Invasive pneumococcal disease in children aged younger than 5 years in India: a surveillance study

Invasive pneumococcal diseases in Chinese children: a multicentre hospital-based active surveillance from 2019 to 2021

This study aimed to provide data for the clinical features of invasive pneumococcal disease (IPD) and the molecular characteristics of Streptococcus pneumoniae isolates from paediatric patients in China. We conducted a multi-centre prospective study for IPD in 19 hospitals across China from January 2019 to December 2021. Data of demographic characteristics, risk factors for IPD, death, and disability was collected and analysed. Serotypes, antibiotic susceptibility, and multi-locus sequence typing (MLST) of pneumococcal isolates were also detected. A total of 478 IPD cases and 355 pneumococcal isolates were enrolled. Among the patients, 260 were male, and the median age was 35 months (interquartile range, 12-46 months). Septicaemia (37.7%), meningitis (32.4%), and pneumonia (27.8%) were common disease types, and 46 (9.6%) patients died from IPD. Thirty-four serotypes were detected, 19F (24.2%), 14 (17.7%), 23F (14.9%), 6B (10.4%) and 19A (9.6%) were common serotypes. Pneumococcal isolates were highly resistant to macrolides (98.3%), tetracycline (94.1%), and trimethoprim/sulfamethoxazole (70.7%). Non-sensitive rates of penicillin were 6.2% and 83.3% in non-meningitis and meningitis isolates. 19F-ST271, 19A-ST320 and 14-ST876 showed high resistance to antibiotics. This multi-centre study reports the clinical features of IPD and demonstrates serotype distribution and antibiotic resistance of pneumococcal isolates in Chinese children. There exists the potential to reduce IPD by improved uptake of pneumococcal vaccination, and continued surveillance is warranted.

Clinical characteristics and risk factors for poor outcomes of invasive pneumococcal disease in pediatric patients in China

BACKGROUND

Invasive pneumococcal disease (IPD) is a significant health concern in children worldwide. In this study, we aimed to analyze the clinical features, antibiotic resistance, and risk variables for poor outcomes in patients with IPD in Hangzhou.

METHODS

A retrospective single-centre study was performed using the pediatric intensive care (PIC) database from 2010 to 2018. The clinical characteristics, laboratory data, antimicrobial resistance, and risk factors for in-hospital mortality and sepsis in patients with IPD in intensive care units (ICUs) were analyzed systematically.

RESULTS

A total of 178 IPD patients were included in the study. The majority of the IPD children were 2-10 years old. Antimicrobial resistance tests of S. pneumoniae isolates revealed high resistance to erythromycin, tetracycline and compound sulfamethoxazole (SMZ-Co). All the isolates were sensitive to vancomycin, linezolid, moxifloxacin, telithromycin, ofloxacin, and levofloxacin. IPD patients may experience poor outcomes, including death and sepsis. The in-hospital mortality was 3.93%, and 34.27% of patients suffered from sepsis. Temperature (OR 3.80, 95% CI 1.62-8.87; P = 0.0021), Partial Pressure of Oxygen in Arterial Blood (PaO2) (OR 0.99, 95% CI 0.98-1.00; P = 0.0266), and albumin (OR 0.89, 95% CI 0.80-0.99; P = 0.0329) were found to be independent risk factors for sepsis in children with IPD.

CONCLUSION

Pediatric IPD deserves attention in China. Appropriate surveillance and antibiotic selection are crucial in managing resistant strains. Early identification of high-risk individuals with risk factors contributes to the development of appropriate treatment strategies.

Immunogenicity and safety of a 14-valent pneumococcal polysaccharide conjugate vaccine (PNEUBEVAX 14™) administered to 6-8 weeks old healthy Indian Infants: A single blind, randomized, active-controlled, Phase-III study

BACKGROUND

Introduction of pneumococcal conjugate vaccines (PCVs) reduced the number of cases of pneumococcal disease (PD). However, there is an increase in clinical and economic burden of PD from serotypes that are not part of the existing pneumococcal vaccines, particularly impacting pediatric and elder population. In addition, the regions where the PCV is not available, the disease burden remains high. In this study, immunogenicity and safety of the BE's 14-valent PCV (PNEUBEVAX 14™; BE-PCV-14) containing two additional epidemiologically important serotypes (22F and 33F) was evaluated in infants in comparison to licensed vaccine, Prevenar-13 (PCV-13).

METHODS

This is a pivotal phase-3 single blind randomized active-controlled study conducted at 12 sites across India in 6-8 weeks old healthy infants at 6-10-14 weeks dosing schedule to assess immunogenic non-inferiority and safety of a candidate BE-PCV-14. In total, 1290 infants were equally randomized to receive either BE-PCV-14 or PCV-13. Solicited local reactions and systemic events, adverse events (AEs), serious AEs (SAEs), and medically attended AEs (MAAEs) were recorded. Immunogenicity was assessed by measuring anti-PnCPS (anti-pneumococcal capsular polysaccharide) IgG concentration and functional antibody titers through opsonophagocytic activity (OPA), one month after completing three dose schedule. Cross protection to serotype 6A offered by serotype 6B was also assessed in this study.

FINDINGS

The safety profile of BE-PCV-14 was comparable to PCV-13 vaccine. Majority of reported AEs were mild in nature. No severe or serious AEs were reported in both the treatment groups. For the twelve common serotypes and for the additional serotypes (22F and 33F) in BE-PCV-14, NI criteria was demonstrated as defined by WHO TRS-977. Primary immunogenicity endpoint was met in terms of IgG immune responses for all 14 serotypesof BE-PCV-14. Moreover, a significant proportion of subjects (69%) seroconverted against serotype 6A, even though this antigen was not present in BE-PCV-14. This indicates that serotype 6B of BE-PCV-14 cross protects serotype 6A. BE-PCV-14 also elicited comparable serotype specific functional OPA immune responses to all the serotypes common to PCV-13.

INTERPRETATIONS

BE-PCV-14 was found to be safe and induced robust and functional serotype specific immune responses to all 14 serotypes. It also elicited cross protective immune response against serotype 6B.These findings suggest that BE-PCV-14 can be safely administered to infants and achieve protection against pneumococcal disease caused by serotypes covered in the vaccine. The study was prospectively registered with clinical trial registry of India - CTRI/2020/02/023129.

Capsular typing of Streptococcus pneumoniae isolated from clinical specimens in Gauhati Medical College and hospital, Assam, India

PURPOSE

Streptococcus pneumoniae is an important human respiratory tract pathogen causing pneumococcal diseases in majority of children and adults. The capsule is a significant virulence factor of Pneumococci which determines the bacterial serotype and is the component used for synthesis of pneumococcal vaccines. This cross-sectional study aimed to isolate Streptococcus pneumoniae from clinical samples and determine the occurrence of its circulating serotypes in Assam, North East India.

MATERIALS AND METHODS

A total of 80 clinical samples were collected from June 2019 to May 2020 from patients clinically suspected from pneumococcal infection and also included samples routinely sent to bacteriology laboratory. Isolation and identification of S. pneumoniae was performed using conventional culture and molecular methods. Antibiotic susceptibility patterns were monitored. Capsular serotyping was performed using PCR of cpsA gene followed by DNA sequencing.

RESULTS

Majority of the cases suspected of pneumococcal infection belong to the paediatric group aged less than 5 years. Out of 80 samples, 10 (12.50%) were found to be positive by PCR of recP gene. Culture was positive in 80% (8/10) of the total positives. Co-trimoxazole resistance was seen in 33.33% of the isolate from sputum. Serotypes 6A, 6B, 6C and 19F were detected in our region, out of which 6C is a non-vaccine serotype.

CONCLUSION

Continued surveillance is needed to monitor trends in non-vaccine serotypes that may emerge as highly associated with antibiotic resistance. Also, the need to continuous monitoring of the antibiotic susceptibility of S. pneumoniae in North eastern parts of India is of outmost importance.

