Biomedical subjects

Michael Pichichero

Publications and source records attributed to Michael Pichichero.

9 recordsLinked to original sources

PubMed2006

A multicenter, open label, double tympanocentesis study of high dose cefdinir in children with acute otitis media at high risk of persistent or recurrent infection.

BACKGROUND: Given the relatively high prevalence of recurrent and persistent acute otitis media (AOM) and the prominent etiologic role of Streptococcus pneumoniae, especially penicillin-nonsusceptible strains in children with these conditions, new alternative treatments are desirable. METHODS: Children 6 months-4 years of age with AOM considered to be at risk for recurrent or persistent infection received large dosage cefdinir 25 mg/kg oral suspension once daily for 10 days. Children were evaluated pretreatment (day 1), on therapy (days 4-6), end of therapy (days 12-14) and at follow-up (days 25-28). All children had tympanocentesis at enrollment. In culture-positive children, tympanocentesis was repeated after 3-5 days (days 4-6) unless evidence of absence of middle ear effusion was documented. RESULTS: Of 447 children enrolled, 230 were clinically and bacteriologically evaluable (74% 2 years old or younger; 57% treated for AOM in previous 3 months). Bacteriologic eradication, based on repeat tympanocentesis on days 4-6, was achieved in 74% (170 of 230) of children; 76% (201 of 266) of AOM pathogens were eradicated. Eradication of penicillin-susceptible, -intermediate and -resistant S. pneumoniae was 91% (50 of 55), 67% (18 of 27) and 43% (10 of 23), respectively (P < 0.001); eradication of H. influenzae was 72% (90 of 125). Overall clinical response at days 12-14 was 83% (76 and 82% for children with S. pneumoniae and Haemophilus influenzae, respectively). Sustained clinical response at days 25-28 was 85%. Clinical response was 83% for culture-positive children versus 96% for culture-negative children at baseline tympanocentesis (P < 0.001). CONCLUSIONS: In this study of AOM among children at risk for persistent or recurrent infection, large dose cefdinir resulted in an overall successful clinical response at end of treatment of 83%. This regimen was efficacious against penicillin-susceptible S. pneumoniae, but effectiveness was markedly decreased against nonsusceptible strains and was moderate for H. influenzae strains.

Acute Disease↗

PubMed2006

Immune memory in children previously vaccinated with an experimental quadrivalent meningococcal polysaccharide diphtheria toxoid conjugate vaccine.

BACKGROUND: In a previous study, a meningococcal diphtheria toxoid conjugate vaccine (MCV-4) triggered robust bactericidal antibody responses against serogroups A, C, Y, and W-135 in 2- to 10-year-old children. A subset of participants, 2 to 3 years of age at the initial vaccination, was evaluated for persistence of antibody, immune memory, and antibody avidity. METHODS: Participants were healthy children vaccinated 23 to 36 months earlier with MCV-4 (primed) or newly recruited meningococcal vaccine-naive 4-year-olds. Participants in both groups were alternately allocated to provide sera 8 or 28 days after administration of one tenth of the recommended dose of a meningococcal polysaccharide vaccine (PSV-4). Immune responses were assessed in sera obtained at baseline and either 8 or 28 days after reduced-dose PSV-4 administration. Safety was monitored. RESULTS: Before PSV-4 challenge, serum bactericidal antibody geometric mean titers (SBA GMTs) were higher for all 4 serogroups in the MCV-4-primed group than in the vaccine-naive group. SBA GMTs, geometric mean concentrations of immunoglobulin G (IgG) and geometric mean avidity indices for all 4 serogroups were significantly higher among MCV-4-primed versus vaccine-naive participants in the cohorts evaluated at 8 or 28 days after PSV-4 challenge. Adverse events were generally mild, self-limited, and comparable in all groups of children. CONCLUSIONS: Persistence of bactericidal antibody was seen for 23 to 36 months after a primary dose of MCV-4 in young children. Booster responses and avidity maturation were evident after a challenge with reduced-dose polysaccharide vaccine.

Antibodies, Bacterial↗

PubMed2006

An open-label, double tympanocentesis study of levofloxacin therapy in children with, or at high risk for, recurrent or persistent acute otitis media.

