Natasha B Halasa

University of Utah, Salt Lake City, Utah, United States

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Publications (37)205.69 Total impact

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    ABSTRACT: A multi-national prospective study of pediatric patients with invasive candidiasis between August 2007 and September 2012 was performed and included 441 infections. Variation in infecting Candida species and antifungals utilized was noted between US and non-US sites. Antifungal-associated adverse events were most common with polyene use.
    The Pediatric Infectious Disease Journal 06/2014; · 3.57 Impact Factor
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    ABSTRACT: Vitamin D deficiency is well recognized in selected Middle Eastern countries, but neonatal vitamin D status is not well studied in Jordan and other nearby countries. The aim of this study is to determine the prevalence of vitamin D deficiency in Jordanian newborns and risk factors associated with low levels. This is a prospective cohort study of newborn infants who were delivered at the Al Bashir Government Hospital in Amman, Jordan, from January 31, 2010, to January 27, 2011. Heel stick blood samples for 25-hydroxyvitamin D [25(OH)D] levels were obtained within 96 hours of birth. Maternal dress pattern, vitamin supplementation, smoke exposure during pregnancy, mode of delivery, gestational age, and birth weight were documented. Samples were obtained from 3,731 newborns. Median gestational age was 39 weeks, median birth weight was 3.1 kilograms, median maternal age was 27 years, and median newborn 25(OH)D level was 8.6nmol/L. A total of 3,512 newborns (94.1%) in this study were vitamin D deficient (< 50 nmol/L). Lower gestational age, maternal smoke exposure, and birth during winter months were associated with lower infant vitamin D levels, while vitamin D supplementation and time spent outside during pregnancy were associated with higher vitamin D levels. The prevalence of severely low vitamin D levels in newborn infants in Amman, Jordan, is substantial, even in newborns born during the spring and summer months. Vitamin D supplementation is needed in this population.
    Global journal of health science 01/2014; 6(1):162-71.
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    ABSTRACT: Although children with acute lymphoblastic leukemia (ALL) mount immune responses after vaccination with the trivalent influenza vaccine (TIV), these responses are lower compared to controls. Recently, a high dose (HD) TIV was found to increase the level of antibody response in elderly patients compared to the standard dose (SD) TIV. We hypothesized that the HD TIV would be well-tolerated and more immunogenic compared to the SD TIV in pediatric subjects with ALL. This was a randomized, double-blind, phase I safety trial comparing the HD to the SD TIV in children with ALL. Our secondary objective was immunogenicity. Subjects were randomized 2:1 to receive either the HD (60 µg) or the SD (15 µg) TIV. Local and systemic reactions were solicited, hemagglutinin inhibition titers to influenza virus antigens were measured, and monitoring labs were collected prior to and/or after each vaccination. Fifty subjects were enrolled (34 HD, 16 SD). Mean age was 8.5 years; 63% were male, and 80% were in maintenance therapy. There were no significant differences reported in local or systemic symptoms. No severe adverse events were attributed to vaccination. No significant differences between the HD and SD TIV groups were noted for immune responses. No differences were noted between the HD and SD TIV groups for solicited systemic and local reactions. Since this study was not powered for immunogenicity, a phase II trial is needed to determine the immunogenicity of HD versus SD TIV in the pediatric ALL population. Pediatr Blood Cancer © 2013 Wiley Periodicals, Inc.