Estimation of baseline IgG antibody levels to 23 pneumococcal vaccine-type capsular polysaccharides in healthy vaccine naïve Indian adults

Since immunological responses to pneumococcal vaccines are assessed by a fold-increase in antibody levels relative to pre-immunization levels, it is therefore critical to determine baseline antibody levels to establish putative threshold as a measure of normal response. Herein, for the first time, we measured baseline IgG antibody levels in 108 healthy unvaccinated Indian adults using WHO-recommended ELISA. Median baseline IgG concentration ranged between 0.54 µg/mL to 12.35 µg/mL. Highest levels of baseline capsule polysaccharide (cPS)-specific IgG were found against types 14, 19A, and 33F. Whereas, lowest baseline IgG levels were observed against types 3, 4, and 5. Overall, ∼79 % of study population had median baseline IgG levels ≥1.3 µg/mL against 74 % of cPS's. Substantial baseline antibody levels in unvaccinated adults were observed. The study would be critical in bridging gaps in baseline immunogenicity data and may offer a valuable foundation for evaluating immune response of Indian adults to pneumococcal vaccination.

A scoping review on laboratory surveillance in the WHO Southeast Asia Region: Past, present and the future

Background

The South-East Asia (SEA) region bears a significant proportion of the world's communicable disease burden. The onset of the COVID-19 pandemic has further affected the situation. A well-established laboratory-based surveillance (LBS) can reduce the burden of infectious diseases. In light of this, the review collated the existing literature on LBS system in the region and the modifications adopted by the surveillance systems during the pandemic.

Methodology

We followed the guidelines for scoping review as prescribed by Arskey and O'Malley. We comprehensively searched three databases (PubMed, Scopus and CINAHL) and supplemented it with grey literature search. The screening of the articles was conducted at the title and abstract followed by full-text screening. This was followed by data extraction using a pre-tested data extraction tool by two independent reviewers. The results were presented narratively.

Results

Including 75 relevant articles and documents, we compiled a list of surveillance systems. A shift from paper to dual (paper and electronic) modalities was identified across the countries. This largely low- and middle-income countries (LMIC) area face challenges in reporting, resources, and collaboration-related issues. While some countries have well-established National Reference Laboratories; others have more private than public-owned laboratories. Given the COVID-19 pandemic, modifications to the existing laboratory capacities to enable real-time surveillance was identified. Laboratory capacity complemented with genomic surveillance can indubitably aid in disease detection and control. Limitations due to inaccessible government portals, and language barriers are acknowledged. This review identified a comprehensive list of surveillance systems in the region, challenges faced in using these surveillance systems and inform the decision makers about the benefits of integrating fragmented surveillance systems.

Conclusion

Regionally and nationally integrated genomic and laboratory surveillance systems justify capital investments, as their payoffs rationalise such costs owing to economies of scale over time. Further, as data flows are harmonized and standardized, algorithm- and computing-based pattern recognition methods allow for targeted and accurate disease prediction when integrated with, potentially, climate and weather systems data. Trained human resources are a sine qua non to optimize such investments, but in the medium to long run, such investments will buttress initiatives in other arenas at the regional level.

Effect of reduced two-dose (1+1) schedule of 10 and 13-valent pneumococcal conjugate vaccines (SynflorixTM and Prevenar13TM)) on nasopharyngeal carriage and serotype-specific immune response in the first two years of life: Results from an open-labelled randomized controlled trial in Indian children

INTRODUCTION

This study aimed to assess the effect of a reduced dose regime (1 + 1) of PCV10 and PCV13 along with 3-dose regimes on pneumococcal vaccine-type (VT) carriage and immunogenicity in the first two years of life in PCV-naïve Indian children.

METHODS

A total of 805 healthy infants aged 6-8 weeks were randomised to 7 groups (n = 115). Six groups received Synflorix^TM(PCV10) or Prevenar13^TM(PCV13) in the following schedules: 3 + 0 (three primary at 6, 10, and 14 weeks); 2 + 1 (two primary 6 and 14 weeks with booster at 9 months; 1 + 1 (one primary at 14 weeks with booster at 9 months). The 7th group was a PCV-naïve control group. Nasopharyngeal swabs were collected at 6, 18 weeks, 9, 10, 15, and 18 months of age. Venous blood samples were collected at 18 weeks, 9, 10, and 18 months of age for assessment of sero-specific IgG antibodies. Additionally, functional activity using a serotype specific opsonophagocytic assay (OPA) was assessed at 10 and 18 months of age in a subset (20%) of participants.

RESULTS

All schedules of PCV13 showed significant 13VT carriage reduction in the second year of life as compared to control. At 15 months of age, PCV13 (1 + 1) showed 45 % reduction in 13VT-carriage compared to the control [OR = 0.55 (95% CI; 0.31-0.97), p= 0.038]. None of the PCV10 schedules showed significant reduction in 10VT carriage in the second year. Although not powered for these outcomes, at 18 months of age, 1 + 1 and 2 + 1 schedules of both vaccines demonstrated higher sero-responders for all serotypes, higher geometric mean concentrations (GMC) for all serotypes except 23F [with both vaccines], higher percent OPA responders and OPA geometric mean titres (GMT) compared to the 3 + 0 schedules for all serotypes.

CONCLUSION

The reduced dose schedule (1 + 1) of PCV13 results in significant VT-carriage reduction in the second year of life. Immune protection provided by 1 + 1 schedules of PCV10 and PCV13 in the second year of life is comparable to WHO-recommended 3-dose schedules.

Serotype Distribution and Antimicrobial Resistance of Streptococcus pneumoniae Causing Invasive Pneumococcal Disease in Korea Between 2017 and 2019 After Introduction of the 13-Valent Pneumococcal Conjugate Vaccine

Background

Streptococcus pneumoniae is a serious pathogen causing various infections in humans. We evaluated the serotype distribution and antimicrobial resistance of S. pneumoniae causing invasive pneumococcal disease (IPD) after introduction of pneumococcal conjugate vaccine (PCV)13 in Korea and investigated the epidemiological characteristics of multidrug-resistant (MDR) isolates.

Methods

S. pneumoniae isolates causing IPD were collected from 16 hospitals in Korea between 2017 and 2019. Serotyping was performed using modified sequential multiplex PCR and the Quellung reaction. Antimicrobial susceptibility tests were performed using the broth microdilution method. Multilocus sequence typing was performed on MDR isolates for epidemiological investigations.

Results

Among the 411 S. pneumoniae isolates analyzed, the most prevalent serotype was 3 (12.2%), followed by 10A (9.5%), 34 (7.3%), 19A (6.8%), 23A (6.3%), 22F (6.1%), 35B (5.8%), 11A (5.1%), and others (40.9%). The coverage rates of PCV7, PCV10, PCV13, and pneumococcal polysaccharide vaccine (PPSV)23 were 7.8%, 7.8%, 28.7%, and 59.4%, respectively. Resistance rates to penicillin, ceftriaxone, erythromycin, and levofloxacin were 13.1%, 9.2%, 80.3%, and 4.1%, respectively. MDR isolates accounted for 23.4% of all isolates. Serotypes 23A, 11A, 19A, and 15B accounted for the highest proportions of total isolates at 18.8%, 16.7%, 14.6%, and 8.3%, respectively. Sequence type (ST)166 (43.8%) and ST320 (12.5%) were common among MDR isolates.

Conclusions

Non-PCV13 serotypes are increasing among invasive S. pneumoniae strains causing IPD. Differences in antimicrobial resistance were found according to the specific serotype. Continuous monitoring of serotypes and antimicrobial resistance is necessary for the appropriate management of S. pneumoniae infections.

Antimicrobial Resistance: The 'Other' Pandemic! : Based on 9th Dr. I. C. Verma Excellence Award for Young Pediatricians Delivered as Oration on 19th Sept. 2021

Antimicrobial resistance is projected to kill 10 million people by 2050. The biggest driver of antimicrobial resistance is excessive/unrestricted use of antimicrobials in humans and animals. Antimicrobial resistance is a problem in all types of pathogens including bacteria, mycobacteria, viruses, fungi, and parasites both globally and India and in both adults and children. The areas of greatest concern for India is the epidemic of MDR and XDR tuberculosis and resistance in gram-negative pathogens. The alarming rate of extended spectrum beta lactamase (ESBL) production in Enterobacteriales in both community and health care-associated infections is driving carbapenem use. Rates of carbapenem resistance are now significantly high in health care-associated gram negative pathogens with associated high mortality rates. The key solution to this antimicrobial resistance crisis needs participation of all stakeholders and lies in promoting rational antimicrobial therapy.