BACKGROUND: Levofloxacin has excellent activity against common respiratory pathogens and therefore is likely to be effective in treating children with persistent or recurrent otitis media. OBJECTIVE: The objective of this study was to assess the efficacy and safety of levofloxacin treatment in the eradication of bacterial pathogens from the middle ear fluid (MEF) of children with, or at high risk for, persistent or recurrent otitis media. METHODS: An open-label multicenter trial was conducted that involved tympanocentesis at entry and selectively 3 to 5 days after starting levofloxacin (10 mg/kg twice a day for 10 days). RESULTS: : Two hundred five children (80% < or =2 years) were enrolled. One child did not have a confirmed diagnosis of acute otitis media and did not return for follow-up visits. Of the remaining 204 children, 94 (46%) had bilateral infection and 63 (31%) were receiving antimicrobials immediately before entry. One hundred five isolates of Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and Streptococcus. pyogenes were recovered in pure or mixed cultures. All isolates were susceptible to levofloxacin. During-treatment bacterial eradication from MEF occurred in 88% (78 of 89) of bacteriologically evaluable patients, including 90% (65 of 72) of children < or =24 months of age. Bacteria initially isolated from MEF were eradicated in 31 of 37 (84%) children infected with S. pneumoniae and in 54 of 54 (100%) children infected with H. influenzae. Overall, clinical success rate after therapy was 94% for the total study population and 92% for the bacteriologically evaluable population. Levofloxacin was well tolerated. Vomiting (4%) was the most common treatment-limiting adverse event. CONCLUSIONS: Levofloxacin was safe and effective in treating and eradicating common bacterial pathogens from MEF in children with, or at risk for, recurrent or persistent otitis media.

Acute Disease↗

PubMed2006

Immunogenicity and safety of an inactivated hepatitis A vaccine administered concomitantly with diphtheria-tetanus-acellular pertussis and haemophilus influenzae type B vaccines to children less than 2 years of age.

OBJECTIVE: The availability of a hepatitis A virus vaccine for infant and early childhood immunization could reduce the transmission of hepatitis A virus in the United States. This study evaluated the immunogenicity and safety of a hepatitis A virus vaccine (Havrix, GlaxoSmithKline Biologicals, Rixensart, Belgium) administered concomitantly with diphtheria-tetanus-acellular pertussis and Haemophilus influenzae type b vaccines to children < 2 years. METHODS: In this open, comparative, multicenter study, 1084 healthy children aged 11 to 25 months were allocated (4:4:3:3:4 ratio) to 5 treatment groups based on age and previous vaccination history. Subjects 11 to 13 months of age received 2 doses of hepatitis A virus vaccine 6 months apart (N = 243). Subjects aged 15 to 18 months received 2 doses of hepatitis A virus vaccine 6 months apart (N = 241); or hepatitis A virus vaccine, diphtheria-tetanus-acellular pertussis, and H influenzae type b at month 0 and the second dose of hepatitis A virus vaccine 6 months later (N = 183); or diphtheria-tetanus-acellular pertussis and H influenzae type b at month 0 and hepatitis A virus vaccine at months 1 and 7 (N = 175). Subjects 23 to 25 months of age received hepatitis A virus vaccine at months 0 and 6 (N = 242). Immune responses were measured at baseline and 30 days after vaccine doses, and solicited and unsolicited adverse events were collected. RESULTS: After 2 doses of hepatitis A virus vaccine, all of the subjects in all of the groups were seropositive. Coadministration of hepatitis A virus vaccine with diphtheria-tetanus-acellular pertussis and H influenzae type b vaccines did not impact the immunogenicity of the 3 vaccines, except for the antipertussis toxoid vaccine response, which was slightly decreased. Hepatitis A virus vaccine was well tolerated in children 11 to 25 months of age. CONCLUSION: The administration of 2 doses of hepatitis A virus vaccine on a 0- and 6-month schedule starting at 11 to 13 months of age or at 15 to 18 months of age was as immunogenic and well tolerated as the administration of 2 doses in children 2 years of age. Immune responses to diphtheria-tetanus-acellular pertussis and H influenzae type b either given alone or coadministered with hepatitis A virus vaccine were similar except for antipertussis toxoid response.

Antibody Formation↗

PubMed2006

Considerations in the use of antibiotics for streptococcal pharyngitis.

Microbiologic testing is recommended to diagnose GABHS pharyngitis and is required to maximize the selection of patients at highest risk of complications from true infection. The primary goal of therapy is eradication of GABHS. Penicillin has been the first-line treatment of choice for nonallergic patients; yet, there may be reason to reexamine the role of penicillin since there are now considerable data from clinical trials, pooled multicenter studies, and meta-analyses demonstrating frequent bacteriologic and clinical failure. While the contribution of pathogen resistance remains unclear, evolving evidence suggests that these failures also may be related to bacterial coaggregation or copathogenicity; GABHS reinfection; antibiotic nonadherence or subtherapeutic drug levels; penicillin tolerance; or blunting of an effective immune response. At the same time, some clinical evidence suggests that treatment failure with some cephalosporins may occur less frequently than with penicillin. Although cephalosporins are generally more expensive than oral penicillin, the benefits of cephalosporins include activity against BLPB and evolving data that support less frequent dosing than penicillin. Consequently, a reassessment of the role of cephalosporins in the treatment of pharyngitis may be appropriate.

