Here are the selected readings for the summer:

• In 2012, Botswana introduced the 13-valent pneumococcal conjugate vaccine (PCV-13) into its childhood immunization program, achieving coverage rates above 90% by 2014. Despite this success, this vaccination campaign has been followed by an increase in infections caused by non-vaccine serotypes, including some with a high prevalence of antibiotic resistance. The study by Hurst and colleagues examined the serotype distribution and antibiotic resistance of pneumococcal isolates from infants in the African country between 2016 and 2019, by collecting nasopharyngeal swabs and performing capsular serotyping and AST with E-tests. At the time of sample collection, more than four infants out of five had received at least one dose of PCV-13, and more than half had completed the three-dose series. Among the pneumococcal isolates identified, vaccine serotypes accounted for 27%. Penicillin resistance increased from 41% in 2016 to 71% in 2019, and non-susceptibility to trimethoprim-sulfamethoxazole rose from 55% in 2016 to 79% in 2019. Multi-drug resistance and amoxicillin resistance were found in 1% of the isolates. In conclusion, the researchers discovered that PCV-13 serotypes still accounted for a significant portion of isolates years after the vaccine’s introduction. The increase in penicillin resistance and low ceftriaxone resistance support using third-generation cephalosporins for empirically treating suspected bacterial meningitis.
• Self-sampling has the potential to overcome declining participation and inequalities in cervical screening programs; still, pilot studies are necessary to overcome variables and highlight the real-world benefits of this innovative testing method. YouScreen is a HPV screening program we have been partnering with for years, aiming to assess the impact of offering self-sampling to non-attenders. Between January and November 2021, self-sampling kits were distributed to non-attenders either opportunistically during any consultation in primary care or via direct mail 15 months after routine invitation. Primary outcomes included the monthly proportion of non-attenders screened, change in coverage, and uptake within 90 days. The study found that more than 8000 women provided self-samples, and responders represented the ethnically diverse non-attendee population. Kits offered opportunistically in primary care had a return rate of 65.5%, while directly mailed kits had a return rate of 12.9%. The self-sampling intervention increased the number of non-attenders screened per month, improving HPV screening coverage without any adverse effects. Dr Lim and colleagues concluded that opportunistic offering self-sampling in primary care could enhance coverage and potentially reach underserved populations in England.
• Multi-drug-resistant E. coli poses a significant global public health challenge, especially in the southern countries of the world – although these strains often spread to other regions through travelers. To understand the full extent of the genetic diversity of E. coli colonizing local populations, Tamim Khawaja and colleagues quantified genetic diversity and associated antimicrobial resistance (AMR) of E. coli individuals in the Punjab province, Pakistan, assessing the impact of antibiotic use. Rectal swab and stool samples were cultured, and DNA extracted from these cultures was sequenced to capture the genetic and AMR diversity of E. coli. The study assembled 5,247 E. coli genomes from 1,411 samples, revealing significant genetic diversity in gut colonization. The genetic lineages and AMR determinants in the Punjabi population differed notably from those in high-income countries. Antibiotic use increased the prevalence of well-known globally circulating MDR clinical strains. These findings suggest that longitudinal, multi-regional genomics-based surveillance of both colonization and infections is necessary to develop a mechanistic understanding of the interplay between ecology and evolution in maintaining and disseminating MDR E. coli.

Read the full studies: