Cindy Firnhaber

Right to Care, Johannesburg, Gauteng, South Africa

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Publications (12)33.46 Total impact

  • Journal of clinical virology: the official publication of the Pan American Society for Clinical Virology 01/2014; · 3.12 Impact Factor
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    ABSTRACT: Background: There is little evidence comparing treatment outcomes between adolescents and other age groups particularly in resource limited settings. Methods: Retrospective analysis of data from 7 HIV clinics across urban Gauteng (n=5) and rural Mpumalanga (n=2), South Africa. The analysis compared HIV-positive ART-naive young adolescents (10-14years), older adolescents (15-19) and young adults (20-24years) to adults (≥24years) initiated onto standard first-line antiretroviral therapy (ART) between April 2004-August 2010. Log-binomial regression was used to estimate relative risk (RR) of failure to suppress viral load (≥400copies/ml) or failure to achieve an adequate CD4 response at 6 or 12months. The effect of age group on virological failure, mortality and loss to follow-up (LTFU;≥90d since scheduled visit date) was estimated using Cox proportional hazards models. Results: Of 42,427 patients initiating ART, 310(0.7%) were young adolescents, 342(0.8%) were older adolescents and 1599(3.8%) were young adults. Adolescents were similar to adults in terms of proportion male, baseline CD4 count, hemoglobin and TB. Compared to adults, both older adolescents (6months RR 1.75 95% CI 1.25-2.47) and young adults (6months RR 1.33 95% CI 1.10-1.60 and 12months RR 1.64 95% CI 1.23-2.19) were more likely to have an unsuppressed viral load and were more likely to fail virologically (HR 2.90 95% CI 1.74-4.86; HR 2.94 95% CI 1.63-5.31). There was no difference in risk of mortality by age category, compared to adults. Young adolescents were less likely to be LTFU at any time period after ART initiation (HR 0.43 95% CI 0.26-0.69) whereas older adolescents and young adults were more likely to be LTFU after ART initiation (HR 1.38 95% CI 1.07-1.78; HR 1.52 95% CI 1.34-1.72) compared to adults. Conclusion: HIV-infected adolescents and young adults between 15-24years have poorer ART treatment outcomes. Interventions are needed to help improve outcomes and retention in care in this unique population.
    AIDS research and human retroviruses 02/2013; · 2.18 Impact Factor
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    ABSTRACT: Little is known about the impact of pregnancy on response to highly active antiretroviral therapy (HAART) in sub-Saharan Africa. We examined the effect of incident pregnancy after HAART initiation on clinical response to HAART. We evaluated a prospective clinical cohort of adult women initiating HAART in Johannesburg, South Africa between 1 April 2004 and 31 March 2011, and followed up until an event, transfer, drop-out, or administrative end of follow-up on 30 September 2011. Women over age 45 and women who were pregnant at HAART initiation were excluded from the study. Main exposure was having experienced pregnancy after HAART initiation; main outcome was death and (separately) death or new AIDS event. We calculated adjusted hazard ratios (HRs) and 95% confidence limits (CL) using marginal structural Cox proportional hazards models. The study included 7,534 women, and 20,813 person-years of follow-up; 918 women had at least one recognized pregnancy during follow-up. For death alone, the weighted (adjusted) HR was 0.84 (95% CL 0.44, 1.60). Sensitivity analyses confirmed main results, and results were similar for analysis of death or new AIDS event. Incident pregnancy was associated with a substantially reduced hazard of drop-out (HR = 0.62, 95% CL 0.51, 0.75). Recognized incident pregnancy after HAART initiation was not associated with increases in hazard of clinical events, but was associated with a decreased hazard of drop-out. High rates of pregnancy after initiation of HAART may point to a need to better integrate family planning services into clinical care for HIV-infected women.
