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Low Pneumococcal Colonization Rate in HIV+ Adults in PCV-13 Vaccine Era
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IDSA/IDWeek 2015, October 7-11, San Diego
Mark Mascolini
Pneumococcal colonization and nasal carriage rates proved low in HIV-positive adults after introduction of the 13-valent pneumococcal conjugate vaccine (PCV-13) for children in studies from Syracuse, New York [1] and Norfolk, Virginia [2].
HIV-positive adults run a 35-fold higher risk of invasive pneumococcal disease (IPD) than the general population, noted researchers at the Eastern Virginia Medical School [2]. US authorities added PCV-13 to the childhood vaccination scheduled in 2010 and recommended PCV-13 for HIV-positive adults in 2012. The Syracuse and Norfolk teams undertook these studies to determine whether those recommendations have affected pneumococcal colonization or nasal carriage in adults with HIV.
The Syracuse study, conducted by researchers from the State University of New York Upstate Medical Center, involved 414 HIV-positive adults seen at a designated AIDS center between December 2013 and March 2015 [1]. Three quarters of the group (73%) were men and median age measured 48 years. Most people (94%) were taking antiretroviral therapy, and 10% were taking sulfamethoxazole/trimethoprim prophylaxis. About half of the study group (51%) had a comorbidity that raised the risk of IPD. Twelve people (3%) had received PCV-13 and 220 (53%) had got the pneumococcal polysaccharide vaccine-23.
Pneumococcus could be isolated from only 18 of 707 nasopharyngeal samples (2.5%) in 15 of 414 participants (3.6%). Respiratory symptoms proved more likely in people with than without pneumococcal colonization (46% versus 27%, P = 0.02). But colonization was not linked to gender, race, comorbidities, antibiotic use, smoking, alcohol use, intravenous drug use, children in the household, vaccine status, absolute neutrophil count, CD4 count, or viral load.
The researchers concluded that "current pneumococcal colonization rates in HIV-infected adults are below historical rates suggesting reduction due to the widespread use of PCV-13" [1].
The Norfolk study involved 155 adults with well-controlled HIV infection (median CD4 count 606) who received or were scheduled to receive PCV-13 at the Eastern Virginia Medical School HIV clinic in 2013 or 2014 [2]. Health workers collected nasal swabs from 105 people just before they got PCV-13, from 100 of these people 4 to 6 weeks later, and from 50 additional people 11 to 13 months after PCV-13 vaccination.
One of 255 nasal swabs (0.4%) from 155 people (0.6%) grew pneumococcus. The single person with nasal carriage of pneumococcus had received the PCV-13 vaccine 1 year earlier, and the isolate detected was not among those covered by the vaccine.
The Virginia team concluded that pneumococcal nasal carriage rates are very low in adults with well-controlled HIV infection 3 years after PCV-13 went on the childhood vaccination schedule. Whether the adults had received PCV-13 themselves did not affect results. The researchers noted that further study is needed to see whether introduction of PCV-13 has affected IPD rates in this adult population.
References
1. Feola F, Bonville C, Cibula D, et al. Nasopharyngeal colonization with pneumococci in HIV-infected adults following the introduction of pneumococcal conjugate vaccine-13 in children. IDWeek 2015, October 7-11, San Diego. Abstract 1693. https://idsa.confex.com/idsa/2015/webprogram/Paper50891.html
2. Jaghori F, Siik J, Rossheim A, Troy S. Pneumococcal nasal carriage in HIV-infected adults in the post-PCV-13 era. IDWeek 2015, October 7-11, San Diego. Abstract 1693. https://idsa.confex.com/idsa/2015/webprogram/Paper51694.html
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Reported by Jules Levin
Background: Before widespread use of pneumococcal conjugate vaccine (PCV) in children, 14-20% of HIV-infected adults were colonized with pneumococci. We characterized nasopharyngeal pneumococcal colonization among HIV-infected adults following the introduction of PCV-13.
Methods: HIV-infected adults seeking care at the Designated AIDS Center in Syracuse, NY between December 2013 and March 2015 were eligible. Following informed consent, an NP sample was collected, and patient demographics, medical and social history including risk factors for invasive pneumococcal disease (IPD) recorded. Pneumococci were identified from the samples using standard microbiologic techniques.
Results: 707 nasopharyngeal samples were collected from 414 HIV-infected adults; 301 (73%) were males. Mean and median ages were 46.3 and 48 years, respectively. 391 (94%) and 42 (10%) were taking anti-retroviral therapy and sulfamethoxazole/trimethoprim prophylaxis, respectively. In addition to HIV infection, 210 (51%) had another co-morbidity placing them at increased risk for IPD. 12 (3%) had received PCV-13 and 220 (53%) had received pneumococcal polysaccharide vaccine-23 as recommended. Pneumococcus was isolated from 18/707 (2.5%) of samples and from 15/414 (3.6%) of patients. Colonization status was not associated with gender, race, co-morbidities, antibiotic use, smoking, alcohol use, intravenous drug use, children in the household, vaccine status, absolute neutrophil count, CD4 count, or viral load, however, colonized adults were more likely to have respiratory symptoms than those who were not colonized (46% vs 27%, p=0.02).
Conclusion: Current pneumococcal colonization rates in HIV-infected adults are below historical rates suggesting reduction due to the widespread use of PCV-13. When present, colonization may be associated with respiratory symptoms.
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