Methicillin-Resistant Staphylococcus aureus Carriage among Neonate Mothers, Healthcare Workers, and Environmental Samples in Neonatal Intensive Care Units: A Systematic Review.

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a significant cause of morbidity and mortality among neonates admitted to neonatal intensive care units (NICUs). The MRSA colonization of neonates, attributed to various sources, including mothers, healthcare workers, and environmental surfaces, can lead to severe infection, prolonged hospital stays, and even death, imposing substantial economic burdens. Given the pressing need to mitigate MRSA spread in these vulnerable environments, further examination of the subject is warranted. This systematic review is aimed at synthesizing available evidence on MRSA carriage proportions among mothers of newborns, healthcare workers, and environmental surfaces in NICUs. Methodology. We included observational studies published in English or French from database inception to March 21, 2023. These studies focused on MRSA in nonoutbreak NICU settings, encompassing healthy neonate mothers and healthcare workers, and environmental surfaces. Literature search involved systematic scanning of databases, including Medline, Embase, Web of Science, Global Health, and Global Index Medicus. The quality of the selected studies was assessed using the Hoy et al. critical appraisal scale. The extracted data were summarized to calculate the pooled proportion of MRSA positives, with a 95% confidence interval (CI) based on the DerSimonian and Laird random-effects model. Results: A total of 1891 articles were retrieved from which 16 studies were selected for inclusion. Most of the studies were from high-income countries. The pooled proportion of MRSA carriage among 821 neonate mothers across four countries was found to be 2.1% (95% CI: 0.3-5.1; I2 = 76.6%, 95% CI: 36.1-91.5). The proportion of MRSA carriage among 909 HCWs in eight countries was determined to be 9.5% (95% CI: 3.1-18.4; I2 = 91.7%, 95% CI: 87.1-94.6). The proportion of MRSA carriage among HCWs was highest in the Western Pacific Region, at 50.00% (95% CI: 23.71-76.29). In environmental specimens from five countries, a pooled proportion of 16.6% (95% CI: 3.5-36.0; I2 = 97.7%, 95% CI: 96.6-98.4) was found to be MRSA-positive. Conclusion: With a significant heterogeneity, our systematic review found high MRSA carriage rates in neonate mothers, healthcare workers, and across various environmental surfaces in NICUs, posing a potential risk of nosocomial infections. Urgent interventions, including regular screening and decolonization of MRSA carriers, reinforcing infection control measures, and enhancing cleaning and disinfection procedures within NICUs, are crucial. This trial is registered with CRD42023407114.

Epidemiología molecular de la colonización nasofaríngea neumocócica en niños de Sevilla, tras la implementación del programa de vacunación con VNC13 en Andalucía (España) / Molecular epidemiology of pneumococcal carriage in children from Seville, following implementation of the PCV13 immunization program in Andalusia, Spain

Introducción: El programa de vacunación universal con la vacuna antineumocócica conjugada 13-valente (VNC13) se implantó en Andalucía en diciembre de 2016. Métodos: Estudio transversal de colonización nasofaríngea por Streptococcus pneumoniae. Se seleccionó a 397 niños sanos en centros de atención primaria de Sevilla durante los periodos 1/4/2018-28/2/2020 y 1/11/2021-28/2/2022 (periodo VNC13). Se utilizó una colección histórica de un estudio de colonización desarrollado en niños sanos y con infección respiratoria superior entre el 1/01/2006 y el 30/06/2008 (periodo VNC7) para comparar las distribuciones de serotipos/genotipos y las tasas de resistencias antibióticas. Resultados: Un total de 76 (19%) niños estaban colonizados con S. pneumoniae en el periodo VNC13 y se dispuso de 154 aislamientos del periodo VNC7. La colonización por serotipos incluidos en VNC13 disminuyó significativamente entre los periodos VNC13 y VNC7 (11 vs. 38%; p=0,0001); los serotipos 19F (8%), 3 (1%) y 6B (1%) fueron los únicos serotipos vacunales circulantes. Los serotipos 15B/C y 11A fueron los serotipos no VNC13 más prevalentes durante el periodo VNC13 (14% y 11%, respectivamente); este último se incrementó de forma significativa entre periodos de tiempo (p=0,04). El serotipo 11A solo se asoció en el periodo VNC13 con variantes resistentes a la ampicilina del clon Spain9V-ST156 (ST6521 y genéticamente relacionado ST14698), no detectados en el periodo anterior. Conclusiones: Hubo una circulación muy residual de los serotipos vacunales durante el periodo VNC13, con excepción del serotipo19F. El serotipo 11A se incrementó de forma significativa entre los periodos VNC13 y VNC7 por expansión clonal del genotipo resistente a la ampicilina ST6521.(AU)

