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Public Health

Aga Khan University

Streptococcus pneumoniae

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Full-Text Articles in Pathology

A Streptococcus Pneumoniae Lineage Usually Associated With Pneumococcal Conjugate Vaccine (Pcv) Serotypes Is The Most Common Cause Of Serotype 35b Invasive Disease In South Africa, Following Routine Use Of Pcv, Kedibone M. Ndlangisa, Mignon Du Plessis, Stephani Lo, Linda De Gouveia, Chrispin Chaguza, Martin Antonio, Brenda Kwambana-Adams, Jennifer Cornick, Dean B. Everett, Sadia Shakoor Apr 2022

A Streptococcus Pneumoniae Lineage Usually Associated With Pneumococcal Conjugate Vaccine (Pcv) Serotypes Is The Most Common Cause Of Serotype 35b Invasive Disease In South Africa, Following Routine Use Of Pcv, Kedibone M. Ndlangisa, Mignon Du Plessis, Stephani Lo, Linda De Gouveia, Chrispin Chaguza, Martin Antonio, Brenda Kwambana-Adams, Jennifer Cornick, Dean B. Everett, Sadia Shakoor

Department of Pathology and Laboratory Medicine

Pneumococcal serotype 35B is an important non-conjugate vaccine (non-PCV) serotype. Its continued emergence, post-PCV7 in the USA, was associated with expansion of a pre-existing 35B clone (clonal complex [CC] 558) along with post-PCV13 emergence of a non-35B clone previously associated with PCV serotypes (CC156). This study describes lineages circulating among 35B isolates in South Africa before and after PCV introduction. We also compared 35B isolates belonging to a predominant 35B lineage in South Africa (GPSC5), with isolates belonging to the same lineage in other parts of the world. Serotype 35B isolates that caused invasive pneumococcal disease in South Africa in …


The Role Of Interspecies Recombination In The Evolution Of Antibiotic-Resistant Pneumococci, Joshua C. D'Aeth, Mark Pg Van Der Linden, Lesley Mcgee, Herminia De Lencastre, Paul Turner, Jae-Hoon Song, Stephanie W. Lo, Rebecca A. Gladstone, Gps Consortium, Sadia Shakoor Jul 2021

The Role Of Interspecies Recombination In The Evolution Of Antibiotic-Resistant Pneumococci, Joshua C. D'Aeth, Mark Pg Van Der Linden, Lesley Mcgee, Herminia De Lencastre, Paul Turner, Jae-Hoon Song, Stephanie W. Lo, Rebecca A. Gladstone, Gps Consortium, Sadia Shakoor

Department of Pathology and Laboratory Medicine

Multidrug-resistant Streptococcus pneumoniae emerge through the modification of core genome loci by interspecies homologous recombinations, and acquisition of gene cassettes. Both occurred in the otherwise contrasting histories of the antibiotic-resistant S. pneumoniae lineages PMEN3 and PMEN9. A single PMEN3 clade spread globally, evading vaccine-induced immunity through frequent serotype switching, whereas locally circulating PMEN9 clades independently gained resistance. Both lineages repeatedly integrated Tn916-type and Tn1207.1-type elements, conferring tetracycline and macrolide resistance, respectively, through homologous recombination importing sequences originating in other species. A species-wide dataset found over 100 instances of such interspecific acquisitions of resistance cassettes and flanking …


Impact Of 10-Valent Pneumococcal Conjugate Vaccine (Pcv10) On Nasopharyngeal Carriage In Children 2 Years Of Age: Data From A Four-Year Time Series Cross-Sectional Study From Pakistan, Muhammad Imran Nisar, Shahira Shahid, Sajid Muhammad, Farah Khalid, Amjad Hussain, Sheraz Ahmed, Sadia Shakoor, Furqan Kabir, Aneeta Hotwani, Syed Asad Ali, Anita K. M. Zaidi, Fyezah Jehan, Najeeha Talat Iqbal Feb 2021

