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Infection with human immunodeficiency virus type I (HIV-I) is characterized by the progressive deterioration of the immune and nervous systems and disorders of the blood, heart, lungs, kidneys, and gastrointestinal tract. The replication of HIV leads to high levels of the virus in the blood, and enhances the transmission and development of the disease. Studies show that HIV-I infects the CD4+ lymphocytes, a type of immune cell, in blood and brain cells derived from monocytes, a type of white blood cell. Increases in the number of infected cells and the quantity of viral DNA produced are associated with progression of HIV disease. HIV p24 antigen is a measure of HIV-1 replication and can be detected in the early stages of HIV disease and when there are low numbers of CD4+ cells. The presence of cell-free HIV in the blood (virus not associated with cells) is also a measure of HIV-1 replication and was shown to increase in relation to elevations in p24 antigen levels and disease progression. The relations between levels of cell-free HIV in the blood, patient age at diagnosis, number of CD4+ lymphocytes, indicators of HIV infection, clinical stage of disease, and response to antiviral agents were assessed in 68 adults and 9 children with HIV-I infection. Viremia, or the presence of cell-free HIV in the blood, had developed in 18 of 68 adults and 5 of 9 children. Among the adults, viremia was detected in none of the patients without symptoms; 4 of 34 patients with AIDS-related complex (ARC); and 14 of 15 patients with AIDS. Patients with CD4+ lymphocyte numbers greater than 400 per cubic millimeter had no viremia, whereas cell-free HIV was detected in the blood of 3 of 17 patients with CD4+ counts between 200 to 400 per cubic millimeter and 15 of 16 patients with less than 200 CD4+ lymphocytes per cubic millimeter. All children infected with HIV during pregnancy or childbirth developed viremia regardless of the number of CD4+ cells, duration of infection, or clinical stage. Viremia was less prevalent among children infected at an older age. The antiviral agent zidovudine was effective in decreasing the amount of cell-free HIV in eight patients. (Consumer Summary produced by Reliance Medical Information, Inc.)

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IMPORTANCE: Most studies examining the association of prenatal antiretroviral (ARV) exposures with congenital anomalies (CAs) in children born to human immunodeficiency virus (HIV)–infected women have been reassuring, but some evidence suggests an increased risk with specific ARV agents. OBJECTIVE: To evaluate the association of in utero ARV exposures with CAs in HIV-exposed uninfected children. DESIGN, SETTING, AND PARTICIPANTS: Prospective cohort study design. The Pediatric HIV/AIDS Cohort Study’s Surveillance Monitoring of ART Toxicities (SMARTT) Study was performed at 22 US medical centers among 2580 HIV-exposed uninfected children enrolled in the SMARTT Study between March 23, 2007, and June 18, 2012. EXPOSURES: First-trimester exposure to any ARV and to specific ARV medications. MAIN OUTCOMES AND MEASURES: The primary end point was a CA based on physician review of infant physical examinations according to the Antiretroviral Pregnancy Registry modification of the Metropolitan Atlanta Congenital Defects Program. Rates of CAs were estimated overall and by birth year. Logistic regression models were used to evaluate the association of CAs with first-trimester ARV exposures, adjusting for demographic and maternal characteristics. RESULTS: Congenital anomalies occurred in 175 of 2580 children, yielding a prevalence of 6.78% (95% CI, 5.85%-7.82%); 242 major CAs were confirmed, including 72 musculoskeletal and 55 cardiovascular CAs. The prevalence of CAs increased significantly among successive birth cohorts (3.8% for children born before 2002 and up to 8.3% for those born 2008-2010). In adjusted models, no association of first-trimester exposures with CAs was found for any ARV, for combination ARV regimens, or for any drug class. No individual ARV in the reverse transcriptase inhibitor drug classes was associated with an increased risk of CAs. Among protease inhibitors, higher odds of CAs were observed for atazanavir sulfate (adjusted odds ratio [aOR], 1.95; 95% CI, 1.24-3.05) and for ritonavir used as a booster (aOR, 1.56; 95% CI, 1.11-2.20). With first-trimester atazanavir exposure, risks were highest for skin (aOR, 5.23) and musculoskeletal (aOR, 2.55) CAs. CONCLUSIONS AND RELEVANCE: Few individual ARVs and no drug classes were associated with an increased risk of CAs in HIV-exposed infants after adjustment for calendar year and maternal characteristics. While the overall risk remained low, a relative increase was observed in successive years and with atazanavir exposure. Given the low absolute CA risk, the benefits of recommended ARV therapy use during pregnancy still outweigh such risks, although further studies are warranted.

