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Dive into the research topics where Jennifer L. Evans is active.

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Featured researches published by Jennifer L. Evans.


The Lancet | 2010

Artesunate versus quinine in the treatment of severe falciparum malaria in African children (AQUAMAT): an open-label, randomised trial.

Arjen M. Dondorp; Caterina I. Fanello; Ilse C. E. Hendriksen; Ermelinda Gomes; Amir Seni; Kajal D. Chhaganlal; Kalifa Bojang; Rasaq Olaosebikan; Nkechinyere Anunobi; Kathryn Maitland; Esther Kivaya; Tsiri Agbenyega; Samuel Blay Nguah; Jennifer L. Evans; Samwel Gesase; Catherine Kahabuka; George Mtove; Behzad Nadjm; Jacqueline L. Deen; Juliet Mwanga-Amumpaire; Margaret Nansumba; Corine Karema; Noella Umulisa; Aline Uwimana; Olugbenga A. Mokuolu; Ot Adedoyin; Wahab Babatunde Rotimi Johnson; Antoinette Tshefu; Marie Onyamboko; Tharisara Sakulthaew

Summary Background Severe malaria is a major cause of childhood death and often the main reason for paediatric hospital admission in sub-Saharan Africa. Quinine is still the established treatment of choice, although evidence from Asia suggests that artesunate is associated with a lower mortality. We compared parenteral treatment with either artesunate or quinine in African children with severe malaria. Methods This open-label, randomised trial was undertaken in 11 centres in nine African countries. Children (<15 years) with severe falciparum malaria were randomly assigned to parenteral artesunate or parenteral quinine. Randomisation was in blocks of 20, with study numbers corresponding to treatment allocations kept inside opaque sealed paper envelopes. The trial was open label at each site, and none of the investigators or trialists, apart from for the trial statistician, had access to the summaries of treatment allocations. The primary outcome measure was in-hospital mortality, analysed by intention to treat. This trial is registered, number ISRCTN50258054. Findings 5425 children were enrolled; 2712 were assigned to artesunate and 2713 to quinine. All patients were analysed for the primary outcome. 230 (8·5%) patients assigned to artesunate treatment died compared with 297 (10·9%) assigned to quinine treatment (odds ratio [OR] stratified for study site 0·75, 95% CI 0·63–0·90; relative reduction 22·5%, 95% CI 8·1–36·9; p=0·0022). Incidence of neurological sequelae did not differ significantly between groups, but the development of coma (65/1832 [3·5%] with artesunate vs 91/1768 [5·1%] with quinine; OR 0·69 95% CI 0·49–0·95; p=0·0231), convulsions (224/2712 [8·3%] vs 273/2713 [10·1%]; OR 0·80, 0·66–0·97; p=0·0199), and deterioration of the coma score (166/2712 [6·1%] vs 208/2713 [7·7%]; OR 0·78, 0·64–0·97; p=0·0245) were all significantly less frequent in artesunate recipients than in quinine recipients. Post-treatment hypoglycaemia was also less frequent in patients assigned to artesunate than in those assigned to quinine (48/2712 [1·8%] vs 75/2713 [2·8%]; OR 0·63, 0·43–0·91; p=0·0134). Artesunate was well tolerated, with no serious drug-related adverse effects. Interpretation Artesunate substantially reduces mortality in African children with severe malaria. These data, together with a meta-analysis of all trials comparing artesunate and quinine, strongly suggest that parenteral artesunate should replace quinine as the treatment of choice for severe falciparum malaria worldwide. Funding The Wellcome Trust.


Nature Genetics | 2014

Reappraisal of known malaria resistance loci in a large multicenter study

Kirk A. Rockett; Geraldine M. Clarke; Kathryn Fitzpatrick; Christina Hubbart; Anna Jeffreys; Kate Rowlands; Rachel Craik; Muminatou Jallow; David J. Conway; Kalifa Bojang; Margaret Pinder; Stanley Usen; Fatoumatta Sisay-Joof; Giorgio Sirugo; Ousmane Toure; Mahamadou A. Thera; Salimata Konate; Sibiry Sissoko; Amadou Niangaly; Belco Poudiougou; V. Mangano; Edith C. Bougouma; Sodiomon B. Sirima; David Modiano; Lucas Amenga-Etego; Anita Ghansah; Kwadwo A. Koram; Michael D. Wilson; Anthony Enimil; Jennifer L. Evans

