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Linley L.,Centers for Disease Control and Prevention | Ethridge S.F.,Centers for Disease Control and Prevention | Oraka E.,ICF International | Owen S.M.,Centers for Disease Control and Prevention | And 6 more authors.
Journal of Clinical Virology | Year: 2013

Background: The use of Western blot (WB) as a supplemental test after reactive sensitive initial assays can lead to inconclusive or misclassified HIV test results, delaying diagnosis. Objective: To determine the proportion of specimens reactive by immunoassay (IA) but indeterminate or negative by WB that could be resolved by alternative supplemental tests recommended under a new HIV diagnostic testing algorithm. Study design: Remnant HIV diagnostic specimens that were reactive on 3rd generation HIV-1/2 IA and either negative or indeterminate by HIV-1 WB from 11 health departments were tested with the Bio-Rad Multispot HIV-1/HIV-2 Rapid Test (Multispot) and the Gen-Probe APTIMA HIV-1 RNA Qualitative Assay (APTIMA). Results: According to the new testing algorithm, 512 (89.8%) specimens were HIV-negative, 55 (9.6%) were HIV-1 positive (including 19 [3.3%] that were acute HIV-1 and 9 [1.6%] that were positive for HIV-1 by Multispot but APTIMA-negative), 2 (0.4%) were HIV-2 positive, and 1 (0.2%) was HIV-positive, type undifferentiated. 47 (21.4%) of the 220 WB-indeterminate and 8 (2.3%) of the 350 WB-negative specimens were HIV-1 positive. Conclusion: Applying the new HIV diagnostic algorithm retrospectively to WB-negative and indeterminate specimens, the HIV infection status could be established for nearly all of the specimens. IA-reactive HIV-infected persons with WB-negative results had been previously misclassified as uninfected, and HIV diagnosis was delayed for those with WB-indeterminate specimens. These findings underscore the limitations of the WB to confirm HIV infection after reactive results from contemporary 3rd or 4th generation IAs that can detect HIV antibodies several weeks sooner than the WB. © 2013.


Mullapudi S.,North Carolina State University | Mullapudi S.,North Carolina State Laboratory of Public Health | Siletzky R.M.,North Carolina State University | Kathariou S.,North Carolina State University
Applied and Environmental Microbiology | Year: 2010

Two different cadA cadmium resistance determinants (cadA1, first identified in Tn5422, and cadA2, associated with pLM80) were detected among cadmium-resistant Listeria monocytogenes strains from turkey processing plants. Prevalence of cadA1 versus cadA2 was serotype associated. Cadmium-resistant isolates that were also resistant to benzalkonium chloride (BC) were more likely to harbor cadA2 alone or together with cadA1 than isolates that were cadmium resistant but BC susceptible. Copyright © 2010, American Society for Microbiology. All Rights Reserved.


Keys J.R.,University of North Carolina at Chapel Hill | Leone P.A.,University of North Carolina at Chapel Hill | Eron J.J.,University of North Carolina at Chapel Hill | Alexander K.,University of North Carolina at Chapel Hill | And 2 more authors.
Journal of Medical Virology | Year: 2014

North Carolina locates acute HIV cases by pooled nucleic acid testing of HIV-antibody negative serum samples. Here, 224 pools of 80 HIV-negative samples (N=17,920) were screened for viral RNA from HCV, GBV-C, and influenza A. No evidence of influenza A was found, but HCV and GBV-C were common (1.2% and 1.7% prevalence, respectively), demonstrating the utility of pooled testing in locating individuals that may remain undiagnosed otherwise. By sequencing positive pools, potential transmission clusters may be located as well. J. Med. Virol. 86:473-477, 2014. © 2013 Wiley Periodicals, Inc.


Russell M.D.,North Carolina State Laboratory of Public Health | Russell M.D.,Center for Food Safety and Applied Nutrition | Correa M.T.,North Carolina State University | Stauber C.E.,Georgia State University | And 2 more authors.
Journal of Food Protection | Year: 2010

Migrant and seasonal farmworkers provide much of the necessary labor to harvest and process agricultural commodities desired by consumers. Little is known about the health status (especially the parasitic burden) of farm laborers, who handpick agricultural items such as fruits and vegetables, despite being implicated as a means of foodborne pathogen transmission. The goal of this research was to develop a framework to investigate enteric parasitic infections among Hispanic farmworkers in Eastern North Carolina. Seventy-one interviews were conducted, 16 stool samples were collected, and two parasite-positive workers were found. In addition, some potentially harmful health practices (e.g., self-medication) were identified. Further research is necessary to fully understand the scope of farmworker health issues and the potential risk of disseminating foodborne pathogens to humans. The study model presented provides a geographically expandable format to allow for various types of health investigations including the prevalence of other pathogens.


