Pneumococcal Carriage and Vaccine Coverage in Retirement Community Residents

Nasopharyngeal Carriage Rate of Streptococcus pneumoniae, Related Risk Factors, and Antibiotic Susceptibility Among Inmates in Hawassa Central Prison Institute: Hawassa, Sidama National Region, Ethiopia

Background

The bacterium Streptococcus pneumoniae commonly causes severe bacterial illnesses in both children and adults. S. pneumoniae is the most fatal bacterial pathogen, causing 50% of the deaths from lower respiratory infections in people of all ages.

Objectives

This study was aimed to determine a nasopharyngeal carriage rate of S. pneumoniae, related risk factors, and antibiotic susceptibility among prisoners in Hawassa Central Prison Institute Hawassa, Ethiopia.

Methods

From July to August 2021, a cross-sectional investigation was carried out in Hawassa prison. All randomly chosen adult volunteers were a part of the study. In this study, about 330 different people were included. Within 3 h of collection, the swab specimen was inoculated onto 5% sheep blood agar; the inoculated medium was then incubated for 18-24 h at 35-37 °C in a CO2-enriched environment. Following incubation, the S. pneumoniae colonies were suspected, but the usual colony shape, alpha-hemolysis, Gram staining, optochin susceptibility, and bile solubility test allowed for confirmation. Antimicrobial susceptibility testing was carried out in accordance with the Clinical and Laboratory Standards Institute's guidelines.

Results

Overall carriage rate of S. pneumoniae among adult individuals were 41 (12.7%). The carriage rate of S. pneumoniae was affected by age classes that 39-48 years (OR = 4.82, 95%CI = 1.49-15.56, p = .009), 49-58 years (OR = 5.27, 95%CI = 1.27-21.89, p = .022), and greater than 58 years (OR = 4.36, 95%CI = 1.13-16.90, p = .033); cigarette smoking (OR = 3.41, 95%CI = 1.16-10.01, p = .026); and sharing beds (OR = 3.91, 95%CI = 1.27-12.07, p = .018). The majority of the isolates are susceptible for clindamycin (87.8%) and resistant for chloramphenicol (56%). Multidrug resistance was observed in 36.7%.

Conclusions

The overall carriage rate of S. pneumoniae was 12.7%. Age, cigarette smoking, and sharing beds in the same prison room had a substantial impact on this nasopharyngeal carriage rate. Chloramphenicol (56%), erythromycin (41.5%), tetracycline (39%), and co-trimoxazole (34.1%) resistance were seen in the majority of S. pneumoniae isolates. Early detection, hygiene maintenance, and appropriate treatment are necessary.

Pneumococcal carriage in adults aged 50 years and older in outpatient health care facility during pandemic COVID-19 in Novi Sad, Serbia

Background

Data related to carriage of Streptococcus pneumoniae (Spn) and antimicrobial resistance patterns in middle-aged and older adults are limited. We assessed the carriage of Spn, and its antibiotic resistance patterns, among participants ≥50 years of age living in the city of Novi Sad during the second year of COVID-19 pandemic.

Methods

Analysis of prospectively collected data among participants with or without symptoms of upper respiratory tract infection who visited their elected physicians in the Primary Health Care Centre of Novi Sad (outpatient facility) was conducted from May 18, 2021 to December 7, 2021. Both nasopharyngeal (NP) and oropharyngeal (OP) samples from each participant were collected.

Results

A total of 1042 samples from 521 study subjects (1 NP and 1 OP sample from each person) were collected. Sixteen samples from the same number of persons (3.1%, 95% confidence interval: 1.76%-4.94%) were culture positive for the presence of Spn. Overall, the median age of study participants was 71 years (range, 50–93 years; 90th percentile, 77 years), and most (197/521, 37.8%) of them were 70–79 years of age. A majority of the study subjects were: females (324/521; 62.2%), sampled during May and June 2021 (376/521, 72.2%), those who did not have contact with children aged 0–10 years in the family (403/521; 77.4%), without smokers in the household (443/521; 85.0%), and those who did not receive vaccine against Spn (519/521; 99.6%). Out of 16 Spn positive samples, for six participants, Spn carriage serotypes were obtained and there were four vaccine (6A, 11A, 15B, and 18C) serotypes, and two (6C and 35F) non-vaccine serotypes. Remaining 10 (62.50%) samples were non-typeable isolates of pneumococci. Among four vaccine serotypes, two (6A and 18C) were represented in PCV13, and 18C along with the other two (11A and 15B) in PPSV23 vaccine. The highest level of resistance of Spn isolates was observed for erythromycin, (10 or 62.50%), and tetracycline, (7 or 43.75%), one isolate showed resistance to penicillin, ampicillin, and amoxicillin/amoxicillin-clavulanic acid, while none of them were resistant to ceftriaxone, trimethoprim/sulfamethoxazole and levofloxacin. There were three multi-drug resistant isolates; one was identified as 6C (non-vaccine serotype), and two other were non-typeable isolates of Spn.

