Last data update: Dec 09, 2024. (Total: 48320 publications since 2009)
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Query Trace: Newell K[original query] |
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Nirsevimab effectiveness against medically attended respiratory syncytial virus illness and hospitalization among Alaska native children - Yukon-Kuskokwim Delta Region, Alaska, October 2023-June 2024
Lefferts B , Bressler S , Keck JW , Desnoyers C , Hodges E , January G , Morris K , Herrmann L , Singleton R , Aho S , Rogers J , Newell K , Ohlsen E , Link-Gelles R , Dawood FS , Bruden D , Fischer M , Klejka J , Scobie HM . MMWR Morb Mortal Wkly Rep 2024 73 (45) 1015-1021 Respiratory syncytial virus (RSV) is a leading cause of hospitalization among young children. Historically, American Indian and Alaska Native (AI/AN) children have experienced high rates of RSV-associated hospitalization. In August 2023, a preventive monoclonal antibody (nirsevimab) was recommended for all infants aged <8 months (born during or entering their first RSV season) and for children aged 8-19 months (entering their second RSV season) who have increased risk for severe RSV illness, including all AI/AN children. This evaluation in Alaska's Yukon-Kuskokwim Delta region estimated nirsevimab effectiveness among AI/AN children in their first or second RSV seasons during 2023-2024. Among 472 children with medically attended acute respiratory illness (ARI), 48% overall had received nirsevimab ≥7 days earlier (median = 91 days before the ARI-related visit). For children in their first RSV season (292), nirsevimab effectiveness was 76% (95% CI = 42%-90%) against medically attended RSV illness and 89% (95% CI = 32%-98%) against RSV hospitalization. For children in their second RSV season (180), effectiveness against medically attended RSV illness was 88% (95% CI = 48%-97%). Nirsevimab is effective for preventing severe RSV illness among infants entering their first RSV season and children entering their second season with increased risk for severe RSV, including all AI/AN children. |
Fatal borealpox in an immunosuppressed patient treated with antivirals and vaccinia immunoglobulin - Alaska, 2023
Rogers JH , Westley B , Mego T , Newell KG , Laurance J , Smith L , Parker J , Park SY , Venkatasubrahmanyam S , Noll N , Bercovici S , Rao AK , McCollum AM , Davidson W , Carson WC , Townsend MB , Doty JB , Hutson C , Li Y , Wilkins K , Deng J , Gigante CM , Satheshkumar PS , Tuttle A , Villalba JA , Bhatnagar J , Reagan-Steiner S , Castrodale LJ , McLaughlin JB . Clin Infect Dis 2024 BACKGROUND: Borealpox virus (BRPV, formerly known as Alaskapox virus) is a zoonotic member of the Orthopoxvirus genus first identified in a person in 2015. In the six patients with infection previously observed BRPV involved mild, self-limiting illness. We report the first fatal BRPV infection in an immunosuppressed patient. METHODS: A man aged 69 years from Alaska's Kenai Peninsula was receiving anti-CD20 therapy for chronic lymphocytic leukemia. He presented to care for a tender, red papule in his right axilla with increasing induration and pain. The patient failed to respond to multiple prescribed antibiotic regimens and was hospitalized 65 days postsymptom onset for progression of presumed infectious cellulitis. BRPV was eventually detected through orthopoxvirus real-time polymerase chain reaction testing of mucosal swabs. He received combination antiviral therapy, including 21 days of intravenous tecovirimat, intravenous vaccinia immunoglobulin, and oral brincidofovir. Serial serology was conducted on specimens obtained posttreatment initiation. FINDINGS: The patient's condition initially improved with plaque recession, reduced erythema, and epithelization around the axillary lesion beginning one-week post-therapy. He later exhibited delayed wound healing, malnutrition, acute renal failure, and respiratory failure. He died 138 days postsymptom onset. Serologic testing revealed no evidence the patient generated a humoral immune response. No secondary cases were detected. CONCLUSION: This report demonstrates that BRPV can cause overwhelming disseminated infection in certain immunocompromised patients. Based on the patient's initial response, early BRPV identification and antiviral therapies might have been beneficial. These therapies, in combination with optimized immune function, should be considered for patients at risk for manifestations of BRPV. |
Characterizing the etiology of recurrent tuberculosis using whole genome sequencing-Alaska, USA, 2008-2020
