Rebecca Nowak

Dr. Rebecca Nowak

orcid

Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
1 April 2019 in JAIDS Journal of Acquired Immune Deficiency Syndromes
Verified
Journal Article
Closed access
RNRebecca Nowak
Rebecca Nowak
AMAndrew Mitchell
Andrew Mitchell
TCTrevor A. Crowell
Trevor A. Crowell
HLHongjie Liu
Hongjie Liu
SKSosthenes Ketende
Sosthenes Ketende
OGon behalf of the TRUST/RV368 Study Group
on behalf of the TRUST/RV368 Study Group
Background: To date, HIV incidence studies among men who have sex with men (MSM) across sub-Saharan Africa have focused on studying sexual risk practices with less focus on sexual networks. Setting: TRUST/RV368 conducted in Abuja and Lagos, Nigeria, recruited MSM using respondent-driven sampling and followed HIV-negative men for incident infection over 4 years. Methods: Four-hundred forty-one HIV-uninfected MSM underwent a parallel rapid HIV testing algorithm every 3 months for up to 18 months. HIV incidence per 100 person-years (PY) and 95% confidence intervals (CIs) were estimated using Poisson regression. Individual and network characteristics were examined using multivariable Cox-proportional hazards regression adjusted and unadjusted for respondent-driven sampling weights. Results: Among cohort members with a median age of 23 years [interquartile range (IQR): 20–27], 81 HIV infections occurred over 527 PY (incidence 15.4/100 PY; 95% CI: 12.3 to 19.0). The incidence rate was highest among 16–19 year olds as compared to those 25 years or older (30.9/100 PY; 95% CI: 22.1 to 45.3 vs. 6.9/100 PY; 95% CI: 4.2 to 10.9, respectively). Individual determinants included receptive partnerships, condomless sex, no history of testing for HIV, and rectal gonorrhea. Sexual networks were larger and consisted of an older sexual partner, although there was no clustering by recruitment networks. Conclusions: These HIV incidence data reinforce the unmet HIV prevention needs among young MSM in Nigeria. Even in the context of emerging HIV diagnostic and prevention strategies, structural challenges including stigma and criminalization of same-sex practices highlight the need for novel implementation approaches in the context of MSM-friendly services.

27 March 2017 in AIDS
Verified
Journal Article
Closed access
RNRebecca Nowak
Rebecca Nowak
SBSoren Bentzen
Soren Bentzen
JRJacques Ravel
Jacques Ravel
TCTrevor A. Crowell
Trevor A. Crowell
WDWuese Dauda
Wuese Dauda
MCManhattan E. Charurat
Manhattan E. Charurat
Objective: Untreated advanced HIV infection alters the gut microbiota, but it is unclear whether antiretroviral therapy (ART) reverses these changes. We compared the composition of the rectal microbiota among three groups of men who have sex with men (MSM): HIV-uninfected, untreated HIV, and ART-treated HIV-infected. Design: A cross-sectional study was conducted among 130 MSM (55 HIV-uninfected, 41 untreated HIV, and 34 ART-treated HIV) in Abuja, Nigeria. Methods: Bacterial 16S rRNA genes were amplified from rectal swabs, sequenced and clustered into Genera-level operational taxonomic units. Alpha diversity was quantified using the Shannon index and compared among groups using the Kruskal–Wallis test; associations with other scale variables were quantified using Spearman's rank correlation (Rs). The relative abundance of the top 15 taxa was compared according to HIV infection/treatment status using the Wilcoxon rank sum test. Results: HIV-treated MSM had a decrease in a commensal phylum, Bacteroidetes (P < 0.01). Alpha diversity was positively correlated with viral loads (Rs = 0.32, P < 0.01). Statistically significant shifts in relative abundance of rectal microbiota for the HIV-treated group included a decrease in the most abundant bacteria, Prevotella (P = 0.02) and an increase in pathogenic bacteria, Peptoniphilus (P = 0.04), Finegoldia (P = 0.01), Anaerococcus (P = 0.03), and Campylobacter (P = 0.03) compared with the other groups. Conclusion: Untreated HIV infection does not significantly alter the rectal microbiota, whereas prior treatment is associated with a shift toward a more pathogenic pattern of microbiota. Treatment with an antibiotic, co-trimoxazole, in conjunction with ART may have contributed to this shift.