Clinical characteristics, antimicrobial resistance, and risk factors for mortality in paediatric invasive pneumococcal disease in Beijing, 2012-2017

Background

To analyse clinical characteristics, antibiotic susceptibility, and risk factors for mortality in paediatric invasive pneumococcal disease (IPD) in Beijing.

Methods

Paediatric IPD patients in our hospital were retrospectively collected from 2012 to 2017. Clinical manifestations, laboratory tests, antimicrobial susceptibility and serotype of isolates, and risk factors for mortality of IPD were analysed.

Results

Overall, 186 IPD cases were enrolled. The major manifestations were meningitis (76), pneumonia with bacteraemia (60), bacteraemia without focus (21), and pneumonia with empyaema (22). Of 72 cases with underlying diseases, leukaemia (18.0%), congenital heart disease (15.3%), primary immunodeficiency disease (12.5%), nephrotic syndrome (12.5%), and cerebrospinal fluid leakage (12.5%) were most common. In total 96.9% of isolates would have been covered by the pneumococcal conjugate vaccine (PCV13), including 19F (32.8%), 19A (23.4%), 4 (17.2%), and 23F (9.4%). Nonsusceptibility rates of penicillin, cefotaxime, and cefepime among nonmeningitis patients increased between 2012 and 2017; The mortality rate was 21.5%. Meningitis, respiratory failure, multiple organ failure, and white blood cell count < 4000 cells/μL were independent risk factors for mortality.

Conclusion

Meningitis was the most common clinical manifestation of IPD, and was frequently associated with death. Strains in the PCV13 vaccine would cover most of the cases, and so wider use of PCV13 should be considered.

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.

Impact of the introduction of pneumococcal conjugate vaccination on invasive pneumococcal disease and pneumonia in The Gambia: 10 years of population-based surveillance

Background

The Gambia introduced seven-valent pneumococcal conjugate vaccine (PCV7) in August 2009, followed by PCV13 in May, 2011, using a schedule of three primary doses without a booster dose or catch-up immunisation. We aimed to assess the long-term impact of PCV on disease incidence.

Methods

We did 10 years of population-based surveillance for invasive pneumococcal disease (IPD) and WHO defined radiological pneumonia with consolidation in rural Gambia. The surveillance population included all Basse Health and Demographic Surveillance System residents aged 2 months or older. Nurses screened all outpatients and inpatients at all health facilities using standardised criteria for referral. Clinicians then applied criteria for patient investigation. We defined IPD as a compatible illness with isolation of Streptococcus pneumoniae from a normally sterile site (cerebrospinal fluid, blood, or pleural fluid). We compared disease incidence between baseline (May 12, 2008–May 11, 2010) and post-vaccine years (2016–2017), in children aged 2 months to 14 years, adjusting for changes in case ascertainment over time.

Findings

We identified 22 728 patients for investigation and detected 342 cases of IPD and 2623 cases of radiological pneumonia. Among children aged 2–59 months, IPD incidence declined from 184 cases per 100 000 person-years to 38 cases per 100 000 person-years, an 80% reduction (95% CI 69–87). Non-pneumococcal bacteraemia incidence did not change significantly over time (incidence rate ratio 0·88; 95% CI, 0·64–1·21). We detected zero cases of vaccine-type IPD in the 2–11 month age group in 2016–17. Incidence of radiological pneumonia decreased by 33% (95% CI 24–40), from 10·5 to 7·0 per 1000 person-years in the 2–59 month age group, while pneumonia hospitalisations declined by 27% (95% CI 22–31). In the 5–14 year age group, IPD incidence declined by 69% (95% CI −28 to 91) and radiological pneumonia by 27% (95% CI −5 to 49).

Interpretation

Routine introduction of PCV13 substantially reduced the incidence of childhood IPD and pneumonia in rural Gambia, including elimination of vaccine-type IPD in infants. Other low-income countries can expect substantial impact from the introduction of PCV13 using a schedule of three primary doses.

Funding

Gavi, The Vaccine Alliance; Bill & Melinda Gates Foundation; UK Medical Research Council; Pfizer Ltd.

Hospitalization for Invasive Pneumococcal Diseases in Young Children before Use of 13-Valent Pneumococcal Conjugate Vaccine, Suzhou, China

A 13-valent pneumococcal conjugate vaccine against invasive pneumococcal disease (IPD) was introduced in China in April 2017. We describe 105 children <5 years of age who were hospitalized for IPD at Soochow University Affiliated Children’s Hospital in Suzhou, China, during January 2010–December 2017. We calculated the incidence of hospitalization for IPD as 14.55/100,000 children in Suzhou. We identified 8 different capsular serotypes: 6B (28.4% of cases), 14 (18.9% of cases), 19A (18.9% of cases), 19F (12.2% of cases), 23F (10.8% of cases), 20 (4.1% of cases), 9V (4.1% of cases), and 15B/C (2.7% of cases). These results provide baseline data of IPD before the introduction of this vaccine in China, enabling researchers to better understand its effects on IPD incidence.

Hospital-based sentinel surveillance for bacterial meningitis in under-five children prior to the introduction of the PCV13 in India

INTRODUCTION

A hospital-based sentinel surveillance network for bacterial meningitis was established in India to estimate the burden of bacterial meningitis, and the proportion of major vaccine-preventable causative organisms. This report summarises the findings of the surveillance conducted between March 2012, and September 2016 in eleven hospitals.

METHODS

We enrolled eligible children with bacterial meningitis in the age group of one to 59 months. CSF samples were collected and processed for biochemistry, culture, latex agglutination, and real-time PCR. Pneumococcal isolates were serotyped and tested for antimicrobial susceptibility.

RESULTS

Among 12 941 enrolled suspected meningitis cases, 586 (4.5%) were laboratory confirmed. S. pneumoniae (74.2%) was the most commonly detected pathogen, followed by H. influenzae (22.2%), and N. meningitidis (3.6%). Overall 58.1% of confirmed bacterial meningitis cases were children aged between one, and 11 months. H. influenzae meningitis cases had a high (12.3%) case fatality rate. The serotypes covered in PCV13 caused 72% pneumococcal infections, and the most common serotypes were 14 (18.3%), 6B (12.7%) and 19F (9.9%). Non-susceptibility to penicillin was 57%. Forty-five (43.7%) isolates exhibited multidrug resistance, of which 37 were PCV13 serotype isolates.

CONCLUSIONS

The results are representative of the burden of bacterial meningitis among under-five children in India. The findings were useful in rolling out PCV in the National Immunization Program. The non-susceptibility to penicillin and multidrug resistance was an important observation. Timely expansion of PCV across India will significantly reduce the burden of antimicrobial resistance. Continued surveillance is needed to understand the trend after PCV expansion in India.

Carriage rates and antimicrobial sensitivity of pneumococci in the upper respiratory tract of children less than ten years old, in a north Indian rural community

Pneumococcal carriage studies are important for vaccine introduction and treatment strategies. Pneumococcal carriage rates estimated in this cohort study among children in a rural community of northern India. Between August 2012 and August 2014, trained nurses made weekly home visits to screen enrolled children aged <10 years for acute upper or lower respiratory infections (AURI/ALRI) in Ballabgarh, Haryana. Nasal swab from infants aged <1year and throat swab from children aged ≥1 year were collected. All specimens were cultured for pneumococci; isolates were serotyped and subjected to antimicrobial susceptibility testing. During the study period, 4348 nasal/throat swabs collected from children with clinical features of ARI (836 ALRI, 2492 AURI) and from 1020 asymptomatic children. Overall pneumococcal carriage was 5.1%, the highest carriage rate among children <1 year of age (22.6%). The detection rates were higher among children with ARI (5.6%; 95% CI: 4.8–6.4) than asymptomatic children (3.3%; 95% CI: 2.3–4.6). Among 220 pneumococcal isolates, 42 diverse serotypes were identified, with 6B/C (8.6%), 19A (7.2%), 19F (6.8%), 23F (6.4%), 35A/B/C (6.4%), 15B (5%), 14 (4.5%) and 11A/C/D (3.2%) accounting for 50%. Forty-five percent of the serotypes identified are included in the current formulation of 13-valent pneumococcal conjugate vaccine. Ninety-six percent of isolates were resistant to co-trimoxazole, 9% were resistant to erythromycin, and 10% had intermediate resistance to penicillin with minimum inhibitory concentration ranges (0.125 to 1.5 μg/ml). Pneumococcal detection was relatively low among children in our study community but demonstrated a diverse range of serotypes and half of these serotypes would be covered by the current formulation of 13-valent pneumococcal vaccine.