Springer YP , Tompkins ML , Newell K , Jones M , Burns S , Chandler B , Cowan LS , Kammerer JS , Posey JE , Raz KM , Rothoff M , Silk BJ , Vergnetti YL , McLaughlin JB , Talarico S . J Infect Dis 2024 BACKGROUND: Understanding the etiology of recurrent tuberculosis (rTB) is important for effective TB control. Prior to the advent of whole genome sequencing (WGS), attributing rTB to relapse or reinfection using genetic information was complicated by the limited resolution of conventional genotyping methods. METHODS: We applied a systematic method of evaluating whole genome single nucleotide polymorphism (wgSNP) distances and results of phylogenetic analyses to characterize the etiology of rTB in American Indian and Alaska Native (AIAN) persons in Alaska during 2008-2020. We contextualized our findings through descriptive analyses of surveillance data and results of a literature search for investigations that characterized rTB etiology using WGS. RESULTS: The percentage of TB cases in AIAN persons in Alaska classified as recurrent episodes (11.8%) was three times the national percentage (3.9%). Of 38 recurrent episodes included in genetic analyses, we attributed 25 (65.8%) to reinfection based on wgSNP distances and phylogenetic analyses; this proportion was the highest among 16 published point estimates identified through the literature search. By comparison, we attributed 11 of 38 (28.9%) and 6 of 38 (15.8%) recurrent episodes to reinfection based on wgSNP distances alone and on conventional genotyping methods, respectively. CONCLUSIONS: WGS and attribution criteria involving genetic distances and patterns of relatedness can provide an effective means of elucidating rTB etiology. Our findings indicate that rTB occurs at high proportions among AIAN persons in Alaska and is frequently attributable to reinfection, reinforcing the importance of active surveillance and control measures to limit the spread of TB disease in Alaskan AIAN communities. |
Using geographic disaggregation to compare tuberculosis epidemiology among American Indian and Alaska native persons-USA, 2010-2020
Springer YP , Kammerer JS , Felix D , Newell K , Tompkins ML , Allison J , Castrodale LJ , Chandler B , Helfrich K , Rothoff M , McLaughlin JB , Silk BJ . J Racial Ethn Health Disparities 2024 BACKGROUND: American Indian and Alaska Native (AIAN) populations are frequently associated with the highest rates of tuberculosis (TB) disease of any racial/ethnic group in the USA. We systematically investigated variation in patterns and potential drivers of TB epidemiology among geographically distinct AIAN subgroups. METHODS: Using data reported to the National Tuberculosis Surveillance System during 2010-2020, we applied a geographic method of data disaggregation to compare annual TB incidence and the frequency of TB patient characteristics among AIAN persons in Alaska with AIAN persons in other states. We used US Census data to compare the prevalence of substandard housing conditions in AIAN communities in these two geographic areas. RESULTS: The average annual age-adjusted TB incidence among AIAN persons in Alaska was 21 times higher than among AIAN persons in other states. Compared to AIAN TB patients in other states, AIAN TB patients in Alaska were associated with significantly higher frequencies of multiple epidemiologic TB risk factors (e.g., attribution of TB disease to recent transmission, previous diagnosis of TB disease) and significantly lower frequencies of multiple clinical risk factors for TB disease (e.g., diagnosis with diabetes mellitus, end-stage renal disease). Occupied housing units in AIAN communities in Alaska were associated with significantly higher frequencies of multiple measures of substandard housing conditions compared to AIAN communities in other states. CONCLUSIONS: Observed differences in patient characteristics and substandard housing conditions are consistent with contrasting syndromes of TB epidemiology in geographically distinct AIAN subgroups and suggest ways that associated public health interventions could be tailored to improve efficacy. |
Effects of rurality on distance and time traveled to receive vaccination against Mpox - New Mexico and Idaho 2022-2023
Stadelman-Behar AM , Cahill ME , Newell K , Sievers M , Gehre M , Carter KK , Sosin DM , Torrone EA . Sex Transm Dis 2023 We compared mpox vaccination access between urban and rural residents who received ≥1 JYNNEOS dose using immunization data in Idaho and New Mexico. Rural residents traveled five times farther and three times longer than urban residents to receive mpox vaccination. Increasing mpox vaccine availability to healthcare facilities might increase uptake. |
Temporally associated invasive pneumococcal disease and SARS-CoV-2 infection, Alaska, USA, 2020-2021
Newell K , Fischer M , Massey S , Orell L , Steinberg J , Tompkins M , Castrodale L , McLaughlin J . Emerg Infect Dis 2023 29 (9) 1765-1771 Streptococcus pneumoniae can co-infect persons who have viral respiratory tract infections. However, research on S. pneumoniae infections that are temporally associated with SARS-CoV-2 infections is limited. We described the epidemiology and clinical course of patients who had invasive pneumococcal disease (IPD) and temporally associated SARS-CoV-2 infections in Alaska, USA, during January 1, 2020-December 23, 2021. Of 271 patients who had laboratory-confirmed IPD, 55 (20%) had a positive SARS-CoV-2 test result. We observed no major differences in age, race, sex, or underlying medical conditions among IPD patients with and without SARS-CoV-2. However, a larger proportion of IPD patients with SARS-CoV-2 died (16%, n = 9) than for those with IPD alone (4%, n = 9) (p<0.01). IPD patients with SARS-CoV-2 were also more likely to be experiencing homelessness (adjusted OR 3.5; 95% CI 1.7-7.5). Our study highlights the risk for dual infection and ongoing benefits of pneumococcal and COVID-19 vaccination, especially among vulnerable populations. |