Conclusions

In this first study conducted in Serbia on Spn carriage in adults ≥50 years of age, we found low prevalence of Spn carriage and identified 6 serotypes of Spn, four of which were represented in vaccines. These results may support future Spn colonization studies among middle-aged and older adults.

Nasopharyngeal Carriage and Serotype Distribution of Streptococcus pneumoniae in Elderly: A Cross-sectional Study in Turkey

Objective

The incidence and mortality of invasive pneumococcal disease are much higher in people over 65 years compared to the general population. The incidence of the disease and the distribution of serotypes changed with the spread of childhood conjugate pneumococcal vaccines and the use of vaccines in the adult age group. Nasopharyngeal carriage is an important stage in the disease pathogenesis. In this study, we aimed to determine the pneumococcal carriage prevalence and serotype distribution in adults aged ≥ 65 years living in a nursing home.

Materials and Methods

The nasopharyngeal swabs were taken from ≥ 65 years old people living in Narlıdere Nursing Home. The specimens were cultured and pneumococci were isolated according to colony appearance, optochin sensitivity and solubility in bile salts. Pneumococcal serotypes were identified using the capsule swelling reaction.

Results

Pneumococcus was isolated in 10 of 341 subjects and the pneumococcal carriage prevalence was 2.9%. Advanced age, immunocompromised status and chronic renal failure were associated with pneumococcal carriage. In multivariate model, having immunocompromised status was significantly associated with carriage. Serotypes/serogroups of pneumococci were 7F, 23F, 10, 11, 15. 17, 20 and 33. The 13 valent conjugated pneumococcal vaccine serotype carriage prevalence was 0.6%.

Conclusion

Although pneumococcal colonization in older people is uncommon, most of the isolated serotypes are not PCV13 serotypes. The monitoring of pneumococcal serotypes can offer useful information about the circulation of this pathogen among older people and the potential protective effect of pneumococcal vaccines.

The nose is the best niche for detection of experimental pneumococcal colonisation in adults of all ages, using nasal wash

Previous studies have suggested that the pneumococcal niche changes from the nasopharynx to the oral cavity with age. We use an Experimental Human Pneumococcal Challenge model to investigate pneumococcal colonisation in different anatomical niches with age. Healthy adults (n = 112) were intranasally inoculated with Streptococcus pneumoniae serotype 6B (Spn6B) and were categorised as young 18-55 years (n = 57) or older > 55 years (n = 55). Colonisation status (frequency and density) was determined by multiplex qPCR targeting the lytA and cpsA-6A/B genes in both raw and culture-enriched nasal wash and oropharyngeal swab samples collected at 2-, 7- and 14-days post-exposure. For older adults, raw and culture-enriched saliva samples were also assessed. 64% of NW samples and 54% of OPS samples were positive for Spn6B in young adults, compared to 35% of NW samples, 24% of OPS samples and 6% of saliva samples in older adults. Many colonisation events were only detected in culture-enriched samples. Experimental colonisation was detected in 72% of young adults by NW and 63% by OPS. In older adults, this was 51% by NW, 36% by OPS and 9% by saliva. The nose, as assessed by nasal wash, is the best niche for detection of experimental pneumococcal colonisation in both young and older adults.

