Clinical Burden of Invasive Pneumococcal Disease in Selected Developing Countries

A Little Neutrophil Predominance May Not Be a Harbinger of Death: Clinical and Laboratory Characteristics of Meningitis in Jordan

Background This study aims to evaluate the clinical features, laboratory findings, and outcomes of children and adults diagnosed with meningitis in Jordan. Methodology This is a retrospective chart review study that targeted patients diagnosed with meningitis at King Abdullah University Hospital, a tertiary care center in Northern Jordan, from March 21, 2015, to March 31, 2019. Patients were included in this study if they were older than 28 days and had no risk factors for meningitis. Results A total of 169 patients met the inclusion criteria. Males were overrepresented (67%) and were significantly younger than females (6 vs. 17 years, p = 0.01). Positive meningeal signs were not predictive of greater cerebrospinal fluid leukocytosis (p = 0.348), and they did not provide sufficient sensitivity to be used as screening tools. The most common etiology was aseptic (49%), followed by enterovirus (43%), while bacterial meningitis was an uncommon diagnosis (3.5%). Nearly half of the patients took antibiotics prior to their hospital presentation. During in-hospital admission, six patients died, four of whom had bacterial and two had aseptic meningitis. Enteroviral meningitis showed neutrophil predominance in 44% of cases on lumbar puncture and had a higher neutrophil proportion compared to aseptic meningitis (p = 0.026). Streptococcus pneumoniae was the most common bacterial etiology identified. Conclusions Meningitis in Jordan is most commonly of aseptic and enteroviral origin, and these etiologies carry significantly more favorable outcomes compared to bacterial meningitis. Enteroviral meningitis displays a higher percentage of neutrophils in cerebrospinal fluid compared to aseptic meningitis. S. pneumoniae is the leading cause of bacterial meningitis. Slight neutrophil predominance above half is a weak predictor of bacterial meningitis due to the small contribution of bacteria as a cause among enteroviruses and aseptic etiologies.

Pediatric Invasive Pneumococcal Disease (IPD) in Yogyakarta, Indonesia: A Case Series

Given the fact that invasive pneumococcal disease (IPD) has a high clinical burden, particularly among children in developing countries, data on its occurrence and clinical profile in Indonesia is still insufficient. We presented 3 cases of IPD in children who were admitted to Dr. Sardjito General Hospital, Yogyakarta, Indonesia between 2016 and 2019. While our first 2 patients had milder course of disease, our third patient who presented with meningoencephalitis had poor outcome. Risk factors shown in our cases were young age and malignancy history. Multiple antibiotic resistance was observed in our isolates. The fact that none of our patients have received pneumococcal vaccination marks the necessity of this vaccine especially for at-risk children.

Multicentric Analysis of Erythromycin Resistance Determinants in Invasive Streptococcus pneumoniae; Associated Serotypes and Sequence Types in India

Streptococcus pneumoniae is the major cause of childhood pneumonia and related deaths in India. Widespread use of erythromycin for the treatment of pneumonia has led to the emergence of erythromycin resistance. Despite this increase in erythromycin resistance, there are very little data on resistance determinants from India. Hence, we aimed to perform the molecular characterization of erythromycin-resistant invasive pneumococcal isolates in India. In this study, 250 erythromycin-resistant invasive isolates obtained from four Indian hospitals between 2014 and 2019 were included. The isolates were reconfirmed by standard CDC protocols, followed by detection of erm(B), mef(A/E) genes, and screening for mutations in 23S rRNA, ribosomal proteins L4 and L22. Among the 250 erythromycin-resistant isolates, 46% (n = 114) and 35% (n = 87) carried the mef(A/E) gene and erm(B) gene, respectively; both genes were present in 8% (n = 20) of the isolates and 12% (n = 29) of the studied strains did not bear any of them. The major mutations associated with erythromycin resistance in 23S rRNA, such as A2060C, A2061G, and C2613G, were absent. The predominant serotypes were 19F, 14, 23F, 6A, 6B, 19A, and 9V. The major clonal complexes were CC320, followed by CC230 and CC63. The predominant gene was mef(A/E), and most of the serotypes were PCV13 (54%). This study contributes to the baseline understanding of the erythromycin resistance determinants associated with the serotypes and sequence types (ST) of Indian invasive S. pneumoniae.