Multipathogen outbreak of bacillus cereus and clostridium perfringens among hospital workers in Alaska, August 2021
Newell K , Helfrich K , Isernhagen H , Jones M , Stickel G , McKeel H , Castrodale L , McLaughlin J . Public Health Rep 2023 333549231170220 OBJECTIVE: Clostridium perfringens and Bacillus cereus are common causes of reported foodborne illness. On August 6, 2021, the Alaska Division of Public Health identified a multipathogen gastrointestinal outbreak among hospital staff in Homer, Alaska. The objectives of this study were to identify the outbreak source and prevent future illness. METHODS: We conducted a retrospective cohort study of hospital staff who participated in luncheon events during August 5-7, 2021, and used an online survey to identify hospital staff with gastrointestinal illness. We defined case patients as people who reported new-onset gastrointestinal illness (diarrhea or abdominal cramping) after food consumption during the luncheon events. We calculated adjusted odds ratios of gastrointestinal illness associated with reported food exposures. We tested available food samples for C perfringens and B cereus and tested case patient stool specimens for C perfringens. We conducted an environmental investigation at the implicated vendor site. RESULTS: Of 202 survey responses, 66 (32.7%) people reported acute gastrointestinal illness: 64 (97.0%) reported diarrhea, 62 (94.9%) reported abdominal cramps, and none were hospitalized. Of 79 people who consumed ham and pulled pork sandwiches, 64 (81.0%) met the case definition; this food item was significantly associated with increased odds of gastrointestinal illness (adjusted odds ratio = 296.4; 95% CI, 76.7-2019.1). C perfringens and B cereus were isolated at confirmatory levels from sandwich samples. C perfringens enterotoxin was detected in all 5 stool specimens tested. Environmental investigators observed other food items at the sandwich vendor that were refrigerated outside the required temperature range (>41 °F); no clear handling deficiencies for the implicated food were identified. CONCLUSION: Quick notification and effective collaboration can help detect an outbreak, identify the responsible food vehicle, and mitigate further risk. |
The effect of interventions distributing home fortification products on infant and young child feeding (IYCF) practices: A systematic narrative review
Locks LM , Newell KB , Imohe A , Moloney GM , Shaker L , Paudyal N , Jefferds MED . Matern Child Nutr 2023 19 (3) e13488 Interventions distributing micronutrient powders (MNPs) and small-quantity lipid-based nutrient supplements (SQ-LNS), or home fortification products (HFPs), have the potential to improve infant and young child feeding (IYCF) practices and children's nutrition. We systematically searched for studies on the effect of interventions distributing HFP on IYCF practices. We identified 12 (8 MNP, 4 SQ-LNS) studies: seven programmes with IYCF behaviour change communications (BCC) and MNP (IYCF-MNP) and one provided MNP without IYCF BCC (MNP only). Three SQ-LNS studies came from randomised trials without an IYCF component (SQ-LNS only) and one from a programme with both IYCF BCC and SfQ-LNS (IYCF-SQ-LNS). Five IYCF-MNP programmes reported positive associations with some IYCF practices-four with minimum dietary diversity, two with minimum meal frequency, four with minimum acceptable diet, and three with the initiation of complementary foods at 6 months. Two reported no association between MNP and IYCF indicators, and one reported a decline in IYCF practices during the intervention, although it also reported significant changes to the IYCF programme during the evaluation period. Two studies from interventions that distributed SQ-LNS (one from a related set of randomised controlled trials and the sole IYCF-SQ-LNS programme) reported a positive association with IYCF practices; one trial reported no change in breast milk intake with the provision of SQ-LNS and one found no association with IYCF practices. SQ-LNS and MNP can address nutrient gaps for young children in low-resource settings; our findings indicate that programmes that combine HFP with IYCF interventions may also contribute to improved IYCF practices in some settings. |
Increased Mortality among Persons with Symptomatic COVID-19 During the Period of SARS-CoV-2 B.1.617.2 (Delta Variant) Predominance-Alaska, November 2020-October 2021.