    Pediatric Blood & Cancer 11/2013; · 2.35 Impact Factor
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    ABSTRACT: Hospitalized children < 2 years of age in Amman, Jordan, admitted for fever and/or respiratory symptoms, were tested for Middle East respiratory syndrome coronavirus (MERS-CoV): MERS-CoV by real-time RT-PCR (rRT-PCR). This was a prospective year-round viral surveillance study in children <2 years of age admitted with acute respiratory symptoms and/or fever from March 2010 to September 2012 and enrolled from a government-run hospital, Al-Bashir in Amman, Jordan. Clinical and demographic data, including antibiotic use, were collected. Combined nasal/throat swabs were collected, aliquoted, and frozen at -80°C. Specimen aliquots were shipped to Vanderbilt University and the Centers for Disease Control and Prevention (CDC), and tested by rRT-PCR for MERS-CoV. Of the 2433 subjects enrolled from 16 March 2010 to 10 September 2012, 2427 subjects had viral testing and clinical data. Of 1898 specimens prospectively tested for other viruses between 16 March 2010 and 18 March 2012, 474 samples did not have other common respiratory viruses detected. These samples were tested at CDC for MERS-CoV and all were negative by rRT-PCR for MERS-CoV. Of the remaining 531 samples, collected from 19 March 2012 to 10 September 2012 and tested at Vanderbilt, none were positive for MERS-CoV. Our negative findings from a large sample of young Jordanian children hospitalized with fever and/or respiratory symptoms suggest that MERS-CoV was not widely circulating in Amman, Jordan, during the 30-month period of prospective, active surveillance occurring before and after the first documented MERS-CoV outbreak in the Middle East region.
    Clinical Microbiology and Infection 10/2013; · 4.58 Impact Factor
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    ABSTRACT: BACKGROUND:: Invasive meningococcal infections can be devastating. Substantial endotoxemia releases mature and immature neutrophils. Endothelial margination of mature neutrophils may increase the immature to total neutrophil ratio. These changes have not been previously well-described in invasive meningococcal disease. METHODS:: Using 2001-2011 data from the US Multicenter Meningococcal Surveillance Study, the diagnostic sensitivity and clinical correlates of white blood cell count (WBC), absolute neutrophil count (ANC), immature neutrophil count (INC), and immature-to-total neutrophil ratio (ITR) were evaluated alone and in combination at the time of diagnosis of invasive meningococcal disease. RESULTS:: 216 patients were evaluated: meningococcemia (65), meningitis (145), and other foci (6). ANC ≤ 1000/mm or ≥ 10,000/mm was present in 137 (63%), INC ≥ 500/mm in 170 (79%), and ITR ≥0.20 in 139 (64%). One or more of these 3 criteria were met in 204/216 (94%). Results were similar for meningococcemia and meningitis subgroups. All 13 cases with mildest disease met one or more of the 3 criteria. Eight children presented with absolute neutrophil counts <1000/mm: three of them died and a fourth required partial amputation in all four limbs. CONCLUSIONS:: Invasive meningococcal disease is characterized by striking abnormalities in absolute neutrophil count, immature neutrophil count, and/or immature-to-total neutrophil ratio. Neutropenia was associated with a poor prognosis. Notably, without immature neutrophil counts, 37% of cases would have been missed. Automated methods not measuring immature WBCs should be avoided when assessing febrile children. Serious infection should be considered when counts meet any of the three criteria.
    The Pediatric Infectious Disease Journal 06/2013; · 3.57 Impact Factor
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    ABSTRACT: BACKGROUND:: Invasive pneumococcal disease (IPD) rates decreased after 7-valent pneumococcal conjugate vaccine (PCV7) introduction in 2000. We assessed whether previously described decreases were sustained. METHODS:: Active laboratory-based surveillance identified IPD cases in five Tennessee Counties. For each case, clinical data were collected, and antibiotic susceptibility testing and serotyping were performed. Penicillin-resistance was defined as intermediate-or high-level resistance to penicillin. Serotypes were classified as PCV7, PCV13 (six additional serotypes not in PCV7), pneumococcal polysaccharide vaccine (PPV23, 11 additional serotypes not in PCV13, and non-vaccine serotypes. Total and penicillin-resistant IPD rates were calculated for persons <2, 2-14, and >15 years of age before (1998-99) and after (2001-2008) PCV7 introduction. RESULTS:: Annual IPD rates in children <2 years of age declined by 75% after PCV7 introduction (p<0.001). Annual IPD rates in children 2-14 years of age declined by 51% after PCV7 introduction (p<0.001). IPD rates in persons ≥15 of age years initially decreased 40% from 22 to 13 per 100,000 person-years (from 1998 through 2004), and then increased to 18 per 100,000 person-years in 2008. Both IPD and penicillin-resistant IPD PCV7 serotypes were almost completely eliminated in all age groups by 2008. During 2005-2008, 52.5%, 58%, and 38% of IPD serotypes in children <2, 2-14, and >15 years of age, respectively were the additional 6 serotypes in PCV13. CONCLUSIONS:: Overall, 9 years following PCV7 introduction both penicillin-susceptible and resistant IPD rates PCV7 serotypes have been nearly eliminated in Tennessee in all age groups. Total IPD rates remain reduced in children <15 years of age; whereas total IPD rates in persons ≥15 years of age have approached pre-PCV7 rates due to modest increases in non-vaccine serotypes.