Experimental Human Pneumococcal Colonization in Older Adults Is Feasible and Safe, Not Immunogenic

Rationale: Pneumococcal colonization is key to the pathogenesis of invasive disease but is also immunogenic in young adults, protecting against recolonization. Colonization is rarely detected in older adults, despite high rates of pneumococcal disease.Objectives: To establish experimental human pneumococcal colonization in healthy adults aged 50-84 years, to measure the immune response to pneumococcal challenge, and to assess the protective effect of prior colonization against autologous strain rechallenge.Methods: Sixty-four participants were inoculated with Streptococcus pneumoniae (serotype 6B; 80,000 cfu in each nostril). Colonization was determined by bacterial culture of nasal wash, and humoral immune responses were assessed by anticapsular and antiprotein IgG concentrations.Measurements and Main Results: Experimental colonization was established in 39% of participants (25/64) with no adverse events. Colonization occurred in 47% (9/19) of participants aged 50-59 compared with 21% (3/14) in those aged ≥70 years. Previous pneumococcal polysaccharide vaccination did not protect against colonization. Colonization did not confer serotype-specific immune boosting, with a geometric mean titer (95% confidence interval) of 2.7 μg/ml (1.9-3.8) before the challenge versus 3.0 (1.9-4.7) 4 weeks after colonization (P = 0.53). Furthermore, pneumococcal challenge without colonization led to a drop in specific antibody concentrations from 2.8 μg/ml (2.0-3.9) to 2.2 μg/ml (1.6-3.0) after the challenge (P = 0.006). Antiprotein antibody concentrations increased after successful colonization. Rechallenge with the same strain after a median of 8.5 months (interquartile range, 6.7-10.1) led to recolonization in 5/16 (31%).Conclusions: In older adults, experimental pneumococcal colonization is feasible and safe but demonstrates different immunological outcomes compared with younger adults in previous studies.

The impact of pharmacist-led educational intervention on pneumococcal vaccine awareness and acceptance among elderly in Jordan

Limited data exist regarding pneumococcal vaccination coverage among the elderly in Middle Eastern countries including Jordan. The pharmacists' role in improving vaccine acceptance has become increasingly evident. Yet, large-scale studies of the assessment of the pharmacists' role on pneumococcal vaccines acceptance among the elderly are scarce. Hence, we assessed for the first time the current state of knowledge and pneumococcal vaccination coverage among the elderly and the role of pharmacist-led educational intervention on the attitude, awareness, vaccine acceptance, and prompts for physician consultation regarding pneumococcal vaccines in Jordan. This interventional study enrolled 916 randomly selected adults aged ≥ 65 years in Amman, Jordan. We showed that only 3.9% of the participants have ever heard about pneumococcal disease with 0.5% vaccination coverage. Immediately after educational intervention, 21.7% of the participants perceived pneumococcal disease as a threat, 52.1% of them believed in the importance of the vaccine, and 93.9% of them were willing to consult a physician in this regard. At a two-month follow-up, 30.5% had a positive attitude toward the vaccine and 36% consulted their physician regarding the vaccine. Vaccination coverage was significantly increased to 1.9% (P value = 0.008). The main obstacles against vaccination were a negative attitude and that physicians had not recommended the vaccine. Vaccine uptake was significantly associated with physician consultation (P value = 0.011). Insurance, employment, attitude, and reading the booklet significantly predicted physician consultation. In conclusion, very low pneumococcal vaccination coverage was observed among the elderly in Jordan. Enrollment of pharmacists in immunization education and recommendation is suggested to improve pneumococcal vaccine coverage among the elderly in Jordan.

Upper airways colonisation of Streptococcus pneumoniae in adults aged 60 years and older: A systematic review of prevalence and individual participant data meta-analysis of risk factors

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Systematic review and meta-analysis of 18 studies and more than 6000 participants.

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Adults over the age of 60 had a pooled prevalence of pneumococcal carriage of 9%.

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Risk factors: contact with children, smoking and residing in a nursing home.

Background

Colonisation with Streptococcus pneumoniae can lead to invasive pneumococcal disease and pneumonia. Pneumococcal acquisition and prevalence of colonisation are high in children. In older adults, a population susceptible to pneumococcal disease, colonisation prevalence is reported to be lower, but studies are heterogeneous.