Mooring EQ , Newell K , Castrodale L , Tompkins M , Frank M , McLaughlin J . Clin Infect Dis 2022 75 S298-S302 We compared the mortality risk in Alaska among persons with symptomatic COVID-19 during the period the Delta variant was dominant to those with symptomatic COVID-19 before Delta predominance. The Delta period was associated with 2.43-fold higher odds of death. Unvaccinated persons were 4.49 times more likely to die than fully vaccinated persons. |
Contribution of maternal ART and breastfeeding to 24-month survival in HIV-exposed uninfected children: an individual pooled analysis of African and Asian studies
Arikawa S , Rollins N , Jourdain G , Humphrey J , Kourtis AP , Hoffman I , Essex M , Farley T , Coovadia HM , Gray G , Kuhn L , Shapiro R , Leroy V , Bollinger RC , Onyango-Makumbi C , Lockman S , Marquez C , Doherty T , Dabis F , Mandelbrot L , Le Coeur S , Rolland M , Joly P , Newell ML , Becquet R . Clin Infect Dis 2017 66 (11) 1668-1677 Background: Increasing numbers of HIV-infected pregnant women receive antiretroviral therapy (ART) to prevent mother-to-child transmission (PMTCT). Studies suggested that HIV-exposed uninfected (HEU) children face higher mortality than HIV-unexposed children, but evidence mostly relates to the pre-ART era, breastfeeding of limited duration and considerable maternal mortality. Maternal ART and prolonged breastfeeding under cover of ART may improve survival, although this has not been reliably quantified. Methods: Individual data on 19,219 HEU children from 21 PMTCT trials/cohorts undertaken 1995-2015 in Africa and Asia were pooled and the association between 24-month mortality and maternal/infant factors quantified using random-effects Cox proportional hazards models accounting for between-study heterogeneity. Adjusted attributable fractions of risks computed using the predict function in the R package "frailtypack" estimate the relative contribution of risk factors to overall mortality in HEU children. Results: Cumulative incidence of death was 5.5% (95%CI: 5.1-5.9) by age 24 months. Low birth weight (LBW<2500g, adjusted Hazard Ratio (aHR: 2.9), no breastfeeding (aHR: 2.5) and maternal death (aHR: 11.1) were significantly associated with increased mortality. Maternal ART (aHR: 0.5) was significantly associated with lower mortality. At population level, LBW accounted for 16.2% of child deaths by 24 months, never breastfeeding for 10.8%, mother not receiving ART for 45.6%, and maternal death for 4.3%; these factors combined explained 63.6% of deaths by age 24 months. Conclusion: Survival of HEU children could be substantially improved if public health strategies provided all mothers living with HIV with ART and supported optimal infant feeding and care for LBW neonates. |
Campylobacter fetus infections in humans: exposure and disease
Wagenaar JA , van Bergen MA , Blaser MJ , Tauxe RV , Newell DG , van Putten JP . Clin Infect Dis 2014 58 (11) 1579-86 Campylobacter fetus can cause intestinal illness and, occasionally, severe systemic infections. Infections mainly affect persons at higher risk, including elderly and immunocompromised individuals and those with occupational exposure to infected animals. Outbreaks are infrequent but have provided insight into sources. Source attribution of sporadic cases through case-control interviews has not been reported. The reservoirs for C. fetus are mainly cattle and sheep. Products from these animals are suspected as sources for human infections. Campylobacter fetus is rarely isolated from food, albeit selective isolation methods used in food microbiology are not suited for its detection. We hypothesize that the general population is regularly exposed to C. fetus through foods of animal origin, cross-contaminated foodstuffs, and perhaps other, as yet unidentified, routes. Campylobacter fetus infection should be suspected particularly in patients with nonspecific febrile illness who are immunocompromised or who may have been occupationally exposed to ruminants. |
National and regional estimates of term and preterm babies born small for gestational age in 138 low-income and middle-income countries in 2010