    The Pediatric Infectious Disease Journal 01/2013; · 3.57 Impact Factor
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    ABSTRACT: BACKGROUND:: Candida species are the third most common cause of pediatric healthcareassociated bloodstream infection in the United States and Europe. To our knowledge, this report from the International Pediatric Fungal Network is the largest prospective, multi-center observational study dedicated to pediatric and neonatal invasive candidiasis. METHODS:: From 2007-2011, we enrolled 196 pediatric and 25 neonatal patients with invasive candidiasis. RESULTS:: Non-albicans Candida species predominated in pediatric (56%) and neonatal (52%) age groups, yet C. albicans was the most common in both groups. Successful treatment responses were observed in pediatric (76%) and neonatal patients (92%). Infection with C. parapsilosis led to successful responses in pediatric (92%) and neonatal (100%) patients, while infection with C. glabrata was associated a lower successful outcome in pediatric patients (55%). The most commonly used primary antifungal therapies for pediatric invasive candidiasis were fluconazole (21%), liposomal amphotericin B (20%), and micafungin (18%). Outcome of pediatric invasive candidiasis was similar in response to polyenes (73%), triazoles (67%) and echinocandins (73%). The most commonly used primary antifungal therapies for neonatal invasive candidiasis were fluconazole (32%), caspofungin (24%), and liposomal amphotericin B (16%) and micafungin (8%). Outcomes of neonatal candidiasis by antifungal class again revealed similar response rates amongst the classes. CONCLUSIONS:: We found a predominance of non-albicans Candida infection in children and similar outcomes based on antifungal class used. This international collaborative study sets the foundation for large epidemiologic studies focusing on the unique features of neonatal and pediatric candidiasis and comparative studies of therapeutic interventions in these populations.
    The Pediatric Infectious Disease Journal 09/2012; · 3.57 Impact Factor
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    ABSTRACT: : To evaluate the prevalence of fungal infections (both pre-cannulation and post-cannulation) while on extracorporeal membrane oxygenation support and the associated morbidity and mortality. : Retrospective cohort study. : The Extracorporeal Life Support Organization database is an international voluntary registry of clinical data for patients placed on extracorporeal membrane oxygenation. The database was queried for all patients on extracorporeal membrane oxygenation from 1997 to 2009. Patient and extracorporeal membrane oxygenation data collected included age, support type, length of support, infection status and organism code, discharge status, complications, and component failures. Outcomes of interest were mortality, extracorporeal membrane oxygenation-related patient complications, and mechanical component failures. : From 1997 to 2009, there were 21,073 patients' extracorporeal membrane oxygenation runs analyzed of which 12,933 were in the neonatal group (0-30 days), 6,073 were in the pediatric group (31 days to <18 yrs old), and 2,067 were in the adult group (≥18 yrs). The prevalence of fungal infection during extracorporeal membrane oxygenation varied by age group and timing of infection and ranged from 0.04% to 5%. Fungal infections pre-extracorporeal membrane oxygenation and on-extracorporeal membrane oxygenation conferred a statistically significant higher relative risk of mortality for all age groups and varied by support type and timing of infection. Extracorporeal membrane oxygenation-related complications and component failures were not statistically significantly affected by infection status. : Fungal infection before or during extracorporeal membrane oxygenation increases the odds of mortality and the magnitude of this effect is dependent upon age-group and timing of infection. This increased mortality was not the result of increased patient or mechanical complications during extracorporeal membrane oxygenation. For patients with fungal infections pre-extracorporeal membrane oxygenation, 82%-89% demonstrated presumed clearance during extracorporeal membrane oxygenation. Although the risk of mortality increased with fungal infections, it does not appear that fungal infection before or during extracorporeal membrane oxygenation is a contraindication to initiation or continuation of support.