A systematic literature review on the prevalence and etiology of meningitis among critically ill and hospitalized patients in India

BACKGROUND

In India, owing to multiple factors, such as insufficient laboratory capacity, poor reporting systems due to limited access to healthcare facilities and limited disease surveillance programmes, the actual disease burden of meningitis is unknown and may be largely under-reported.

OBJECTIVE

A systematic literature review was performed to describe: (a) the prevalence of meningitis; and (b) its etiological pathogen across different regions, age groups and patients with comorbidities.

METHOD

A systematic literature search was conducted between 1990 and 2020 using PubMed and Google Scholar databases to identify Indian studies reporting the prevalence rates and etiology of meningitis. A total of 51 studies were included in the final analysis.

RESULTS

A total of 38 studies reported prevalence of meningitis and 21 studies reported data on the etiology of meningitis in India. These studies included mixed patient populations: (a) pyogenic meningitis; (b) meningitis in sick or hospitalized patients with tuberculosis, acute febrile encephalopathy syndrome, septicaemia, invasive pneumococcal disease or respiratory compromise; and (c) meningitis patients with comorbidities. The prevalence of confirmed bacterial meningitis in the pediatric population (0-14 years) ranged between 0.5% and 61.8%. A total of seven studies reported the prevalence of meningitis in patients of all age groups (0-75 years), with prevalence ranging between 8.68% and 78.85%. Cryptococcal meningitis was predominant in patients with positive HIV/AIDS, with a prevalence ranging between 2.09% and 53.1%. Streptococcus pneumoniae was found to be the predominant pathogen causing meningitis across different regions of India, with a frequency ranging from 4% to 61.8% in patients of all age groups.

CONCLUSION

This systematic literature review displayed the possible range of frequency of bacterial meningitis pathogens across a wide variety of age groups in different regions of India. Further studies are warranted to monitor meningitis cases, which may facilitate the development of prevention and treatment strategies in India.

IMPACT OF MOLECULAR METHOD FOR THE DIAGNOSIS OF ACUTE BACTERIAL MENINGITIS IN A TERTIARY HEALTH CARE CENTRE IN NORTH INDIA

Background. Acute bacterial meningitis is one of the significant infectious diseases that add an immense burden to the health system. Proper management of meningitis is an invincible need to overcome the severe consequences. Objectives. The aim of the study is detection of the etiological agents of acute bacterial meningitis by PCR. Methods. Total 267 CSF samples collected from suspected bacterial meningitis cases were processed for the detection of S. pneumoniae, H. influenzae, N. meningitidis, E. coli and Group B streptococci by conventional and molecular diagnosis method. CSF was inoculated on Blood, chocolate and MacConkey agar plates and incubated at 37 °C for 24-48 hrs. Bacteria grown were identified by Matrix assisted laser desorption/ionization time of flight (MALDI-TOF). Multiplex PCR of the enlisted bacteria was performed using DNA extracted from CSF by DNA extraction kit (Qiagen, USA). Results. 5 (1.87%) out of the total 267 CSF samples were culture positive (3 S. pneumoniae and 2 E. coli) and 28 (10.49%) had detectable DNA by conventional PCR. Out of these 28 samples, 20 (71.43%) were S. pneumoniae and 8 (28.57%) were E. coli. 15 (53.57%) out of total S. pneumoniae were present in children below 5 years of age. Similarly, E. coli was predominant in neonates. Sensitivity and specificity of the PCR was 100% and 95-98% respectively. Conclusions. Streptococcus pneumoniae is the commonest cause of community acquired bacterial meningitis in children below five years of age. Hence, for the promising outcome, PCR should be implemented for the diagnosis of acute bacterial meningitis.

Serotypes and Antimicrobial Susceptibility of Nasopharyngeal Isolates of Streptococcus pneumoniae from Children Less Than 5 Years Old in Egypt

Purpose

Streptococcus pneumoniae (S. pneumoniae) is the etiology of severe and life-threatening infections in children less than 5 years old. Though pneumococcal conjugate vaccines (PCVs) are effective in the prevention of pneumococcal infections, yet they are not included in the National Immunization Program in Egypt pending the identification of pathogenic serotypes. As S. pneumoniae colonization of the pharynx predisposes to pneumonia and invasive pneumococcal disease (IPD) caused by the colonizing serotypes, identification of the nasopharyngeal (NP) serotypes can be a surrogate to the invasive serotypes. In this study, we aimed to 1. Identify the serotypes and antimicrobial susceptibility testing (AST) of Streptococcus pneumoniae colonizing the nasopharynx of Egyptian children younger than 5 years in two successive winter seasons. 2. Correlate the identified serotypes with vaccine coverage of the 13-valent conjugate pneumococcal vaccines (PCV13). 3. Compare the serotypes and AST of S. pneumoniae from NP to those of IPD that were routinely identified in our clinical laboratory during the study period.

Materials and Methods

The study was conducted in two successive winter seasons (December 2015–March 2016; December 2016–March 2017). We enrolled 334 children, aged 6 months to 5 years, attending the outpatient general clinics of Cairo University Children Hospital, excluding those with fever, signs of infection, history of antibiotic intake or hospitalization in the preceding month. We tested NP swabs for S. pneumoniae by culture and real-time PCR. Serotyping was performed by sequential multiplex PCR for all positive samples. AST was done to S. pneumoniae isolates by Vitek-2™ (BioMérieux, Marcy-L’Etoile, France). We included routinely detected S. pneumoniae from sterile body sites during the study period, and identified their serotypes and AST.

Results

PCR was positive for pneumococci in 217 out of 334 pharyngeal swabs (65%), including 186 typable samples. The most common serotypes were serotypes 1, 6ABC, 19 F, 5 and 18ABC. By culture, we isolated only 110 out of 334 pharyngeal swabs (32.9%). The theoretical coverage of the PCV13 vaccine for the detected serotypes was 77.4%. The AST of NP isolates revealed low susceptibility rates to all antimicrobials except for vancomycin, linezolid, levofloxacin and clindamycin. During the study period, we identified 40 IPD; 21 identified by PCR and 19 by culture. The commonest pneumococcal serotypes were 1, 18ABC, 6ABC and 5. The PCV13 coverage was 75%. By Vitek-2, the isolates showed 100%, 100%, 94.7%, 89.5%, 84.2%, 84.2% and 78.9% susceptibility to vancomycin, linezolid, clindamycin, levofloxacin, penicillin, cefotaxim and erythromycin, respectively.

Conclusion

Based on the serotype vaccine coverage and the emerging antimicrobial resistance of S. pneumoniae, PCVs will be valuable to Egyptian children.

Liver Abscess due to Streptococcus pneumoniae: A Clinical Rarity

We report a case of pyogenic liver abscess caused by a rare causative agent, Streptococcus pneumoniae. A 45-year-old man with underlying uncontrolled diabetes mellitus who had stopped taking his daily dose of insulin since the last 4 days, presented with pain in the abdominal area of one-day duration. Upon his admission to achieve diabetic control, a routine ultrasound examination of abdomen revealed incidentally, a large abscess in the left lobe of the liver with impending rupture. Culture of the ultrasound-guided liver aspirate pus yielded pure growth of a penicillin-susceptible S. pneumoniae isolate. After 4 weeks of parenteral ceftriaxone therapy along with intensive regimen for diabetic control, the liver abscess became resolved, and the patient improved and was discharged with no residual infection or recurrence at four months and at one-year follow-up. A review of relevant literature related to S. pneumoniae liver abscess revealed a mention of such entity only on 4 previous occasions. The present case highlights an important though rare manifestation of S. pneumoniae infection and emphasizes the need to establish an early diagnosis of S. pneumoniae infection for improved patient survival and favourable outcome.

National, regional, and state-level burden of Streptococcus pneumoniae and Haemophilus influenzae type b disease in children in India: modelled estimates for 2000-15

Background

India accounts for a disproportionate burden of global childhood illnesses. To inform policies and measure progress towards achieving child health targets, we estimated the annual national and state-specific childhood mortality and morbidity attributable to Streptococcus pneumoniae and Haemophilus influenzae type b (Hib) between 2000 and 2015.

