Trends in mortality and antibiotic resistance among HIV-infected patients with invasive pneumococcal disease

Burden of Vaccine-Preventable Diseases in People Living with HIV

Vaccine-preventable diseases (VPDs) pose a serious public health concern for people living with HIV (PLH). PLH experience a delayed and weakened response to many vaccines available, compared to the general population. Lower seroconversion rates, along with a decreased efficacy and durability of vaccines, increases the susceptibility of PLH to VPDs. Vaccination guidelines specifically targeting this population have been modified to overcome these challenges. However, vaccine uptake remains suboptimal due to multiple barriers, highlighting the need for further studies and the additional implementation of public health measures specifically tailored to PLH.

Immunogenicity and Efficacy of Vaccination in People Living with Human Immunodeficiency Virus

People living with HIV (PLWH) remain at high risk of mortality and morbidity from vaccine-preventable diseases, even though antiretroviral therapy (ART) has restored life expectancy and general well-being. When, which, and how many doses of vaccine should be administered over the lifetime of PLWH are questions that have become clinically relevant. Immune responses to most vaccines are known to be impaired in PLWH. Effective control of viremia with ART and restored CD4+ T-cell count are correlated with an improvement in responsiveness to routine vaccines. However, the presence of immune alterations, comorbidities and co-infections may alter it. In this article, we provide a comprehensive review of the literature on immune responses to different vaccines in the setting of HIV infection, emphasizing the potential effect of HIV-related factors and presence of comorbidities in modulating such responses. A better understanding of these issues will help guide vaccination and prevention strategies for PLWH.

Burden of pneumococcal disease among adults in Southern Europe (Spain, Portugal, Italy, and Greece): a systematic review and meta-analysis

The aim was to summarize pneumococcal disease burden data among adults in Southern Europe and the potential impact of vaccines on epidemiology. Of 4779 identified studies, 272 were selected. Invasive pneumococcal disease (IPD) incidence was 15.08 (95% CI 11.01-20.65) in Spain versus 2.56 (95% CI 1.54-4.24) per 100,000 population in Italy. Pneumococcal pneumonia incidence was 19.59 (95% CI 10.74-35.74) in Spain versus 2.19 (95% CI 1.36-3.54) per 100,000 population in Italy. Analysis of IPD incidence in Spain comparing pre-and post- PCV7 and PCV13 periods unveiled a declining trend in vaccine-type IPD incidence (larger and statistically significant for the elderly), suggesting indirect effects of childhood vaccination programme. Data from Portugal, Greece and, to a lesser extent, Italy were sparse, thus improved surveillance is needed. Pneumococcal vaccination uptake, particularly among the elderly and adults with chronic and immunosuppressing conditions, should be improved, including shift to a higher-valency pneumococcal conjugate vaccine when available.

High rate of antimicrobial resistance and multiple mutations in the dihydrofolate reductase gene among Streptococcus pneumoniae isolated from HIV-infected adults in a community setting in Tanzania

OBJECTIVES

The aim of this study was to characterize molecular mechanisms of resistance to trimethoprim and other antibiotics in Streptococcus pneumoniae isolates from HIV-infected adults in Dar es Salaam, Tanzania.

METHODS

A total of 1877 nasopharyngeal swabs were collected and screened for pneumococcal colonization from 537 newly diagnosed individuals with HIV at four clinic visits during a 1-year follow-up from 2017-2018 as part of the randomized clinical trial CoTrimResist (ClinicalTrials.gov ID: NCT03087890).

RESULTS

A total of 76 pneumococcal isolates were obtained. Of the 70 isolates that could be serotyped, 42 (60.0%) were vaccine serotypes included in pneumococcal conjugate vaccine 23 (PCV23). The majority of isolates (73.7%; 56/76) were non-susceptible to penicillin (MICs of 0.06-2μg/mL). Isolates were frequently resistant to co-trimoxazole (trimethoprim/sulfamethoxazole) (71.1%) but less so to azithromycin (22.4%), erythromycin (21.1%), chloramphenicol (18.4%), tetracycline (14.5%), clindamycin (10.5%) and levofloxacin (0%). Moreover, 26.3% were multidrug-resistant (resistant to ≥3 antibiotic classes). Vaccine-type pneumococci were resistant to more classes of antibiotics, were more frequently resistant to erythromycin, azithromycin, clindamycin and tetracycline, and had higher MICs to penicillin (median, 0.19μg/mL; range, 0.002-1.5μg/mL) compared with non-vaccine serotypes (median, 0.125μg/mL; range, 0.012-0.25μg/mL) (P=0.003). Co-trimoxazole-resistant isolates carried from 1 to 11 different mutations in the dihydrofolate reductase (DHFR) gene, most commonly Ile100Leu (100%), Glu20Asp (91.8%), Glu94Asp (61.2%), Leu135Phe (57.1%), His26Tyr (53.1%), Asp92Ala (53.1%) and His120Gln (53.1%).

