Issue 33, August 22, 2017

CDC Science Clips: Volume 9, Issue 33, August 22, 2017

Science Clips is produced weekly to enhance awareness of emerging scientific knowledge for the public health community. Each article features an Altmetric Attention scoreExternal to track social and mainstream media mentions!

  1. Top Articles of the Week
    Selected weekly by a senior CDC scientist from the standard sections listed below.
    The names of CDC authors are indicated in bold text.
    • Communicable Diseases
      1. HIV-associated mortality in the era of antiretroviral therapy scale-up – Nairobi, Kenya, 2015External
        Young PW, Kim AA, Wamicwe J, Nyagah L, Kiama C, Stover J, Oduor J, Rogena EA, Walong E, Zielinski-Gutierrez E, Imbwaga A, Sirengo M, Kellogg TA, De Cock KM.
        PLoS One. 2017 ;12(8):e0181837.

        BACKGROUND: Declines in HIV prevalence and increases in antiretroviral treatment coverage have been documented in Kenya, but population-level mortality associated with HIV has not been directly measured. In urban areas where a majority of deaths pass through mortuaries, mortuary-based studies have the potential to contribute to our understanding of excess mortality among HIV-infected persons. We used results from a cross-sectional mortuary-based HIV surveillance study to estimate the association between HIV and mortality for Nairobi, the capital city of Kenya. METHODS AND FINDINGS: HIV seropositivity in cadavers measured at the two largest mortuaries in Nairobi was used to estimate HIV prevalence in adult deaths. Model-based estimates of the HIV-infected and uninfected population for Nairobi were used to calculate a standardized mortality ratio and population-attributable fraction for mortality among the infected versus uninfected population. Monte Carlo simulation was used to assess sensitivity to epidemiological assumptions. When standardized to the age and sex distribution of expected deaths, the estimated HIV positivity among adult deaths aged 15 years and above in Nairobi was 20.9% (95% CI 17.7-24.6%). The standardized mortality ratio of deaths among HIV-infected versus uninfected adults was 4.35 (95% CI 3.67-5.15), while the risk difference was 0.016 (95% CI 0.013-0.019). The HIV population attributable mortality fraction was 0.161 (95% CI 0.131-0.190). Sensitivity analyses demonstrated robustness of results. CONCLUSIONS: Although 73.6% of adult PLHIV receive antiretrovirals in Nairobi, their risk of death is four-fold greater than in the uninfected, while 16.1% of all adult deaths in the city can be attributed to HIV infection. In order to further reduce HIV-associated mortality, high-burden countries may need to reach very high levels of diagnosis, treatment coverage, retention in care, and viral suppression.

    • Disaster Control and Emergency Services
      1. Proposed Exposure And Symptom Triage (EAST) tool to assess radiation exposure after a nuclear detonationExternal
        Hick JL, Bader JL, Coleman CN, Ansari AJ, Chang A, Salame-Alfie A, Hanfling D, Koerner JF.
        Disaster Medicine and Public Health Preparedness. 2017 :1-10.

        One of the biggest medical challenges after the detonation of a nuclear device will be implementing a strategy to assess the severity of radiation exposure among survivors and to triage them appropriately. Those found to be at significant risk for radiation injury can be prioritized to receive potentially lifesaving myeloid cytokines and to be evacuated to other communities with intact health care infrastructure prior to the onset of severe complications of bone marrow suppression. Currently, the most efficient and accessible triage method is the use of sequential complete blood counts to assess lymphocyte depletion kinetics that correlate with estimated whole-body dose radiation exposure. However, even this simple test will likely not be available initially on the scale required to assess the at-risk population. Additional variables such as geographic location of exposure, sheltering, and signs and symptoms may be useful for initial sorting. An interdisciplinary working group composed of federal, state, and local public health experts proposes an Exposure And Symptom Triage (EAST) tool combining estimates of exposure from maps with clinical assessments and single lymphocyte counts if available. The proposed tool may help sort survivors efficiently at assembly centers near the damage and fallout zones and enable rapid prioritization for appropriate treatment and transport.

    • Immunity and Immunization
      1. Early impact of rotavirus vaccine in under 5 year old children hospitalized due to diarrhea, SwazilandExternal
        Maphalala G, Phungwayo N, Masona G, Lukhele N, Tsegaye G, Dube N, Sindisiwe D, Khumalo L, Daniel F, Katsande R, Tate JE, Mwenda JM, Weldegebriel G.
        Vaccine. 2017 Aug 01.