Methods

In this modelling study, we used vaccine clinical trial data to estimate the proportion of pneumonia deaths attributable to pneumococcus and Hib. The proportion of meningitis deaths attributable to each pathogen was derived from pathogen-specific meningitis case fatality and bacterial meningitis case data from surveillance studies. We applied these proportions to modelled state-specific pneumonia and meningitis deaths from 2000 to 2015 prepared by the WHO Maternal and Child Epidemiology Estimation collaboration (WHO/MCEE) on the basis of verbal autopsy studies from India. The burden of clinical and severe pneumonia cases attributable to pneumococcus and Hib was ascertained with vaccine clinical trial data and state-specific all-cause pneumonia case estimates prepared by WHO/MCEE by use of risk factor prevalence data from India. Pathogen-specific meningitis cases were derived from state-level modelled pathogen-specific meningitis deaths and state-level meningitis case fatality estimates. Pneumococcal and Hib morbidity due to non-pneumonia, non-meningitis (NPNM) invasive syndromes were derived by applying the ratio of pathogen-specific NPNM cases to pathogen-specific meningitis cases to the state-level pathogen-specific meningitis cases. Mortality due to pathogen-specific NPNM was calculated with the ratio of pneumococcal and Hib meningitis case fatality to pneumococcal and Hib meningitis NPNM case fatality. Census data from India provided the population at risk.

Findings

Between 2000 and 2015, estimates of pneumococcal deaths in Indian children aged 1–59 months fell from 166 000 (uncertainty range [UR] 110 000–198 000) to 68 700 (44 600–86 000), while Hib deaths fell from 82 600 (52 300–112 000) to 15 600 (9800–21 500), representing a 58% (UR 22–78) decline in pneumococcal deaths and an 81% (59–91) decline in Hib deaths. In 2015, national mortality rates in children aged 1–59 months were 56 (UR 37–71) per 100 000 for pneumococcal infection and 13 (UR 8–18) per 100 000 for Hib. Uttar Pradesh (18 900 [UR 12 300–23 600]) and Bihar (8600 [5600–10 700]) had the highest numbers of pneumococcal deaths in 2015. Uttar Pradesh (9300 [UR 5900–12 700]) and Odisha (1100 [700–1500]) had the highest numbers of Hib deaths in 2015. Less conservative assumptions related to the proportion of pneumonia deaths attributable to pneumococcus indicate that as many as 118 000 (UR 69 000–140 000) total pneumococcal deaths could have occurred in 2015 in India.

Interpretation

Pneumococcal and Hib mortality have declined in children aged 1–59 months in India since 2000, even before nationwide implementation of conjugate vaccines. Introduction of the Hib vaccine in several states corresponded with a more rapid reduction in morbidity and mortality associated with Hib infection. Rapid scale-up and widespread use of the pneumococcal conjugate vaccine and sustained use of the Hib vaccine could help accelerate achievement of child survival targets in India.

Funding

Bill & Melinda Gates Foundation.

Hospital-based sentinel surveillance for Streptococcus pneumoniae and other invasive bacterial diseases in India (HBSSPIBD): design and methodology

INTRODUCTION

Streptococcus pneumoniae is one of the frequently isolated organisms and an important aetiological agent of invasive bacterial diseases (IBD) like pneumonia, meningitis and sepsis. As a measure to control the burden of IBD, the Government of India introduced Pneumoccocal Conjugate Vaccine-13 (PCV-13) in the Universal Immunization Program in high burden districts of five states in a phased manner from 2017 onwards. It is essential to understand the trend of circulating pneumococcal serotypes associated with IBD in the prevaccination and postvaccination scenarios to decide on the expansion of vaccination programmes and PCV reformulation. This manuscript describes the protocol for hospital-based sentinel surveillance for S. pneumoniae and other organisms causing IBD across various geographical regions in India.

METHODS AND ANALYSIS

Hospital-based surveillance is established in selected hospitals to recruit children aged 1-59 months with symptoms of pneumonia and other IBD. Diagnostic criteria were adapted from standard WHO case definitions. Case Report Forms (CRFs) are used to collect data from the enrolled children. Blood, cerebrospinal fluid (CSF) and other normally sterile body fluids are collected and subjected to microscopy, cytology, latex agglutination, biochemistry, bacteriological culture and real-time PCR as applicable. Pneumococcal isolates are serotyped and tested for assessing antimicrobial resistance patterns. Data will be analysed by simple descriptive statistics to estimate the proportion of pneumonia and other IBD due to S. pneumoniae, Hemophilus influenzae type b and Neisseria meningitidis. Prevalence of bacterial infection, circulating pneumococcal serotypes, antibiotic resistance patterns, serotype variability across seasons and regions will be described in terms of percentage with 95% confidence interval.

ETHICS AND DISSEMINATION

The institutional review boards of the coordinating centre, all sentinel sites, regional and national reference laboratories approved the project. The results will be published in peer-reviewed journals and shared with stakeholders for deciding on revising vaccination strategy appropriately.

Serotype Distribution and Antibiotic Susceptibility of Streptococcus pneumoniae Isolates in Tehran, Iran: A Surveillance Study

Introduction

Encapsulated Streptococcus pneumoniae strains cause high morbidity and mortality, mainly in countries with no pneumococcal conjugate vaccines (PCVs) immunization program. This study investigated the epidemiological changes of S. pneumoniae isolates including serotype distribution and antimicrobial susceptibility in Tehran, Iran.

Methods

A total of 80 S. pneumoniae samples were collected from patients admitted to Shariati hospital over two periods. Half of the isolates were collected from February to September 2017 and the other half from July 2018 to March 2019. The antimicrobial susceptibility testing and PCV-13 serotype coverage of S. pneumoniae isolates were evaluated among patients with invasive and non-invasive infections.

Results

The most common serotypes were 23F (17.5%), 14 (16.3%), 3 (16.3%) 19F (12.5%), and 19A (12.5%) in the present study. The vaccine coverage rates of PCV-7, PCV-10 and PCV-13 were 52.6%, 52.6%, and 83.7%, respectively. S. pneumoniae isolates with the serotype of the PCV-13 showed an increasing trend during the study. Nearly half of the S. pneumoniae strains were MDR, while MDR serotype 19A increased (40%) during the study periods. A small minority of isolates (16%) belonged to non-vaccine serotypes, 65% of which were assigned to MDR. In general, the frequency of penicillin resistant and MDR strains were estimated about 27.5% and 51%, respectively. An increase was observed in resistance to erythromycin and co-trimoxazole.

Conclusion

The results showed that majority of the circulating serotypes in our study are related to PCV-13 serotypes. The use of conjugate vaccine in the immunization program and surveillance of antimicrobial resistance can be effective in reducing the pneumococcal clinical burden.

Assessment of an Antibody-in-Lymphocyte Supernatant Assay for the Etiological Diagnosis of Pneumococcal Pneumonia in Children

New diagnostic tests for the etiology of childhood pneumonia are needed. We evaluated the antibody-in-lymphocyte supernatant (ALS) assay to detect immunoglobulin (Ig) G secretion from ex vivo peripheral blood mononuclear cell (PBMC) culture, as a potential diagnostic test for pneumococcal pneumonia. We enrolled 348 children with pneumonia admitted to Patan Hospital, Kathmandu, Nepal between December 2015 and September 2016. PBMCs sampled from participants were incubated for 48 h before harvesting of cell culture supernatant (ALS). We used a fluorescence-based multiplexed immunoassay to measure the concentration of IgG in ALS against five conserved pneumococcal protein antigens. Of children with pneumonia, 68 had a confirmed etiological diagnosis: 12 children had pneumococcal pneumonia (defined as blood or pleural fluid culture-confirmed; or plasma CRP concentration ≥60 mg/l and nasopharyngeal carriage of serotype 1 pneumococci), and 56 children had non-pneumococcal pneumonia. Children with non-pneumococcal pneumonia had either a bacterial pathogen isolated from blood (six children); or C-reactive protein <60 mg/l, absence of radiographic consolidation and detection of a pathogenic virus by multiplex PCR (respiratory syncytial virus, influenza viruses, or parainfluenza viruses; 23 children). Concentrations of ALS IgG to all five pneumococcal proteins were significantly higher in children with pneumococcal pneumonia than in children with non-pneumococcal pneumonia. The concentration of IgG in ALS to the best-performing antigen discriminated between children with pneumococcal and non-pneumococcal pneumonia with a sensitivity of 1.0 (95% CI 0.73-1.0), specificity of 0.66 (95% CI 0.52-0.78) and area under the receiver-operating characteristic curve (AUROCC) 0.85 (95% CI 0.75-0.94). Children with pneumococcal pneumonia were older than children with non-pneumococcal pneumonia (median 5.6 and 2.0 years, respectively, p < 0.001). When the analysis was limited to children ≥2 years of age, assay of IgG ALS to pneumococcal proteins was unable to discriminate between children with pneumococcal pneumonia and non-pneumococcal pneumonia (AUROCC 0.67, 95% CI 0.47-0.88). This method detected spontaneous secretion of IgG to pneumococcal protein antigens from cultured PBMCs. However, when stratified by age group, assay of IgG in ALS to pneumococcal proteins showed limited utility as a test to discriminate between pneumococcal and non-pneumococcal pneumonia in children.