Lee ACC , Katz J , Blencowe H , Cousens S , Kozuki N , Vogel JP , Adair L , Baqui AH , Bhutta ZA , Caulfield LE , Christian P , Clarke SE , Ezzati M , Fawzi W , Gonzalez R , Huybregts L , Kariuki S , Kolsteren P , Lusingu J , Marchant T , Merialdi M , Mongkolchati A , Mullany LC , Ndirangu J , Newell ML , Nien JK , Osrin D , Roberfroid D , Rosen HE , Sania A , Silveira MF , Tielsch J , Vaidya A , Willey BA , Lawn JE , Black RE . Lancet Glob Health 2013 1 (1) e26-e36 Background: National estimates for the numbers of babies born small for gestational age and the comorbidity with preterm birth are unavailable. We aimed to estimate the prevalence of term and preterm babies born small for gestational age (term-SGA and preterm-SGA), and the relation to low birthweight (<2500 g), in 138 countries of low and middle income in 2010. Methods: Small for gestational age was defined as lower than the 10th centile for fetal growth from the 1991 US national reference population. Data from 22 birth cohort studies (14 low-income and middle-income countries) and from the WHO Global Survey on Maternal and Perinatal Health (23 countries) were used to model the prevalence of term-SGA births. Prevalence of preterm-SGA infants was calculated from meta-analyses. Findings: In 2010, an estimated 324 million infants were born small for gestational age in low-income and middle-income countries (27% of livebirths), of whom 106 million infants were born at term and low birthweight. The prevalence of term-SGA babies ranged from 53% of livebirths in east Asia to 415% in south Asia, and the prevalence of preterm-SGA infants ranged from 12% in north Africa to 30% in southeast Asia. Of 18 million low-birthweight babies, 59% were term-SGA and 41% were preterm-SGA. Two-thirds of small-for-gestational-age infants were born in Asia (174 million in south Asia). Preterm-SGA babies totalled 28 million births in low-income and middle-income countries. Most small-for-gestational-age infants were born in India, Pakistan, Nigeria, and Bangladesh. Interpretation: The burden of small-for-gestational-age births is very high in countries of low and middle income and is concentrated in south Asia. Implementation of effective interventions for babies born too small or too soon is an urgent priority to increase survival and reduce disability, stunting, and non-communicable diseases. |
Differential profiles and inhibitory effect on rotavirus vaccines of non-antibody components in breast milk from mothers in developing and developed countries
Moon SS , Tate JE , Ray P , Dennehy PH , Archary D , Coutsoudis A , Bland R , Newell ML , Glass RI , Parashar U , Jiang B . Pediatr Infect Dis J 2013 32 (8) 863-70 BACKGROUND: Live oral rotavirus vaccines have been less immunogenic and efficacious for children of developing countries than for those in middle income and industrialized countries and the basis for these differences is not fully understood. Recently, we demonstrated that breastmilk from mothers in India had significantly higher IgA and neutralizing activity against rotavirus that could reduce the effective titer of rotavirus vaccines reaching the gut when compared to that from mothers in the US. We extended our study to understand the specific contribution of those non-antibody components in breastmilk to the neutralizing activity against rotavirus vaccine we observed. METHODS: Breastmilk samples were collected from mothers of breast-feeding infants aged between 4 to 29 weeks (i.e., vaccine eligible age) in India (N=40), South Africa (N=50) and the United States (N=51). We examined breastmilk for lactoferrin, lactadherin, rotavirus-specific IgA, and neutralizing activity against three rotavirus vaccine strains: Rotarix; RotaTeq G1; and 116E using enzyme immunoassays; a plaque reduction assay; or a microneutralization assay. FINDINGS: We observed higher levels of lactoferrin, lactadherin, IgA, and neutralizing activity in breastmilk specimens from Indian and South African women than those from American women. We demonstrated positive associations between levels of lactoferrin or IgA and neutralizing activity in Indian and South African specimens, but not in American specimens. We demonstrated that the inhibitory effect of lactoferrin was dose- or species-dependent, as evidenced by greater reduction in titer of Rotarix and 116E by human lactoferrin. Lactadherin also exhibited inhibitory activity to rotavirus vaccines but appeared to be less effective. INTERPRETATION: The lower immunogenicity and efficacy of rotavirus vaccines in developing countries could be explained, in part, by synergistic inhibitory effect of high levels of antibody and non-antibody components in breastmilk consumed by infants at the time of immunization. Therefore, there is a need for alternative rotavirus vaccine strategies in breastfeeding populations. |