CONCLUSION

Streptococcus pneumoniae isolated from HIV-diagnosed patients were frequently non-susceptible to penicillin and co-trimoxazole. Most isolates carried multiple mutations in DHFR.

Incidence and Risk Factors for Invasive Pneumococcal Disease and Community-acquired Pneumonia in Human Immunodeficiency Virus-Infected Individuals in a High-income Setting

BACKGROUND

Although people living with human immunodeficiency virus (PLWH) are at increased risk of invasive pneumococcal disease (IPD) and community-acquired pneumonia (CAP), it is unclear whether this remains the case in the setting of early initiation of combination antiretroviral therapy (cART), at high CD4 cell counts. This is important, as pneumococcal vaccination coverage in PLWH is low in Europe and the United States, despite longstanding international recommendations.

METHODS

We identified all CAP and IPD cases between 2008 and 2017 in a cohort of PLWH in a Dutch HIV referral center. We calculated incidence rates stratified by CD4 count and cART status and conducted a case-control study to identify risk factors for CAP in PLWH receiving cART.

RESULTS

Incidence rates of IPD and CAP in PLWH were 111 and 1529 per 100 000 patient-years of follow-up (PYFU). Although IPD and CAP occurred more frequently in patients with CD4 counts <500 cells/μL (incidence rate ratio [IRR], 6.1 [95% confidence interval, 2.2-17] and IRR, 2.4 [95% confidence interval, 1.9-3.0]), the incidence rate in patients with CD4 counts >500 cells/μL remained higher compared with the general population (946 vs 188 per 100 000 PYFU). All IPD isolates were vaccine serotypes. Risk factors for CAP were older age, CD4 counts <500 cells/μL, smoking, drug use, and chronic obstructive pulmonary disease.

CONCLUSIONS

The incidence of IPD and CAP among PLWH remains higher compared with the general population, even in those who are virally suppressed and have high CD4 counts. With all serotyped IPD isolates covered by pneumococcal vaccines, our study provides additional argumentation against the poor current adherence to international recommendations to vaccinate PLWH.

Pneumococcal vaccination in adult people living with HIV on suppressive antiretroviral therapy: a case-control study

There is little information on the effectiveness of the pneumococcal vaccines (PVs), especially for the pneumococcal conjugate vaccines (PCVs), in HIV-infected patients in the modern antiretroviral era. This is a case–control study where cases were people living with HIV (PLWH) with confirmed pneumococcal infection (CPI) and controls were PLWH without CPI matched with cases by gender and year of HIV diagnosis. The selection process was blinded to the study factor (vaccination). Sample size estimation yielded 61 cases and 183 controls. We analyzed the effect of PV on CPI using Cox proportional-hazards regression model with time-dependent covariates. We included 256 subjects: 64 cases, and 192 controls. PVs had been administered to 115 (45%) patients. Only the modified Charlson Comorbidity Index (HR 1.16, 95%CI 1.06–1.27, P = 0.001) and the CD4 nadir (HR 0.99, 95% CI 0.98–0.99, P = 0.001) were independently associated with CPI. Receipt of PV was not associated with CPI after adjusting in the multivariate model with time protection as a dependent covariate (HR 0.65, 95% CI 0.35–1.32 P = 0.250). We also investigated the influence of different immunization schedules. In an adjusted model, we found no evidence of protection against CPI, including double immunization schedules (HR 0.42 95%CI 0.15–1.19 P = 0.102). In this case–control study, we could not show an association between pneumococcal vaccination and confirmed pneumococcal infection, although a protective effect of particular schedules of immunization cannot be ruled out.