        BACKGROUND: Swaziland introduced rotavirus vaccine in the National Immunization Program, in May 2015, with the objective of reducing the burden of rotavirus diarrheal disease. We monitored the early impact of the vaccine in reducing rotavirus diarrhea. METHODS: We conducted sentinel rotavirus surveillance from January 2013 to December 2016 in children under five years of age admitted due to diarrhea attending Mbabane Government Referral Hospital in the Hhohho Region and Raleigh Fitkin Memorial Hospital in the Manzini Region. All cases had stool samples collected and tested for rotavirus antigen by enzyme immunoassay. RESULTS: Between 2013 and 2016, 596 samples were collected and tested. Rotavirus positivity reduced from average of 50.8% (172/338) (in 2013-2014 (pre vaccine period)) to 29% (24/82) in 2016, post-vaccine introduction. The median age of children with rotavirus infection increased from average of 10months in 2013-2014 to 13.7months in 2016. The peak season for all-cause diarrhea and rotavirus-specific hospitalizations among children under five years of age was June-August in all years with a blunting of the peak season in 2016. Rotavirus positivity among children 0-11months reduced from an average of 49% in 2013-2014 (116/236) to 33% (15/45) in 2016, a 33% reduction following rotavirus vaccine introduction. CONCLUSION: There has been a rapid reduction of all-cause diarrhea and rotavirus hospitalizations in Swaziland, particularly in young children and during the rotavirus season, after the introduction rotavirus vaccine. Continued surveillance is needed to monitor the long-term impact of rotavirus vaccine introduction.

    • Parasitic Diseases
      1. Prevalence and risk factors associated with lymphatic filariasis in American Samoa after mass drug administrationExternal
        Coutts SP, King JD, Pa’au M, Fuimaono S, Roth J, King MR, Lammie PJ, Lau CL, Graves PM.
        Trop Med Health. 2017 ;45:22.

        BACKGROUND: In 2000, American Samoa had 16.5% prevalence of lymphatic filariasis (LF) antigenemia. Annual mass drug administration (MDA) was conducted using single-dose albendazole plus diethylcarbamazine from 2000 to 2006. This study presents the results of a 2007 population-based PacELF C-survey in all ages and compares the adult filarial antigenemia results of this survey to those of a subsequent 2010 survey in adults with the aim of improving understanding of LF transmission after MDA. RESULTS: The 2007 C-survey used simple random sampling of households from a geolocated list. In 2007, the overall LF antigen prevalence by immunochromatographic card test (ICT) for all ages was 2.29% (95% CI 1.66-3.07). Microfilaremia prevalence was 0.27% (95% CI 0.09-0.62). Increasing age (OR 1.04 per year, 95% CI 1.02-1.05) was significantly associated with ICT positivity on multivariate analysis, while having ever taking MDA was protective (OR 0.39, 95% CI 0.16-0.96). The 2010 survey used a similar spatial sampling design. The overall adult filarial antigenemia prevalence remained relatively stable between the surveys at 3.32% (95% CI 2.44-4.51) by ICT in 2007 and 3.23 (95% CI 2.21-4.69) by Og4C3 antigen in 2010. However, there were changes in village-level prevalence. Eight village/village groupings had antigen-positive individuals identified in 2007 but not in 2010, while three villages/village groupings that had no antigen-positive individuals identified in 2007 had positive individuals identified in 2010. CONCLUSIONS: After 7 years of MDA, with four rounds achieving effective coverage, a representative household survey in 2007 showed a decline in prevalence from 16.5 to 2.3% in all ages. However, lack of further decline in adult prevalence by 2010 and fluctuation at the village level showed that overall antigenemia prevalence at a broader scale may not provide an accurate reflection of ongoing transmission at the village level.

    • Zoonotic and Vectorborne Diseases
      1. Knowledge, attitudes, and practices among members of households actively monitored or quarantined to prevent transmission of Ebola virus disease – Margibi County, Liberia: February-March 2015External
        Wilken JA, Pordell P, Goode B, Jarteh R, Miller Z, Saygar BG, Maximore L, Borbor WM, Carmue M, Walker GW, Yeiah A.
        Prehosp Disaster Med. 2017 Jul 27:1-6.