Stout J.E.,Duke University | Gadkowski L.B.,Duke University | Gadkowski L.B.,Eastern Virginia Medical School | Rath S.,North Carolina State Laboratory of Public Health | And 3 more authors.
Clinical Infectious Diseases | Year: 2011

Background. Pedicure-associated nontuberculous mycobacterial furunculosis has been reported in the setting of either outbreaks or sporadic case reports. The epidemiology of these infections is not well understood. Methods. Systematic surveillance for pedicure-associated nontuberculous mycobacterial furunculosis was conducted in 2 North Carolina counties from 1 January 2005 through 31 December 2008. A subset of implicated nail salons and control salons was inspected and sampled for nontuberculous mycobacteria. Results. Forty cases of suspected or confirmed pedicure-associated nontuberculous mycobacterial furunculosis were reported during the 4-year study period. Furunculosis incidence in the surveillance region was 1.00, 0.96, 0.83, and 0.89 cases per 100000 population in 2005, 2006, 2007, and 2008, respectively. The responsible organisms primarily belonged to the Mycobacterium chelonae/abscessus group (30 [91%] of 33 isolates). Thirteen implicated salons and 11 control salons were visited and environmentally sampled. An assortment of nontuberculous mycobacteria was cultured from footbaths, but there was no association between the species distribution of the environmental isolates and implication of the salon in human infection. Evidence of suboptimal cleaning (visible debris or surface biofilms) was observed in at least 1 footbath for 11 of 13 implicated salons and 4 of 11 control salons (P =. 032). Conclusions. Pedicure-associated mycobacterial furunculosis was endemic in these 2 North Carolina counties during 2005-2008. Suboptimal footbath cleaning may have contributed to these infections, which suggests straightforward means of potential prevention. The relative rarity of this type of infection in the setting of nearly ubiquitous exposure to these pathogens suggests that as yet undefined host-specific or procedure-related factors may be involved in susceptibility to these infections. © 2011 The Author.


Vaughn M.F.,University of North Carolina at Chapel Hill | Vaughn M.F.,Rho Inc. | Johnson J.,North Carolina State Laboratory of Public Health | Daves G.,North Carolina State Laboratory of Public Health | And 4 more authors.
Journal of Clinical Microbiology | Year: 2014

Increasing entomologic and epidemiologic evidence suggests that spotted fever group rickettsiae (SFGR) other than Rickettsia rickettsii are responsible for spotted fever rickettsioses in the United States. A retrospective seroepidemiologic study was conducted on stored acute- and convalescent-phase sera that had been submitted for Rocky Mountain spotted fever testing to the North Carolina State Laboratory of Public Health. We evaluated the serologic reactivity of the paired sera to R. rickettsii, Rickettsia parkeri, and Rickettsia amblyommii antigens. Of the 106 eligible pairs tested, 21 patients seroconverted to one or more antigens. Cross-reactivity to multiple antigens was observed in 10 patients, and seroconversions to single antigens occurred in 11 patients, including 1 against R. rickettsii, 4 against R. parkeri, and 6 against R. amblyommii. Cross-absorption of cross-reactive sera and/or Western blots identified two presumptive cases of infection with R. parkeri, two presumptive cases of infection with R. rickettsii, and one presumptive case of infection with R. amblyommii. These findings suggest that species of SFGR other than R. rickettsii are associated with illness among North Carolina residents and that serologic testing using R. rickettsii antigen may miss cases of spotted fever rickettsioses caused by other species of SFGR. Copyright © 2014, American Society for Microbiology. All Rights Reserved.


Husain M.,Aurora University | Jones-Carson J.,Aurora University | Liu L.,Aurora University | Song M.,Aurora University | And 6 more authors.
Infection and Immunity | Year: 2014

Herein we report an important role for the ferric uptake regulator (Fur) in the resistance of Salmonella enterica serovar Typhimurium to the reactive nitrogen species produced by inducible nitric oxide (NO) synthase in an NRAMP1r murine model of acute systemic infection. The expression of fur protected Salmonella grown under normoxic and hypoxic conditions against the bacteriostatic activity of NO. The hypersusceptibility of fur-deficient Salmonella to the cytotoxic actions of NO coincides with a marked repression of respiratory activity and the reduced ability of the bacteria to detoxify NO. A fur mutant Salmonella strain contained reduced levels of the terminal quinol oxidases of the electron transport chain. Addition of the heme precursor δ-aminolevulinic acid restored the cytochrome content, respiratory activity, NO consumption, and wild-type growth in bacteria undergoing nitrosative stress. The innate antinitrosative defenses regulated by Fur added to the adaptive response associated with the NO-detoxifying activity of the flavohemoprotein Hmp. Our investigations indicate that, in addition to playing a critical role in iron homeostasis, Fur is an important antinitrosative determinant of Salmonella pathogenesis. © 2014, American Society for Microbiology.