Background: The 13-valent pneumococcal conjugate vaccine (PCV13) universal vaccination program was introduced in December 2016 in Andalusia. Methods: A cross-sectional study was conducted on the molecular epidemiology of pneumococcal nasopharyngeal colonization. A total of 397 healthy children were recruited from primary healthcare centres in Seville for the periods 1/4/2018 to 28/2/2020 and 1/11/2021 to 28/2/2022 (PCV13 period). Data from a previous carriage study conducted among healthy and sick children from 1/01/2006 to 30/06/2008 (PCV7 period) were used for comparison of serotype/genotype distributions and antibiotic resistance rates. Results: Overall, 76 (19%) children were colonized with S. pneumoniae during the PCV13 period and there were information available from 154 isolates collected during the PCV7 period. Colonization with PCV13 serotypes declined significantly in the PCV13 period compared with historical controls (11 vs. 38%, P=0.0001), being serotypes 19F (8%), 3 (1%) and 6B (1%) the only circulating vaccine types. Serotypes 15B/C and 11A were the most frequently identified non-PCV13 serotypes during the PCV13 period (14% and 11%, respectively); the later one increased significantly between time periods (P=0.04). Serotype 11A was exclusively associated in the PCV13 period with ampicillin-resistant variants of the Spain9V-ST156 clone (ST6521 and genetically related ST14698), not detected in the preceding period. Conclusions: There was a residual circulation of vaccine types following PCV13 introduction, apart from serotype 19F. Serotype 11A increased between PCV13 and PCV7 periods due to emergence and clonal expansion of ampicillin-resistant genotype ST6521.(AU)

Streptococcus pneumoniae as a colonizing agent of the Nasopharynx - Oropharynx in adults: A systematic review and meta-analysis.

BACKGROUND: Streptococcus pneumoniae (Spn) is a commensal pathogen that usually colonizes the upper respiratory tract of children. Likewise, Spn colonization has been considered a critical factor in the development of pneumococcal invasive disease. However, Spn prevalence in adults remains unclear. This study performs a systematic review and meta-analysis to explore the prevalence of Spn Nasopharynx - Oropharynx Colonization (NOC) in adults. METHODS: A Systematic review of scientific databases was utilized to identify eligible studies that follow strict selection criteria. Subsequently, a meta-analysis was conducted to establish NOC prevalence in adults (≥18 years old). The heterogeneity and sensitivity analyses were assessed using the microorganism identification technique, sample type, and age subgroups. RESULTS: Initial selection includes 69 studies, with 37 selected for the meta-analysis, involving 23,724 individuals. The overall prevalence (95 % CI) of Spn NOC among adults was 6 % (5-9). The subgroup analysis revealed that young adults (YA), 18-64 years old, had a prevalence of 10 %, whereas older adults (OA), ≥65 years old, had a prevalence of 2 %. The identification of Spn NOC may vary depending on the method of diagnosis used. High heterogeneity (I2 > 90 %) was observed but diminished to 70 % when the analysis was restricted to oropharyngeal swabs as an identification method. Furthermore, heterogeneity decreased to 58 % when exclusively employing traditional culture as the identification method. CONCLUSIONS: This study found a low prevalence of Spn NOC in adults. Notably, the prevalence of Spn NOC was higher in younger adults than in older adults. It is essential to highlight a significant heterogeneity among studies, which indicates there is no standardized method of Spn NOC identification.