Immunogenicity and safety of 13-valent pneumococcal conjugate vaccine in HIV-infected adults in the era of highly active antiretroviral therapy: analysis stratified by CD4 T-cell count

HIV-infected patients are 30- to 100-fold more susceptible to invasive pneumococcal diseases than are healthy adults. Pneumococcal vaccination may be the best way to decrease the large pneumococcal disease burden, but the optimal timing of vaccination is still unclear. In this study, HIV-infected subjects aged ≥18 years were recruited and divided into 2 age-matched groups: group 1 (subjects with CD4 T-cell count ≥350 cells/µL) and group 2 (CD4 T-cell count <350 cells/µL). Multiplex opsonophagocytic killing assay was used to compare immunogenicity after immunization with 13-valent pneumococcal conjugate vaccine (PCV13). Among 70 subjects, 67 (group 1, N = 34; group 2, N = 33) were available for the assessment of immunogenicity and safety. With respect to the post-vaccination geometric mean titer (GMT) ratios, the non-inferiority criteria were not met. Post-vaccination GMTs were significantly lower in group 2 compared to group 1 for all 4 pneumococcal serotypes (5, 6B, 18C, and 19A) tested. PCV13 was safe and well tolerated in HIV-infected patients irrespective of immune status. In conclusion, PCV13 showed significantly inferior immunogenicity among HIV-infected patients with CD4 T-cell count <350 cells/µL compared to those with a higher CD4 T-cell count.

Incidence of invasive pneumococcal disease in immunocompromised patients: A systematic review and meta-analysis

BACKGROUND

Invasive pneumococcal disease (IPD) is associated with high morbidity and mortality, with immunocompromised patients (ICPs) at particular risk. Therefore, guidelines recommend pneumococcal vaccination for these patients. However, guidelines are scarcely underpinned with references to incidence studies of IPD in this population. This, potentially results in unawareness of the importance of vaccination and low vaccination rates. The objective of this systematic review and meta-analysis was to assess the incidence of IPD in ICPs.

METHODS

We systematically searched PubMed and Embase to identify studies in English published before December 6th, 2017 that included terms related to 'incidence', 'rate', 'pneumococcal', 'pneumoniae', 'meningitis', 'septicemia', or 'bacteremia'. We focused on patients with HIV, transplantation and chronic inflammatory diseases.

RESULTS

We included 45 studies in the systematic review reporting an incidence or rate of IPD, defined as isolation of Streptococcus pneumoniae from a normally sterile site. Random effects meta-analysis of 38 studies showed a pooled IPD incidence of 331/100,000 person years in patients with HIV in the late-antiretroviral treatment era in non-African countries, and 318/100,000 in African countries; 696 and 812/100,000 in patients who underwent an autologous or allogeneic stem cell transplantation, respectively; 465/100,000 in patients with a solid organ transplantation; and 65/100,000 in patients with chronic inflammatory diseases. In healthy control cohorts, the pooled incidence was 10/100,000.

DISCUSSION

ICPs are at increased risk of contracting IPD, especially those with HIV, and those who underwent transplantation. Based on our findings, we recommend pneumococcal vaccination in immunocompromised patients.

PROSPERO REGISTRATION

ID: CRD42016048438.

Invasive pneumococcal disease (IPD) in HIV infected patients in Israel since the introduction of pneumococcal conjugated vaccines (PCV): Analysis of a nationwide surveillance study, 2009-2014

STUDY AIM

to assess the incidence, risk factors and outcome of invasive pneumococcal disease (IPD) among the Israeli HIV population. A matched case-control study nested in a nationwide, prospective, population-based, cohort of adult IPD was performed. In addition, the HIV-IPD patients were compared to the general adult HIV population in Israel.

STUDY PERIOD

from the introduction of PCV into the national immunization program (NIP) in July 2009 to June 2014. Each HIV patient within the IPD cohort was matched to 4 non-HIV controls. Serotyping was performed by a central laboratory using the Quellung reaction. Thirty-five IPD episodes in 33 HIV patients were identified, with a median annual incidence of 128/100,000 HIV+ persons compared to 5.1/100,000 in the age-matched, non-HIV population. Compared to the general HIV population, HIV-IPD patients practiced intravenous drug use more frequently and originated from a country with generalized epidemic (OGE), mainly non-citizens lacking medical insurance. The proportion of men who have sex with men (MSM) was lower than in the general HIV population. Pneumonia was the most common clinical presentation (81%), while meningitis occurred in only one patient. Outcomes were similar to those of the IPD non-HIV population. Nineteen serotypes were identified, of which only 42% were covered by PCV13 vaccine. By 2014, none of the HIV-IPD cases belonged to serotypes covered by PCV13. In conclusion, most HIV IPD cases were from marginalized populations with poor access to health services. A decrease in IPD cases covered by PCV 13 was observed.