    Pediatric Critical Care Medicine 07/2012; 13(5):e288-93. · 2.35 Impact Factor
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    ABSTRACT: Influenza virus causes a spectrum of illness in transplant recipients with a high rate of lower respiratory disease. Seasonal influenza vaccination is an important public health measure recommended for transplant recipients and their close contacts. Vaccine has been shown to be safe and generally well tolerated in both adult and pediatric transplant recipients. However, responses to vaccine are variable and are dependent on various factors including time from transplantation and specific immunosuppressive medication. Seasonal influenza vaccine has demonstrated safety and no conclusive evidence exists for a link between vaccination and allograft dysfunction. Annually updated trivalent inactivated influenza vaccines have been available and routinely used for several decades, although newer influenza vaccination formulations including high-dose vaccine, adjuvanted vaccine, quadrivalent inactivated vaccine and vaccine by intradermal delivery system are now available or will be available in the near future. Safety and immunogenicity data of these new formulations in transplant recipients requires investigation. In this document, we review the current state of knowledge on influenza vaccines in transplant recipients and make recommendations on the use of vaccine in both adult and pediatric organ transplant recipients.
    American Journal of Transplantation 10/2011; 11(10):2020-30. · 6.19 Impact Factor
  • Natasha B Halasa
    The Journal of Infectious Diseases 09/2011; 204(10):1471-4. · 5.85 Impact Factor
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    ABSTRACT: The safety of intranasal live-attenuated influenza vaccine (LAIV) in immunocompromised children with cancer is unknown. The objective of this study was to describe the safety and immunogenicity of LAIV in mild to moderately immunocompromised children with cancer. We conducted a multicenter, randomized, double-blind study of LAIV versus placebo in children aged 5-17 years with cancer. LAIV (frozen formulation) or allantoic fluid/buffer was administered intranasally. Reactogenicity, adverse events, blood for immune assays, and nasal swabs for viral shedding were obtained during 5 visits over the first 42 days postvaccination; information concerning serious adverse events (SAEs) was collected for 180 days. 20 subjects were enrolled (LAIV, n=10; placebo, n=10) with a mean age of 12.2 years. Ten subjects had hematologic malignancy (LAIV, n=4; placebo, n=6); 10 subjects had solid tumors (LAIV, n=6; placebo, n=4). One subject was excluded from immunogenicity analysis for not receiving a full dose of LAIV. LAIV resulted in an increased incidence of runny nose/nasal congestion occurring in all LAIV recipients; no related SAEs were observed. Four of 10 LAIV recipients shed vaccine virus, with none exceeding 7-10 days duration. LAIV demonstrated modest immunogenicity by hemagglutination inhibition (≥ 4 fold rise for any strain, 33%) and microneutralization assays (≥ 4 fold rise for any strain, 44%). In this small pilot study conducted in mild to moderately immunocompromised children with cancer, runny nose/nasal congestion was increased in LAIV recipients, no related SAEs occurred, and prolonged viral shedding was not detected. Moderate immunogenicity was demonstrated in this small group of individuals.