Distribution of Staphylococcus aureus carriage among healthcare workers in a Japanese convalescent and rehabilitation hospital.

Earlobes, nasal cavities, and fingers of 145 healthcare workers in convalescent and rehabilitation hospital (60 nurses and 85 rehabilitation healthcare workers) were sampled. Of the 3 sites sampled, Staphylococcus aureus was detected in one or more sites in 25 nurses and 27 rehabilitation workers. S. aureus was detected in all 3 sites in 2 (8.0%) nurses and 2 (7.4%) rehabilitation workers, and the S. aureus isolates in each case showed related PFGE pattern. S. aureus was detected in both the fingers and nasal cavities of 5 (18.5%) of the rehabilitation healthcare workers; in all 5 cases, the PFGE patterns of the S. aureus isolates from each site belonged to same cluster based on PFGE. Of the 2 cases in which methicillinresistant S. aureus (MRSA) was recovered from earlobes, fingers, and nasal cavities, in both cases, MRSA isolates from the 3 sites were the same clone according to PFGE analysis and SCCmec type IV. As S. aureus was detected in pierced earlobes of nurses, hand hygiene must be practiced after touching pierced earlobes and before patient contact. The same S. aureus clone in the nasal cavity and earlobes indicates that the route of transmission is through the fingers.

Impact of pneumococcal conjugate vaccination on pneumococcal nasopharyngeal carriage in the Gambia: Population-based cross-sectional surveys.

BACKGROUND: The introduction of pneumococcal conjugate vaccines (PCV) has reduced carriage of vaccine-type (VT) pneumococci in many settings. We determined the impact of The Gambia's national PCV programme on carriage of VT pneumococci in the population. METHODS: Seven-valent PCV (PCV7) was introduced in August 2009 without catch-up and with doses scheduled at 2, 3, 4 months of age; it was replaced by PCV13 in May 2011. We did cross-sectional carriage surveys in 2009, 2015, and 2017 in age-stratified, population-based samples. Nasopharyngeal specimens were collected and processed according to WHO guidelines. We calculated observed and adjusted prevalence ratios (PR) of VT carriage before and after PCV introduction. FINDINGS: We enrolled 2988, 3162, and 2709 participants in 2009, 2015, and 2017 respectively. The baseline (2009) prevalence of VT pneumococcal carriage among children aged 0-4 years was 42.6 %, which declined to 14.9 % and 17.5 % in 2015 and 2017 respectively (adjPR 0.32 [95 % CI 0.27, 0.38] and 0.38 [0.31, 0.46] respectively). VT prevalence among children aged 5-14 years was 16.6 %, 15.1 %, and 15.8 % in the three surveys (2017 vs 2009, adjPR 0.70 [0.58, 0.83]). VT prevalence among 15-44 year-olds was 6.4 %, 5.7 %, and 7.1 % in the three surveys (2017 vs 2009, adjPR 0.59 [0.46, 0.75]), while in those aged ≥ 45 years it was 4.5 %, 6.5 %, and 4.5 % respectively. Non-VT carriage increased in all age-groups. Prevalent residual serotypes were 34 and 15B (age 0-4 years), 3 and 34 (age 5-14 years), and 3 and 16F (age ≥ 15 years). CONCLUSIONS: Introduction of PCV was associated with reduced VT pneumococcal carriage in young, and older children, although with substantial residual prevalence. Persisting VT, and non-VT, carriage indicate significant, persistent transmission of pneumococci in the population.

Immunization with a whole cell vaccine reduces pneumococcal nasopharyngeal density and shedding, and middle ear infection in mice.