1 April 2016 in Sexually Transmitted Diseases
Verified
Journal Article
Closed access
RNRebecca Nowak
Rebecca Nowak
PGPatti E. Gravitt
Patti E. Gravitt
XHXin He
Xin He
SKSosthenes Msc Ketende
Sosthenes Msc Ketende
WDWuese Mbbs Dauda
Wuese Mbbs Dauda
MCManhattan E. Charurat
Manhattan E. Charurat
Background Prevalence estimates of anal high-risk human papillomavirus (HR-HPV) are needed in sub-Saharan Africa where HIV is endemic. This study evaluated anal HR-HPV in Nigeria among HIV-positive and HIV-negative men who have sex with men (MSM) for future immunization recommendations. Methods We conducted a cross-sectional study to compare the prevalence of anal HR-HPV infections between 64 HIV-negative and 90 HIV-positive MSM. Multivariate Poisson regression analyses were used to examine demographic and behavioral risk factors associated with any HR-HPV infections. Results The median age of the 154 participants was 25 years (interquartile range, 22–28 years; range, 16–38 years), and the median age at initiation of anal sex with another man was 16 years (interquartile range, 13–18 years; range, 7–29 years). The prevalence of anal HR-HPV was higher among HIV-positive than HIV-negative MSM (91.1% vs. 40.6%, P < 0.001). In the multivariate analysis, HIV infection (adjusted prevalence ratio [aPR], 2.02; 95% confidence interval [CI], 1.49–2.72), 10 years or more since anal sexual debut (aPR, 1.26; 95% CI, 1.07–1.49), and concurrent relationships with men (aPR, 1.32; 95% CI, 1.04–1.67) were associated with increased anal HR-HPV prevalence. Conclusions Anal HR-HPV infection is high for young Nigerian MSM, and rates are amplified in those coinfected with HIV. Providing universal coverage as well as catch-up immunization for young MSM may be an effective anal cancer prevention strategy in Nigeria.

1 July 2020 in American Journal of Epidemiology
Verified
Journal Article
Open access
PDF file
JAJura L Augustinavicius
Jura L Augustinavicius
SBStefan D Baral
Stefan D Baral
SMSarah M Murray
Sarah M Murray
KJKevon Jackman
Kevon Jackman
QXQian-Li Xue
Qian-Li Xue
JKJeremy C Kane
Jeremy C Kane
Overcoming stigma affecting gay, bisexual, and other men who have sex with men (MSM) is a foundational element of an effective response to the human immunodeficiency virus (HIV) pandemic. Quantifying the impact of stigma mitigation interventions necessitates improved measurement of stigma for MSM around the world. In this study, we explored the underlying factor structure and psychometric properties of 13 sexual behavior stigma items among 10,396 MSM across 8 sub-Saharan African countries and the United States using cross-sectional data collected between 2012 and 2016. Exploratory factor analyses were used to examine the number and composition of underlying stigma factors. A 3-factor model was found to be an adequate fit in all countries (root mean square error of approximation = 0.02–0.05; comparative fit index/Tucker-Lewis index = 0.97–1.00/0.94–1.00; standardized root mean square residual = 0.04–0.08), consisting of “stigma from family and friends,” “anticipated health-care stigma,” and “general social stigma,” with internal consistency estimates across countries of α = 0.36–0.80, α = 0.72–0.93, and α = 0.51–0.79, respectively. The 3-factor model of sexual behavior stigma cut across social contexts among MSM in the 9 countries. These findings indicate commonalities in sexual behavior stigma affecting MSM across sub-Saharan Africa and the United States, which can facilitate efforts to track progress on global stigma mitigation interventions.