Many human genetic associations with resistance to malaria have been reported, but few have been reliably replicated. We collected data on 11,890 cases of severe malaria due to Plasmodium falciparum and 17,441 controls from 12 locations in Africa, Asia and Oceania. We tested 55 SNPs in 27 loci previously reported to associate with severe malaria. There was evidence of association at P < 1 × 10−4 with the HBB, ABO, ATP2B4, G6PD and CD40LG loci, but previously reported associations at 22 other loci did not replicate in the multicenter analysis. The large sample size made it possible to identify authentic genetic effects that are heterogeneous across populations or phenotypes, with a striking example being the main African form of G6PD deficiency, which reduced the risk of cerebral malaria but increased the risk of severe malarial anemia. The finding that G6PD deficiency has opposing effects on different fatal complications of P. falciparum infection indicates that the evolutionary origins of this common human genetic disorder are more complex than previously supposed.


The Journal of Infectious Diseases | 2002

Hepatitis C Virus Seroconversion among Young Injection Drug Users: Relationships and Risks

Judith A. Hahn; Kimberly Page-Shafer; Paula J. Lum; Philippe Bourgois; Ellen Stein; Jennifer L. Evans; Michael P. Busch; Leslie H. Tobler; Bruce Phelps; Andrew R. Moss

The present study examined reasons for the high incidence of hepatitis C virus (HCV) infection among young injection drug users (IDUs). IDUs <30 years old who tested negative for HCV antibody were enrolled in a prospective cohort. Risk factors for seroconversion were examined using time-dependent regression analyses: 48 of 195 IDUs seroconverted to HCV, for an incidence rate of 25.1/100 person-years (95% confidence interval, 18.7-32.9/100 person-years). Independent risk factors included sharing needles with an HCV-infected sex partner (borderline statistical significance, P=.11) or a person who was not a sex partner, sharing nonsterile drug-preparation equipment, pooling money with another IDU to buy drugs, and exchanging sex for money. Ubiquitous behaviors among young IDUs, such as the forming of injecting or sexual partnerships and consequent sharing of needles and drug preparation equipment, are risk factors for HCV. Interventions to reduce HCV transmission must recognize the importance of relationships on injecting risk.


Journal of Urban Health-bulletin of The New York Academy of Medicine | 2003

Gender differences in sexual and injection risk behavior among active young injection drug users in San Francisco (the UFO Study).

Jennifer L. Evans; Judith A. Hahn; Kimberly Page-Shafer; Paula J. Lum; Ellen Stein; Peter J. Davidson; Andrew R. Moss

Female injection drug users (IDUs) represent a large proportion of persons infected with HIV in the United States, and women who inject drugs have a high incidence of hepatitis B virus (HBV) and hepatitis C virus (HCV) injection. Therefore, it is important to understand the role of gender in injection risk behavior and the transmission of blood-borne virus. In 2000–2002, 844 young (<30 years old) IDUs were surveyed in San Francisco. We compared self-reported risk behavior between 584 males and 260 female participants from cross-sectional baseline data. We used logistic regression to determine whether demographic, structural, and relationship variables explained increased needle borrowing, drug preparation equipment sharing, and being injected by another IDU among females compared to males. Females were significantly younger than males and were more likely to engage in needle borrowing, ancillary equipment sharing, and being injected by someone else. Females were more likely than males to report recent sexual intercourse and to have IDU sex partners. Females and males were not different with respect to education, race/ethnicity, or housing status. In logistic regression models for borrowing a used needle and sharing drug preparation equipment, increased risk in females was explained by having an injection partner who was also a sexual partner. Injecting risk was greater in the young female compared to male IDUs despite equivalent frequency of injecting. Overlapping sexual and injection partnerships were a key factor in explaining increased injection risk in females. Females were more likely to be injected by another IDU even after adjusting for years injecting, being in a relationship with another IDU, and other potential confounders. Interventions to reduce sexual and injection practices that put women at risk of contracting hepatitis and HIV are needed.