Anti-Bacterial Agents↗

PubMed2005

Comparative trial of the safety and immunogenicity of quadrivalent (A, C, Y, W-135) meningococcal polysaccharide-diphtheria conjugate vaccine versus quadrivalent polysaccharide vaccine in two- to ten-year-old children.

BACKGROUND: A quadrivalent meningococcal diphtheria conjugate vaccine (MCV-4) has been developed to provide T-cell dependent immune responses against 4 major disease-causing serogroups (A, C, Y, W-135). METHODS: In a comparative, randomized, modified double blind, controlled study in healthy 2- to 10-year-old U.S. children, safety and immunogenicity profiles of MCV-4 (n = 696) were compared with those of a licensed quadrivalent polysaccharide vaccine, Menomune A/C/Y/W-135 (PSV-4, n = 702). Vaccine-related adverse reactions were assessed for 28-day and 6-month follow-up periods. Serum bactericidal activity (SBA) was assayed in prevaccination, day 28 and 6-month postvaccination sera samples. RESULTS: Both vaccines were well-tolerated, with no vaccine-related serious adverse events and similar rates of mostly mild local and systemic reactions. Functional antibody (SBA) seroconversion percentages were significantly higher for all 4 serogroups in the MCV-4 group. The SBA geometric mean titers against serogroups A, C, Y and W-135 with MCV-4 were 1700, 354, 637 and 750, respectively, compared with PSV-4 (893, 231, 408 and 426) 28 days postvaccination (P < 0.001 for all comparisons). This significant difference persisted through 6 months. CONCLUSIONS: In 2- to 10-year-old children MCV-4 had a safety profile similar to that of PSV-4 and elicited significantly higher and more persistent serum bactericidal antibody responses against meningococcal serogroups A, C, Y and W-135 than did the licensed polysaccharide vaccine.

Antibodies, Bacterial↗

PubMed2005

Randomized, investigator-blinded, multicenter, comparative study of gatifloxacin versus amoxicillin/clavulanate in recurrent otitis media and acute otitis media treatment failure in children.

BACKGROUND: Recurrent otitis media and acute otitis media treatment failure are commonly encountered in the pediatric population. OBJECTIVE: To compare the clinical efficacy of gatifloxacin with amoxicillin/clavulanate for the treatment of acute otitis media treatment failure and recurrent otitis media. METHODS: Three hundred fifty-four children 6 months-7 years with recurrent otitis media and/or acute otitis media failure were stratified according to age (younger than 2 years versus 2 years or older) and then randomly assigned to 10 days of treatment with gatifloxacin 10 mg/kg once daily or amoxicillin/clavulanate 90 mg/6.4 mg in 2 divided doses. Tympanocentesis was performed in 116 children with acute otitis media treatment failure and 52 with recurrent otitis media at study entry to validate the clinical diagnosis and provide microbiologic data. The primary outcome measure was clinical resolution of infection at the test-of-cure visit 3-10 days after completing treatment. RESULTS: Clinical resolution of acute otitis media was observed in 79.0% (49 of 62) of clinically evaluable children younger than 2 years and 90.3% (56 of 62) of those 2 years or older who were treated with gatifloxacin as compared with 77.6% (45 of 58) of children younger than 2 years and 79.7% (47 of 59) of children 2 years or older treated with amoxicillin/clavulanate. In patients with acute otitis media treatment failure, clinical response rates for children younger than 2 years and those 2 years or older were 87.5% (21 of 24) and 97.0% (32 of 33) with gatifloxacin versus 63.6% (14 of 22) and 83.9% (26 of 31) with amoxicillin/clavulanate. The corresponding clinical response rates in patients with recurrent otitis media were 79.2% (19 of 24) and 85.7% (18 of 21) with gatifloxacin and 90.5% (19 of 21) and 76.0% (19 of 25) with amoxicillin/clavulanate. Clinical success in those subjects having pretreatment middle ear fluid pathogens was similar for the 2 regimens [80.0% (24 of 30) gatifloxacin, 77.1% (27 of 35) amoxicillin/clavulanate]. Emergence of fluoroquinolone-resistant strains was not observed. Both drugs were generally well-tolerated. Diarrhea was the most common drug-related adverse event (10% gatifloxacin, 18% amoxicillin/clavulanate). No evidence of abnormal joint or gait findings was found during a 12-month follow-up. CONCLUSIONS: Gatifloxacin once daily is at least as effective and well-tolerated as amoxicillin/clavulanate twice daily in children with acute otitis media treatment failure or recurrent otitis media. There was no evidence of arthrotoxicity or emergence of fluoroquinolone-resistant bacteria in gatifloxacin-treated children.