    PLoS ONE 01/2013; 8(3):e58117. · 3.53 Impact Factor
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    ABSTRACT: OBJECTIVE:: Recent studies have raised concerns about a change in rates of pregnancy among HIV-negative women exposed to tenofovir.Here, our objective was todetermine among HIV-positive women whether use of tenofovir at HAART initiation or thereafter is associated with subsequent changes in incidence of pregnancy. DESIGN:: Analysis of prospectively collected clinical data. METHODS:: We used Cox proportional hazards models and logistic regression to estimate hazard ratios and odds-ratios for the association of baseline tenofovir use and time to first incident pregnancy. We used marginal structural Cox models to estimate hazard ratios for the association of current tenofovir use and time to first incident pregnancy. RESULTS:: We studied 7,275 women, of whom 1,199 were initiated on tenofovir-based HAART regimens, and who experienced a total of 894 pregnancies in 17,200 person-years of follow-up. Analyses showed slight reductions in hazards of pregnancy among women who used tenofovir, but without sufficient precision to draw strong conclusions. Sensitivity analyses confirmed main results. CONCLUSIONS:: Tenofovir may be associated with a lower hazard or rate of pregnancy in women receiving HAART. However, conclusions are limited by low precision, the observational nature of the data, and possible uncontrolled confounding by temporal trends in contraception use and other factors.
    AIDS (London, England) 08/2012; · 4.91 Impact Factor
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    ABSTRACT: Peripheral neuropathy (PN) is associated with advanced HIV disease and may be a complication of antiretroviral therapy (ART) or anti-tuberculosis (TB) drugs, specifically isoniazid (INH). The effect of non-ART-drug-related PN on treatment outcomes is yet to be determined. We analysed prospectively collected cohort data for HIV-infected ART-naive adults initiating ART at the Themba Lethu Clinic, Johannesburg, South Africa from June 2004 to June 2009. Patients who presented with signs and symptoms of numbness or dysesthesia prior to initiation of ART were defined as having PN. Cox proportional hazard models were used to estimate the effect of PN alone (HIV-related PN) or PN with a history of INH use (TB-related PN) on mortality, lost to follow-up (LTFU), persistent and recurrent PN by 12 months of follow-up. Of the 9,399 patients initiating ART, 3.9 % had HIV-related PN while a further 1.8 % had TB-related PN. Patients with PN did not have a significantly higher risk of mortality compared to those without PN (hazard ratio (HR) 1.17 95 % CI 0.92-1.49). Patients with TB-related PN were less likely to be LTFU by 12 months (HR 0.65 95 % CI 0.44-0.97) compared to those without PN. Patients with HIV-related PN were at increased risk of persistent PN at 3 months post-ART initiation. Patients with HIV-related PN had a similar risk of recurrent PN compared to those with TB-related PN (HR 1.28 95 % CI 0.72-2.27). We demonstrate that patients with PN at initiation of ART present with advanced HIV disease. Completion of TB treatment may reduce the risk of persistent PN in patients with TB-related PN. Use of HIV drugs, even neurotoxic ones, may overall limit neuropathy.
    Journal of NeuroVirology 04/2012; 18(3):162-71. · 2.85 Impact Factor
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    ABSTRACT: Pregnancy is a common indication for initiation of highly active antiretroviral therapy (HAART) in sub-Saharan Africa. Our objective was to evaluate how pregnancy at treatment initiation predicts virologic response to HAART. We evaluated an open cohort of 9173 patients who initiated HAART between April 2004 and September 2009 in the Themba Lethu Clinic in Johannesburg, South Africa. Risk ratios were estimated using log-binomial regression; hazard ratios were estimated using Cox proportional hazards models; time ratios were estimated using accelerated failure time models. We controlled for calendar date, age, ethnicity, employment status, history of smoking, tuberculosis, WHO stage, weight, body mass index, hemoglobin, CD4 count and CD4 percent, and whether clinical care was free. Extensive sensitivity and secondary analyses were performed. During follow-up, 822 nonpregnant women and 70 pregnant women experienced virologic failure. In adjusted analyses, pregnancy at baseline was associated with reduced risk of virologic failure by 6 months [risk ratio 0.66, 95% confidence limits (CL): 0.35 to 1.22] and with reduced hazard of virologic failure over follow-up (hazard ratio: 0.69, 95% CL: 0.50 to 0.95). The adjusted time ratio for failure was 1.44 (95% CL: 1.13 to 1.84), indicating 44% longer time to event among women pregnant at baseline. Sensitivity analyses generally confirmed main findings. Pregnancy at HAART initiation is not associated with increased risk of virologic failure at 6 months or during longer follow-up.