Family history of colorectal cancer: clinicians' preventive recommendations and patient behavior.
Zlot AI , Silvey K , Newell N , Coates RJ , Leman R . Prev Chronic Dis 2012 9 E21 Few population-based studies have addressed the role that family history of colorectal cancer (CRC) plays in clinician decision making or patient health choices. The objective of this study was to evaluate the effect of family history of CRC on clinician practice, patient CRC screening, and patient preventive behavior. We analyzed 2008 Oregon Behavioral Risk Factor Surveillance System data to examine associations between family history of CRC and 1) patient-reported clinician recommendations, 2) perceived risk of developing CRC, 3) adoption of preventive and screening behaviors, and 4) CRC risk factors among 1,795 respondents without CRC. A family history of CRC was positively associated with a higher likelihood of respondents reporting that their clinicians discussed colorectal cancer screening (OR, 4.2; 95% CI, 2.4-7.4) and of respondents having colorectal screening within the recommended time period (OR, 2.2; 95% CI, 1.3-3.9). A family history of CRC was also associated with respondents reporting lifestyle changes to prevent CRC (OR, 2.6; 95% CI, 1.7-4.0). A family history of CRC may prompt clinicians to recommend screening and preventive behavior changes and motivate patients to adopt such strategies. |
Maternal HIV-1 disease progression 18-24 months postdelivery according to antiretroviral prophylaxis regimen (triple-antiretroviral prophylaxis during pregnancy and breastfeeding vs zidovudine/single-dose nevirapine prophylaxis): the Kesho Bora randomized controlled trial
Dioulasso B , Faso B , Meda N , Fao P , Ky-Zerbo O , Gouem C , Somda P , Hien H , Ouedraogo PE , Kania D , Sanou A , Kossiwavi IA , Sanogo B , Ouedraogo M , Siribie I , Valea D , Ouedraogo S , Some R , Rouet F , Rollins N , McFetridge L , Naidu K , Luchters S , Reyners M , Irungu E , Katingima C , Mwaura M , Ouattara G , Mandaliya K , Wambua S , Thiongo M , Nduati R , Kose J , Njagi E , Mwaura P , Newell ML , Mepham S , Viljoen J , Bland R , Mthethwa L . Clin Infect Dis 2012 55 (3) 449-460 BACKGROUND: Antiretroviral (ARV) prophylaxis effectively reduces mother-to-child transmission of human immunodeficiency virus type 1 (HIV). However, it is unclear whether stopping ARVs after breastfeeding cessation affects maternal HIV disease progression. We assessed 18-24-month postpartum disease progression risk among women in a randomized trial assessing efficacy and safety of prophylactic maternal ARVs. METHODS: From 2005 to 2008, HIV-infected pregnant women with CD4+ counts of 200-500/mm(3) were randomized to receive either triple ARV (zidovudine, lamivudine, and lopinavir/ritonavir during pregnancy and breastfeeding) or AZT/sdNVP (zidovudine until delivery with single-dose nevirapine without postpartum prophylaxis). Maternal disease progression was defined as the combined endpoint of death, World Health Organization clinical stage 4 disease, or CD4+ counts of <200/mm(3). RESULTS: Among 824 randomized women, 789 had at least 1 study visit after cessation of ARV prophylaxis. Following delivery, progression risk up to 24 months postpartum in the triple ARV arm was significantly lower than in the AZT/sdNVP arm (15.7 vs 28.3; P =. 001), but the risks of progression after cessation of ARV prophylaxis (rather than after delivery) were not different (15.0 vs 13.8 18 months after ARV cessation). Among women with CD4+ counts of 200-349/mm(3) at enrollment, 24.0 (95 confidence interval [CI], 15.7-35.5) progressed with triple ARV, and 23.0 (95 CI, 17.8-29.5) progressed with AZT/sdNVP, whereas few women in either arm (<5) with initial CD4+ counts of >=350/mm(3) progressed. CONCLUSIONS: Interrupting prolonged triple ARV prophylaxis had no effect on HIV progression following cessation (compared with AZT/sdNVP). However, women on triple ARV prophylaxis had lower progression risk during the time on triple ARV. Given the high rate of progression among women with CD4+ cells of <350/mm(3), ARVs should not be discontinued in this group. CLINICAL TRIALS REGISTRATION: ISRCTN71468410. (2012 The Author.) |