    Vaccine 05/2011; 29(24):4110-5. · 3.77 Impact Factor
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    ABSTRACT: Human metapneumovirus (HMPV) has recently been identified as an important cause of acute respiratory infections (ARI) in children worldwide. However, there is little systematic data on its frequency and importance as a cause of ARI in the Middle East. We conducted a viral surveillance study in children <5 years of age admitted with respiratory symptoms and/or fever at two major tertiary care hospitals in Amman, Jordan from 1/18-3/29/07. Nose and throat swabs were collected and tested for HMPV and other respiratory viruses by real-time RT-PCR. A total of 743 subjects were enrolled. Forty-four (6%) subjects were positive for HMPV, 467 (64%) were positive for RSV and 13 (1.3%) had co-infection with both HMPV and RSV. The frequency of HMPV in January, February, and March was 4.1%, 3.0%, and 11.9% respectively. Clinical features associated with HMPV infection were similar to those of other respiratory viruses, except children with HMPV were more likely to present with fever than children not infected with HMPV. Children with HMPV and RSV co-infection were administered supplemental oxygen and were admitted to the ICU more frequently than children infected with HMPV alone or RSV alone, though these differences did not reach statistical significance. We conclude that HMPV is an important cause of acute respiratory infections in children in Amman, Jordan. Longer surveillance studies are needed to better understand the seasonal epidemiology of HMPV and to assess if co-infection with HMPV and RSV leads to more severe illness.
    Journal of Medical Virology 05/2010; 82(6):1012-6. · 2.37 Impact Factor
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    ABSTRACT: Acute respiratory infections (ARI) play a major role in hospitalizations in the Middle East, but the specific viral causes are unknown. We conducted prospective viral surveillance in children <5 y of age admitted with ARI and/or fever at 2 dissimilar hospitals in Amman, Jordan during peak respiratory syncytial virus (RSV) season. We collected prospective clinical and demographic data and obtained nose/throat swabs for testing for RSV by real-time polymerase chain reaction (RT-PCR). We obtained clinical and laboratory data for 728/743 (98%) subjects enrolled. The children's median age was 4.3 months, 58.4% were males, 87% were breastfed, 4% attended day care, 67% were exposed to smokers, 7% were admitted to the intensive care unit, and 0.7% died (n = 5). Out of 728 subjects, 467 (64%) tested positive by RT-PCR for RSV. Comparing RSV-positive with RSV-negative subjects, the RSV-positive subjects had lower median age (3.6 vs 6.4 months, p < 0.001) and fewer males (55% vs 64%, p = 0.02). RSV-positive children had higher rates of oxygen use (72% vs 42%, p < 0.001), a longer hospital stay (5 vs 4 days, p = 0.001), and higher hospital charges (US$538 vs US$431, p < 0.001) than RSV-negative children. In young hospitalized Jordanian infants, the medical and financial burden of RSV was found to be high. Effective preventive measures, such as an RSV vaccine, would have a significant beneficial impact.
    Scandinavian Journal of Infectious Diseases 05/2010; 42(5):368-74. · 1.71 Impact Factor
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    ABSTRACT: The cause of historically higher rates of invasive pneumococcal disease among blacks than whites has remained unknown. We tested the hypothesis that sickle cell trait or hemoglobin C trait is an independent risk factor for invasive pneumococcal disease. Eligible children were born in Tennessee (1996-2003), had a newborn screen, enrolled in TennCare aged <1 year, and resided in a Tennessee county with laboratory-confirmed, pneumococcal surveillance. Race/ethnicity was ascertained from birth certificates. Children were followed through 2005 until loss of enrollment, pneumococcal disease episode, fifth birthday, or death. We calculated incidence rates by race/ethnicity and hemoglobin type before and after pneumococcal conjugate vaccine (PCV7) introduction. Poisson regression analyses compared invasive pneumococcal disease rates among blacks with sickle cell trait or hemoglobin C trait with whites and blacks with normal hemoglobin, controlling for age, gender, time (pre-PCV7, transition year, or post-PCV7) and high-risk conditions (eg, heart disease). Over 10 years, 415 invasive pneumococcal disease episodes occurred during 451,594 observed child-years. Before PCV7 introduction, disease rates/100,000 child-years were 2941 for blacks with sickle cell disease, 258 for blacks with sickle cell trait or hemoglobin C trait and 188, 172, and 125 for blacks, whites, and Hispanics with normal hemoglobin. Post-PCV7, rates declined for all groups. Blacks with sickle cell trait or hemoglobin C trait had 77% (95% CI = 22-155) and 42% (95% CI = 1-100) higher rates than whites and blacks with normal hemoglobin. Black children with sickle cell trait or hemoglobin C trait have an increased risk of invasive pneumococcal disease.