Pneumococcal Conjugate Vaccines (PCVs) have substantially reduced the burden of disease caused by Streptococcus pneumoniae (the pneumococcus). However, protection is limited to vaccine serotypes, and when administered to children who are colonized with pneumococci at the time of vaccination, immune responses to the vaccine are blunted. Here, we investigate the potential of a killed whole cell pneumococcal vaccine (WCV) to reduce existing pneumococcal carriage and mucosal disease when given therapeutically to infant mice colonized with pneumococci. We show that a single dose of WCV reduced pneumococcal carriage density in an antibody-dependent manner. Therapeutic vaccination induced robust immune responses to pneumococcal surface antigens CbpA, PspA (family 1) and PiaA. In a co-infection model of otitis media, a single dose of WCV reduced pneumococcal middle ear infection. Lastly, in a two-dose model, therapeutic administration of WCV reduced nasal shedding of pneumococci. Taken together, our data demonstrate that WCV administered in colonized mice reduced pneumococcal density in the nasopharynx and the middle ear, and decreased shedding. WCVs would be beneficial in low and middle-income settings where pneumococcal carriage in children is high.

Prevalence and factors associated with methicillin-resistant Staphylococcus aureus colonization on admission to geriatric care units: impact on screening practices.

OBJECTIVES: Universal screening for methicillin-resistant Staphylococcus aureus (MRSA) entails additional costs, and there is no consensus for targeted screening for high-risk units. The aims of this study were to determine the prevalence of MRSA in geriatric care units, and to identify the factors associated with MRSA colonization on admission. METHODS: This retrospective case-control study (1:1) in the geriatric care unit of six Belgian hospitals covered the period from 1st January 2021 to 31st December 2022. Cases were patients with a positive MRSA screening result within 48 h of admission to the geriatric care unit, and controls were patients with a negative screening result. RESULTS: In total, 556 patients were included in this study (278 in each group). Prevalence per 100 admissions for the total sample was 2.3 [95% confidence interval (CI) 2.2-2.6]. Significant multi-variate factors associated with MRSA carriage on admission were: history of MRSA, nursing home origin, and chronic skin lesions. Applying these three factors would give an area under the receiver operating characteristic (ROC) curve of 0.73 (95% CI 0.71-0.77), and would allow screening to be carried out in only 55.4% of cases (95% CI 51.2-59.6%). CONCLUSIONS: Using these factors as screening criteria in geriatric care units could significantly reduce the number of patients screened for MRSA, while maintaining satisfactory sensitivity and specificity.

Co-occurrence of bacteria and viruses and serotype distribution of Streptococcus pneumoniae in the nasopharynx of Tanzanian children below 2 years of age following introduction of the PCV13.

Introduction: Pneumococcal conjugate vaccines have reduced severe disease attributed to vaccine-type pneumococci in children. However, the effect is dependent on serotype distribution in the population and disease development may be influenced by co-occurrence of viral and bacterial pathogens in the nasopharynx. Methods: Following introduction of the 13-valent pneumococcal conjugate vaccine (PCV13) in Tanzania we performed repeated cross-sectional surveys, including 775 children below 2 years of age attending primary healthcare centers. All children were sampled from nasopharynx and pneumococci were detected by single-target PCR. Pneumococcal serotypes/groups and presence of viruses and other bacteria were determined by two multiplex PCR assays. Results: The prevalence of PCV13 vaccine-type pneumococci decreased by 50%, but residual vaccine-types were still detected in 21% of the children 2 years after PCV13 introduction. An increase in the non-vaccine-type 15 BC was observed. Pneumococci were often co-occurring with Haemophilus influenzae, and detection of rhino/enterovirus was associated with higher pneumococcal load. Discussion: We conclude that presence of residual vaccine-type and emerging non-vaccine-type pneumococci in Tanzanian children demand continued pneumococcal surveillance. High co-occurrence of viral and bacterial pathogens may contribute to the disease burden and indicate the need of multiple public health interventions to improve child health in Tanzania.

Carriage of methicillin-resistant Staphylococcus aureus in children <6 years old: a retrospective follow-up study of the natural course and effectiveness of decolonization treatment.