        BACKGROUND: In early 2015, a patient from a cluster of cases of Ebola Virus Disease (EVD) in Monrovia, Liberia traveled to a rural village in Margibi County, potentially exposing numerous persons. The patient died in the village and post-mortem testing confirmed Ebola Virus infection. Problem The Margibi County Health Team (CHT; Kakata, Margibi, Liberia) needed to prevent further transmission of EVD within and outside of the affected villages, and they needed to better understand the factors that support or impede compliance with measures to stop the spread of EVD. METHODS: In February-March 2015, the Margibi CHT instituted a 21-day quarantine and active monitoring for two villages where the patient had contact with numerous residents, and a 21-day active monitoring for five other villages where the patient had possible contact with an unknown number of persons. One contact developed EVD and quarantine was extended an additional 12 days in one village. In April 2015, the Margibi CHT conducted a household-based EVD knowledge, attitudes, and practices (KAP) survey of the seven villages. From April 24-29, 2015, interview teams approached every household in the seven villages and collected information on demographics, knowledge of EVD, attitudes about quarantine to prevent the spread of EVD, and their quarantine experiences and practices. Descriptive statistics were calculated. RESULTS: One hundred fifteen interviews were conducted, representing the majority of the households in the seven villages. Most (99%) correctly identified touching an infected person’s body fluids and contact with the body of someone who has died from EVD as transmission routes. However, interviewees sometimes incorrectly identified mosquito bites (58%) and airborne spread (32%) as routes of EVD transmission, and 72% incorrectly identified the longest EVD incubation period as </=seven days. Eight of 16 households in the two quarantined villages (50%) reported times when there was not enough water or food during quarantine. Nine of 16 (56%) reported that a household member had illnesses or injuries during quarantine; of these, all (100%) obtained care from a clinic, hospital, or Ebola treatment unit (ETU). CONCLUSION: Residents’ knowledge of EVD transmission routes and incubation period were suboptimal. Public health authorities should consider assessing residents’ understanding of Ebola transmission routes and effectively educate them to ensure correct understanding. Quarantined residents should be provided with sufficient food, water, and access to medical care.

  2. CDC Authored Publications
    The names of CDC authors are indicated in bold text.
    Articles published in the past 6-8 weeks authored by CDC or ATSDR staff.
    • Chronic Diseases and Conditions
      1. Philadelphia telemedicine glaucoma detection and follow-up study: Methods and screening resultsExternal
        Hark LA, Katz LJ, Myers JS, Waisbourd M, Johnson D, Pizzi LT, Leiby BE, Fudemberg SJ, Mantravadi AV, Henderer JD, Zhan T, Molineaux J, Doyle V, Divers M, Burns C, Murchison AP, Reber S, Resende A, Bui TD, Lee J, Crews JE, Saaddine JB, Lee PP, Pasquale LR, Haller JA.
        Am J Ophthalmol. 2017 Jun 30.

        PURPOSE: To describe methodology and screening results from the Philadelphia Telemedicine Glaucoma Detection and Follow-up Study. DESIGN: Screening program results for a prospective, randomized clinical trial. MATERIALS AND METHODS: Individuals were recruited who were African-American, Hispanic/Latino, or Asian over age 40 years; Caucasian individuals over age 65 years; any ethnicity over age 40 years with a family history of glaucoma or diabetes. Primary care offices and Federally Qualified Health Centers were used for telemedicine (Visit 1). Two posterior fundus photographs and 1 anterior segment photograph were captured per eye in each participant, using a non-mydriatic, auto-focus, hand-held fundus camera (Volk Optical, Mentor, Ohio, USA). Medical and ocular history, family history of glaucoma, visual acuity, and intraocular pressure measurements using the ICarerebound tonometer (ICare, Helsinki, Finland) were obtained. Images were read remotely by a trained retina reader and a glaucoma specialist. RESULTS: From 4/1/15, to 2/6/17, 906 individuals consented and attended Visit 1. Of these, 553 participants were female (61.0%) and 550 were African American (60.7%), with a mean age of 58.7 years. A total of 532 (58.7%) participants had diabetes, and 616 (68%) had a history of hypertension. During Visit 1, 356 (39.3%) participants were graded with a normal image. Using image data from the worse eye, 333 (36.8%) were abnormal and 155 (17.1%) were unreadable. A total of 258 (28.5%) had a suspicious nerve; 62 (6.8%) had ocular hypertension, 102 (11.3%) had diabetic retinopathy; and 68 (7.5%) had other retinal abnormalities. CONCLUSION: An integrated telemedicine screening intervention in primary care offices and Federally Qualified Health Centers detected high rate of suspicious optic nerves, ocular hypertension, and retinal pathology.

