Serotype distribution and antimicrobial resistance of Streptococcus pneumoniae in children with acute bacterial meningitis in Mozambique: implications for a national immunization strategy

Streptococcus pneumoniae vaccination strategies and its expected impact on penicillin non-susceptibility in children under the age of five: Let's recap!

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The efficacy of PCVs currently used in children under 5 years of age is threatened by the emergence of invasive and resistant non-vaccine serotypes worldwide.

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Resistant NVT strains are emerging in IPD in children < 5 years mainly serotypes 24F, 15A, 11A and 33F along with serotype 19A in PCV-10 settings.

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Continuous surveillance is necessary in IPD in children under five to monitor the long-term effect of PCV-10 and PCV-13 on penicillin resistance trends.

The impact of pneumococcal conjugate vaccines (PCVs) on invasive pneumococcal disease (IPD) burden has been extensively studied in children aged<5 years; however, a pooled estimation of the effect of PCVs on penicillin non-susceptible pneumococci (PNSP) has not yet been performed. We aimed to identify whether the introduction of PCV-10 and PCV-13 had led to the decrease of the overall PNSP rate in children < 5 years. We conducted a systematic review of published surveillance studies reporting the rate of PNSP rates in children < 5 in countries where PCV10/13 were introduced. The overall observed trend onwards the introduction of PCV-10 and PCV-13 is a decrease in PNSP among children < 5 years in surveillance sites located in PCV-13 countries. We identified an increase of PNSP rates (serotype 19A) in PCV-10 settings. Resistant NVT strains are emerging in IPD in children < 5 years mainly serotypes 24F, 15A, 11A and 33F along with serotype 19A in PCV-10 settings. Continuous surveillance is necessary in IPD in children under five to monitor the long-term effect of PCV-10 and PCV-13 on penicillin resistance trends.

The Burden of Invasive Bacterial Disease and the Impact of 10-Valent Pneumococcal Conjugate Vaccine in Children <5 years hospitalized for Meningitis in Lusaka, Zambia, 2010-2019

BACKGROUND

Despite the availability of vaccines, invasive bacterial diseases remain a public health concern and cause childhood morbidity and mortality. We investigated the characteristics of etiological agents causing bacterial meningitis in children <5 years in the years pre- (2010-2012) and post- (2014-2019) 10-valent pneumococcal conjugate vaccine (PCV10) introduction in Zambia.

METHODS

Streptococcus pneumoniae (Spn), Haemophilus influenzae (Hi), and Neisseria meningitidis (Nm) from cerebrospinal fluid (CSF) were identified by microbiological culture and/or real-time polymerase chain reaction.

RESULTS

During the surveillance period, a total of 3811 children were admitted with suspected meningitis, 16% (598 of 3811) of which were probable cases. Bacterial meningitis was confirmed in 37% (221 of 598) of the probable cases. Spn pneumoniae, Hi, and Nm accounted for 67% (148 of 221), 14% (31 of 221), and 19% (42 of 221) of confirmed cases, respectively. Thirty-six percent of pneumococcal meningitis was caused by 10-valent pneumococcal conjugate vaccine (PCV10) serotypes, 16% 13-valent pneumococcal conjugate vaccine and 39% by nonvaccine serotype (NVS). There was an association between the introduction of PCV10 vaccination and a decrease in both Spn meningitis and the proportion of PVC10 serotypes in the postvaccination period. Antimicrobial susceptibility of 47 Spn isolates revealed 34% (16 of 47) penicillin resistance. The 31 serotyped Hi accounted for 74% type b (Hib) and 10% type a (Hia). All 42 serogrouped Nm belonged to serogroup W.

CONCLUSIONS

There was a decline in pneumococcal meningitis and proportion of PCV10 serotypes in the postvaccination period. However, the serotype replacement with non-PCV10 serotypes and penicillin resistance warrant continued surveillance to inform policy.

Clinical features of bacterial meningitis among hospitalised children in Kenya

BACKGROUND

Diagnosing bacterial meningitis is essential to optimise the type and duration of antimicrobial therapy to limit mortality and sequelae. In sub-Saharan Africa, many public hospitals lack laboratory capacity, relying on clinical features to empirically treat or not treat meningitis. We investigated whether clinical features of bacterial meningitis identified prior to the introduction of conjugate vaccines still discriminate meningitis in children aged ≥60 days.