Children who acquire HIV infection perinatally are at higher risk of early death than those acquiring infection through breastmilk: a meta-analysis
Becquet R , Marston M , Dabis F , Moulton LH , Gray G , Coovadia HM , Essex M , Ekouevi DK , Jackson D , Coutsoudis A , Kilewo C , Leroy V , Wiktor SZ , Nduati R , Msellati P , Zaba B , Ghys PD , Newell ML . PLoS One 2012 7 (2) e28510 BACKGROUND: Assumptions about survival of HIV-infected children in Africa without antiretroviral therapy need to be updated to inform ongoing UNAIDS modelling of paediatric HIV epidemics among children. Improved estimates of infant survival by timing of HIV-infection (perinatally or postnatally) are thus needed. METHODOLOGY/PRINCIPAL FINDINGS: A pooled analysis was conducted of individual data of all available intervention cohorts and randomized trials on prevention of HIV mother-to-child transmission in Africa. Studies were right-censored at the time of infant antiretroviral initiation. Overall mortality rate per 1000 child-years of follow-up was calculated by selected maternal and infant characteristics. The Kaplan-Meier method was used to estimate survival curves by child's HIV infection status and timing of HIV infection. Individual data from 12 studies were pooled, with 12,112 children of HIV-infected women. Mortality rates per 1,000 child-years follow-up were 39.3 and 381.6 for HIV-uninfected and infected children respectively. One year after acquisition of HIV infection, an estimated 26% postnatally and 52% perinatally infected children would have died; and 4% uninfected children by age 1 year. Mortality was independently associated with maternal death (adjusted hazard ratio 2.2, 95%CI 1.6-3.0), maternal CD4<350 cells/ml (1.4, 1.1-1.7), postnatal (3.1, 2.1-4.1) or peri-partum HIV-infection (12.4, 10.1-15.3). CONCLUSIONS/RESULTS: These results update previous work and inform future UNAIDS modelling by providing survival estimates for HIV-infected untreated African children by timing of infection. We highlight the urgent need for the prevention of peri-partum and postnatal transmission and timely assessment of HIV infection in infants to initiate antiretroviral care and support for HIV-infected children. |
Determination of optimal paths to task goals using expert system based on GOMS model
Oyewole SA , Haight JM . Comput Human Behav 2011 27 (2) 823-833 Website users often experience several difficulties while trying to access or navigate a website. This is mostly due to their inability to familiarize themselves with the structures in the website or as a result of complex procedures which prevent them from reaching their goals. It is therefore, important to develop a methodology or guidance technique for assisting website users to achieve their goals. A type of expert system that provides the needed guidance necessary in order to achieve these goals was proposed in this paper. A sample website was initially designed, and the analysis of website menu structure was conducted. The rules to find the optimal path are established based on the Goals, Operators, Methods, and Selection rules (GUMS) model by considering individual preferences on input devices. Derivatives of the GUMS model such as the Cognitive Perceptual Model GUMS, Natural GUMS Language, GUMS Language and GUMS Language Evaluation and Analysis were reviewed. The Card, Moran and Newell (CMN) GUMS technique was selected as the primary inference engine of the proposed expert system. This was primarily based on the highly efficient and exemplary capability of the CMN-GUMS to predict both operator sequence and execution time. The expert system was finally constructed from the result of the acquired knowledge base and other applicable rules. (C) 2010 Elsevier Ltd. All rights reserved. |