Methods

This is a systematic review and meta-analysis of prevalence of, and risk factors for, pneumococcal colonisation in adults ≥ 60 years of age (PROSPERO #42016036891). We identified peer-reviewed studies reporting the prevalence of S. pneumoniae colonisation using MEDLINE and EMBASE (until April 2016), excluding studies of acute disease. Participant-level data on risk factors were sought from each study.

Findings

Of 2202 studies screened, 29 were analysable: 18 provided participant-level data (representing 6290 participants). Prevalence of detected pneumococcal colonisation was 0–39% by conventional culture methods and 3–23% by molecular methods. In a multivariate analysis, colonisation was higher in persons from nursing facilities compared with the community (odds ratio (OR) 2•30, 95% CI 1•26–4•21 and OR 7•72, 95% CI 1•15–51•85, respectively), in those who were currently smoking (OR 1•69, 95% CI 1•12–2•53) or those who had regular contact with children (OR 1•93, 95%CI 1•27–2•93). Persons living in urban areas had significantly lower carriage prevalence (OR 0•43, 95%CI 0•27–0•70).

Interpretation

Overall prevalence of pneumococcal colonisation in older adults was higher than expected but varied by risk factors. Future studies should further explore risk factors for colonisation, to highlight targets for focussed intervention such as pneumococcal vaccination of high-risk groups.

Funding

No funding was required.

Upper respiratory tract colonization with Streptococcus pneumoniae in adults

INTRODUCTION

Most of the current evidence regarding pneumococcal upper respiratory colonization in adults suggests that despite high disease burden, carriage prevalence is low. Contemporary studies on adult pneumococcal colonization have largely followed the pediatric approach by which samples are obtained mostly from the nasopharynx and bacterial detection is evaluated by routine culture alone. Recent evidence suggests that the 'pediatric approach' may be insufficient in adults and pneumococcal detection in this population may be improved by longitudinal studies that include samples from additional respiratory sites combined with more extensive laboratory testing.

AREAS COVERED

In this article, relevant literature published in peer review journals on adult pneumococcal colonization, epidemiology, detection methods, and recommendations were reviewed.

EXPERT OPINION

Respiratory carriage of Streptococcus pneumoniae has been underestimated in adults. Contemporary pneumococcal carriage studies in adults that collect samples from alternative respiratory sites such as the oropharynx, saliva, or nasal wash; are culture-enriched for pneumococcus; and use molecular diagnostic methods designed to target two pneumococcal DNA sequences should enhance pneumococcal detection in the adult respiratory tract. This finding may have implications for the interpretation of dynamics of pneumococcal transmission and vaccination.

[Alterations in responses to vaccines in older people]

The aging population raises a number of public health issues including a need to address the severity and frequency of infections observed in older people. Vaccines play an important role in prevention. However, immunosenescence alters the intensity and quality of vaccine responses, thus limiting the impact of recommendations directed after 65 years for vaccination against flu, pneumococci, pertussis, tetanus and zoster. Immunosenescence, aggravated by co-morbidities, varies with age, becoming apparent after 60-65 years and more profound after 85 years. All stages of vaccine responses are affected by immunosenescence, from the innate immunity required to activate these responses to the induction of protective antibody responses and immune memory. Nevertheless, the capacity to develop new responses to primary vaccination is more affected than the ability to respond to recalls, although this is also impaired. Responses to vaccines are differentially altered depending on vaccine and age. Influenza vaccines are modestly immunogenic and several meta-analyses agree an estimate for efficacy of about 50% against virologically-proven flu and 40% against flu-related deaths. The anti-pneumococcal 23-valent non-conjugated vaccine does not induce memory while the 13-valent conjugated one does, but their efficacy are likely to be similar between 70 to 52% before 75 years. A sequential vaccination program with the 13-valent primo-vaccination followed by the 23-valent, recommended in immune-suppressed patients, is currently being studied in France. The waning of immunity to pertussis makes recalls necessary in the elderly who develop good antibody responses. Several research avenues are currently being pursued to try improve the degree of protection conferred by these vaccines in elderly.