Cost-Effectiveness and Budget Impact Analyses of Pneumococcal Vaccination in Indonesia

As a country with the high number of deaths due to pneumococcal disease, Indonesia has not yet included pneumococcal vaccination into the routine program. This study aimed to analyse the cost-effectiveness and the budget impact of pneumococcal vaccination in Indonesia by developing an age-structured cohort model. In a comparison with no vaccination, the use of two vaccines (PCV10 and PCV13) within two pricing scenarios (UNICEF and government contract price) was taken into account. To estimate the cost-effectiveness value, a 5-year time horizon was applied by extrapolating the outcome of the individual in the modelled cohort until 5 years of age with a 1-month analytical cycle. To estimate the affordability value, a 6-year period (2019-2024) was applied by considering the government's strategic plan on pneumococcal vaccination. In a comparison with no vaccination, the results showed that vaccination would reduce pneumococcal disease by 1,702,548 and 2,268,411 cases when using PCV10 and PCV13, respectively. Vaccination could potentially reduce the highest treatment cost from the payer perspective at $53.6 million and $71.4 million for PCV10 and PCV13, respectively. Applying the UNICEF price, the incremental cost-effectiveness ratio (ICER) from the healthcare perspective would be $218 and $162 per QALY-gained for PCV10 and PCV13, respectively. Applying the government contract price, the ICER would be $987 and $747 per QALY-gained for PCV10 and PCV13, respectively. The result confirmed that PCV13 was more cost-effective than PCV10 with both prices. In particular, introduction cost per child was estimated to be $0.91 and vaccination cost of PCV13 per child (3 doses) was estimated to be $16.61 and $59.54 with UNICEF and government contract prices, respectively. Implementation of nationwide vaccination would require approximately $73.3-$75.0 million (13-14% of routine immunization budget) and $257.4-$263.5 million (45-50% of routine immunization budget) with UNICEF and government contract prices, respectively. Sensitivity analysis showed that vaccine efficacy, mortality rate, and vaccine price were the most influential parameters affecting the ICER. In conclusion, pneumococcal vaccination would be a highly cost-effective intervention to be implemented in Indonesia. Yet, applying PCV13 with UNICEF price would give the best cost-effectiveness and affordability values on the routine immunization budget.

Pneumococcal Vaccination for Children in Asian Countries: A Systematic Review of Economic Evaluation Studies

Background: Evidence on costs and health benefits of pneumococcal conjugate vaccine (PCV) for children in Asian countries is limited but growing. As a region with a considerably high burden of pneumococcal disease, it is prominent to have a comprehensive overview on the cost-effectiveness of implementing and adopting a PCV vaccination program. Methods: We conducted a systematic review from Pubmed and Embase to identify economic evaluation studies of PCV for children in Asian countries up to May 2020. Data extraction included specific characteristics of the study, input parameters, cost elements, cost-effectiveness results, and key drivers of uncertainty. The Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRISMA) statement was followed for this systematic review. The reporting quality of the included studies was evaluated using the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) statement. Results: After the screening process on both the title and abstract and full text of 518 records, a total of 25 studies fulfilled the inclusion criteria, and were included in the review. The majority of included studies demonstrates that PCV for children is cost-effective in most of the Asian region, and even cost-saving in some countries. Most of the included studies implemented cost utility analysis (CUA) using either quality-adjusted life years (QALYs) or disability-adjusted life years (DALYs). Overall, the main drivers affecting the cost effectiveness were vaccine price, burden regarding pneumonia-related parameters, and the inclusion of herd effects. Conclusion: The children pneumococcal vaccination program appears to be a cost-effective intervention in Asia, and even cost-saving in certain conditions. Vaccine price, pneumonia-related disease burden, and the inclusion of the herd effect are observed as important key drivers in estimating cost-effectiveness in this region. Incorporating PCV in vaccination programs in this region was found to be highly favorable.