    • Communicable Diseases
      1. Impact of pregnancy on observed sex disparities among adults hospitalized with laboratory-confirmed influenza, FluSurv-NET, 2010-2012External
        Kline K, Hadler JL, Yousey-Hindes K, Niccolai L, Kirley PD, Miller L, Anderson EJ, Monroe ML, Bohm SR, Lynfield R, Bargsten M, Zansky SM, Lung K, Thomas AR, Brady D, Schaffner W, Reed G, Garg S.
        Influenza Other Respir Viruses. 2017 Jul 13.

        INTRODUCTION: Previous FluSurv-NET studies found that adult females had a higher incidence of influenza-associated hospitalizations than males. To identify groups of women at higher risk than men, we analyzed data from 14 FluSurv-NET sites that conducted population-based surveillance for laboratory-confirmed influenza-associated hospitalizations among residents of 78 US counties. METHODS: We analyzed 6292 laboratory-confirmed, geocodable (96%) adult cases collected by FluSurv-NET during the 2010-12 influenza seasons. We used 2010 US Census and 2008-2012 American Community Survey data to calculate overall age-adjusted and age group-specific female:male incidence rate ratios (IRR) by race/ethnicity and census tract-level poverty. We used national 2010 pregnancy rates to estimate denominators for pregnant women aged 18-49. We calculated male:female IRRs excluding them and IRRs for pregnant:non-pregnant women. RESULTS: Overall, 55% of laboratory-confirmed influenza cases were female. Female:male IRRs were highest for females aged 18-49 of high neighborhood poverty (IRR 1.50, 95% CI 1.30-1.74) and of Hispanic ethnicity (IRR 1.70, 95% CI 1.34-2.17). These differences disappeared after excluding pregnant women. Overall, 26% of 1083 hospitalized females aged 18-49 were pregnant. Pregnant adult females were more likely to have influenza-associated hospitalizations than their non-pregnant counterparts (relative risk [RR] 5.86, 95% CI 5.12-6.71), but vaccination levels were similar (25.5% vs 27.8%). CONCLUSIONS: Overall rates of influenza-associated hospitalization were not significantly different for men and women after excluding pregnant women. Among women aged 18-49, pregnancy increased the risk of influenza-associated hospitalization sixfold but did not increase the likelihood of vaccination. Improving vaccination rates in pregnant women should be an influenza vaccination priority.

      2. HIV care and treatment of American Indians/Alaska natives with diagnosed HIV infection – 27 states and the District of Columbia, 2012External
        Mitsch A, Surendera Babu A, Seneca D, Whiteside YO, Warne D.
        Int J STD AIDS. 2017 Sep;28(10):953-961.

        The objective of this study was to measure linkage to care, retention in care, and suppressed viral load (VL) among American Indians/Alaska Natives (AIs/ANs) aged >/=13 years with diagnosed HIV infection. We used national HIV case surveillance data to measure linkage to care, defined as >/=1 CD4 or VL test </=1 month after HIV diagnosis during 2013; retention in care, defined as >/=2 CD4 or VL tests >/=3 months apart during 2012; and suppressed VL, defined as <200 copies/mL at the most recent VL test during 2012. In 2013, 74.1% of AIs/ANs were linked to care. At year-end 2012, 46.9% of AIs/ANs were retained in care and 45.1% were virally suppressed. A lower percentage of females (41.3%), compared with males (46.5), were virally suppressed. By age group, the lowest percentage of virally suppressed AIs/ANs (37.5%) were aged 13-34 years. To improve individual health and to prevent HIV among AIs/ANs, outcomes must improve – particularly for female AIs/ANs and for AIs/ANs aged 13-34 years. Screening for HIV infection in accordance with Centers for Disease Control and Prevention’s testing recommendations can lead to improvements along the continuum of HIV care.

      3. The role of screening and treatment in national progress toward hepatitis C elimination – Georgia, 2015-2016External
        Nasrullah M, Sergeenko D, Gvinjilia L, Gamkrelidze A, Tsertsvadze T, Butsashvili M, Metreveli D, Sharvadze L, Alkhazashvili M, Shadaker S, Ward JW, Morgan J, Averhoff F.
        MMWR Morb Mortal Wkly Rep. 2017 Jul 28;66(29):773-776.