Nasopharyngeal carriage of Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus in a Brazilian elderly cohort

We aimed to investigate the nasopharyngeal colonization (NPC) by Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus in the elderly population and to assess the demographic factors associated with NPC. This was an observational cohort study in which outpatients aged ≥60 years were enrolled from April to August 2017, with a follow-up visit from September through December 2017. Nasopharyngeal (NP) swabs were collected, bacteria were detected and isolated, and isolates were subjected to phenotypic and molecular characterization using standard microbiological techniques. At enrolment, the rates of S. aureus, methicillin-resistant S. aureus (MRSA), H. influenzae, and S. pneumoniae among 776 elderly outpatients were 15.9%, 2.3%, 2.5%, and 2.2%, respectively. Toxin production was detected in 21.1% of methicillin-susceptible S. aureus, and three SCCmec types were identified: II/IIb, IVa, and VI. At the follow-up visit, all carriage rates were similar (p > 0.05) to the rates at enrolment. Most of S. pneumoniae serotypes were not included in pneumococcal conjugate vaccines (PCVs), except for 7F, 3, and 19A. All strains of H. influenzae were non-typeable. Previous use of antibiotics and 23-valent pneumococcal polysaccharide vaccination (p < 0.05) were risk factors for S. aureus and MRSA carriage; S. aureus colonization was also associated with chronic kidney disease (p = 0.021). S. pneumoniae carriage was associated with male gender (p = 0.032) and an absence of diabetes (p = 0.034), while not receiving an influenza vaccine (p = 0.049) and chronic obstructive pulmonary disease (p = 0.031) were risk factors for H. influenzae colonization. The frailty of study participants was not associated with colonization status. We found a higher S. aureus carriage rate compared with the S. pneumoniae- and H. influenzae-carriage rates in a well-attended population in a geriatric outpatient clinic. This is one of the few studies conducted in Brazil that can support future colonization studies among elderly individuals.

Effect of prior vaccination on carriage rates of Streptococcus pneumoniae in older adults: A longitudinal surveillance study

INTRODUCTION

Pneumococcus is a commensal of the upper respiratory tract and colonization is common in young children. Carriage studies have provided insights on vaccine effects in children and may also be useful for assessing vaccines in adults. However, culture based prevalence studies in older adults describe low colonization rates. Therefore, we assessed cumulative incidence of pneumococcal colonization in older adults using polymerase chain reaction (PCR) targeting the lytA gene and risk factors for carriage.

METHODS

100 community-dwelling adults ≥65 years were enrolled the winter of 2015 and followed biweekly for 12 months. Medical, vaccination and illness history as well as nasopharyngeal (NP) and oropharyngeal (OP) samples were collected. Combined OP and NP were incubated in enrichment broth and screened using real-time lytA PCR. Samples from new colonization events (lytA PCR+) were cultured on gentamicin blood agar plates. Isolates identified by colony morphology as S. pneumoniae were serotyped using a multiplex combined immunoassay-PCR platform which classifies 96 serotypes. Cumulative incidence of pneumococcal carriage was calculated and risk factors for carriage assessed.

RESULTS

The cumulative incidence of colonization was 41% by PCR and 14% by culture. Monthly prevalence ranged from 0 to 17% by PCR and 1 to 4% by culture with peaks in the spring and fall. Demographics were similar between colonized and never colonized subjects although colonized were younger (72.4 vs. 75.0 years, P = 0.06). Vaccination with any pneumococcal vaccine before or during study period was associated with decreased risk of becoming colonized (p < 0.001) as was vaccination with either the 13-valent conjugated pneumococcal vaccine (PCV13) or 23-valent polysaccharide vaccine (PPSV23) (p < 0.001).

CONCLUSION

Pneumococcal colonization in older adults as detected by lytA PCR is frequent and pneumococcal vaccination appears to be associated with decreased risk of carriage. Further study is needed to understand the biological significance of molecular detection of pneumococcus in adults.

Naso- and oropharyngeal bacterial carriage in nursing home residents: Impact of multimorbidity and functional impairment

OBJECTIVE

From April 2013 to February 2014 we performed a multicentre prospective cross-sectional study in 541 German nursing home residents. We determined pharyngeal carriage of Streptococcus pneumoniae (primary objective) and other bacteria (secondary objective) in naso- and oropharyngeal swabs by culture-based standard procedures and explored the influence of multimorbidity and functional status on bacterial carriage.