In vitro and in vivo characterization of the interaction, proinflammatory, immunomodulatory and antigenic properties of capsular polysaccharide from Streptococcus pneumoniae serotype 1

Pneumococcal capsular polysaccharide (PCP) is the major virulence determinant of Streptococcus pneumoniae (pneumococcus). Strains devoid of the capsule are avirulent or highly attenuated. PCP is present in soluble form and on pneumococci in infected individuals. The present study was undertaken to study the interaction of PCP from serotype 1 (PCP1) with immune cells, and its proinflammatory, immunomodulatory and antigenic properties. Binding of PCP1 to the surface of immune cells led to proinflammatory cytokine production which was not cell line or cytokine restricted. HEK293T transfectants expressing TLR1 and TLR2 produced IL-8 upon stimulation with PCP1, untransfected cells did not do so. PCP1 failed to induce TNF-α production from RAW264.7 cells when pre-incubated with a TLR2 blocking antibody. The surface binding of PCP1 was abrogated in the presence of TLR2 blocking antibody. PCP1 failed to bind TLR2 deficient RAW264.7 cells and induce TNF-α production. Unlike PCP1, alkali-treated PCP1 failed to stimulate RAW264.7 cells to produce TNF-α indicating the importance of alkali-sensitive moieties like O-acetyl groups. Alkali-treated PCP1 elicited lower anti-PCP1 antibody response. Mice experiments suggested that alkali-sensitive groups are significant target of protective antibodies in PCP1 immunized mice. Our findings demonstrate that PCP1 is an important modulator of immune response against pneumococci.

Molecular capsular typing and multi locus sequence typing of invasive, non-invasive and commensal Streptococcus pneumoniae isolates from North India

Purpose

The purpose of this study is to determine the antimicrobial susceptibility pattern, serotype distribution and sequence type (ST) of Streptococcus pneumoniae isolates from invasive and non-invasive infection and correlate it with isolates from commensal nasopharyngeal flora to ascertain their role in infection.

Materials and Methods

S. pneumoniae isolates from blood, cerebrospinal fluid, pleural fluid and respiratory secretions (sputum, bronchoalveolar lavage and nasopharyngeal swab/throat swab) were analysed to determine ST, serotype and antimicrobial susceptibility pattern. Serotyping was performed by multiplex polymerase chain reactions as well as by quellung reaction. Antimicrobial susceptibility testing was determined using Kirby Bauer's disc diffusion method as per the Clinical Laboratory Standards Institute guidelines. Minimum inhibitory concentration was determined using E-test for penicillin. Multilocus sequence typing (MLST) was done to understand genetic relatedness and evolutionary relationship among strains.

Results

A total of 125 S. pneumoniae isolates were collected, including 25 from invasive pneumococcal disease, 25 from non-invasive and 75 from nasopharyngeal swab of healthy children (Commensal). Resistance to penicillin, erythromycin, and co-trimoxazole was observed in 14.4%, 12% and 81.6% of the isolates, respectively, by KirbyBauer's disc diffusion method. Serotype 14 was found to be the most prevalent in invasive and non-invasive isolates, while serotype 6 was the most common in commensal isolates. New STs were found among invasive (ST13826, ST13827), non-invasive (ST13823, ST13824, and ST13961) and commensal (ST13825) isolates.

Conclusion

MLST sequence analysis shows that invasive isolates were found to be clustered with non-invasive and commensal isolates. Analysis of MLST suggests the possibility of genetic relatedness and exchange of genetic material between invasive, non-invasive and commensal isolates.

Antimicrobial susceptibility profile & resistance mechanisms of Global Antimicrobial Resistance Surveillance System (GLASS) priority pathogens from India

Antimicrobial resistance is a major concern globally. Infections due to drug-resistant pathogens are becoming difficult and a challenge to treat. As treatment choices are limited due to the high-drug resistance rates, there is an increase in the health care cost, duration of hospital stay, morbidity and mortality rates. Understanding the true burden of antimicrobial resistance for a geographical location is important to guide effective empirical therapy. To have a national data, it is imperative to have a systemic data capturing across the country through surveillance studies. Very few surveillance studies have been conducted in India to generate national data on antimicrobial resistance. This review aims to report the cumulative antibiogram and the resistance mechanisms of Global Antimicrobial Resistance Surveillance System (GLASS) priority pathogens from India.

Hemolytic uremic syndrome in a developing country: Consensus guidelines

BACKGROUND

Hemolytic uremic syndrome (HUS) is a leading cause of acute kidney injury in children. Although international guidelines emphasize comprehensive evaluation and treatment with eculizumab, access to diagnostic and therapeutic facilities is limited in most developing countries. The burden of Shiga toxin-associated HUS in India is unclear; school-going children show high prevalence of anti-factor H (FH) antibodies. The aim of the consensus meeting was to formulate guidelines for the diagnosis and management of HUS in children, specific to the needs of the country.

METHODS

Four workgroups performed literature review and graded research studies addressing (i) investigations, biopsy, genetics, and differential diagnosis; (ii) Shiga toxin, pneumococcal, and infection-associated HUS; (iii) atypical HUS; and (iv) complement blockade. Consensus statements developed by the workgroups were discussed during a consensus meeting in March 2017.

RESULTS

An algorithm for classification and evaluation was developed. The management of Shiga toxin-associated HUS is supportive; prompt plasma exchanges (PEX) is the chief therapy in patients with atypical HUS. Experts recommend that patients with anti-FH-associated HUS be managed with a combination of PEX and immunosuppressive medications. Indications for eculizumab include incomplete remission with plasma therapy, life-threatening features, complications of PEX or vascular access, inherited defects in complement regulation, and recurrence of HUS in allografts. Priorities for capacity building in regional and national laboratories are highlighted.

CONCLUSIONS

Limited diagnostic capabilities and lack of access to eculizumab prevent the implementation of international guidelines for HUS in most developing countries. We propose practice guidelines for India, which will perhaps be applicable to other developing countries.

Nasopharyngeal carriage of Streptococcus pneumoniae serotypes among children in India prior to the introduction of pneumococcal conjugate vaccines: a cross-sectional study

BACKGROUND

Streptococcus pneumoniae is a major cause of pneumonia, meningitis, and other serious infections among children in India. India introduced the 13-valent pneumococcal conjugate vaccine (PCV) in several states in 2017, and is expected to expand to nationwide coverage in the near future. To establish a baseline for measuring the impact of PCV in India, we assessed overall and serotype-specific nasopharyngeal carriage in two pediatric populations.

METHODS

A cross-sectional study was conducted in Palwal District, Haryana, from December 2016 to July 2017, prior to vaccine introduction. Children 2-59 months of age with clinical pneumonia seeking healthcare and those in the community with no clear illness were targeted for enrollment. A nasopharyngeal swab was collected and tested for pneumococcus using conventional culture and sequential multiplex PCR. Isolates were tested for antimicrobial resistance using an E test. Children were considered colonized if pneumococcus was isolated by culture or PCR. The prevalence of pneumococcal and serotype-specific colonization was compared between groups of children using log-binomial regression.