Impact Of 10-Valent Pneumococcal Conjugate Vaccine (Pcv10) On Nasopharyngeal Carriage In Children 2 Years Of Age: Data From A Four-Year Time Series Cross-Sectional Study From Pakistan, Muhammad Imran Nisar, Shahira Shahid, Sajid Muhammad, Farah Khalid, Amjad Hussain, Sheraz Ahmed, Sadia Shakoor, Furqan Kabir, Aneeta Hotwani, Syed Asad Ali, Anita K. M. Zaidi, Fyezah Jehan, Najeeha Talat Iqbal

Department of Paediatrics and Child Health

The dataset described in this paper was collected for a time-series cross-sectional study exploring the impact of 10-valent Pneumococcal Conjugate Vaccine (PCV10) on nasopharyngeal (NP) carriage in children under 2 years of age from a rural population in Sindh, Pakistan. The study was carried out in two union councils of Matiari - Khyber and Shah Alam Shah Jee Wasi (Latitude 25.680298 / Longitude 68.502711). Data was collected on socio-demographics, clinical characteristics and vaccination status using android phone-based application. NP samples were collected using standard World Health Organisation (WHO) techniques, culture and serotyping was done using sequential Multiplex PCR described by …


Direct And Indirect Effect Of 10 Valent Pneumococcal Vaccine On Nasopharyngeal Carriage In Children Under 2 Years Of Age In Matiari, Pakistan, Muhammad Imran Nisar, Sheraz Ahmed, Fyezah Jehan, Shahira Shahid, Sadia Shakoor, Furqan Kabir, Aneeta Hotwani, Sahrish Munir, Sajid Muhammad, Farah Khalid, Syed Asad Ali, Anita K. M. Zaidi, Najeeha Talat Iqbal Jan 2021

Direct And Indirect Effect Of 10 Valent Pneumococcal Vaccine On Nasopharyngeal Carriage In Children Under 2 Years Of Age In Matiari, Pakistan, Muhammad Imran Nisar, Sheraz Ahmed, Fyezah Jehan, Shahira Shahid, Sadia Shakoor, Furqan Kabir, Aneeta Hotwani, Sahrish Munir, Sajid Muhammad, Farah Khalid, Syed Asad Ali, Anita K. M. Zaidi, Najeeha Talat Iqbal

Department of Paediatrics and Child Health

Background: Pakistan introduced Ten-valent pneumococcal-conjugate-vaccine PCV10 in 2012 as a 3 + 0 schedule without catch-up.
Methods: Children <2 years old in Matiari, Sindh provided nasopharyngeal swabs between 2014 and 2018, which were cultured for pneumococcus and serotyped through multiplex PCR at the Aga Khan University Hospital. Carriage rates over time for Vaccine-Type (VT) and Non-VT (NVT) serotypes were used to estimate direct, indirect, total and overall effects of vaccination. Regression analysis was used to determine factors associated with VT carriage.
Results: Pneumococcus was detected in 2370/3140 (75%). VT carriage decreased overall, 16.1-9.6% (p-trend <0.001); vaccinated (all 3 doses of PCV10 received) 11.3-8.1% (p-trend 0.031) and unvaccinated (no PCV10 dose received) 17.4-10.3% (p-trend 0.003) with a decline in serotypes 6B, 9V/9A and 19F. Immunization increased from 41.0% to 68.4% (p-trend 0.001). Direct effect of vaccine was 32.8% (95% CI 14.7-47.0%) and indirect effect 44.6%(95% CI 40.6-48.6%). Factors associated with decreased VT colonization were education 1-5 years (aOR 0.7, 95%CI 0.6-1.0), history of difficulty breathing (aOR 0.7, 95%CI 0.5-1.0), exposure to smoke (aOR 0.8, 95% CI 0.6-1.0), child fully immunized (aOR 0.7, 95%CI 0.5-1.0) and enrolled in 3rd (aOR 0.6, 95%CI 0.4-0.8) and 4th (aOR 0.6, 95%CI 0.5-0.9) year of the study whereas history of runny nose (aOR 1.5, 95% CI 1.2-1.9) was positively associated.
Conclusions: Decrease in VT pneumococcal carriage in vaccinated and unvaccinated children indicates herd immunity. Sustained increase in vaccine coverage and close long-term surveillance is warranted.