Immunization of HIV-infected adult patients - French recommendations

Human immunodeficiency virus (HIV)-infected patients remain at increased risk of infection including vaccine-preventable diseases. Vaccines are therefore critical components in the protection of HIV-infected patients from an increasing number of preventable diseases. However, missed opportunities for vaccination among HIV-infected patients persist and vaccine coverage in this population could be improved. This article presents the French recommendations regarding immunization of HIV-infected adults in the light of the evidence-based literature on the benefits and the potential risks of vaccines among this vulnerable population.

Invasive Pneumococcal Disease Among HIV-Infected and HIV-Uninfected Adults in a Large Integrated Healthcare System

It is unclear whether HIV-infected individuals remain at higher risk of invasive pneumococcal disease (IPD) compared with HIV-uninfected individuals. We conducted a cohort study of HIV-infected and demographically matched HIV-uninfected adults within Kaiser Permanente Northern California during the period 1996-2011. We used Poisson models to obtain rate ratios (RRs) for incident IPD associated with HIV infection and other risk factors. Among 13,079 HIV-infected and 137,643 HIV-uninfected adults, the IPD rate per 100,000 person-years was 160 (n = 109 events) for HIV-infected and 8 (n = 75 events) for HIV-uninfected subjects, with an adjusted RR of 13.0 [95% confidence interval (CI): 9.1-18.7]. For HIV-infected individuals, IPD incidence per 100,000 person-years decreased by 71% during study follow-up, from 305 in 1996-1999 to 88 in 2010-2011 (p < 0.001), with an adjusted RR of 6.6 (95% CI: 2.7-16.1) compared with HIV-uninfected subjects in 2010-2011. Risk factors for IPD among HIV-infected individuals included black compared with white race/ethnicity, smoking, cancer, and higher HIV RNA levels. The 23-valent pneumococcal polysaccharide vaccination was not associated with a reduced risk of IPD in HIV-infected or HIV-uninfected individuals. Among HIV-infected IPD cases, the most common serotype was 19A (33%), and 59% of serotypes were covered by the 13-valent pneumococcal conjugate vaccine (PCV13). Despite a dramatic decline in IPD incidence for HIV-infected adults since 1996, IPD rates were nearly sevenfold higher compared with HIV-uninfected adults in recent years, even after adjustment for risk factors. Timely antiretroviral therapy initiation, risk reduction strategies, and recent guidelines recommending PCV13 use may further reduce IPD incidence among HIV patients.

Prevention and treatment of opportunistic infections and other coinfections in HIV-infected patients: May 2015

Despite the huge advance that antiretroviral therapy represents for the prognosis of infection by the human immunodeficiency virus (HIV), opportunistic infections (OIs) continue to be a cause of morbidity and mortality in HIV-infected patients. OIs often arise because of severe immunosuppression resulting from poor adherence to antiretroviral therapy, failure of antiretroviral therapy, or unawareness of HIV infection by patients whose first clinical manifestation of AIDS is an OI. The present article updates our previous guidelines on the prevention and treatment of various OIs in HIV-infected patients, namely, infections by parasites, fungi, viruses, mycobacteria, and bacteria, as well as imported infections. The article also addresses immune reconstitution inflammatory syndrome.

Pneumococcal vaccination among HIV-infected adult patients in the era of combination antiretroviral therapy

HIV-infected patients remain at higher risk for pneumococcal disease than the general population despite immune reconstitution and suppression of HIV replication with combination antiretroviral therapy. Vaccination with 23-valent pneumococcal polysaccharide vaccine (PPV23) composed of T-cell-independent antigens has been recommended to reduce the risk of pneumococcal disease in HIV-infected adults. However, given the heterogeneity of study design, execution and subjects enrolled, studies examining serological responses to PPV23 yielded conflicting results and observational studies of clinical effectiveness only provided moderate evidence to support the routine use of PPV23 in HIV-infected adults. Pneumococcal conjugate vaccine (PCV), with conjugation of the capsular polysaccharide to a protein carrier, is more immunogenic than PPV23 and has been demonstrated to protect against pneumococcal disease in HIV-infected children and recurrent invasive pneumococcal disease in HIV-infected adolescents and adults. Guidelines have recently been revised to recommend that HIV-infected patients aged 19 y or older receive one dose of 13-valent pneumococcal conjugate vaccine (PCV13) followed by a booster vaccination with PPV23. In this paper, we review the studies using different vaccination strategies to improve immunogenicity among HIV-infected adult patients.