RESULTS

Among 601 children enrolled, 91 had clinical pneumonia and 510 were community children. The proportion colonized with S. pneumoniae was 74.7 and 54.5% among children with clinical pneumonia and community children, respectively (adjusted prevalence ratio: 1.38; 95% confidence interval: 1.19, 1.60). The prevalence of PCV13 vaccine-type colonization was similar between children with clinical pneumonia (31.9%) and community children (28.0%; p = 0.46). The most common colonizing serotypes were 6A, 6B, 14, 19A, 19F, and 23F, all of which are included in the PCV13 vaccine product. Antimicrobial resistance to at least one drug was similar between isolates from children with clinical pneumonia (66.1%) and community children (61.5%; p = 0.49); while resistance to at least two drugs was more common among isolates from children with clinical pneumonia (25.8% vs. 16.4%; p = 0.08). Resistance for all drugs was consistently higher for PCV13 vaccine-type serotypes compared to non-vaccine serotypes in both groups.

CONCLUSION

This study provides baseline information on the prevalence of serotype-specific pneumococcal colonization among children prior to the introduction of PCV in India. Our results suggest a role for pneumococcal vaccines in reducing pneumococcal colonization and antimicrobial resistant isolates circulating in India.

Pneumococcal conjugate vaccine rollout in India: Expectations and challenges

India is one among the four Asian countries with the greatest number of deaths due to pneumococcal infection among children under 5 years. pneumococcal conjugate vaccine (PCV) has been introduced in a phased manner in five major Indian states. Ambiguity remains in choosing the appropriate type of PCV and optimum schedule with maximum effectiveness specific for each country. Here, we discuss the evidences with respect to serotype coverage, immunogenicity, reactogenicity and dosage schedule for introduction of PCV13 in India. In addition, the expected PCV impact and the challenges are detailed. PCV13 is expected to provide >75% serotype coverage for invasive pneumococcal disease (IPD) serotypes in Indian children combined with the replacement by nonvaccine serotypes which is unpredictable due to lack of complete data. Nasopharyngeal (NP) surveillance is easy, feasible and can replace IPD surveillance in resource-poor settings. Continuous IPD as well as NP surveillance in all the regions are necessary to assess the impact of PCV in India.

Pneumococcal vaccines

Streptococcus pneumoniae continues to take a heavy toll on childhood mortality and morbidity across the developing world. An estimated 10.6 million invasive pneumococcal diseases (IPDs) occur every year, with nearly 1 million deaths in children under 5 years of age. Introduction of vaccines in the childhood immunisation programme in developed world has brought down the incidence of the disease considerably. However, childhood immunocompromising illnesses including HIV have increased the risk of IPD several folds. There is also a growing concern on the increasing antibiotic resistance among these invasive strains to penicillin, other beta-lactams and macrolides, making treatment difficult and expensive. It is estimated that about 62% of IPD worldwide is caused by the 10 most common serotypes. Although the ranking of individual pneumococcal serotypes causing serious disease varies among nations, the 7-13 serotypes included in pneumococcal conjugate vaccines (PCVs) may prevent 50%-80% of all paediatric pneumococcal diseases globally. The World Health Organization has recommended the use of PCV-10/13 in the national immunisation programmes (NIPs) of developing countries. Four doses of PCV-13 have been recommended by the US Association of Pediatrics and Centers for Disease Control and Prevention, at intervals of each 2 months for the first 6 months and by the 12^th to 15^th months after birth. This is expected to reduce the morbidity and mortality associated with IPD and simultaneously decrease colonisation with circulating antibiotic-resistant strains in immunized communities. Nevertheless, continued surveillance of antimicrobial resistance in non-vaccine serotypes is necessary to prevent the resurgence of resistance. Other virulence factors which are not serotype specific also need to be studied to overcome the drawbacks of serotype-specific pneumococcal vaccines. PCV-13 was launched during May 2017 under the NIP of five Indian states with the highest pneumococcal diseases in the country and is expected to be rolled out in the other parts of the country in the coming days.

ASSOCIATION OF MENINGITIS AND PERICARDITIS IN INVASIVE PNEUMOCOCCAL DISEASE: A RARE CASE

Objective:

To report a rare case of a child with invasive pneumococcal disease that presented meningitis associated with pericarditis.

Case description:

This report describes the unfavorable clinical course of a previously healthy 6-months-old female infant who initially presented symptoms of fever and respiratory problems. A chest X-ray revealed an increased cardiac area with no radiographic changes in the lungs. After identifying a pericardial effusion, the patient experienced seizures and went into coma. Pneumonia was excluded as a possibility during the clinical investigation. However, Streptococcus pneumoniae was identified in the cerebrospinal fluid and blood cultures. An initial neurological examination showed that the patient was brain dead, which was then later confirmed according to protocol.

Comments:

Purulent pericarditis has become a rare complication of invasive pneumococcal disease since the advent of antibiotic therapy. Patients with extensive pneumonia are primarily predisposed and, even with early and adequate treatment, are prone to high mortality rates. The association of pneumococcal meningitis and pericarditis is uncommon, and therefore difficult to diagnose. As such, diagnostic suspicion must be high in order to institute early treatment and increase survival.

Incidence and aetiology of bacterial meningitis among children aged 1-59 months in South Asia: systematic review and meta-analysis

BACKGROUND

Bacterial meningitis is a significant cause of morbidity and mortality worldwide among children aged 1-59 months. We aimed to describe its burden in South Asia, focusing on vaccine-preventable aetiologies.

METHODS

We searched five databases for studies published from January 1, 1990, to April 25, 2017. We estimated incidence and aetiology-specific proportions using random-effects meta-analysis. In secondary analyses, we described vaccine impact and pneumococcal meningitis serotypes.

RESULTS

We included 48 articles cumulatively reporting 20,707 cases from 1987 to 2013. Mean annual incidence was 105 (95% confidence interval [CI], 53-173) cases per 100,000 children. On average, Haemophilus influenzae type b (Hib) accounted for 13% (95% CI, 8-19%) of cases, pneumococcus for 10% (95% CI, 6-15%), and meningococcus for 1% (95% CI, 0-2%). These meta-analyses had substantial between-study heterogeneity (I² > 78%, P < 0.0001). Among studies reporting only confirmed cases, these three bacteria caused a median of 78% cases (IQR, 50-87%). Hib meningitis incidence declined by 72-83% at sentinel hospitals in Pakistan and Bangladesh, respectively, within two years of implementing nationwide vaccination. On average, PCV10 covered 49% (95% CI, 39-58%), PCV13 covered 51% (95% CI, 40-61%), and PPSV23 covered 74% (95% CI, 67-80%) of pneumococcal meningitis serotypes. Lower PCV10 and PCV13 serotype coverage in Bangladesh was associated with higher prevalence of serotype 2, compared to India and Pakistan.

CONCLUSIONS

South Asia has relatively high incidence of bacterial meningitis among children aged 1-59 months, with vaccine-preventable bacteria causing a substantial proportion. These estimates are likely underestimates due to multiple epidemiological and microbiological factors. Further research on vaccine impact and distribution of pneumococcal serotypes will inform vaccine policymaking and implementation.

Burden of bacterial meningitis in India: Preliminary data from a hospital based sentinel surveillance network

BACKGROUND

Worldwide, acute bacterial meningitis is a major cause of high morbidity and mortality among under five children, particularly in settings where vaccination for H. influenzae type b, S. pneumoniae and N. meningitidis is yet to be introduced in the national immunization programs. Estimation of disease burden of bacterial meningitis associated with these pathogens can guide the policy makers to consider inclusion of these newer vaccines in the immunization programs. A network of hospital based sentinel surveillance was established to generate baseline data on the burden of bacterial meningitis among children aged less than 5 years in India and to provide a platform for impact assessment following introduction of the Pentavalent and Pneumococcal Conjugate Vaccines (PCV).

METHODS

During surveillance carried out in select hospitals across India in 2012-2013, information regarding demographics, immunization history, clinical history, treatment details and laboratory investigations viz. CSF biochemistry, culture, latex agglutination and PCR was collected from children aged 1 to 59 months admitted with suspected bacterial meningitis.