METHODS

We conducted a retrospective cohort study to validate seven clinical features identified in 2002 (KCH-2002): bulging fontanel, neck stiffness, cyanosis, seizures outside the febrile convulsion age range, focal seizures, impaired consciousness, or fever without malaria parasitaemia and Integrated Management of Childhood Illness (IMCI) signs: neck stiffness, lethargy, impaired consciousness or seizures, and assessed at admission in discriminating bacterial meningitis after the introduction of conjugate vaccines. Children aged ≥60 days hospitalised between 2012 and 2016 at Kilifi County Hospital were included in this analysis. Meningitis was defined as positive cerebrospinal fluid (CSF) culture, organism observed on CSF microscopy, positive CSF antigen test, leukocytes ≥50/μL, or CSF to blood glucose ratio <0.1.

RESULTS

Among 12,837 admissions, 98 (0.8%) had meningitis. The presence of KCH-2002 signs had a sensitivity of 86% (95% CI 77-92) and specificity of 38% (95% CI 37-38). Exclusion of 'fever without malaria parasitaemia' reduced sensitivity to 58% (95% CI 48-68) and increased specificity to 80% (95% CI 79-80). IMCI signs had a sensitivity of 80% (95% CI 70-87) and specificity of 62% (95% CI 61-63).

CONCLUSIONS

A lower prevalence of bacterial meningitis and less typical signs than in 2002 meant the lower performance of KCH-2002 signs. Clinicians and policymakers should be aware of the number of lumbar punctures (LPs) or empirical treatments needed for each case of meningitis. Establishing basic capacity for CSF analysis is essential to exclude bacterial meningitis in children with potential signs.

Acute bacterial meningitis

Purpose of review

Community-acquired bacterial meningitis is a continually changing disease. This review summarises both dynamic epidemiology and emerging data on pathogenesis. Updated clinical guidelines are discussed, new agents undergoing clinical trials intended to reduce secondary brain damage are presented.

Recent findings

Conjugate vaccines are effective against serotype/serogroup-specific meningitis but vaccine escape variants are rising in prevalence. Meningitis occurs when bacteria evade mucosal and circulating immune responses and invade the brain: directly, or across the blood–brain barrier. Tissue damage is caused when host genetic susceptibility is exploited by bacterial virulence. The classical clinical triad of fever, neck stiffness and headache has poor diagnostic sensitivity, all guidelines reflect the necessity for a low index of suspicion and early Lumbar puncture. Unnecessary cranial imaging causes diagnostic delays. cerebrospinal fluid (CSF) culture and PCR are diagnostic, direct next-generation sequencing of CSF may revolutionise diagnostics. Administration of early antibiotics is essential to improve survival. Dexamethasone partially mitigates central nervous system inflammation in high-income settings. New agents in clinical trials include C5 inhibitors and daptomycin, data are expected in 2025.

Summary

Clinicians must remain vigilant for bacterial meningitis. Constantly changing epidemiology and emerging pathogenesis data are increasing the understanding of meningitis. Prospects for better treatments are forthcoming.

Increasing incidence of penicillin- and cefotaxime-resistant Streptococcus pneumoniae causing meningitis in India: Time for revision of treatment guidelines?

PURPOSE

Pneumococcal meningitis is a life-threatening infection, requiring prompt diagnosis and effective treatment. Penicillin resistance in pneumococcal infections is a concern. Here, we present the antibiotic susceptibility profile of pneumococcal meningeal isolates from January 2008 to August 2016 to elucidate treatment guidelines for pneumococcal meningitis.

MATERIALS AND METHODS

Invasive pneumococcal isolates from all age groups, were included in this study. Minimum inhibitory concentrations for the isolates were identified by agar dilution technique and VITEK System 2. Serotyping of isolates was done by co-agglutination technique.