1 October 2020 in Journal of the International AIDS Society
Verified
Journal Article
Open access
HRHabib O Ramadhani
Habib O Ramadhani
TCTrevor A. Crowell
Trevor A. Crowell
RNRebecca Nowak
Rebecca Nowak
NNNicaise CDC Ndembi
Nicaise CDC Ndembi
BKBlessing O Kayode
Blessing O Kayode
MCManhattan E Charurat
Manhattan E Charurat
Introduction: Young men who have sex with men (MSM) and transgender women (TGW) face stigmas that hinder access to healthcare. The aim of the study was to understand age‐related determinants of healthcare needs and engagement among MSM and TGW.Methods: The TRUST/RV368 cohort provides integrated prevention and treatment services for HIV and other sexually transmitted infections (STIs) tailored to the needs of sexual and gender minorities. MSM and TGW aged ≥16 years in Abuja and ≥18 years Lagos, Nigeria, completed standardized behavioural questionnaires and were tested for HIV, Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) every three months for up to 18 months. Logistic regression was used to estimate adjusted odds ratios (aORs) for associations of age and other factors with outcomes of interest upon enrolment, including HIV care continuum steps – HIV testing, ART initiation and viral suppression <1000 copies/mL. Cox proportional hazards models were used to calculate adjusted hazard ratios (aHRs) for associations with incident infections.Results: Between March 2013 and February 2019, 2123 participants were enrolled with median age 23 (interquartile range 21 to 27) years. Of 1745 tested, 865 (49.6%) were living with HIV. HIV incidence was 11.6/100 person‐years [PY], including 23.1/100PY (95% CI 15.5 to 33.1) among participants aged 16 to 19 years and 23.8/100 PY (95% CI 13.6 to 39.1) among TGW. Compared to participants aged ≥25 years, those aged 16 to 19 years had decreased odds of prior HIV testing (aOR 0.40 [95% CI 0.11 to 0.92]), disclosing same‐sex sexual practices to healthcare workers (aOR 0.53 [95% CI 0.36 to 0.77]) and receiving HIV prevention information (aOR 0.60 [95% CI 0.41 to 0.87]). They had increased odds of avoiding healthcare (aOR 1.94 [95% CI 1.3 to 2.83]) and engaging in transactional sex (aOR 2.76 [95% CI 1.92 to 3.71]). Age 16 to 19 years was independently associated with increased incidence of HIV (aHR 4.09 [95% CI 2.33 to 7.49]), NG (aHR 3.91 [95% CI 1.90 to 8.11]) and CT (aHR 2.74 [95% CI 1.48 to 5.81]).Conclusions: Young MSM and TGW demonstrated decreased healthcare engagement and higher incidence of HIV and other STIs as compared to older participants in this Nigerian cohort. Interventions to address unique obstacles to healthcare engagement by adolescents and young adults are needed to curb the spread of HIV and other STIs among MSM and TGW in Nigeria.

1 December 2020 in Papillomavirus Research
Verified
Journal Article
Open access
RNRebecca Nowak
Rebecca Nowak
LSLisa M. Schumaker
Lisa M. Schumaker
NANicholas P. Ambulos
Nicholas P. Ambulos
NNNicaise Ndembi
Nicaise Ndembi
WDWuese Dauda
Wuese Dauda
SVSandhya Vasan
Sandhya Vasan
Anal precancers and cancers can be detected during screening with high-resolution anoscopy (HRA). The sensitivity of HRA depends on the burden and duration of human papillomavirus (HPV) among those screened as well as anoscopist proficiency, which is highly correlated with prior screening experience. Our objective was to compare the identification and type of HPV and the likelihood of HRA-detected precancer for men who have sex with men (MSM) undergoing their first HRA-screening in Nigeria. MSM were recruited from an HIV test-and-treat cohort, TRUST/RV368, into a new anal cancer screening program. Anal swabs obtained during screening underwent Ion Torrent next-generation sequencing using barcoded HPV PCR broad-spectrum primers 5+/6+ to detect up to 161 HPVs. All high-risk (HR) HPVs and the most abundant low-risk (LR)-HPVs were evaluated as type-specific infections with some categorized as belonging to a multiple infection. HRA screening results included benign, low-grade squamous intraepithelial lesions (LSIL), or HSIL as detected by cytology or histology. Multivariable logistic regression was used to assess the association of HPV and other cofactors with any SIL. Among 342 MSM, 60% were HIV-infected, 89% were under 35 years of age, and 51% had 8 or more years since anal coital debut. Of those with SIL, 89% had LSIL and only 11% had HSIL. Prevalence of any HPV and high-risk (HR)-HPV was 92% and 74%, respectively. The most prevalent genotypes in rank order were HPV6 (31%), HPV16 (23%), HPV42 (20%), HPV11 (18%), HPV45 (18%), and HPV51 (17%). For multiple HR-HPVs, 31% had a single HR-HPV, 32% had 2-3, and 10% had 4 or more. Low-risk HPVs, type 6 and/or 11, were common (42%) and were significantly associated with SIL (adjusted odds ratio [aOR]:1.8, 95% confidence interval [CI]: 1.1-3.1) together with perianal warts (aOR:6.7, 95% CI: 3.3-13.5). In contrast, HR-HPV and multiple HR-HPVs were not significantly associated with SIL (all p > 0.05). Detection of HSIL was low. Although HR-HPV was abundant, HSIL development also depends on the duration of HR-HPV infections and the anoscopist's level of experience. As our cohort ages and the anoscopist becomes more skilled, detection of HSIL will likely improve.