Net survival of perinatally and postnatally HIV-infected children: a pooled analysis of individual data from sub-Saharan Africa
Marston M , Becquet R , Zaba B , Moulton LH , Gray G , Coovadia H , Essex M , Ekouevi DK , Jackson D , Coutsoudis A , Kilewo C , Leroy V , Wiktor S , Nduati R , Msellati P , Dabis F , Newell ML , Ghys PD . Int J Epidemiol 2011 40 (2) 385-96 BACKGROUND: Previously, HIV epidemic models have used a double Weibull curve to represent high initial and late mortality of HIV-infected children, without distinguishing timing of infection (peri- or post-natally). With more data on timing of infection, which may be associated with disease progression, a separate representation of children infected early and late was proposed. METHODS: Paediatric survival post-HIV infection without anti-retroviral treatment was calculated using pooled data from 12 studies with known timing of HIV infection. Children were grouped into perinatally or post-natally infected. Net mortality was calculated using cause-deleted life tables to give survival as if HIV was the only competing cause of death. To extend the curve beyond the available data, children surviving beyond 2.5 years post infection were assumed to have the same survival as young adults. Double Weibull curves were fitted to both extended survival curves to represent survival of children infected perinatally or through breastfeeding. RESULTS: Those children infected perinatally had a much higher risk of dying than those infected through breastfeeding, even allowing for background mortality. The final-fitted double Weibull curves gave 75% survival at 5 months after infection for perinatally infected, and 1.1 years for post-natally infected children. An estimated 25% of the early infected children would still be alive at 10.6 years compared with 16.9 years for those infected through breastfeeding. CONCLUSIONS: The increase in available data has enabled separation of child mortality patterns by timing of infection allowing improvement and more flexibility in modelling of paediatric HIV infection and survival. |
Antiretroviral therapy and preterm delivery-a pooled analysis of data from the United States and Europe
Townsend C , Schulte J , Thorne C , Dominguez KI , Tookey PA , Cortina-Borja M , Peckham CS , Bohannon B , Newell ML . BJOG 2010 117 (11) 1399-410 OBJECTIVE: To investigate reported differences in the association between highly active antiretroviral therapy (HAART) in pregnancy and the risk of preterm delivery among HIV-infected women. DESIGN: Combined analysis of data from three observational studies. SETTING: USA and Europe. POPULATION: A total of 19, 585 singleton infants born to HIV-infected women, 1990-2006. METHODS: Data from the Pediatric Spectrum of HIV Disease project (PSD), a US monitoring study, the European Collaborative Study (ECS), a consented cohort study, and the National Study of HIV in Pregnancy and Childhood (NSHPC), the United Kingdom and Ireland surveillance study. MAIN OUTCOME MEASURE: Preterm delivery rate (<37 weeks of gestation). RESULTS: Compared with monotherapy, HAART was associated with increased preterm delivery risk in the ECS (adjusted odds ratio [AOR] 2.40, 95% CI 1.49-3.86) and NSHPC (AOR 1.43, 95% CI 1.10-1.86), but not in the PSD (AOR 0.92, 95% CI 0.67-1.26), after adjusting for relevant covariates. Because of heterogeneity, data were not pooled for this comparison, but heterogeneity disappeared when HAART was compared with dual therapy (P = 0.26). In a pooled analysis, HAART was associated with 1.5-fold increased odds of preterm delivery compared with dual therapy (95% CI 1.19-1.87, P=0.001), after adjusting for covariates. CONCLUSIONS: Heterogeneity in the association between HAART and preterm delivery was not explained by study design, adjustment for confounders or a standard analytical approach, but may have been the result of substantial differences in populations and data collected. The pooled analysis comparing HAART with dual therapy showed an increased risk of preterm delivery associated with HAART. |
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