        Georgia, a country in the Caucasus region of Eurasia, has a high prevalence of hepatitis C virus (HCV) infection. In April 2015, with technical assistance from CDC, Georgia embarked on the world’s first program to eliminate hepatitis C, defined as a 90% reduction in HCV prevalence by 2020 (1,2). The country committed to identifying infected persons and linking them to care and curative antiviral therapy, which was provided free of charge through a partnership with Gilead Sciences (1,2). From April 2015 through December 2016, a total of 27,595 persons initiated treatment for HCV infection, among whom 19,778 (71.7%) completed treatment. Among 6,366 persons tested for HCV RNA >/=12 weeks after completing treatment, 5,356 (84.1%) had no detectable virus in their blood, indicative of a sustained virologic response (SVR) and cure of HCV infection. The number of persons initiating treatment peaked in September 2016 at 4,595 and declined during October-December. Broader implementation of interventions that increase access to HCV testing, care, and treatment for persons living with HCV are needed for Georgia to reach national targets for the elimination of HCV.

    • Genetics and Genomics
      1. Genome-wide association study to identify variants associated with acute severe vaso-occlusive pain in sickle cell anemiaExternal
        Chaturvedi S, Bhatnagar P, Bean CJ, Steinberg MH, Milton JN, Casella JF, Barron-Casella E, Arking DE, DeBaun MR.
        Blood. 2017 Aug 03;130(5):686-688.

        [No abstract]

    • Health Behavior and Risk
      1. Risky trade: Individual and neighborhood-level socio-demographics associated with transactional sex among urban African American MSMExternal
        Stevens R, Icard L, Jemmott JB, O’Leary A, Rutledge S, Hsu J, Stephens-Shields A.
        J Urban Health. 2017 Aug 01.

        There is a clear, persistent association between poverty and HIV risk and HIV infection. Low educational attainment, neighborhood disadvantage, and residential instability are ways in which poverty is instrumentally experienced in urban America. We investigated the role of lived poverty at both the individual and neighborhood levels in transactional sex behavior among African American men who have sex with men (MSM) residing in urban neighborhoods. Using population-averaged models estimated by generalized estimating equation (GEE) models, we identified individual-level and neighborhood-level factors that are associated with exchanging sex for drugs and/or money. We tested the association between neighborhood and individual-level socioeconomic status and HIV risk behavior by combining area-based measures of neighborhood quality from the US Census with individual survey data from 542 low-income African American MSM. The primary outcome measure was self-reported transactional sex defined as exchanging sex for drugs or money. Individual-level covariates included high school non-completion, income, and problem drug use. Neighborhood-level covariates were high school non-completion and poverty rates. The findings suggested that educational attainment is associated with both the individual level and neighborhood level. Participants were more likely to engage in transactional sex if they did not complete high school (OR = 1.78), and similarly if their neighbors did not complete high school (OR = 7.70). These findings suggest potential leverage points for both community-level interventions and advocacy for this population, particularly related to transactional sex and education, and will aid HIV prevention efforts that seek to address the contextual constraints on individual risk behavior.

    • Healthcare Associated Infections
      1. Outbreak of septic arthritis associated with intra-articular injections at an outpatient practice – New Jersey, 2017External
        Ross K, Mehr J, Carothers B, Greeley R, Benowitz I, McHugh L, Henry D, DiFedele L, Adler E, Naqvi S, Lifshitz E, Tan C, Montana B.
        MMWR Morb Mortal Wkly Rep. 2017 Jul 28;66(29):777-779.

        On March 6, 2017, the New Jersey Department of Health (NJDOH) was notified of three cases of septic arthritis in patients who had received intra-articular injections for osteoarthritic knee pain at a private outpatient practice. The practice voluntarily closed the next day. NJDOH, in conjunction with the local health department and the New Jersey Board of Medical Examiners, conducted an investigation and identified 41 cases of septic arthritis associated with intra-articular injections administered during 250 patient visits at the same practice, including 30 (73%) patients who required surgery. Bacterial cultures of synovial fluid or tissue from 15 (37%) patients were positive; all recovered organisms were oral flora. An infection prevention assessment of the practice identified multiple breaches of recommended infection prevention practices, including inadequate hand hygiene, inappropriate use of pharmacy bulk packaged (PBP) products as multiple-dose containers and handling PBP products outside of required pharmacy conditions, and preparation of syringes up to 4 days in advance of their intended use. No additional septic arthritis cases were identified after infection prevention recommendations were implemented within the practice.