The Journal of Infectious Diseases | 2009

Acute Hepatitis C Virus Infection in Young Adult Injection Drug Users: A Prospective Study of Incident Infection, Resolution, and Reinfection

Kimberly Page; Judith A. Hahn; Jennifer L. Evans; Stephen Shiboski; Paula J. Lum; Eric Delwart; Leslie H. Tobler; William Andrews; Lia Avanesyan; Stewart Cooper; Michael P. Busch

BACKGROUND Hepatitis C virus (HCV) infection, clearance, and reinfection are best studied in injection drug users (IDUs), who have the highest incidence of HCV and are likely to represent most infections. METHODS A prospective cohort of HCV-negative young IDUs was followed up from January 2000 to September 2007, to identify acute and incident HCV and prospectively study infection outcomes. RESULTS Among 1,191 young IDUs screened, 731 (61.4%) were HCV negative, and 520 (71.1%) of the 731 were enrolled into follow-up. Cumulative HCV incidence was 26.7/100 person-years of observation (95% confidence interval [CI], 21.5-31.6). Of 135 acute/incident HCV infections, 95 (70.4%) were followed; 20 (21.1%) of the 95 infections cleared. Women had a significantly higher incidence of viral clearance than did men (age-adjusted hazard ratio, 2.91 [95% CI, 1.68-5.03]) and also showed a faster rate of early HCV viremia decline (P < .01). The estimated reinfection rate was 24.6/100 person-years of observation (95% CI, 11.7-51.6). Among 7 individuals, multiple episodes of HCV reinfection and reclearance were observed. CONCLUSIONS In this large sample of young IDUs, females show demonstrative differences in their rates of viral clearance and kinetics of early viral decline. Recurring reinfection and reclearance suggest possible protection against persistent infection. These results should inform HCV clinical care and vaccine development.


American Journal of Public Health | 2005

Revolving Doors: Imprisonment Among the Homeless and Marginally Housed Population

Margot B. Kushel; Judith A. Hahn; Jennifer L. Evans; David R. Bangsberg; Andrew R. Moss

OBJECTIVES We studied a sample of homeless and marginally housed adults to examine whether a history of imprisonment was associated with differences in health status, drug use, and sexual behaviors among the homeless. METHODS We interviewed 1426 community-based homeless and marginally housed adults. We used multivariate models to analyze factors associated with a history of imprisonment. RESULTS Almost one fourth of participants (23.1%) had a history of imprisonment. Models that examined lifetime substance use showed cocaine use (odds ratio [OR]=1.67; 95% confidence interval [CI]=1.04, 2.70), heroin use (OR=1.51; 95% CI=1.07, 2.12), mental illness (OR=1.41; 95% CI=1.01, 1.96), HIV infection (OR=1.69; 95% CI=1.07, 2.64), and having had more than 100 sexual partners were associated with a history of imprisonment. Models that examined recent substance use showed past-year heroin use (OR = 1.65; 95% CI = 1.14, 2.38) and methamphetamine use (OR=1.49; 95% CI=1.00, 2.21) were associated with lifetime imprisonment. Currently selling drugs also was associated with lifetime imprisonment. CONCLUSIONS Despite high levels of health risks among all homeless and marginally housed people, the levels among homeless former prisoners were even higher. Efforts to eradicate homelessness also must include the unmet needs of inmates who are released from prison.


Nature | 2012

Genome-wide association study indicates two novel resistance loci for severe malaria

Christian Timmann; Thorsten Thye; Maren Vens; Jennifer L. Evans; Jürgen May; Christa Ehmen; Jürgen Sievertsen; Birgit Muntau; Gerd Ruge; Wibke Loag; Daniel Ansong; Sampson Antwi; Emanuel Asafo-Adjei; Samuel Blay Nguah; Kingsley Osei Kwakye; Alex Osei Yaw Akoto; Justice Sylverken; Michael Brendel; Kathrin Schuldt; Christina Loley; Andre Franke; Christian G. Meyer; Tsiri Agbenyega; Andreas Ziegler; Rolf D. Horstmann