ABSTRACTThe 13-valent pneumococcal conjugate vaccine (PCV13) was introduced in the United States in 2010 for the prevention of invasive pneumococcal disease (IPD) and otitis media. While many studies have reported its potential efficacy for IPD, not much is known about the epidemiology of noninvasive disease following its introduction. We characterized the capsular types and surface protein genes of noninvasive pediatric pneumococcal isolates collected between 2002 and 2010 (n= 1,058) at Children's of Alabama following the introduction of PCV7 and tested a subset of noninvasive and previously characterized IPD isolates for the presence of the pspA, pspC, and rrgCgenes, which encode protection-eliciting proteins. PCV7 serotypes had dramatically decreased by 2010 (P< 0.0001), and only 50% of all noninvasive infections were caused by the PCV13 capsular serotypes. Serotype 19A accounted for 32% of the noninvasive isolates, followed by serotypes 35B (9%), 19F (7%), and 6C (6%). After 7 years of PCV7 usage, there were no changes in the frequencies of the pspAor pspCgenes; 96% of the strains were positive for family 1 or 2 pspAgenes, and 81% were also positive for pspC. Unexpectedly, more noninvasive than invasive strains were positive for rrgC(P< 0.0001), and the proportion of rrgC-positive strains in 2008 to 2010 was greater than that in 2002 to 2008 (IPD, P< 0.02; noninvasive, P< 0.001). Serotypes 19F, 19A, and 35B were more frequently rrgCpositive (P< 0.005) than other serotypes. A vaccine containing antigens, such as PspA, PspC, and/or RrgC, can provide coverage against most non-PCV13-type pneumococci. Continued surveillance is critical for optimal future vaccine development.

ABSTRACTPneumococcal conjugate vaccines (PCVs) are recommended for the prevention of invasive pneumococcal disease (IPD) in young children. Since the introduction of the heptavalent pneumococcal vaccine (PCV7) in 2000, IPD caused by serotypes in the vaccine has almost been eliminated, and previously uncommon capsular serotypes now cause most cases of pediatric IPD in the United States. One way to protect against these strains would be to add cross-reactive protein antigens to new vaccines. One such protein is pneumococcal surface protein A (PspA). Prior to 2000, PspA families 1 and 2 were expressed by 94% of isolates. Because PCV7 vaccine pressure has resulted in IPD caused by capsular serotypes that were previously uncommon and unstudied for PspA expression, it was possible that many of the new strains expressed different PspA antigens or even lacked PspA. Of 157 pediatric invasive pneumococcal isolates collected at a large pediatric hospital in Alabama between 2002 and 2010, only 60.5% had capsular serotypes included in PCV13, which came into general use in Alabama after our strains were collected. These isolates included 17 serotypes that were not covered by PCV13. Nonetheless, pneumococcal capsular serotype replacement was not associated with changes in PspA expression; 96% of strains in this collection expressed PspA family 1 or 2. Continued surveillance will be critical to vaccine strategies to further reduce IPD.

To estimate the prevalence of elevated point-of-care (POC) capillary blood lactate concentrations in human immunodeficiency virus (HIV)-exposed, uninfected children (HEU) and to determine if POC lactate varies with in utero antiretroviral (ARV) exposure.

ABSTRACTWe characterized 32 levofloxacin-nonsusceptible Streptococcus pneumoniae(LNSP) isolates obtained from a broad geographic region of North America over a 5-year period by using capsular serotypes, antimicrobial susceptibility profiles, BOX-PCR, multilocus sequence typing (MLST), and pulsed-field gel electrophoresis (PFGE). Sixteen international clones identified by the Pneumococcal Molecular Epidemiology Network also were included for comparison. Fifteen serotypes were represented, with serogroups 6, 9, 14, 19, and 23 accounting for 63% of isolates. Among isolates whose quinolone resistance-determining regions were sequenced, all contained gyrAand parCpoint mutations. Sixty-three percent were penicillin susceptible, and 84% were erythromycin susceptible. BOX-PCR analysis identified 39 different band patterns among 32 LNSP and 16 international clones and grouped 16 isolates, including 2 international clones, into seven unrelated groups of 2 to 4 isolates each. PFGE analysis identified 35 different band patterns among 32 LNSP and 16 international clones and grouped 21 isolates, including 3 international clones, into eight unrelated groups of 2 to 6 isolates each. MLST performed on 10 isolates identified five allelic profiles and separated 9 isolates into four groups of 2 to 3 isolates each. Overall, each typing method indicated that the LNSP were heterogeneous and that resistance to fluoroquinolones was not closely associated with a particular serotype or with coresistance to other antimicrobial classes and suggests that LNSP have likely arisen through independent mutational events as a result of selective pressure. However, seven LNSP were found to be related to three international clones by PFGE.