    Epidemiology (Cambridge, Mass.) 03/2010; 21(3):340-6. · 5.51 Impact Factor
  • Natasha B Halasa
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    ABSTRACT: To provide an updated review of the epidemiology, clinical presentations, and outcomes of the 2009 pandemic influenza A H1N1 in children. The majority of cases of 2009 pandemic influenza A H1N1 in children have been mild. However, neurological complications, hospitalization, and even deaths have been reported in children. Death and severe illnesses have mostly occurred in children below 5 years of age and children with high-risk conditions. Coinfections with bacteria have also been reported. Most strains are sensitive to oseltamivir and all to zanamivir. Even though the majority of cases of 2009 pandemic influenza A H1N1 are mild, severe disease does occur in children. In addition, neurological complications and coinfection with bacteria exist. Treatment with antiviral medications should be initiated within 48 h to be most effective. When pandemic H1N1 vaccines become available, the safety and efficacy of these vaccines in this vulnerable population will be important to document.
    Current opinion in pediatrics 02/2010; 22(1):83-7. · 2.01 Impact Factor
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    ABSTRACT: Few studies have investigated the disease burden and genetic diversity of human rhinoviruses (HRVs) in developing countries. To assess the burden of HRV in Amman, Jordan, and to characterise clinical differences between HRV groups. We prospectively studied children <5 years, hospitalised with respiratory symptoms and/or fever in Amman, Jordan. Viruses were identified by real-time reverse transcriptase polymerase chain reaction (RT-PCR). VP4/VP2 gene sequencing was performed on HRV-positive specimens. Of the 728 enrolled children, 266 (37%) tested positive for picornaviruses, 240 of which were HRV. Of the HRV-positive samples, 62 (26%) were of the recently identified group HRVC, 131 (55%) were HRVA and seven (3%) were HRVB. The HRVC strains clustered into at least 19 distinct genotypes. Compared with HRVA-infected children, children with HRVC were more likely to require supplemental oxygen (63% vs. 42%, p=0.007) and, when co-infections were excluded, were more likely to have wheezing (100% vs. 82%, p=0.016). There is a significant burden of HRV-associated hospitalisations in young children in Jordan. Infection with the recently identified group HRVC is associated with wheezing and more severe illness.
    Journal of clinical virology: the official publication of the Pan American Society for Clinical Virology 10/2009; 46(1):85-9. · 3.12 Impact Factor
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    Natasha Halasa, Michael Green
    Liver Transplantation 11/2008; 14(10):1389-99. · 3.94 Impact Factor
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    ABSTRACT: To evaluate the safety and immunogenicity of an additional birth dose of diphtheria, tetanus, and acellular pertussis vaccine (DTaP). Fifty infants between 2 to 14 days of age were randomly assigned to receive either DTaP and hepatitis B vaccines (experimental) or hepatitis B alone (control) at birth. At 2, 4, 6, and 17 months of age, DTaP and routine vaccines were administered to both groups. Safety data were collected after each dose, and sera were obtained at birth, 6, 7, 17, and 18 months. Immune responses to pertussis toxin, filamentous hemagglutinin, pertactin, and fimbriae were measured by enzyme-linked immunosorbent assay; responses to other vaccines were assessed. No differences were seen between the 2 groups in either local or systemic reactions; all vaccines were well tolerated. Compared with the control group, infants in the experimental group demonstrated significantly lower geometric mean antibody concentrations for pertussis toxin and pertactin 6, 7, and 18 months, for fimbrae at 6, 7, 17, and 18 months, and for FHA at 18 months, and lower geometric mean antibody concentrations for diphtheria at 7 months. Immune responses to all other vaccine antigens were comparable. Administration of an additional dose of DTaP at birth was safe but was associated with a significantly lower response to diphtheria and 3 of 4 pertussis antigens compared with controls.
