

Background

Pneumococcal pneumonia is the leading cause of under-five mortality globally. The surveillance of pneumococcal serotypes is therefore vital for informing pneumococcal vaccination policy and programmes. Pneumococcal conjugate vaccines (PCVs) have been available as an option in the private healthcare setting and beginning December 2020, PCV10 was incorporated as part of routine national immunisation programme (NIP) in Malaysia. We searched existing literature on pneumococcal serotype distribution across Malaysia to provide an overall view of this distribution before the implementation of PCV10.

Methods

Online databases (PubMed, Ovid MEDLINE and Scopus), reference lists of articles identified, and grey literature (Malaysian Ministry of Health website, WHO website) were systematically searched for relevant literature on pneumococcal serotype distribution across Malaysia up to 10th November 2020. No lower date limit was set to maximise the number of target reports returned. Results of serotypes were split by age categories, including ≤5 years, > 5 years and unreported for those that did not specify.

Results

The search returned 18 relevant results, with a total of 2040 isolates. The most common serotypes across all disease types were 19F (n = 313, 15.3% [95%CI: 13.8–17.0]), 23F (n = 166, 8.1% [95%CI: 7.0–9.4]), 14 (n = 166, 8.1% [95%CI: 7.0–9.4]), 6B (n = 163, 8.0% [95%CI: 6.9–9.2]) and 19A (n = 138, 6.8% [95%CI: 5.8–7.9]).

Conclusion

Four of the most common serotypes across all isolate sources in Malaysia are covered by PCV10, while PCV13 provides greater serotype coverage in comparison to PCV10. There is still a need for surveillance studies, particularly those investigating serotypes in children under 5 years of age, to monitor vaccine effectiveness and pneumococcal population dynamic following implementation of PCV10 into routine immunisation.