Acute Disease↗

PubMed2004

Safety, efficacy, and immunogenicity of a live, quadrivalent human-bovine reassortant rotavirus vaccine in healthy infants.

OBJECTIVES: To investigate safety, efficacy, and immunogenicity of live quadrivalent rotavirus vaccine (QRV) containing human-bovine (WC3) reassortant rotavirus serotypes G1, G2, G3, and P1a. STUDY DESIGN: This was a randomized, double-blinded, placebo-controlled trial. During 1993 to 1994, at 10 US study sites, 439 healthy infants approximately 2 to 6 months of age, were enrolled to receive 3 doses of oral QRV or placebo at approximately 8-week intervals. RESULTS: The vaccine was generally well tolerated; no serious vaccine-related adverse experiences were reported. Risk differences and 95% confidence intervals suggested no differences between vaccine and placebo recipients in the incidences of fever, irritability, vomiting, or diarrhea during the 14 days after any dose. QRV was 74.6% efficacious (95% CI: 49.5%, 88.3%) in preventing rotavirus acute gastroenteritis (AGE), regardless of severity and 100% efficacious (95% CI: 43.5%, 100%) in preventing severe rotavirus AGE through one rotavirus season. Serotype G1 was identified in most infants with rotavirus AGE. A >or=3-fold rise in serum neutralizing antibody to G1 was observed in 57% (45/79) of vaccinees. A >or=3-fold rise in serum anti-rotavirus IgA and fecal anti-rotavirus IgA was observed in 88% (162/185) and 65% (104/159) of vaccinees, respectively. CONCLUSIONS: QRV was generally well tolerated, immungenic, and highly effective against rotavirus gastroenteritis.

Animals↗

PubMed2003

Non-interference between two protein carriers when used with the same polysaccharide for pneumococcal conjugate vaccines in 2-year-old children.

The carriers tetanus toxoid (T) and diphtheria CRM-197 (C) were compared in conjugate vaccines using identical coupling chemistry and polysaccharide (PS) loading, for safety and immunogenicity in 2-year-old children. Also tested were a mixture of halved doses of both carriers bearing the same PS serotypes. For this study, PS types 6A, 14, 19F, and 23F (separately) were coupled to T or C by reductive amination at PS/protein ratios of 0.50+/-0.18. With each carrier the four PS types were combined, giving the tetravalent vaccines "T-6, -14, -19, -23" or "C-6, -14, -19, -23" containing 50 microg of the carrier and roughly 20 microg total PS per ml of saline (no adjuvant). The children received primary (1') injections of 50 microg (protein) of either vaccine or a mixture of 25 microg of both; identical secondary (2') injections were given 2 months afterwards. Sera were taken before the 1' and 2' and 1 month post-2', and serum IgG responses to the four PS were determined by ELISA. For geometric mean (GM) post-1' antibody, "C-6, -14, -19, -23" exceeded "T-6, -14, -19, -23" for type 19F; for 2' antibody, "T-6, -14, -19, -23" exceeded "C-6, -14, -19, -23" for type 14, but "C-6, -14, -19, -23" and the T/C mixture exceeded "T-6, -14, -19, -23" for the type 23F response. No other differences were significant. Analyzed by individual fold-rises, "C-6, -14, -19, -23" and the T/C mixture exceeded "T-6, -14, -19, -23" for types 19F and 23F. Thus, there was no consistent difference between the T and C carriers; rather, the results differed by serotype. When a mixture of halved doses of "T-6, -14, -19, -23" and "C-6, -14, -19, -23" was injected, neither negative nor positive interference with the PS antibody responses was found. Anticipating multivalent PS conjugate vaccines of the future to be used in infancy, this strategy would have two hypothetical advantages worth further investigation-avoiding "carrier epitopic overload" by reducing each carrier dosage and recruiting T-helper activity by both carriers for each PS.

Antibodies, Bacterial↗