Impact of Switch Options on the Economics of Pneumococcal Conjugate Vaccine (PCV) Introduction in Indonesia

As one of Gavi, the Vaccine Alliance (previously the Global Alliance for Vaccines and Immunization), graduating countries, Indonesia is still eligible to access Gavi price for PCV13, PCV10 A and B. This study aims to estimate the economic impact of switch from the existing product/presentation of PCV (single-dose of PCV13) to the new product/presentation of PCV (multi-dose of PCV13, PCV10 A and B) since PCV is one of the most expensive vaccines in the Expanded Program on Immunization (EPI) schedule. Assuming that Gavi-Advance Market Commitment (AMC) price for all PCVs can be accessed in 2021, the use of multi-dose PCV13, PCV10 A and PCV10 B with Gavi-AMC price in 2021–2024 were considered as respective scenarios. The result showed that the scenario assuming the use of single-dose of PCV13 with contract price in 2019–2020 that would be switched into multi-dose of PCV10 B with Gavi-AMC price in 2021–2024 resulted in the highest potential saving, compared with other scenarios. Our analysis suggests an economic advantage to switch from single-dose into a multi-dose presentation. Vaccination coverage, vaccine price, vaccine wastage and additional Gavi-AMC vaccine costs were considered to be the most influential parameter affecting the savings in all scenarios. Applying the effectiveness of PCV13 and PCV10 A on reducing the risk for invasive pneumococcal disease (IPD), potential averted incidence of IPD in children under one year of age during 2019–2024 would be 246,164 and 105,587 in both scenarios. Despite the result confirmed that PCV13 may provide an additional benefit, a more comprehensive economic evaluation study is required to investigate further the comparison of cost-effectiveness values among all PCVs in Indonesia.

Commentary: Why Has Uptake of Pneumococcal Vaccines for Children Been So Slow? The Perils of Undervaluation

Pediatric pneumococcal disease exacts a substantial burden on global health, much of which is vaccine-preventable. Despite this considerable burden and the demonstrably high efficacy of pneumococcal conjugate vaccines (PCVs), the overall level of PCV uptake remains concerningly low, especially compared with that of other childhood-recommended vaccines, such as tuberculosis and polio. A broad set of plausible explanations exists for this low uptake, including logistical challenges, psychosocial factors and affordability. One additional and systematic cause of low uptake, which is the focus of our discussion, is economists' and policymakers' tendency to undervalue vaccination in general by adopting a narrow health sector perspective when performing economic evaluations of vaccines. We present an alternative, societal framework for economic evaluations that encompasses a broader set of socioeconomic benefits in addition to health benefits. Quantifying a more comprehensive taxonomy of PCV's benefits will help to address potential undervaluation and may be sufficient not only to justify recommendation and reimbursement but also to stimulate efforts and investment toward closing coverage gaps.

The Epidemiology and Biostatistics of Pneumococcus

Invasive infections caused by Streptococcus pneumoniae, such as pneumonia, meningitis, and bacteremia, are a major cause of morbidity and mortality in young children and older adults worldwide. The introduction of pneumococcal conjugate vaccines into national childhood immunization programs has led to large and sustained reductions in the incidence of invasive pneumococcal disease across all age groups. Here we describe the epidemiology and biostatistics of pneumococcal disease as well as the impact of vaccination on the burden of pneumococcal disease globally.

Economic burden of pneumococcal infections in children under 5 years of age

The present study aimed to determine the cost of childhood pneumococcal infections under 5 years of age and to provide further data for future health economy studies. Electronic medical records of children diagnosed with meningitis caused by S. pneumoniae and all-cause pneumonia, and acute otitis media (AOM) between January 2013-April 2014 were retrospectively evaluated. Direct costs for the treatments of hospitalized patients (pneumonia and pneumococcal meningitis) including costs of healthcare services consisted of costs of hospital bed, examination, laboratory analyses, scanning methods, consultation, vascular access procedures, and infusion and intravenous treatments. Direct costs for patients (AOM) treated in outpatient setting included constant price paid for the examination and cost of prescribed antibiotics. Indirect costs included cost of work loss of parents and their transportation expenses. Data of 130 children with pneumococcal meningitis (n = 10), pneumonia (n = 53), and AOM (n = 67) were analyzed. The total median cost was €4,060.38 (direct cost: €3,346.38 and indirect cost: €829.18) for meningitis, €835.91 (direct cost: €480.66 and indirect cost: €330.09) for pneumonia, and €117.32 (direct cost: €17.59 and indirect cost: €99.73) for AOM. The medication cost (p = 0.047), indirect cost (p = 0.032), and total cost (p = 0.011) were significantly higher in pneumonia patients aged ≥36 months than those aged <36 months; however, direct cost of AOM were significantly higher in the patients aged <36 months (p = 0.049). Results of the present study revealed that the treatment cost was significantly enhanced for hospitalization and for advanced disease. Thus, preventive actions, mainly vaccination, should be conducted regularly.