RESULTS

Out of 830 invasive pneumococcal isolates, 167 (20.1%) isolates were from meningeal infections. Cumulative penicillin resistance in pneumococcal meningitis was 43.7% and cefotaxime non-susceptibility was 14.9%. Penicillin resistance amongst meningeal isolates in those younger than 5 years, 5-16 years of age and those aged 16 years and older was 59.7%, 50% and 27.3%, respectively, with non-susceptibility to cefotaxime in the same age groups being 18%, 22.2% and 10.4%. Penicillin resistance amongst pneumococcal meningeal isolates increased from 9.5% in 2008 to 42.8% in 2016, whereas cefotaxime non-susceptibility increased from 4.7% in 2008 to 28.5% in 2016. Serotypes 14, 19F, 6B, 6A, 23F, 9V and 5 were the most common serotypes causing meningitis, with the first five accounting for over 75% of resistant isolates.

CONCLUSIONS

The present study reports increasing penicillin resistance and cefotaxime non-susceptibility to pneumococcal meningitis in our setting. This highlights the need for empiric therapy with third-generation cephalosporins and vancomycin for all patients with meningitis while awaiting results of culture and susceptibility testing.

Surveillance of impact of PCV-10 vaccine on pneumococcal meningitis in Mozambique, 2013 - 2015

Background

Vaccination using the 10-valent conjugate vaccine (PCV-10) was introduced into the Extended Program on Immunization in Mozambique in March 2013, however its impact on pediatric pneumococcal meningitis is unknown. In this study, we assessed for the first time the impact of PCV10 on the burden of pneumococcal meningitis in children less than 5 years of age at the three largest hospitals in Mozambique.

Method

Between March 2013 and December 2015, a total of 744 cerebrospinal fluid (CSF) samples were collected from eligible children, of which 160 (21.5%) were positive for S. pneumoniae. Of these, only 86 samples met the criteria for serotyping and were subsequently serotyped using sequential multiplex PCR (SM-PCR), but 17 samples were non-typable.

Results

The proportion of cases of pneumococcal meningitis decreased from 33.6% (124 of 369) in 2013 to 1.9% (3 of 160) in 2015 (p < 0.001). The relative frequency of PCV10 serotype cases also decreased from 84.2% (48 of 57) in 2013 to 0% (0 of 3) in 2015 (p = 0.006). Between 2013 and 2015, serotype coverage of PCV-10 and PCV13 vaccine formulations was 66.7% and 81.2%, respectively.

Conclusion

Altogether, our findings shows that introduction of PCV-10 immunization resulted in rapid decline of pneumococcal meningitis children less than 5 years old in Mozambique. This decline was accompanied by substantial changes in the pattern of circulating pneumococcal serotypes.

Acute bacterial meningitis in children presenting to The Children's Hospital Lahore before and after pneumococcal vaccine in Pakistan National Immunization Program; A comparison

OBJECTIVE

To describe bacteriological profile, morbidity and mortality of acute bacterial meningitis (ABM) in children and to compare these parameters before and after the introduction of Pneumococcal vaccine in Pakistan National Immunization Program.

METHODS

The present descriptive study was conducted at the Department of Paediatric Medicine of The Children's Hospital Lahore from January 2012 to December 2015. A total of 503 children one month to five years of age admitted with diagnosis of meningitis were included. Complete blood count, CSF cytology, biochemistry, culture sensitivity and blood culture sensitivity were performed.

RESULTS

Frequency of meningitis decreased by 50% in 2013-2015 (199 [2012] vs 304 [2013-2015). Most children in both groups were under one year of age. More neurological complications were seen in the group 2, 20% vs 17%. CSF culture positivity decreased from 12% to 6.6%. Streptococcus pneumoniae isolation decreased from 5 (2.5%) in 2012 to 4 (1.3%) in 2013-2015. Refusal to take feed (p=0.002), impaired sensorium (p=<0.001), severe malnutrition (p=0.001), prolonged duration of symptoms (p=<0.001) and incomplete vaccination status (0.005) were associated with mortality. Mortality rate decreased from 20 (10%) in 2012 to 17 (5.6%) in 2013-2015 but more children developed neurological sequelae 2.7% versus 1%.

CONCLUSION

Acute bacterial meningitis mostly affected children <1 year. Frequency of Streptococcus pneumoniae and mortality of meningitis decreased significantly after PCV but more neurological complications developed in those children who were unvaccinated in 2013-2015 compared to 2012.