Malaria causes approximately one million fatalities per year, mostly among African children. Although highlighted by the strong protective effect of the sickle-cell trait, the full impact of human genetics on resistance to the disease remains largely unexplored. Genome-wide association (GWA) studies are designed to unravel relevant genetic variants comprehensively; however, in malaria, as in other infectious diseases, these studies have been only partly successful. Here we identify two previously unknown loci associated with severe falciparum malaria in patients and controls from Ghana, West Africa. We applied the GWA approach to the diverse clinical syndromes of severe falciparum malaria, thereby targeting human genetic variants influencing any step in the complex pathogenesis of the disease. One of the loci was identified on chromosome 1q32 within the ATP2B4 gene, which encodes the main calcium pump of erythrocytes, the host cells of the pathogenic stage of malaria parasites. The second was indicated by an intergenic single nucleotide polymorphism on chromosome 16q22.2, possibly linked to a neighbouring gene encoding the tight-junction protein MARVELD3. The protein is expressed on endothelial cells and might therefore have a role in microvascular damage caused by endothelial adherence of parasitized erythrocytes. We also confirmed previous reports on protective effects of the sickle-cell trait and blood group O. Our findings underline the potential of the GWA approach to provide candidates for the development of control measures against infectious diseases in humans.


BMJ | 2003

Risk of prevalent HIV infection associated with incarceration among injecting drug users in Bangkok, Thailand: case-control study

Aumphornpun Buavirat; Kimberly Page-Shafer; G. J. P. Van Griensven; Jeffrey S. Mandel; Jennifer L. Evans; J Chuaratanaphong; S Chiamwongpat; R Sacks; Andrew R. Moss

Abstract Objectives: To identify risks for HIV infection related to incarceration among injecting drug users in Bangkok, Thailand. Design: Case-control study of sexual and parenteral exposures occurring before, during, and after the most recent incarceration. Setting: Metropolitan Bangkok. Participants: Non-prison based injecting drug users formerly incarcerated for at least six months in the previous five years, with documented HIV serostatus since their most recent release; 175 HIV positive cases and 172 HIV negative controls from methadone clinics. Main outcome measure: Injection of heroin and methamphetamine, sharing of needles, sexual behaviour, and tattooing before, during, and after incarceration. Results: In the month before incarceration cases were more likely than controls to have injected methamphetamine and to have borrowed needles. More cases than controls reported using drugs (60% v 45%; P=0.005) and sharing needles (50% v 31%; P<0.01) in the holding cell before incarceration. Independent risk factors for prevalent HIV infection included injection of methamphetamine before detention (adjusted odds ratio 3.3, 95% confidence interval 1.01 to 10.7), sharing needles in the holding cell (1.9, 1.2 to 3.0), being tattooed while in prison (2.1, 1.3 to 3.4), and borrowing needles after release (2.5, 1.3 to 4.4). Conclusions: Injecting drug users in Bangkok are at significantly increased risk of HIV infection through sharing needles with multiple partners while in holding cells before incarceration. The time spent in holding cells is an important opportunity to provide risk reduction counselling and intervention to reduce the incidence of HIV. What is already known on this topic The incidence of HIV in Thailand is highest among injecting drug users in Bangkok Incarceration is a risk factor for incident HIV infection among Thai injecting drug users What this study adds Injecting drug users are at increased risk of HIV infection from sharing needles with multiple partners while in police holding cells before incarceration Other risk factors include injecting methamphetamine before imprisonment, being tattooed while imprisoned, and sharing needles after release


Clinical Infectious Diseases | 2005

Hepatitis C Virus Infection among Prisoners in the California State Correctional System

Rena K. Fox; Sue Currie; Jennifer L. Evans; Teresa L. Wright; Leslie H. Tobler; Bruce Phelps; Michael P. Busch; Kimberly Page-Shafer