    The Journal of pediatrics 05/2008; 153(3):327-32. · 4.02 Impact Factor
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    ABSTRACT: Trivalent inactivated influenza vaccine (TIV) is not licensed for use in infants <6 months old, the group with the highest influenza hospitalization rates among children. In this prospective, open-label study, 2 doses of TIV were administered to healthy infants aged 10-22 weeks. Adverse reactions were assessed, and hemagglutination inhibition (HAI) antibody titers were determined. Weekly telephone surveillance for influenza-like illness was conducted during the influenza season. A total of 42 infants were enrolled and completed the study. Mild local and systemic reactions were noted. In the first season (2004-2005), postvaccination HAI titers >1:32 were noted for 31.6%, 47.4%, and 21.1% of 19 subjects for H1N1, H3N2, and B strains included in the vaccine, respectively. In the second season (2005-2006), postvaccination HAI titers >1:32 were seen in 45.5%, 59.1%, and 0% of 23 subjects for H1N1, H3N2, and B strains included in the vaccine, respectively. Infants who were seronegative before vaccination (titers <1:8) were significantly more likely to have a 4-fold rise in antibody titer after vaccination, compared with infants who had prevaccination titers >1:8 (P<.001). Two doses of TIV were found to be safe and moderately immunogenic against some influenza strains. The presence of preexisting maternally derived antibody was associated with significantly lower seroresponse rates to vaccination. Whether vaccination with TIV will prevent influenza in these young children remains to be determined.
    The Journal of Infectious Diseases 05/2008; 197(10):1448-54. · 5.85 Impact Factor
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    ABSTRACT: We sought to determine the incidence of invasive pneumococcal disease (IPD) among individuals with sickle cell disease (SCD) before and after the introduction of the pneumococcal conjugate vaccine (PCV). Individuals with SCD who were enrolled in Tennessee Medicaid from January 1995 through December 2004 were identified using SCD-specific International Classification of Diseases, Ninth Revision, Clinical Modification codes. Population-based surveillance data were used to identify individuals with IPD and were linked to patients with SCD in the Tennessee Medicaid database to determine incidence rates of IPD. Clinical data were collected on all subjects with IPD, and antibiotic susceptibility testing and serotyping were performed on all available pneumococcal isolates. We identified 2026 individuals with SCD, who constituted 13,687 person-years of follow-up. During the study period, 37 individuals with SCD developed IPD, and 21 of these patients were aged <5 years. In a comparison of the pre-PCV period (1995-1999) with the post-PCV period (2001-2004), the rate of IPD decreased by 90.8% in children aged <2 years (from 3630 to 335 cases per 100,000 person-years; P<.001) and by 93.4% in children aged <5 years (from 2044 to 134 cases per 100,000 person-years; P<.001). Rates of IPD for patients with SCD who were aged >or=5 years decreased from 161 cases per 100,000 person-years during the pre-PCV period to 99 cases per 100,000 person-years during the post-PCV period (P=.36). The rate of IPD among children with SCD who are aged <5 years has decreased markedly since the introduction of routine administration of PCV to young children.
    Clinical Infectious Diseases 07/2007; 44(11):1428-33. · 9.37 Impact Factor

Publication Stats

888 Citations
205.69 Total Impact Points


  • 2013
    • University of Utah
      • Department of Pediatrics
      Salt Lake City, Utah, United States
  • 2010–2013
    • University of Jordan
      `Ammān, Amman, Jordan
  • 2002–2013
    • Vanderbilt University
      • • Division of Infectious Diseases
      • • Department of Pediatrics
      • • Department of Medicine
      Nashville, Michigan, United States
  • 2005
    • American Economic Association
      United States