BACKGROUND: Decolonization treatment of MRSA carriers is recommended in Denmark, except in households with MRSA-positive children <2 years old (wait-and-see approach). OBJECTIVES: To investigate a wait-and-see approach in children 2-5 years old, and the effect of decolonization treatment of MRSA carriage in all children <6 years old. PATIENTS AND METHODS: In this retrospective follow-up study, we included MRSA carriers <6 years old in the Capital Region of Denmark from 2007 to 2021. Data were collected from laboratory information systems and electronic patient records. We divided children into age groups of <2 years or 2-5 years and decolonization treatment versus no treatment. Treatment was chlorhexidine body washes and nasal mupirocin, sometimes supplemented with systemic antibiotics. Children were followed until becoming MRSA free, or censoring. The probability of becoming MRSA free was investigated with Cox regression (higher HRs indicate faster decolonization). RESULTS: Of 348 included children, 226 were <2 years old [56/226 (25%) received treatment] and 122 were 2-5 years old [90/122 (74%) received treatment]. Multivariable analyses did not show a larger effect of decolonization treatment versus no treatment in <2-year-olds (HR 0.92, 95% CI 0.52-1.65) or 2-5-year-olds (HR 0.54, 95% CI 0.26-1.12). Without treatment, 2-5-year-olds tended to clear MRSA faster than <2-year-olds (HR 1.81, 95% CI 0.98-3.37). CONCLUSIONS: We did not find a larger effect of decolonization treatment versus no treatment in children <6 years old, and 2-5-year-olds tended to become MRSA free faster than <2-year-olds. These results support a wait-and-see approach for all children <6 years old, but further studies are needed.

Prevalence, serogroup distribution and risk factors of Neisseria meningitidis carriage in high school and university students in Hungary.

Neisseria meningitidis causes life-threatening invasive meningococcal disease (IMD) with high mortality worldwide. Asymptomatic pharyngeal meningococcus colonisation is an important reservoir for the spread of the bacterium. The aim of this study was to determine N. meningitidis colonisation rates in asymptomatic high school and university students and to identify risk factors for carriage. Oropharyngeal swab samples and data from a self-reported questionnaire were obtained from overall 610 students, among them 303 university students and 307 high school students, aged between 15 and 31 years in Budapest, Hungary, between November 2017 and December 2018. Meningococcal carriage and serogroup of N. meningitidis were determined by RT-PCR from DNA extracted directly from the specimen. N. meningitidis was identified in 212 (34.8 %) of the participants. Significantly higher carriage rate was found among high school students (48.9 %) compared to university students (20.5 %). Peak of colonisation rate was among 17-19-year-old students (48.7 %). Most carriage isolates were non-typable (87.3 %). From the 212 meningococcus carriers, 19 were colonised by serogroup B (9 %), 5 by serogroup C (2.4 %), and 1 had serogroup Y (0.5 %). Significantly higher colonisation rate was found among males (42.4 %) than in females (33.1 %). Antibiotic use in the past 2 months has decreased the rate of meningococcal colonisation. Recent respiratory infection, active or passive smoking and attending parties have not influenced meningococcal colonisation rate significantly. In conclusion, we have found high asymptomatic meningococcus carriage rate among high school students and young adults, however, the majority of the colonizing meningococci were non-typable.

Low usefulness of reporting tonsillar PCR Ct-values in pharyngeal infections with Fusobacterium necrophorum.

Tonsillar Fusobacterium necrophorum PCR Ct-values were higher in participants with asymptomatic tonsillar carriage than patients with pharyngeal infections. However, Ct-values were not associated with severity of disease or predictive of development of complications and hence lacked clinical usefulness. The reporting of F. necrophorum Ct-values in clinical samples is not recommended.

MRSA throat carriage in two healthcare workers. / MRSA-halsbærerskap hos to helsearbeidere.