BACKGROUND Incarcerated populations are at high risk for hepatitis C virus (HCV) infection, yet prisoners are not routinely screened or treated for HCV infection. Understanding the risk factors of HCV infection among prisoners could help improve HCV interventions. METHODS Prevalence and risk of HCV infection among 469 prisoners entering California State correctional facilities were assessed using HCV antibody screening, HCV RNA measurement, and structured interviews. Multivariate logistic regression analysis was used to identify independent correlates of HCV infection. RESULTS The prevalence of HCV infection was 34.3% overall (95% confidence interval [CI], 30%-38%) and was 65.7% among those with a history of injection drug use (IDU), compared with 10.2% among those with no history of IDU (odds ratio [OR], 17.24; 95% CI, 10.52-28.25). Significant differences in HCV antibody positivity were found in association with age at first detention but not with the nature of the crime. Independent correlates of HCV infection included age, history of IDU, cumulative time of incarceration, biological sex (OR for females subjects compared with males subjects, 0.35; 95% CI, 0.13-0.96), and a history of having sex with a male IDU (OR, 4.42; 95% CI, 1.46-13.37). We identified significant differences in risk factors between male and female subjects--notably, that the risk of HCV infection was significantly elevated among female non-IDUs who reported having sexual partners with a history of IDU. Among non-IDUs, correlates of HCV infection included history of receipt of blood products and cumulative years of incarceration. CONCLUSIONS HCV infection is pervasive among the California prison population, including prisoners who are non-IDUs and women with high-risk sexual behavior. These results should promote consideration of routine HCV antibody screening and behavioral interventions among incarcerated men and women.


JAMA Internal Medicine | 2014

Association of Opioid Agonist Therapy With Lower Incidence of Hepatitis C Virus Infection in Young Adult Injection Drug Users

Judith I. Tsui; Jennifer L. Evans; Paula J. Lum; Judith A. Hahn; Kimberly Page

IMPORTANCE Injection drug use is the primary mode of transmission for hepatitis C virus (HCV) infection. Prior studies suggest opioid agonist therapy may reduce the incidence of HCV infection among injection drug users; however, little is known about the effects of this therapy in younger users. OBJECTIVE To evaluate whether opioid agonist therapy was associated with a lower incidence of HCV infection in a cohort of young adult injection drug users. DESIGN, SETTING, AND PARTICIPANTS Observational cohort study conducted from January 3, 2000, through August 21, 2013, with quarterly interviews and blood sampling. We recruited young adult (younger than 30 years) injection drug users who were negative for anti-HCV antibody and/or HCV RNA. EXPOSURES Substance use treatment within the past 3 months, including non-opioid agonist forms of treatment, opioid agonist (methadone hydrochloride or buprenorphine hydrochloride) detoxification or maintenance therapy, or no treatment. MAIN OUTCOMES AND MEASURES Incident HCV infection documented with a new positive result for HCV RNA and/or HCV antibodies. Cumulative incidence rates (95% CI) of HCV infection were calculated assuming a Poisson distribution. Cox proportional hazards regression models were fit adjusting for age, sex, race, years of injection drug use, homelessness, and incarceration. RESULTS Baseline characteristics of the sample (n = 552) included median age of 23 (interquartile range, 20-26) years; 31.9% female; 73.1% white; 39.7% who did not graduate from high school; and 69.2% who were homeless. During the observation period of 680 person-years, 171 incident cases of HCV infection occurred (incidence rate, 25.1 [95% CI, 21.6-29.2] per 100 person-years). The rate ratio was significantly lower for participants who reported recent maintenance opioid agonist therapy (0.31 [95% CI, 0.14-0.65]; P = .001) but not for those who reported recent non-opioid agonist forms of treatment (0.63 [95% CI, 0.37-1.08]; P = .09) or opioid agonist detoxification (1.45 [95% CI, 0.80-2.69]; P = .23). After adjustment for other covariates, maintenance opioid agonist therapy was associated with lower relative hazards for acquiring HCV infection over time (adjusted hazard ratio, 0.39 [95% CI, 0.18-0.87]; P = .02). CONCLUSIONS AND RELEVANCE In this cohort of young adult injection drug users, recent maintenance opioid agonist therapy was associated with a lower incidence of HCV infection. Maintenance treatment with methadone or buprenorphine for opioid use disorders may be an important strategy to prevent the spread of HCV infection among young injection drug users.

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Kimberly Page

University of New Mexico

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Judith A. Hahn

University of California

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Paula J. Lum

University of California

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Ellen Stein

University of California

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Andrew R. Moss

University of California

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Alya Briceno

University of California

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