    JAIDS Journal of Acquired Immune Deficiency Syndromes 04/2012; 60(5):489-94. · 4.65 Impact Factor
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    ABSTRACT: Hepatitis B virus (HBV) infection with undetectable hepatitis B surface antigen (HBsAg) has been reported in HIV patients, but the clinical significance is unknown. This study presents the prevalence of HBV DNA in HIV-positive patients negative for all HBV serological markers and a retrospective evaluation of the clinical course of mono- and co-infection. Of 502 HIV-positive patients, 222 tested negative for HBsAg, antibody to hepatitis B surface antigen (anti-HBs), and antibody to hepatitis B core antigen (anti-HBc). An in-house real-time PCR targeting the HBV S-region was used to quantify HBV DNA. HBV isolates were genotyped. Baseline demographic and clinical characteristics of HBV DNA-positive and HBV DNA-negative patients were described. Treatment outcomes of patients at 6, 12, and 24 months after initiation of antiretroviral therapy (ART) were summarized. HBV DNA was detected in 5.4% (12/222) of serologically negative patients. Mean HBV viral load was 5359.2 IU/ml (standard deviation (SD) ±12 768.27). Eleven HBV isolates belonged to genotype A and one to genotype C. There were no significant differences in baseline characteristics or clinical course between the HBV DNA-positive and HBV DNA-negative groups. We found 5.4% of the HBV serologically-negative HIV-positive patients had low levels of HBV DNA. There were no significant differences in clinical outcome between the mono- and co-infected groups.
    International journal of infectious diseases: IJID: official publication of the International Society for Infectious Diseases 02/2012; 16(4):e268-72. · 2.17 Impact Factor
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    ABSTRACT: Many resource limited settings (RLS) suffer from high rates of both cervical cancer and HIV. Limited HPV serology data are available from RLS; such data could help describe local patterns of HPV infection and predict vaccine efficacy. To determine seropositivity to HPV types 6, 11, 16 and 18 in HIV-infected women from South Africa (SA), Botswana and Brazil. HPV serotyping for high-risk types 6, 11, 16 and 18 was performed on samples collected from HIV-infected women from 2003-2010 using competitive Luminex Immuno Assay (HPV-4cLIA). We examined the association between seropositivity to these HPV types and country of enrollment, CD4, HIV-1 RNA level, and Pap smear. HPV serology results were available for 487 HIV-infected women (157, 170 and 160 from SA, Botswana and Brazil respectively). Approximately 65% of women had serum antibodies to one of the 4 HPV types and less than 3% of women had antibodies all 4 serotypes. Approximately 30% women demonstrated antibodies to type 16 HPV. Rates of seropositivity to HPV 11, and HPV 16+18 varied significantly between countries. Statistical difference was also shown in women in different age categories in the different countries. There was no difference in serology results compared by CD4 count, HIV viral load or Pap smear results. These data suggest that the quadrivalent vaccine may be effective in preventing HPV infection in these countries.
    Journal of clinical virology: the official publication of the Pan American Society for Clinical Virology 09/2011; 52(3):265-8. · 3.12 Impact Factor
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    ABSTRACT: Little is known about how the prevalence and incidence of neurological disease in HIV-infected patients in resource-limited settings. We present an analysis of neurological and neurocognitive function in antiretroviral naïve individuals in multinational resource-limited settings. This prospective multinational cohort study, a substudy of a large international randomized antiretroviral treatment trial, was conducted in seven low- and middle-income countries in sub-Saharan Africa, South America, and Asia. Subjects were HIV-infected and met regional criteria to initiate antiretroviral therapy. Standardized neurological examination and a brief motor-based neuropsychological examination were administered. A total of 860 subjects were studied. Overall 249 (29%) had one or more abnormalities on neurological examinations, but there was a low prevalence of HIV-associated dementia (HAD) and minor neurocognitive disorder (MND). Twenty percent of subjects had evidence of peripheral neuropathy. There were significant differences across countries (p < 0.001) in neuropsychological test performance. In this first multinational study of neurological function in antiretroviral naïve individuals in resource-limited settings, there was a substantial prevalence of peripheral neuropathy and low prevalence of dementia and other CNS diseases. There was significant variation in neurocognitive test performance and neurological examination findings across countries. These may reflect cultural differences, differences in HIV-related and unrelated diseases, and variations in test administration across sites. Longitudinal follow-up after antiretroviral treatment initiation may help to define more broadly the role of HIV in these differences as well as the impact of treatment on performance.