Incidence and risk factors for invasive pneumococcal disease in HIV-infected and non-HIV-infected individuals before and after the introduction of combination antiretroviral therapy: persistent high risk among HIV-infected injecting drug users

BACKGROUND

Invasive pneumococcal disease (IPD) is an important cause of morbidity among individuals infected with human immunodeficiency virus (HIV). We described incidence and risk factors for IPD in HIV-infected and uninfected individuals.

METHODS

Nationwide population-based cohort study of HIV-infected adults treated at all Danish HIV treatment centers during 1995-2012. Nineteen population-matched controls per HIV-infected individual were retrieved. The risk of IPD was assessed using Poisson regression.

RESULTS

The incidence of IPD was 304.7 cases per 100 000 person-years of follow-up (PYFU) in HIV-infected and 12.8 per 100 000 PYFU in HIV-uninfected individuals. After adjusting for confounders, HIV infection (relative risk [RR], 24.4 [95% confidence interval [CI], 23.7-25.1]), male sex (RR, 1.20 [95% CI, 1.16-1.24]), increasing age (per year) (RR, 1.03 [95% CI, 1.03-1.04]), and calendar period (pre-cART RR, 2.80 [95% CI, 2.70-2.91] compared with late cART) were significantly associated with an increased risk of IPD. Among HIV-infected individuals, male sex (RR, 1.57 [95% CI, 1.49-1.66]), smoking (RR, 1.34 [95% CI, 1.26-1.42]), and injecting drug use (RR, 2.51 [95% CI, 2.26-2.67]) were associated with an increased risk of IPD. Detectable viral loads (RR, 1.88 [95% CI, 1.79-1.98]) and a relative fall in CD4 T-cell counts were also associated with an increased risk (≥500 to 350-500 CD4 T cells/µL: RR, 1.29 [95% CI, 1.21-1.37] and <100 cells/µL: RR, 7.4 [95% CI, 6.87-8.02]). The risk of IPD declined over time, although this was not the case for IDUs where the risk remained unchanged.

CONCLUSIONS

The incidence of IPD in HIV-infected individuals remained significantly higher than the incidence observed in non-HIV-infected subjects, despite the widespread use of cART. IDUs have a persistently high risk of IPD. Injecting drug use, smoking, and the receipt of cART are suitable targets for preventive measures in the future.

Vaccination coverage against hepatitis A and B viruses, Streptococcus pneumoniae, seasonal flu, and A(H1N1)2009 pandemic influenza in HIV-infected patients

BACKGROUND

Several vaccines are recommended in HIV-infected patients due to an increased risk of vaccine-preventable infections, severe forms of the disease, or shared transmission routes. Few data are available regarding vaccination coverage and its determinants in this population.

METHODS

A cross-sectional study was performed in HIV-infected patients included in a hospital-based cohort in 2011. Vaccination coverage against hepatitis A virus (HAV), hepatitis B virus (HBV), seasonal and A(H1N1)2009 pandemic influenza, and invasive pneumococcal diseases (IPD) were recorded. Factors associated with vaccination were assessed by multivariate logistic regression.

RESULTS

2467 patients were included (median age: 47 years; male gender 71.5%; men having sex with men (MSM): 43.9%; CDC stage C: 24.3%; HBV and/or hepatitis C virus co-infection: 14.4%). Median duration of HIV infection was 10 years and 93.1% of patients received combination antiretroviral therapy. At baseline, the median CD4 count was 527 cells/mm(3) and HIV viral load was <50 copies/mL in 83.3% of cases. Vaccination coverage for HBV, HAV, seasonal influenza, A(H1N1)2009 pandemic influenza, and IPD were 61.9%, 47.4%, 30.9, 48.3%, and 64.6%, respectively. Factors independently associated with vaccination were a younger (HBV) or an older age (influenza), male gender (HBV, HAV), MSM (HBV), CD4 count >200/mm(3) and HIV-RNA <50 copies/mL (IPD, influenza), longer duration of HIV infection (IPD, influenza), and follow-up by an experienced physician (HBV, IPD).

CONCLUSIONS

Vaccination coverage remained insufficient for all vaccine-preventable infections investigated in this study. Determinants for vaccination were largely not evidence-based, and efforts should be focused on improving physicians' knowledge about guidelines.