Background: Healthcare workers colonised with methicillin-resistant Staphylococcus aureus (MRSA) experience negative consequences due to work restrictions, long-term sick leave, stigmatisation, eradication failures and psychosocial stress. Throat colonisation is associated with prolonged carriage and non-successful treatment. Case presentation: We describe two Norwegian healthcare students with persistent MRSA throat carriage. After several eradication failures, MRSA eradication was successful only after tonsillectomy. Interpretation: Tonsillectomy is not the solution for persistent MRSA throat carriage in healthcare workers. However, their stories illustrate the challenges they faced during repeated eradication attempts. They suffered considerable psychological stress due to the risk of study disruption and limited career options. The impact of laws and strict guidelines for MRSA-colonised healthcare workers, needs to be re-assessed in order to reduce transmission. We argue that healthcare workers without individual risk factors should be able to work in units considered to pose no risk as long as they undergo individual training in basic infection control measures.

Longitudinal study of meningococcal carriage in adolescents and young adults in South Australia 2017-2020.

BACKGROUND: This analysis investigated longitudinal changes in meningococcal carriage in adolescents in South Australia over 4 years. METHODS: Data from the "B Part of It" study, which included a state-wide cluster randomized controlled trial in secondary-school students (n = 34,489 in 2017 and 2018) and serial cross-sectional studies in school leavers aged 17-25 years (n = 4028 in 2019-2020). Individuals had oropharyngeal swabs collected annually. This study included two unique cohorts: (1) individuals enrolled in 2019, with three consecutive annual swabs taken in 2017, 2018 and 2019; and (2) individuals enrolled in 2020, with swabs taken in 2017, 2018, and 2020. Disease-associated N. meningitidis genogroups were identified using PCR and whole genome sequencing. Univariate analysis identified risk factors for recurrent carriage (≥2). RESULTS: Among school leavers, 50 (1.7%, total n = 2980) had carriage detected at successive visits. In participants with meningococcal carriage at successive visits, 38/50 (76.0%) had the same genogroup detected by porA PCR. Of those, 19 had the same MLST type and demonstrated minimal variation, indicating they most likely had sustained carriage of the same isolate (range 226 to 490 days, mean duration 352 [SD 51] days). In the 2019 school leaver cohort, 6.7% acquired carriage in their first year out of school compared to 3.3% in their final school year. Compared to single carriage detection, recurrent carriage was potentially more likely in older adolescents (16 compared to ≤15 years; OR = 1.97 (95%CI 1.0, 3.86); p = 0.048). CONCLUSION: Whilst carriage is typically transient, some adolescents/young adults may have persistent carriage and are likely to be an important group in the transmission of meningococci.

Prevalence and serotype distribution of nasopharyngeal carriage of Streptococcus pneumoniae among healthy children under 5 years of age in Hainan Province, China.

BACKGROUND: The thirteen-valent pneumococcal conjugate vaccine (PCV13) is not included in the national immunization program and is administered voluntarily with informed consent in China. In preparation for assessing the impact of pilot introduction in Hainan Province, we conducted a carriage study among children under 5 years of age from four locations in Hainan Province, China. METHODS: From March to June 2022, nasopharyngeal (NP) swabs, collected from healthy children aged younger than 59 months who lived in the 4 different locations (Haikou, Wanning, Baisha and Qiongzhong) in Hainan Province, were tested for pneumococcus using conventional culture. Pneumococcal isolates were serotyped using the Quellung reaction. Risk factors associated with pneumococcal colonization were assessed using univariate analysis and multivariable logistic regression adjusting for age, daycare attendance and other factors. RESULTS: Pneumococcus was isolated in 710 (30.4%) of the 2333 children enrolled. Of 737 pneumococci, 29 serotypes were identified; 60.9% were PCV13 serotypes; the most common vaccine serotypes were 6B (20.4%), 19F (13.0%), 6A (11.9%) and 23F (6.1%); and the most common nonvaccine serotypes were 23A (12.9%), 34 (6.1%) and nontypeable (NT) pneumococci (5.6%). Children vaccinated with PCV13 had lower carriage (17.7% vs 32.5%; P = 0.0001) and fewer PCV13 serotypes (41.9% vs 62.7%; P = 0.0017) compared to unimmunized children. After adjustment, NP carriage was higher among children attending daycare (aOR = 2.3, 95% CI: 1.7-3.2), living in rural areas (aOR = 1.4, 95% CI: 1.1-1.8), living with siblings (aOR = 1.3, 95% CI: 1.0-1.6) and whose mothers had completed senior high/technical secondary school (aOR = 1.5, 95% CI: 1.1-2.0). In contrast, completion of 3-4 doses of PCV13 were associated with a lower carriage rate (aOR = 0.6, 95% CI: 0.4-0.9). CONCLUSIONS: We established the baseline of pneumococcal carriage, serotype distribution and PCV13 immunization rates among healthy children under 5 years of age in Hainan Province, prior to the introduction of PCV13 into the national immunization program. The high proportion of PCV13 serotypes suggests that PCV13 introduction will likely have a substantial impact on pneumococcal carriage in Hainan Province.