    Journal of NeuroVirology 07/2011; 17(5):438-47. · 2.85 Impact Factor
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    ABSTRACT: Few data exist regarding the human papillomavirus (HPV) types in penile warts (PW) of HIV-infected men in Africa. Nurses collected penile swabs for HPV typing from 74 HIV-positive men with PW. HPV genotyping was performed using the Roche Linear Array Test. Analysis was performed on data relating to 74 samples. The mean age of the men was 36.0 years and 78.5% (51/65) were uncircumcised. Of the 73/74 validated results, all tested positive for HPV; 42.5% (31/73) and 32.9% (24/73) had HPV types 6 and 11, respectively. 84.9% of men tested positive for any oncogenic type: 20/73 (27.4%) were positive for type 16, 11/73 (15.1%) were positive for type 18 and 8/73 (11.0%) men had both types. Our study shows a high prevalence (68.5%) of HPV type 6 and/or 11 in this male population with PW. Given the poor availability of treatment, a quadrivalent vaccine for men may have significant benefit.
    International Journal of STD & AIDS 02/2011; 22(2):107-9. · 1.00 Impact Factor
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    ABSTRACT: There are approximately 33 million individuals with HIV infection worldwide. The majority of infections are in southern Africa where hepatitis B is also known to be endemic. As access to life-saving antiretroviral therapy (ART) increases, the possibility for hepatitis B treatment resistance increases because most ART regimens contain lamivudine. Patients coinfected with HBV are therefore receiving monotherapy for HBV infection, leading to possible HBV-resistant mutants and the concurrent public health effect thereof. Additional information is needed on the prevalence of HIV-HBV coinfection and treatment response to ART. We present a summary of the information available from South Africa to date.
    Antiviral therapy 01/2010; 15(3 Pt B):499-503. · 3.07 Impact Factor
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    ABSTRACT: We demonstrate the application and comparative interpretations of three tree-based algorithms for the analysis of data arising from flow cytometry: classification and regression trees (CARTs), random forests (RFs), and logic regression (LR). Specifically, we consider the question of what best predicts CD4 T-cell recovery in HIV-1 infected persons starting antiretroviral therapy with CD4 count between 200 and 350 cell/muL. A comparison to a more standard contingency table analysis is provided. While contingency table analysis and RFs provide information on the importance of each potential predictor variable, CART and LR offer additional insight into the combinations of variables that together are predictive of the outcome. In all cases considered, baseline CD3-DR-CD56+CD16+ emerges as an important predictor variable, while the tree-based approaches identify additional variables as potentially informative. Application of tree-based methods to our data suggests that a combination of baseline immune activation states, with emphasis on CD8 T-cell activation, may be a better predictor than any single T-cell/innate cell subset analyzed. Taken together, we show that tree-based methods can be successfully applied to flow cytometry data to better inform and discover associations that may not emerge in the context of a univariate analysis.
    Advances in Bioinformatics 01/2009; 2009:235320.

Publication Stats

49 Citations
33.46 Total Impact Points


  • 2012–2014
    • Right to Care
      Johannesburg, Gauteng, South Africa
    • Duke University
      Durham, North Carolina, United States
  • 2009–2013
    • University of the Witwatersrand
      • • Department of Internal Medicine
      • • Clinical HIV Research Unit (CHRU)
      • • Faculty of Health Sciences
      Johannesburg, Gauteng, South Africa
  • 2010
    • Saint Louis University
      • Department of Internal Medicine
      Saint Louis, MI, United States