    • Laboratory Sciences
      1. Rolling out Xpert MTB/RIF for TB detection in HIV-infected populations: An opportunity for systems strengtheningExternal
        Pathmanathan I, Date A, Coggin WL, Nkengasong J, Piatek AS, Alexander H.
        Afr J Lab Med. 2017 Mar 31;6(2).

        BACKGROUND: To eliminate preventable deaths, disease and suffering due to tuberculosis (TB), improved diagnostic capacity is critical. The Cepheid Xpert(R) MTB/RIF assay is recommended by the World Health Organization as the initial diagnostic test for people with suspected HIV-associated TB. However, despite high expectations, its scale-up in real-world settings has faced challenges, often due to the systems that support it. OPPORTUNITIES FOR SYSTEM STRENGTHENING: In this commentary we discuss needs and opportunities for systems strengthening to support widespread scale-up of Xpert(R) MTB/RIF as they relate to each step within the TB diagnostic cascade, from finding presumptive patients, to collecting, transporting and testing sputum specimens, to reporting and receiving results, to initiating and monitoring treatment and, ultimately, to ensuring successful and timely treatment and cure. Investments in evidence-based interventions at each step along the cascade and within the system as a whole will augment not only the utility of Xpert(R) MTB/RIF, but also the successful implementation of future diagnostic tests. CONCLUSION: Xpert(R) MTB/RIF will only improve patient outcomes if optimally implemented within the context of strong TB programs and systems. Roll-out of this technology to people living with HIV and others in resource-limited settings offers the opportunity to leverage current TB and HIV laboratory, diagnostic and programmatic investments, while also addressing challenges and strengthening coordination between laboratory systems, laboratory-program interfaces, and TB-HIV program interfaces. If successful, the benefits of this tool could extend beyond progress towards global End TB Strategy goals, to improve system-wide capacity for global disease detection and control.

      2. Evolution and current understanding of physicochemical characterization of particulate matter from reactivity controlled compression ignition combustion on a multicylinder light-duty engineExternal
        Storey JM, Curran SJ, Lewis SA, Barone TL, Dempsey AB, Moses-Debusk M, Hanson RM, Prikhodko VY, Northrop WF.
        International Journal of Engine Research. 2017 ;18(5-6):505-519.

        Low-temperature compression ignition combustion can result in nearly smokeless combustion, as indicated by a smoke meter or other forms of soot measurement that rely on absorbance due to elemental carbon content. Highly premixed low-temperature combustion modes do not form particulate matter in the traditional pathways seen with conventional diesel combustion. Previous research into reactivity controlled compression ignition particulate matter has shown, despite a near zero smoke number, significant mass can be collected on filter media used for particulate matter certification measurement. In addition, particulate matter size distributions reveal that a fraction of the particles survive heated double-dilution conditions. This study summarizes research completed at Oak Ridge National Laboratory to date on characterizing the nature, chemistry and aftertreatment considerations of reactivity controlled compression ignition particulate matter and presents new research highlighting the importance of injection strategy and fuel composition on reactivity controlled compression ignition particulate matter formation. Particle size measurements and the transmission electron microscopy results do show the presence of soot particles; however, the elemental carbon fraction was, in many cases, within the uncertainty of the thermal-optical measurement. Particulate matter emitted during reactivity controlled compression ignition operation was also collected with a novel sampling technique and analyzed by thermal desorption or pyrolysis gas chromatography mass spectroscopy. Particulate matter speciation results indicated that the high boiling range of diesel hydrocarbons was likely responsible for the particulate matter mass captured on the filter media. To investigate potential fuel chemistry effects, either ethanol or biodiesel were incorporated to assess whether oxygenated fuels may enhance particle emission reduction. ? 2016 IMechE.

      3. Impact of larger sputum volume on Xpert MTB/RIF assay detection of Mycobacterium tuberculosis in smear-negative individuals with suspected tuberculosisExternal
        Badal-Faesen S, Firnhaber C, Kendall MA, Wu X, Grinsztejn B, Escada R, Fernandez M, Hogg E, Sanne I, Johnson P, Alland D, Mazurek GH, Benator DA, Luetkemeyer AF.
        J Clin Med. 2017 Aug 07;6(8).