Geographical distribution of invasive meningococcal disease and carriage: A spatial analysis.

Little information exists concerning the spatial relationship between invasive meningococcal disease (IMD) cases and Neisseria meningitidis (N. meningitidis) carriage. The aim of this study was to examine whether there is a relationship between IMD and asymptomatic oropharyngeal carriage of meningococci by spatial analysis to identify the distribution and patterns of cases and carriage in South Australia (SA). Carriage data geocoded to participants' residential addresses and meningococcal case notifications using Postal Area (POA) centroids were used to analyse spatial distribution by disease- and non-disease-associated genogroups, as well as overall from 2017 to 2020. The majority of IMD cases were genogroup B with the overall highest incidence of cases reported in infants, young children, and adolescents. We found no clear spatial association between N. meningitidis carriage and IMD cases. However, analyses using carriage and case genogroups showed differences in the spatial distribution between metropolitan and regional areas. Regional areas had a higher rate of IMD cases and carriage prevalence. While no clear relationship between cases and carriage was evident in the spatial analysis, the higher rates of both carriage and disease in regional areas highlight the need to maintain high vaccine coverage outside of the well-resourced metropolitan area.

Effect of nasal carriage of Bacillus species on COVID-19 severity: a cross-sectional study.

Intranasal sprays containing Bacillus species are being researched for treating viral respiratory tract infections. The aim of this study was to assess the relationship between the nasal carriage of Bacillus and COVID-19 severity. This was a cross-sectional study that collected nasopharyngeal samples from adults 18 years and above visiting two COVID-19 testing centers in Lagos, Nigeria, between September 2020 and September 2021. Bacillus species were cultured from the samples and confirmed using 16 s rRNA gene sequencing. The dependent variable was COVID-19 status classified as negative, asymptomatic, mild, or severe. The independent variable was the nasal carriage of Bacillus species. Multinomial regression analysis was done to determine the association between nasal carriage of Bacillus and COVID-19 severity after adjusting for age, sex, and co-morbidity status. A total of 388 participants were included in the study with mean (standard deviation) age of 40.05 (13.563) years. Sixty-one percent of the participants were male, 100 (25.8%) had severe COVID-19, 130 (33.5%) had pre-existing comorbidity, and 76 (19.6%) had Bacillus cultured from their nasopharyngeal specimen. Bacillus species presence was significantly associated with higher odds of severe COVID-19 compared to having a negative COVID-19 status (AOR = 3.347, 95% CI: 1.359, 8.243). However, the presence of Bacillus species was significantly associated with lower odds of severe COVID-19 compared to having a mild COVID-19 status. The study suggests that nasal carriage of Bacillus species is associated with the clinical course of COVID-19 and supports the exploration of Bacillus species in the management of viral respiratory tract infections.IMPORTANCEWith the introduction of intranasal spray containing Bacillus species for the treatment of viral respiratory tract infections, such as COVID-19 and respiratory syncytial virus, identifying the association between the nasal carriage of Bacillus species and COVID-19 susceptibility and severity will help further substantiate the investigation of these bacteria for COVID-19 prevention and treatment. This study evaluated the association between the carriage of Bacillus species in the nasopharyngeal tract and COVID-19 severity and found that the presence of Bacillus species in the nasopharynx may significantly impact the clinical course of COVID-19.