Systematic review of the indirect effect of pneumococcal conjugate vaccine dosing schedules on pneumococcal disease and colonization

BACKGROUND

To aid decision making for pneumococcal conjugate vaccine (PCV) use in infant national immunization programs, we summarized the indirect effects of PCV on clinical outcomes among nontargeted age groups.

METHODS

We systematically reviewed the English literature on infant PCV dosing schedules published from 1994 to 2010 (with ad hoc addition of 2011 articles) for outcomes on children >5 years of age and adults including vaccine-type nasopharyngeal carriage (VT-NP), vaccine-type invasive pneumococcal disease (VT-IPD) and syndromic pneumonia.

RESULTS

Of 12,980 citations reviewed, we identified 21 VT-IPD, 6 VT-NP and 9 pneumonia studies. Of these 36, 21 (58%) included 3 primary doses plus PCV or pneumococcal polysaccharide vaccine (PPV23) booster schedule (3+1 or 3+PPV23), 5 (14%) 3+0, 9 (25%) 2+1 and 1 (3%) 2+0. Most (95%) were PCV7 studies. Among observational VT-IPD studies, all schedules (2+1, 3+0 and 3+1) demonstrated reductions in incidence among young adult groups. Among syndromic pneumonia observational studies (2+1, 3+0 and 3+1), only 3+1 schedules showed significant indirect impact. Of 2 VT-NP controlled trials (3+0 and 3+1) and 3 VT-NP observational studies (2+1, 3+1 and 3+PPV23), 3+1 and 3+PPV23 schedules showed significant indirect effect. The 1 study to directly compare between schedules was a VT-NP study (2+0 vs. 2+1), which found no indirect effect on older siblings and parents of vaccinated children with either schedule.

CONCLUSIONS

Indirect benefit of a 3+1 infant PCV dosing schedule has been demonstrated for VT-IPD, VT-NP and syndromic pneumonia; 2+1 and 3+0 schedules have demonstrated indirect effect only for VT-IPD. The choice of optimal infant PCV schedule is limited by data paucity on indirect effects, especially a lack of head-to-head studies and studies of PCV10 and PCV13.

Impact of pneumococcal conjugate vaccines on nasopharyngeal carriage and invasive disease among unvaccinated people: review of evidence on indirect effects

BACKGROUND

Invasive disease due to Streptococcus pneumoniae remains an important worldwide cause of morbidity and mortality, particularly in young children and the elderly. The development and use of pneumococcal conjugate vaccines (PCVs) have had a dramatic impact on rates of vaccine-type invasive pneumococcal disease (IPD) not only in the pediatric population targeted for vaccination but in non-vaccinated age-groups as well. This indirect effect is directly mediated by a reduction of vaccine-type nasopharyngeal carriage and thus transmission by vaccinated children. Current PCV licensing procedures do not take into consideration nasopharyngeal carriage impact, and thus the indirect effect. This review summarizes the evidence for the indirect effect of PCV on vaccine-type disease and its correlation with changes in carriage among unvaccinated populations, to assess the basis for inclusion of carriage in the PCV licensing process.

METHODS

Randomized controlled trials, surveillance and other observational studies published between 1994 and 2013 were systematically identified from global, regional and review databases and conference abstracts. We included as primary evidence, studies in non-vaccinated groups addressing changes in both vaccine-type IPD and carriage between pre- and post-PCV introduction periods; studies missing one of these four components were included as supporting rather than primary evidence.

RESULTS

We identified studies from 14 countries, nearly all developed countries. Vaccine-type IPD and carriage in non-targeted populations consistently decreased after PCV introduction, with the magnitude of decrease growing over time. Where IPD and carriage were observed in the same population, VT-decreases occurred contemporaneously. These relationships held true across age-groups and between indigenous and non-indigenous populations in the US and Australia.

CONCLUSIONS

Indirect PCV impact on VT-IPD and VT-carriage has been significant. Impact on carriage should be considered for inclusion in the PCV licensure process as a predictor of indirect effects.

Pneumococcal infection--low awareness as a potential barrier to vaccination: results of a European study

INTRODUCTION

Elderly people and adults with chronic disease or compromised immune status are at increased risk of pneumococcal infection, with pneumonia being the most common serious presentation and a significant cause of morbidity and mortality. Most European countries have recommendations for pneumococcal vaccination but vaccination rates have remained low. In the present article, the authors present the results of a European survey that investigated the current level of awareness of pneumococcal infection among primary care physicians and specialists, and attitudes to vaccination in these physicians and members of the general public aged >50 years.