An aggressive therapeutic approach for treatment of HIV in adults consists of combining five or more concurrent antiretrovirals. The clinical benefits of this regimen are often accompanied by increased toxicities. We report the safety and tolerance of multiple drug therapy in HIV-infected children.

ABSTRACTWe studied 198 macrolide-resistant S. pneumoniaeisolates obtained from adults and children to evaluate whether 2-µg clindamycin disks can distinguish between isolates manifestingermB- versus mefE-mediated resistance to clarithromycin and to determine the relative frequency with which each resistance mechanism occurred in these populations. ThemefEgene was predominant among 109 isolates from children, occurring in 73.4% versus 50.6% of 89 isolates from adults. Three isolates (1.5%) did not amplify either gene. Among 125mefE+isolates, the MIC of clarithromycin at which 90% of the isolates tested were inhibited, determined by Etest, was 32 µg/ml versus >256 µg/ml in 70 ermB+isolates. All ermB+isolates were highly resistant to clindamycin (MICs >256 µg/ml), whereas all mefE+isolates were susceptible to clindamycin using the 2-µg disk. Testing S. pneumoniaefrom the respiratory tract for susceptibility to clindamycin by agar disk diffusion is an easy and inexpensive method to estimate the frequency of resistance mediated by ermBin specific patient populations. Macrolide resistance mediated by ermBis usually of greater magnitude than that due to mefE. Clinical studies are needed to determine the significance of high- versus low-level macrolide resistance in S. pneumoniae.

Abstract.: The phylogenetic utility of the IS1167 insertion sequence was examined with restriction fragment length polymorphism (RFLP) analyses of a sample of 50, predominantly invasive, capsular serotype 6B Streptococcus pneumoniae isolates previously characterized by multilocus enzyme electrophoresis (MLEE). The strains represented a genetically diverse assemblage of 34 distinct clonotypes composed of 26 restriction fragment types and 23 multilocus enzyme types. All isolates carried the IS1167 insertion sequence, with an average of 9.5 copies. The cross-classification of isolates based on RFLP and MLEE typing schemes was 81% concordant. Phylogenetic analyses demonstrated a significant (P < 0.0001) association between strains of a given RFLP lineage with those of a given MLEE lineage. A significant correlation (P < 0.00004) was also found between the proportion of restriction fragments shared by any given pair of isolates and their genetic distances estimated from the MLEE data. Parity between the two genetic markers implied that the sampled isolates were in linkage disequilibrium. The existence of nonrandom associations among genetic loci was confirmed by Monte Carlo analyses of the MLEE data. These studies, thus, demonstrated that invasive pneumococcal isolates of a single capsule type recovered on a regional scale can retain a largely clonal population structure over a period of 8 years. The ability to detect linkage disequilibrium and generate relatively congruent dendrograms based on distance and parsimony methods suggested that the restriction fragment data were robust to phylogenetic analysis.

Pneumococcal surface protein A (PspA) has been shown to be a serologically variable virulence factor ofStreptococcus pneumoniae.In mice, PspA can elicit antibodies capable of protecting them against otherwise fatal infections with encapsulated pneumococci. In previous studies it has been reported that almost all isolates have two apparently unlinked genomic sequences that are highly homologous to the 5′ and 3′ halves of Rx1pspA, although out MAbs to PspA have not detected more than one PspA in any given isolate ofS. pneumoniae.Recently, we have identified four isolates from a clone of capsular serotype 6B pneumococci (MC25-28) that simultaneously express two distinct PspAs. Each of the isolates (MC25-28) exhibited the same twoKpnI fragments (each containing aHind III site) that hybridized with Rx1pspA. MAbs specific for PspA detected two PspAs characterized by different molecular weights and different serologic patterns of reactivity (PspA type 6 detected by MAbs XiR278 and 2A4, and PspA type 34 detected only by MAb 7D2) in each of the four isolates. In previous studies XiR278 and 2A4 frequently have been observed to react with PspA epitopes of the same strain. Based on molecular weight data both epitopes were always present on the same molecule. Our present findings raise the possibility that pneumococci make a second serologically variable PspA which is generally not detected by currently available MAbs to PspA.