METHODS

Socio-demographic data, vaccination status, multimorbidity, nutrition and functional status defined by Comprehensive Geriatric Assessment were evaluated. We estimated carriage rates with 95% confidence intervals (CI) and explored potential risk factors by logistic regression analysis.

RESULTS

Pneumococcal post-serotyping carriage rate was 0.8% (95%CI 0.2-1.9%; 4/526). Serotyping revealed serotypes 4, 7F, 23B and 23F and S. pseudopneumoniae in two other cases. Odds of carriage were higher in men (Odds ratio OR 5.3 (95%CI 0.9-29.4)), in malnourished residents (OR 4.6 (0.8-25.7)), residents living in shared rooms (OR 3.0 (0.5-16.5)) or having contact with schoolchildren (OR 2.0 (0.2-17.6)). The most frequent pathogen was Staphylococcus aureus (prevalence 29.5% (25.6-33.6%)) with meticillin-resistant Staphylococcus aureus prevalence of 1.1%. Gram-negative bacteria (GNB) were found in 22.5% (19.0-26.3%) with a prevalence of extended-spectrum beta lactamase (ESBL) producing bacteria of 0.8%. Odds of S. aureus carriage were higher for immobility (OR 1.84 (1.15-2.93)) and cognitive impairment (OR 1.54 (0.98-2.40)). Odds of GNB carriage were higher in residents with more severe comorbidity (OR 1.13 (1.00-1.28)) and malnutrition (OR 1.54 (0.81-2.91)).

CONCLUSIONS

Given the observed data, at least long-term carriage of S. pneumoniae in nursing home residents seems to be rare and rather unlikely to cause nursing home acquired pneumonia. The low rate of colonization with multi drug resistant (MDR) bacteria confirms that nursing home residency is not a risk factor for MDR pneumonia in Germany. For individual risk assessment in this susceptible population, immobility and malnutrition should be considered as signs of functional impairment as well as comorbidity.

Nasopharyngeal Carriage of Streptococcus Pneumoniae and Serotypes Indentified among Nursing Home Residents in Comparison to the Elderly and Patients Younger than 65 Years Living in Domestic Environment

INTRODUCTION

In Slovenia, there is little data available on pneumococcal vaccination rates and no data on asymptomatic NPCR and serotypes in the population of nursing home residents in comparison to the elderly living in domestic environment, therefore the goal was to gain these data.

METHODS

A cross sectional epidemiological study was performed. Nasopharyngeal swabs from 151 nursing home residents, 150 elderly living in domestic environment, and 38 adults less than 65 years old were collected twice (in two consecutive years). The swabs were analysed for pneumococcal identification and serotyping. Patient data were collected from medical files and medical history.

RESULTS

No statistically significant differences in NPCR were seen between compared groups in two consecutive years. An average NPCR in two consecutive years in nursing home residents was 1.45%, in the elderly living in domestic environment 0.85%, and in adults less than 65 years old 7.05%. Serotypes identified among nursing home residents were 6B and 9N, among the group of elderly living in domestic environment, 6A and among adults less than 65 years old, 35F, 18C and 3. Pneumococcal vaccination rates were low (3.3% in nursing home residents, 6% in the elderly from domestic environment and 0% in the group of adults less than 65 years old).

CONCLUSIONS

Our data suggests that NPCR and the proportion of people vaccinated with pneumococcal vaccine among the elderly are low. We identified different serotypes in all groups, only one person was a chronic carrier (serotype 35F).

Pneumococcal Capsular Polysaccharide Immunity in the Elderly

Immunity to pneumococcal infections is impaired in older people, and current vaccines are poorly protective against pneumococcal disease in this population. Naturally acquired immunity to pneumococcal capsular polysaccharides develops during childhood and is robust in young adults but deteriorates with advanced age. In particular, antibody levels and function are reduced in older people. Pneumococcal vaccines are recommended for people >65 years old. However, the benefits of polysaccharide and protein-conjugated vaccines in this population are small, because of both serotype replacement and incomplete protection against vaccine serotype pneumococcal disease. In this review, we overview the immune mechanisms by which naturally acquired and vaccine-induced pneumococcal capsular polysaccharide immunity declines with age, including altered colonization dynamics, reduced opsonic activity of antibodies (particularly IgM), and impaired mucosal immunity.