METHODS

Primary care physicians (n = 1,300) and specialists (n = 926) from 13 Western European countries participated in online/face-to-face interviews, and a further 6,534 individuals aged >50 years from a population sample reflecting local socio-demographic structure participated in telephone/face-to-face interviews.

RESULTS

Pneumonia was the most well-known of the pneumococcal infections amongst primary care physicians and specialists. However, there was a relatively low awareness of the term invasive pneumococcal disease (IPD), with only 50% of primary care physicians and 71% of specialists reporting knowledge of the term IPD. Key factors influencing a physician's decision to prescribe pneumococcal vaccination were the patient's health condition, recommendations from health authorities, and the tolerability of the vaccine. Perceptions regarding vaccination were good amongst the members of the general public; individuals did not fear vaccines or their side effects. The main drivers for vaccination were recommendations from a healthcare professional and, to a lesser extent, that vaccination provides reassurance against contracting a disease.

CONCLUSION

These findings highlight the low awareness of the term IPD in comparison with individual pneumococcal conditions. Given the importance of physician recommendations in encouraging patients to be vaccinated, primary care physicians need to be vigilant of patients at risk of pneumococcal infections in order to increase vaccination rates.

Invasive pneumococcal disease in HIV-infected adults in France from 2000 to 2011: antimicrobial susceptibility and implication of serotypes for vaccination

PURPOSE

Invasive pneumococcal diseases (IPD) remain frequent and severe events in human immunodeficiency virus (HIV)-infected subjects despite the use of antiretroviral therapy and the availability of vaccines. Our aim was to assess the antibiotic susceptibilities and serotypes of strains responsible for IPD in HIV-infected patients.

METHODS

We retrospectively analyzed all Streptococcus pneumoniae strains isolated from normally sterile sites between 2000 and 2011 in HIV-infected patients from a single reference center in Paris. The minimum inhibitory concentrations were determined by the E-test, and serotyping was performed by the antiserum agglutination method.

RESULTS

Among our study group, 41 HIV-infected adults presented 43 IPD during the study period. Of these 41 patients, 78 % were men, and the median age was 43 (range 23-62) years. the median CD4 cell count was 184/mm(3) (6-1,090/mm(3)), 51 % were receiving antiretroviral therapy, and 24 % had plasma HIV-RNA levels of <400 copies/mL. Only two patients had received the pneumococcal polysaccharide 23-valent vaccine (PPV23). Isolates were susceptible to penicillin G, amoxicillin, and cotrimoxazole in 44, 70, and 59 % of cases, respectively, and were significantly less susceptible to these antibiotics than isolates in the French general population during the same period. Among the 27 strains serotyped, 18 different serotypes were observed, of which 19A, 14, 7F, and 6A were the most frequent. Serotype distribution was similar to that in the French general population. The PPV23 vaccine and the 13-valent conjugate vaccine (PCV13) would have theoretically covered 78 and 70 % of cases, respectively.

CONCLUSIONS

In our HIV-infected patient cohort, S. pneumoniae isolates demonstrated higher levels of resistance to beta-lactamines and cotrimoxazole than in the French general population. HIV-infected patients should benefit from the herd protection effect expected from the large-scale vaccination of children by PCV13.

Comparison of serologic responses to vaccination with one dose or two doses of 7-valent pneumococcal conjugate vaccine in HIV-infected adult patients

BACKGROUND

Vaccination with 7-valent pneumococcal conjugate vaccine (PCV) has been shown to decrease the incidence of recurrent invasive pneumococcal disease among HIV-infected adults in Africa. Longitudinal follow-up studies of serologic responses to different doses of 7-valent PCV are rarely performed in HIV-infected adult patients receiving combination antiretroviral therapy (cART).

METHODS

From October 2008 to June 2010, 115 CD4-matched pairs of HIV-infected patients aged ≥ 20 years who had no prior pneumococcal vaccination received one or two doses of 7-valent PCV. Anticapsular antibodies against 4 serotypes (6B, 14, 19F, and 23F) were examined at the 12th, 24th, 36th, and 48th week following vaccination. Significant antibody responses were defined as ≥ 2-fold increase in the IgG level plus a post-vaccination antibody level ≥ 1000 ng/ml.

