Last data update: May 06, 2024. (Total: 46732 publications since 2009)
Records 1-5 (of 5 Records) |
Query Trace: Powell SE[original query] |
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Stability testing of dried Plasmodium falciparum positive quality control samples for malaria rapid diagnostic tests in Liberia and Benin
Ramani S , Kohar HT , Pratt O , Denon YE , Reed CM , Thomas P , Powell SE , Aidoo M . Malar J 2020 19 (1) 288 BACKGROUND: Malaria rapid diagnostic tests (RDTs) are largely responsible for the gains made in the proportion of malaria cases confirmed with a parasitological test. However, quality assurance programs to support their use remain a challenge. A dried tube specimen (DTS) method was developed that showed potential for use as a stable source of quality control (QC) sample for RDTs and for use in external quality assessments or proficiency testing (PT). DTS was further assessed with focus on sample stability under field settings in Benin and Liberia. METHODS: DTS were prepared using Plasmodium falciparum 3D7 or W2 strains at concentrations of 1000, 500 or 0 parasites/µL and tested for baseline reactivity at the Centers for Disease Control and Prevention, Atlanta before shipping. In Benin and Liberia, DTS were stored under refrigeration in a reference laboratory (RL) or in health centres under ambient temperatures. Seven rounds of testing were performed at 4-week intervals during which DTS were tested on RDTs stored at the RL or at health centres. Observed DTS reactivity at the RL and health centres were compared to expected reactivity to determine DTS stability. DTS were also assembled into a PT panel and tested by health facility staff at the mid and end time-points of the study. Daily maximum and minimum storage temperatures for RDTs and DTS were recorded. RESULTS: In Benin, DTS, irrespective of storage conditions, produced the expected reactivity at all time points. However, evidence of degradation was observed at weeks 20 and 24 for DTS stored at ambient temperatures at the health centres and not those stored under refrigeration at the RL. In Liberia, sample degradation was observed starting at week 8 especially among DTS stored at the health facilities. The degradation was associated with prolonged storage of DTS under ambient temperature prior to study commencement and less than optimal storage temperatures at the RL. Use of DTS in a PT enabled identification of health worker errors in performing the tests. CONCLUSION: DTS is a feasible tool for use as QC material and for PT under field conditions. Long-term (> 5 months) storage of DTS requires refrigeration. |
Monitoring effect of human papillomavirus vaccines in US population, Emerging Infections Program, 2008-2012
Hariri S , Markowitz LE , Bennett NM , Niccolai LM , Schafer S , Bloch K , Park IU , Scahill MW , Julian P , Abdullah N , Levine D , Whitney E , Unger ER , Steinau M , Bauer HM , Meek J , Hadler J , Sosa L , Powell SE , Johnson ML , Hpv-Impact Working Group . Emerg Infect Dis 2015 21 (9) 1557-61 In 2007, five Emerging Infections Program (EIP) sites were funded to determine the feasibility of establishing a population-based surveillance system for monitoring the effect of human papillomavirus (HPV) vaccine on pre-invasive cervical lesions. The project involved active population-based surveillance of cervical intraepithelial neoplasia grades 2 and 3 and adenocarcinoma in situ as well as associated HPV types in women >18 years of age residing in defined catchment areas; collecting relevant clinical information and detailed HPV vaccination histories for women 18-39 years of age; and estimating the annual rate of cervical cancer screening among the catchment area population. The first few years of the project provided key information, including data on HPV type distribution, before expected effect of vaccine introduction. The project's success exemplifies the flexibility of EIP's network to expand core activities to include emerging surveillance needs beyond acute infectious diseases. Project results contribute key information regarding the impact of HPV vaccination in the United States. |
Impact of human papillomavirus (HPV) vaccination on HPV 16/18-related prevalence in precancerous cervical lesions