Nasopharyngeal carriage of Streptococcus pneumoniae among children <5 years of age in Indonesia prior to pneumococcal conjugate vaccine introduction.

Pneumococcal conjugate vaccines (PCVs) prevent nasopharyngeal colonization with vaccine serotypes of Streptococcus pneumoniae, leading to reduced transmission of pneumococci and stronger population-level impact of PCVs. In 2017 we conducted a cross-sectional pneumococcal carriage study in Indonesia among children aged <5 years before 13-valent PCV (PCV13) introduction. Nasopharyngeal swabs were collected during visits to community integrated health service posts at one peri-urban and one rural study site. Specimens were analyzed by culture, and isolates were serotyped using sequential multiplex polymerase chain and Quellung reaction. Antibiotic susceptibility was performed by broth microdilution method. We enrolled 1,007 children in Gunungkidul District, Yogyakarta (peri-urban) and 815 in Southwest Sumba, East Nusa Tenggara (rural). Pneumococcal carriage prevalence was 30.9% in Gunungkidul and 87.6% in Southwest Sumba (combined: 56.3%). PCV13 serotypes (VT) carriage was 15.0% in Gunungkidul and 52.6% in Southwest Sumba (combined: 31.8%). Among pneumococcal isolates identified, the most common VT were 6B (16.4%), 19F (15.8%), and 3 (4.6%) in Gunungkidul (N = 323) and 6B (17.6%), 19F (11.0%), and 23F (9.3%) in Southwest Sumba (N = 784). Factors associated with pneumococcal carriage were age (1-2 years adjusted odds ratio (aOR) 1.9, 95% CI 1.4-2.5; 3-4 years aOR 1.5, 95% CI 1.1-2.1; reference <1 year), other children <5 years old in the household (aOR 1.5, 95% CI 1.1-2.0), and presence of ≥1 respiratory illness symptom (aOR 1.8, 95% CI 1.4-2.2). Overall, 61.5% of the pneumococcal isolates were non-susceptible to ≥1 antibiotic class and 13.2% were multi-drug non-susceptible (MDNS) (non-susceptible to ≥3 classes of antibiotics). Among 602 VT isolates, 73.9% were non-susceptible and 19.9% were MDNS. These findings are critical to establish a pre-PCV13 carriage prevalence and demonstrate the complexity in evaluating the impact of PCV13 introduction in Indonesia given the wide variability in the carriage prevalence as shown by the two study sites.

Genetic Determinants in MRSA Carriage and Their Association with Decolonization Outcome.

Methicillin-resistant Staphylococcus aureus (MRSA) colonization increases the risk of infection. Response to decolonization treatment is highly variable and determinants for successful decolonization or failure of eradication treatment are largely unknown. Insight into genetic predictors of eradication failure is potentially useful in clinical practice. The aim of this study was to explore genetic characteristics that are associated with MRSA decolonization failure. This cohort study was performed in a tertiary care hospital in the Netherlands. Patients with ≥ 1 positive MRSA culture from any site and with available whole -genome sequencing data of the MRSA isolate between 2017 and 2022 were included. Lineages, resistance, and virulence factors were stratified by MRSA decolonization outcome. In total, 56 patients were included: 12/56 (21%) with treatment failure and 44/56 (79%) with successful decolonization (with or without preceding treatment). A significant association was found between ciprofloxacin-resistant lineages and failure of eradication (OR 4.20, 95%CI 1.11-15.96, P = 0.04). Furthermore, livestock-associated MRSA and the major community-associated MRSA lineages ST6-t304 and ST8-t008 were associated with successful eradication treatment or spontaneous clearance. In conclusion, this explorative study showed a higher eradication failure rate in complicated MRSA carriers with ciprofloxacin-resistant MRSA lineages, which are predominantly healthcare-associated. Further studies are warranted to confirm the higher eradication failure risk of ciprofloxacin-resistant lineages, and identify the underlying mechanisms.