RESULTS

The most common reported adverse effects were injection site soreness (19.3%) and pain (4.8%). Significant antibody response rate was highest for serotype 14, followed by 23F, 19F, and 6B in all of the four time points examined. At week 48, patients who received two doses of 7-valent PCV had a significantly higher response rate to serotype 6B (P=0.03) and 23F (P=0.01) than those who received one dose; moreover, the former group also had a higher response rate to at least one (P=0.03) and two serotypes (P=0.02) in intention-to-treat analysis than the latter group.

CONCLUSIONS

HIV-infected adult patients on cART who received two doses of 7-valent PCV achieved better serological responses to at least one serotype than those who received one dose during the 48 weeks of follow-up.

Invasive pneumococcal disease in HIV-infected adults: clinical changes after the introduction of the pneumococcal conjugate vaccine in children

BACKGROUND

Few data exist on the implications of widespread use of 7-valent pneumococcal conjugate vaccine in children in the invasive pneumococcal disease (IPD) in HIV-infected adults. We conducted a multicenter study to analyze differences in clinical presentation of IPD between HIV-infected and non-HIV-infected adults in the prevaccine and postvaccine era.

METHODS

Study of all cases of IPD in HIV-infected adults diagnosed since 1996 to 2010. Episodes were classified into prevaccine (1996-2001), early postvaccine (2002-2004), and late postvaccine period (2005-2010). For each case, we identified an HIV-negative control patient with IPD matched by hospital, age, and vaccine period.

RESULTS

Two hundred twenty-one episodes of IPD in HIV-infected patients were diagnosed. The incidence of IPD decreased from 7.81 to 3.69 episodes per 1000 patient-years (-53%; 95% confidence interval: -65% to -36%, P < 0.001) between prevaccine and late postvaccine period. There was an 81% (95% confidence interval: -88% to -69%, P < 0.001) decrease of IPD caused by vaccine serotypes. In late postvaccine period IPD in HIV-infected patients was associated to higher rates of respiratory failure (28.4% vs. 48.4%, P = 0.011), greater intensive care unit admission (8.2% vs. 21.7%, P = 0.02) and a higher need for mechanical ventilation (5.9% vs. 16.3%, P = 0.033). In the prevaccine period, non-HIV-infected patients had a more severe illness than in those with HIV infection; however, these differences disappeared in the late postvaccine period.

CONCLUSIONS

In the late postvaccine era, the incidence of IPD in HIV-infected patients has decreased, however, clinical presentation seems to have changed to a more severe illness. The widespread use of highly active antiretroviral therapy, polyssacharide vaccine, and 7-valent pneumococcal conjugate vaccine has contributed to these changes.

Invasive pneumococcal disease among HIV-positive individuals, 2000-2009

OBJECTIVES

To examine invasive pneumococcal disease (IPD) incidence, the impact of the 7-valent pneumococcal conjugate vaccines (PCV7s) programme on the distribution of Streptococcus pneumoniae serotypes and risk factors for IPD among HIV-positive adults.

METHODS

We analysed adults (aged ≥15 years) reported to the HIV and IPD national datasets in England and Wales (2000-2009). Through data-linkage, changes in IPD incidence and serotype distribution were examined. Risk factors for IPD among HIV-positive adults were assessed using a case-control study.

RESULTS

Among 63,109 HIV-positive adults, 951 were co-infected with IPD. The average annual incidence of IPD was 245 episodes per 100,000 HIV-positive adults and 246 of 100,000 among those aged 15-44 years. Incidence was higher among those not on antiretroviral therapy (ART) (281 of 100,000) and those with severe immunosuppression (563 of 100,000). Among 9283 adults aged 15-44 at IPD diagnosis, 2.4% were living with undiagnosed HIV. The proportion of IPD episodes in HIV-positive adults with serotypes covered by PCV7 was 23% in 2009, a 54% proportional reduction compared with pre-PCV7 (2000-2006); the reduction in adults of unknown HIV status was 70%. The proportion of IPD episodes among HIV-positive adults caused by serotypes covered by PCV13 was 61%. Significant risk factors for IPD in multivariate analysis included older aged (≥65 years), a lower nadir CD4 cell count and no previous ART.

CONCLUSION

An HIV test should be offered and recommended to adults aged 15-44 years without other obvious IPD risk factors. Our study provides an evidence base to policy makers regarding the use of the new PCV13 in HIV-positive adults.