Powell SE , Hariri S , Steinau M , Bauer HM , Bennett NM , Bloch KC , Niccolai LM , Schafer S , Unger ER , Markowitz LE . Vaccine 2012 31 (1) 109-13 BACKGROUND: Vaccination against human papillomavirus (HPV) types 16 and 18 is recommended for girls aged 11 or 12 years with catch-up vaccination through age 26 in the U.S. Cervical intraepithelial neoplasia (CIN) grade 2 or 3 and adenocarcinoma in situ (CIN2+) are used to monitor HPV vaccine impact on cervical disease. This report describes vaccination status in women diagnosed with CIN2+ and examines HPV vaccine impact on HPV 16/18-related CIN2+. METHODS: As part of a vaccine impact monitoring project (HPV-IMPACT), females 18-31 years with CIN2+ were reported from pathology laboratories in CA, CT, NY, OR, TN from 2008 to 2011. One diagnostic block was selected for HPV DNA typing with Roche Linear Array. Demographic, abnormal Papanicolaou (Pap) test dates and vaccine status information were collected. The abnormal Pap test immediately preceding the CIN2+ diagnosis was defined as the 'trigger Pap'. RESULTS: Among 5083 CIN2+ cases reported to date, 3855 had vaccination history investigated; 1900 had vaccine history documented (vaccinated, with trigger Pap dates, or unvaccinated). Among women who initiated vaccination >24 months before their trigger Pap, there was a significantly lower proportion of CIN2+ lesions due to 16/18 compared to women who were not vaccinated (aPR=.67, 95% CI: .48-.94). Among the 1900 with known vaccination status, 20% initiated vaccination on/after their trigger screening. Women aged 21-23 years were more likely to initiate vaccination on/after the trigger Pap compared to 24-26 year olds (29.0% vs. 19.6%, p=.001), as were non-Hispanic blacks compared to non-Hispanic whites (27.3% vs. 19.0%, p=.001) and publicly compared to privately insured women (38.1% vs. 17.4%, p<.0001). CONCLUSION: We found a significant reduction in HPV 16/18-related lesions in women with CIN2+ who initiated vaccination at least 24 months prior to their trigger Pap. These preliminary results suggest early impact of the HPV vaccine on vaccine-type disease, but further evaluation is warranted. |
Human papillomavirus genotypes in high-grade cervical lesions in the United States.
Hariri S , Unger ER , Powell SE , Bauer HM , Bennett NM , Bloch KC , Niccolai LM , Schafer S , Steinau M , Markowitz LE . J Infect Dis 2012 206 (12) 1878-86 BACKGROUND: Two vaccines protect against human papillomaviruses (HPV) 16 and 18 that cause 70% of cervical cancer and 50% of cervical intraepithelial neoplasia 2/3 and adenocarcinoma in situ (CIN2+). Monitoring HPV types in CIN2+ may be used to assess HPV vaccine impact. METHODS: As part of a multi-site vaccine impact monitoring project (HPV-IMPACT), biopsy specimens used to diagnose CIN2+ were obtained for HPV DNA typing for women aged 18-39 years. RESULTS: Among 4,121 CIN2+ cases reported from 2008-2009 in 18-39 year-old women 3,058 (74.2%) were tested; 96% were HPV DNA positive. HPV16 was most common (49.1%), followed by HPV31 (10.4%) and HPV52 (9.7%). HPV18 prevalence was 5.5% overall. Proportion of CIN2+ cases associated with HPV16/18 was highest (56.3%) in 25-29 year-old women. HPV16/18-associated lesions were less common in non-Hispanic blacks (41.9%) and Hispanics (46.3%) compared to non-Hispanic whites (59.1%) (p<.0001); the difference remained significant when adjusted for covariates. Compared to non-Hispanic white, HPV35 and 58 were significantly more common in non-Hispanic black (14.5% vs. 4.2%; 12.3% vs. 3.4%) and HPV45 was higher in Hispanic cases (3.7% vs. 1.5%). CONCLUSION: Age and racial/ethnic differences in HPV type distribution may have implications for vaccine impact, and must be considered in monitoring trends. |
The HPV vaccine impact monitoring project (HPV-IMPACT): assessing early evidence of vaccination impact on HPV-associated cervical cancer precursor lesions.
Hariri S , Unger ER , Powell SE , Bauer HM , Bennett NM , Bloch KC , Niccolai LM , Schafer S , Markowitz LE . Cancer Causes Control 2011 23 (2) 281-8 The following paper describes a collaboration between the Centers for Disease Control and Prevention and five Emerging Infections Program sites to develop a comprehensive population-based approach to monitoring human papillomavirus (HPV) vaccine impact on cervical cancer precursors and associated HPV genotypes. The process of establishing this novel monitoring system is described, and development details such as enumeration of sources for reporting cervical intraepithelial neoplasia 2/3 and adenocarcinoma in situ, approaches to case ascertainment, electronic reporting, and HPV typing are outlined. Implementation of a feasible and sustainable surveillance system for HPV-associated cervical precancers will enable evaluation of the direct impact of HPV vaccination. |
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