SUMMARYStreptococcus pneumoniae is a problematic infectious agent, whose seriousness to human health has been underscored by the recent rise in the frequency of isolation of multidrug-resistant strains. Pneumococcal pneumonia in the elderly is common and often fatal. Young children in the developing world are at significant risk for fatal pneumococcal respiratory disease, while in the developed world otitis media in children results in substantial economic costs. Immunocompromised patients are extremely susceptible to pneumococcal infection. With 90 different capsular types thus far described, the diversity of pneumococci contributes to the challenges of preventing and treating S. pneumoniae infections. The current capsular polysaccharide vaccine is not recommended for use in children younger than 2 years and is not fully effective in the elderly. Therefore, innovative vaccine strategies to protect against this agent are needed. Given the immunogenic nature of S. pneumoniae proteins, these molecules are being investigated as potential vaccine candidates. Pneumococcal surface protein A (PspA) has been evaluated for its ability to elicit protection against S. pneumoniae infection in mouse models of systemic and local disease. This review focuses on immune system responsiveness to PspA and the ability of PspA to elicit cross-protection against heterologous strains. These parameters will be critical to the design of broadly protective pneumococcal vaccines.

Children <2 years old living in the Yukon-Kuskokwim Delta (YKD) region of Alaska have one of the highest pneumococcal bacteremia rates of in the world.

Diseases caused by Streptococcus pneumoniaehave a high impact in young children whose ability to mount antibodies to capsular polysaccharides is impaired. Pneumococcal surface protein A (PspA) is a potential vaccine candidate for this age group.

Examination of several hundred penicillin-resistant clinical isolates of Streptococcus pneumoniae has revealed extensive strain-to-strain variation in the number and molecular size of penicillin-binding proteins (PBPs), This polymorphism has been used to classify resistant isolates into groups (PBP families) that share distinct electrophoretic profiles, We describe herein properties of four such PBP families: two from Spain (and/or Ohio) and one each from Hungary and Alaska. We have discovered that representative isolates assigned to each PBP family also share capsular serotype, antibiotic resistance pattern, pneumococcal surface protein A type, and multilocus enzyme genotype. The results demonstrate independent clonal origin for strains assigned to each PBP family. Each resistant clone occurs with uniquely high incidence within specific geographic areas.

Naturally occurring antibodies reactive with the phosphocholine (PC) determinant of pneumococcal teichoic acids may be useful for evaluating the potential of patients to make antibodies to polysaccharides. Antibodies to PC are present in most adults under the age of 60 years, are absent in very young children, and are present at low levels in WiscottAldrich patients and in IgG2-deficient adults. These last three groups respond very poorly to polysaccharide antigens. Antibodies to PC are also found at low levels in the elderly, a group that has previously been shown to have low levels of antibody to blood groups A and B carbohydrates. The levels of antibody to PC over time were constant in most individuals and, in adults, seemed to show slightly less variation than did titers of antibody to blood group B. Our findings suggest that titers of antibody to PC may be superior to titers of antibody to blood group A or B for monitoring responsiveness to carbohydrate antigens.

Previous studies have suggested that relatively penicillin-resistant (RPR) capsular group 9L strains in western Canada may be clonally related. To test this hypothesis, restriction fragment length polymorphisms (RFLPs) were examined using DNA probes for pspA and a newly recognized pneumococcal genetic element, IS1167. Penicillin-binding proteins (PBPs) and PBP genes from representative strains were also studied. All RPR type 9L strains demonstrated an identical RFLP when probed with IS1167, and 12 of 14 RPR strains had the same RFLP when examined with pspA. Amplification of pspA by polymerase chain reaction and restriction endonuclease digestion showed that the 9L strains had common DNA fragments not identified in any of the penicillin-susceptible strains. The 9L strains apparently have a low-affinity PBP 2B distinct from those of other capsular types. These data derived from new genetic markers and PBP analysis strongly support a clonal origin of RPR type 9L pneumococci of western Canada.

The relationships among capsular type, protein type, and penicillin resistance for capsular group 9 Streptococcus pneumoniae collected in northwestern Canada between 1974 and 1987 were examined. The group 9 relatively penicillin-resistant (RPR) isolates were of the rare 9L capsular type. Of 47 penicillin-susceptible (PS) group 9 isolates that were typed for capsule, only 1 was 9L. Among 29 PS group 9 isolates that were protein typed, 9 protein types were observed. Of the 70 RPR isolates, 51 were protein type P23, 1 was P19, and 18 could not be typed (PO). Protein types P23 differed from PObya single epitope on pneumococcal surface protein A. These results suggest that the Canadian P23 and POcapsular group 9 isolates are likely subclones of a primordial 9L RPR strain.