Hafner M.S.,Louisiana State University | Gates A.R.,Louisiana State University | Mathis V.L.,Louisiana State University | Demastes J.W.,University of Northern Iowa | And 2 more authors.
Journal of Mammalogy | Year: 2011

Thomomys atrovarius is redescribed to include the smooth-toothed pocket gophers that inhabit dry, thornscrub vegetation along the Pacific versant of the Sierra Madre Occidental of Mexico from northern Sinaloa into western Durango, northwestern Jalisco, and western Nayarit. Molecular analyses of mitochondrial and nuclear DNA sequences (including historical samples from museum skins) show high levels of genetic differentiation between T. atrovarius and T. umbrinus of the Sierra Madre Occidental (15.4% cytochrome-b divergence) and Mexican Central Plateau (16.9% divergence). Roughly coincident morphometric and genetic gaps divide T. atrovarius into 2 subspecies, T. a. parviceps in the north and T. a. atrovarius in the south, with probable intergradation in between. Most specimens of T. atrovarius, especially those of the southern subspecies, are distinguished easily from specimens of T. bottae and T. umbrinus on the basis of fur texture, and an analysis of cranial morphometrics shows little overlap between T. atrovarius and other Thomomys clades in Mexico. An analysis of niche parameters shows significantly different climate envelopes for T. atrovarius compared with other species of Thomomys, and a biogeographical review suggests that T. atrovarius has ancestral affinities to the south of its current distribution. A synonymy of T. atrovarius and a key to the currently recognized species of Thomomys in mainland Mexico are provided. © 2011 American Society of Mammalogists.


PubMed | Centers for Disease Control and Prevention, Association of Public Health Laboratories, North Carolina State Laboratory of Public Health, New York State Department of Health and ICF International
Type: | Journal: Journal of clinical virology : the official publication of the Pan American Society for Clinical Virology | Year: 2013

The use of Western blot (WB) as a supplemental test after reactive sensitive initial assays can lead to inconclusive or misclassified HIV test results, delaying diagnosis.To determine the proportion of specimens reactive by immunoassay (IA) but indeterminate or negative by WB that could be resolved by alternative supplemental tests recommended under a new HIV diagnostic testing algorithm.Remnant HIV diagnostic specimens that were reactive on 3rd generation HIV-1/2 IA and either negative or indeterminate by HIV-1 WB from 11 health departments were tested with the Bio-Rad Multispot HIV-1/HIV-2 Rapid Test (Multispot) and the Gen-Probe APTIMA HIV-1 RNA Qualitative Assay (APTIMA).According to the new testing algorithm, 512 (89.8%) specimens were HIV-negative, 55 (9.6%) were HIV-1 positive (including 19 [3.3%] that were acute HIV-1 and 9 [1.6%] that were positive for HIV-1 by Multispot but APTIMA-negative), 2 (0.4%) were HIV-2 positive, and 1 (0.2%) was HIV-positive, type undifferentiated. 47 (21.4%) of the 220 WB-indeterminate and 8 (2.3%) of the 350 WB-negative specimens were HIV-1 positive.Applying the new HIV diagnostic algorithm retrospectively to WB-negative and indeterminate specimens, the HIV infection status could be established for nearly all of the specimens. IA-reactive HIV-infected persons with WB-negative results had been previously misclassified as uninfected, and HIV diagnosis was delayed for those with WB-indeterminate specimens. These findings underscore the limitations of the WB to confirm HIV infection after reactive results from contemporary 3rd or 4th generation IAs that can detect HIV antibodies several weeks sooner than the WB.


PubMed | Centers for Disease Control and Prevention, University of North Carolina at Chapel Hill, North Carolina State Laboratory of Public Health and University of Texas Medical Branch
Type: Journal Article | Journal: Journal of clinical microbiology | Year: 2014

Increasing entomologic and epidemiologic evidence suggests that spotted fever group rickettsiae (SFGR) other than Rickettsia rickettsii are responsible for spotted fever rickettsioses in the United States. A retrospective seroepidemiologic study was conducted on stored acute- and convalescent-phase sera that had been submitted for Rocky Mountain spotted fever testing to the North Carolina State Laboratory of Public Health. We evaluated the serologic reactivity of the paired sera to R. rickettsii, Rickettsia parkeri, and Rickettsia amblyommii antigens. Of the 106 eligible pairs tested, 21 patients seroconverted to one or more antigens. Cross-reactivity to multiple antigens was observed in 10 patients, and seroconversions to single antigens occurred in 11 patients, including 1 against R. rickettsii, 4 against R. parkeri, and 6 against R. amblyommii. Cross-absorption of cross-reactive sera and/or Western blots identified two presumptive cases of infection with R. parkeri, two presumptive cases of infection with R. rickettsii, and one presumptive case of infection with R. amblyommii. These findings suggest that species of SFGR other than R. rickettsii are associated with illness among North Carolina residents and that serologic testing using R. rickettsii antigen may miss cases of spotted fever rickettsioses caused by other species of SFGR.

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