RESULTS

A total of 3104 suspected meningitis cases were enrolled from 19,670 children admitted with fever at the surveillance hospitals. Of these, 257 cases were confirmed as cases of meningitis. They were due to S. pneumoniae (82.9%), H. influenzae type b (14.4%) and N. meningitidis (2.7%). Highest prevalence (55.3%) was observed among children 1 to 11 months. Antimicrobial susceptibility testing revealed considerable resistance among S. pneumoniae isolates against commonly used antibiotics such as cotrimoxazole, erythromycin, penicillin, and cefotaxime. More commonly prevalent serotypes of S. pneumoniae in circulation included 6B, 14, 6A and 19F. More than 90% of serotypes identified were covered by Pneumococcal Conjugate Vaccine 13.

CONCLUSIONS

We observed that S. pneumoniae was the commonest cause of bacterial meningitis in hospitalized children under five years of age in India. Continued surveillance is expected to provide valuable information and trends in future, to take an informed decision on introduction of pneumococcal vaccination in Universal Immunization Programme in India and will also eventually help in post-vaccination impact evaluation.

Potential impact of introducing the pneumococcal conjugate vaccine into national immunisation programmes: an economic-epidemiological analysis using data from India

Pneumococcal pneumonia causes an estimated 105 000 child deaths in India annually. The planned introduction of the serotype-based pneumococcal conjugate vaccine (PCV) is expected to avert child deaths, but the high cost of PCV relative to current vaccines provided under the Universal Immunization Programme has been a concern. Cost-effectiveness studies from high-income countries are not readily comparable because of differences in the distribution of prevalent serotypes, population and health systems. We extended IndiaSim, our agent-based simulation model representative of the Indian population and health system, to model the dynamics of Streptococcus pneumoniae. This enabled us to evaluate serotype and overall disease dynamics in the context of the local population and health system, an aspect that is missing in prospective evaluations of the vaccine. We estimate that PCV13 introduction would cost approximately US$240 million and avert US$48.7 million in out-of-pocket expenditures and 34 800 (95% CI 29 600 to 40 800) deaths annually assuming coverage levels and distribution similar to DPT (diphtheria, pertussis and tetanus) vaccination (~77%). Introducing the vaccine protects the population, especially the poorest wealth quintile, from potentially catastrophic expenditure. The net-present value of predicted money-metric value of insurance for 20 years of vaccination is US$160 000 (95% CI US$151 000 to US$168 000) per 100 000 under-fives, and almost half of this protection is for the bottom wealth quintile (US$78 000; 95% CI 70 800 to 84 400). Extending vaccination to 90% coverage averts additional lives and provides additional financial risk protection. Our estimates are sensitive to immunity parameters in our model; however, our assumptions are conservative, and if willingness to pay per years of life lost averted is US$228 or greater, then introducing the vaccine is more cost-effective than our baseline (no vaccination) in more than 95% of simulations.

Clinical usefulness and accuracy of polymerase chain reaction in the detection of bacterial meningitis agents in pediatric cerebrospinal fluid

Bacterial meningitis poses enormous healthcare challenges due to a high mortality, morbidity and sequelae. Neisseria (N.) meningitidis, Haemophilus (H.) influenzae, Streptococcus (S.) pneumoniae and S. agalactiae remain among the most prevalent infectious agents that cause bacterial meningitis in children. The objective of this study was the simultaneous detection of these pathogens in suspected cerebrospinal fluid (CSF) by using multiplex polymerase chain reaction (mPCR) and compare PCR results with standard diagnostics currently used in clinical practice. CSF specimens were obtained from 515 children (<5 years) clinically suspected of having acute bacterial meningitis. Based on bacterial culture, four isolates of salmonella sp and one Citrobacter freundii isolate were identified. The remaining 510 CSF specimens, having negative culture, were subjected to mPCR. Twenty-three (4.51%) CSF samples yielded a PCR positive signal. The pathogens identified were: S. pneumoniae (n=13), H. influenzae (n=7) and N. meningitidis (n=3). S. agalactiae was not detected. Using sequential multiplex PCR, serogrouping of S. pneumoniae revealed 3 different serotypes: serotype 19A (n=6), 19F (n=4) and serotype 23F (n=3). Only the serotype A was identified for the 3N. meningitidis isolates. Despite vaccination, S. pneumoniae remains a leading cause of pediatric invasive disease. Detecting causative organism remains the most critical aspect for management of children with suspected meningitis. PCR method is more sensitive and rapid than culture for detecting the infectious agents. Institution of PCR diagnostics is recommended for early and appropriate therapy.

Phenotypic and molecular characterization of Streptococcus pneumoniae in pre-conjugate vaccine era: A Chinese hospital-based retrospective study

BACKGROUND

Streptococcus pneumoniae (S. pneumoniae) is an important pathogen in causing global morbidity and mortality among children. This study aimed to determine phenotypic and molecular characteristics of S. pneumoniae causing infections in children under five years in China.

METHODS

A hospital-based retrospective study was conducted. All 537 S. pneumoniae isolates were tested for antimicrobial susceptibility by E-test method, molecular characteristics including resistance genes, virulence genes and serotypes by multiplex polymerase chain reaction (PCR) method, and sequence types (STs) by sequencing seven housekeeping genes. Minimum spanning tree and correspondence analysis were used to reveal the potential relationship between serotypes and STs.

RESULTS

Most of S. pneumoniae isolates were resistant to erythromycin (93.9%) and tetracycline (86.4%), with the predominant resistance genes being erm(B) (92.6%) and tet(M) (95.5%). The prevalent serotypes were 19F, 6B, 19A, 23F and 14, the coverage rate of PCV13 was high in 85.8%, and the predominant STs were ST271, ST320, ST3173, ST81 and ST876. A significant correlation existed between STs and serotypes, with ST271/19F and ST320/19A as the most prevalent clones. Notably, ST271/19F and ST320/19A isolates were associated with resistance to specific antibiotics and carrying of mef(A/E), rlrA and sipA genes.

CONCLUSIONS

Our findings suggest the introduction of PCV13 vaccine to Chinese children, and underscore the value of monitoring multiple characteristics to detect new epidemiologic trends and provide implications for the formulation of multivalent pneumococcal vaccines.

Safety and immunogenicity of a novel multiple antigen pneumococcal vaccine in adults: A Phase 1 randomised clinical trial

BACKGROUND

Pneumococcal vaccines, combining multiple protein antigens, provide an alternative approach to currently marketed vaccines and may provide broader protection against pneumococcal disease. This trial evaluated the safety and immunogenicity of a novel vaccine candidate PnuBioVax in healthy young adults.

METHODS

In a Phase 1 double-blind study, 36 subjects (18-40 years) were randomised to receive 3 doses of PnuBioVax, 28 days apart, at one of three dose levels (50, 200, 500 µg) or placebo. Safety assessments included rates of emergent adverse events (AEs), injection site and systemic reactions. Immunogenicity endpoints included antibody titre against PnuBioVax and selected pneumococcal antigens.

RESULTS

In the placebo (n=9) and PnuBioVax (n=27) vaccinated subjects, there were 15 and 72, reported TEAEs, respectively. The majority of TEAEs were classified as common vaccine related AEs. There were no serious AEs. Common vaccine-related AEs occurred in 13 PnuBioVax (48%) and 2 placebo (22%) subjects and were all headaches (mild and moderate). Injection site reactions, mostly pain and tenderness (graded mild or moderate) were reported, in particular in the 200 µg and 500 µg PnuBioVax groups. There were no clinically significant changes in vital signs, ECG or blood chemistries. Subjects receiving the higher dose (200 and 500 μg) demonstrated a greater fold increase in IgG titre compared with the starting dose (50 μg) or the placebo group. The fold-increase was statistically significantly higher for 200 and 500µg PnuBioVax vs 50µg PnuBioVax and placebo at each timepoint post-immunisation. Most subjects receiving 200 and 500 µg PnuBioVax demonstrated a ≥2-fold increase in antibody against pneumolysin (Ply), Pneumococcal surface antigen (PsaA), PiaA (Pneumococcal iron acquisition), PspA (Pneumococcal surface protein A) and pilus proteins (RrgB and RrgA).

CONCLUSIONS

All dose levels were considered safe and well tolerated. There was a statistically significant increase in anti-PnuBioVax IgG titres at the 200 and 500 µg dose levels compared to 50 µg and placebo.

TRIAL REGISTRATION NUMBER

NCT02572635https://www.clinicaltrials.gov.