Characterisation of Invasive Streptococcus pneumoniae Isolated from Cambodian Children between 2007 - 2012

BACKGROUND

The 13-valent pneumococcal vaccine (PCV13) was introduced in Cambodia in January 2015. There are limited data concerning the common serotypes causing invasive pneumococcal disease (IPD). Knowledge of the circulating pneumococcal serotypes is important to monitor epidemiological changes before and after vaccine implementation.

METHODS

All episodes of IPD defined by the isolation of Streptococcus pneumoniae from blood, cerebrospinal fluid or other sterile site in Cambodian children admitted to the Angkor Hospital for Children in Siem Reap, Northwestern Cambodia, between 1st January 2007 and 1st July 2012 were retrospectively studied. Streptococcus pneumoniae isolates that could be retrieved underwent phenotypic typing and whole genome sequencing.

RESULTS

There were 90 Cambodian children hospitalized with IPD with a median (IQR) age of 2.3 years (0.9-6.2). The case fatality was 15.6% (95% CI 8-23). Of 50 Streptococcus pneumoniae isolates available for further testing, 46% were penicillin non-susceptible and 8% were ceftriaxone non-susceptible, 78% were cotrimoxazole resistant, 30% were erythromycin resistant and 30% chloramphenicol resistant. There were no significant changes in resistance levels over the five-year period. The most common serotypes were 1 (11/50; 22%), 23F (8/50; 16%), 14 (6/50; 12%), 5 (5/50; 10%) and 19A (3/50; 6%). Coverage by PCV7, PCV10 and PCV13 was 44%, 76% and 92% respectively. We identified novel multilocus sequence types and resistotypes using whole genome sequencing.

CONCLUSIONS

This study suggests IPD is an important disease in Cambodian children and can have a significant mortality. PCV13 coverage of the serotypes determined in studied strains was high and consistent with another recent study. The phenotypic resistance patterns observed were similar to other regional studies. The use of whole genome sequencing in the present study provides additional typing and resistance information together with the description of novel sequence types and resistotypes.

Development of a rapid recombinase polymerase amplification assay for the detection of Streptococcus pneumoniae in whole blood

Background

Streptococcus pneumoniae is an important cause of microbial disease in humans. The introduction of multivalent vaccines has coincided with a dramatic decrease in the number of pneumococcal-related deaths. In spite of this, at a global level, pneumococcal infection remains an important cause of death among children under 5 years of age and in adults 65 years of age or older. In order to properly manage patients and control the spread of infection, a rapid and highly sensitive diagnostic method is needed for routine implementation, especially in resource-limited regions where pneumococcal disease is most prevalent.

Methods

Using the gene encoding leader peptidase A as a molecular diagnostics target, a real-time RPA assay was designed and optimised for the detection of S. pneumoniae in whole blood. The performance of the assay was compared to real-time PCR in terms of its analytical limit of detection and specificity. The inhibitory effect of human genomic DNA on amplification was investigated. The potential clinical utility of the assay was investigated using a small number of clinical samples.

Results

The RPA assay has a limit of detection equivalent to PCR (4.0 and 5.1 genome equivalents per reaction, respectively) and was capable of detecting the equivalent of <1 colony forming unit of S. pneumoniae when spiked into human whole blood. The RPA assay was 100 % inclusive (38/38 laboratory reference strains and 19/19 invasive clinical isolates) and 100 % exclusive; differentiating strains of S. pneumoniae species from other viridans group streptococci, including S. pseudopneumoniae. When applied to the analysis of a small number (n = 11) of clinical samples (blood culture positive for S. pneumoniae), the RPA assay was demonstrated to be both rapid and sensitive.

Conclusions

The RPA assay developed in this work is shown to be as sensitive and as specific as PCR. In terms of reaction kinetics, the RPA assay is shown to exceed those of the PCR, with the RPA running to completion in 20 minutes and capable generating a positive signal in as little as 6 minutes. This work represents a potentially suitable assay for application in point-of-care settings.