        As a strategy to improve the sensitivity of nucleic acid-based testing in acid-fast bacilli (AFB) negative samples, larger volumes of sputum (5-10 mL) were tested with Xpert(R) MTB/RIF from 176 individuals with smear-negative sputum undergoing tuberculosis evaluation. Despite larger volumes, this strategy had a suboptimal sensitivity of 50% (4/8).

    • Statistics as Topic
      1. Bias correction in estimating proportions by pooled testingExternal
        Hepworth G, Biggerstaff BJ.
        Journal of Agricultural, Biological, and Environmental Statistics. 2017 :1-13.

        In the estimation of proportions by pooled testing, the MLE is biased, and several methods of correcting the bias have been presented in previous studies. We propose a new estimator based on the bias correction method introduced by Firth (Biometrika 80:27?38, 1993), which uses a modification of the score function, and we provide an easily computable, Newton?Raphson iterative formula for its computation. Our proposed estimator is almost unbiased across a range of problems, and superior to existing methods. We show that for equal pool sizes the new estimator is equivalent to the estimator proposed by Burrows (Phytopathology 77:363?365, 1987). The performance of our estimator is examined using pooled testing problems encountered in plant disease assessment and prevalence estimation of mosquito-borne viruses. Supplementary materials accompanying this paper appear online.

    • Zoonotic and Vectorborne Diseases
      1. Update: Interim guidance for health care providers caring for pregnant women with possible Zika virus exposure – United States Including U.S. territories), July 2017External
        Oduyebo T, Polen KD, Walke HT, Reagan-Steiner S, Lathrop E, Rabe IB, Kuhnert-Tallman WL, Martin SW, Walker AT, Gregory CJ, Ades EW, Carroll DS, Rivera M, Perez-Padilla J, Gould C, Nemhauser JB, Ben Beard C, Harcourt JL, Viens L, Johansson M, Ellington SR, Petersen E, Smith LA, Reichard J, Munoz-Jordan J, Beach MJ, Rose DA, Barzilay E, Noonan-Smith M, Jamieson DJ, Zaki SR, Petersen LR, Honein MA, Meaney-Delman D.
        MMWR Morb Mortal Wkly Rep. 2017 Jul 28;66(29):781-793.

        CDC has updated the interim guidance for U.S. health care providers caring for pregnant women with possible Zika virus exposure in response to 1) declining prevalence of Zika virus disease in the World Health Organization’s Region of the Americas (Americas) and 2) emerging evidence indicating prolonged detection of Zika virus immunoglobulin M (IgM) antibodies. Zika virus cases were first reported in the Americas during 2015-2016; however, the incidence of Zika virus disease has since declined. As the prevalence of Zika virus disease declines, the likelihood of false-positive test results increases. In addition, emerging epidemiologic and laboratory data indicate that, as is the case with other flaviviruses, Zika virus IgM antibodies can persist beyond 12 weeks after infection. Therefore, IgM test results cannot always reliably distinguish between an infection that occurred during the current pregnancy and one that occurred before the current pregnancy, particularly for women with possible Zika virus exposure before the current pregnancy. These limitations should be considered when counseling pregnant women about the risks and benefits of testing for Zika virus infection during pregnancy. This updated guidance emphasizes a shared decision-making model for testing and screening pregnant women, one in which patients and providers work together to make decisions about testing and care plans based on patient preferences and values, clinical judgment, and a balanced assessment of risks and expected outcomes.

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DISCLAIMER: Articles listed in the CDC Science Clips are selected by the Stephen B. Thacker CDC Library to provide current awareness of the public health literature. An article’s inclusion does not necessarily represent the views of the Centers for Disease Control and Prevention nor does it imply endorsement of the article’s methods or findings. CDC and DHHS assume no responsibility for the factual accuracy of the items presented. The selection, omission, or content of items does not imply any endorsement or other position taken by CDC or DHHS. Opinion, findings and conclusions expressed by the original authors of items included in the Clips, or persons quoted therein, are strictly their own and are in no way meant to represent the opinion or views of CDC or DHHS. References to publications, news sources, and non-CDC Websites are provided solely for informational purposes and do not imply endorsement by CDC or DHHS.

Page last reviewed: January 31, 2019