Response to Antiretroviral Therapy in HIV-Infected Patients Attending a Public, Urban Clinic in Kampala, Uganda

BACKGROUND

Access to antiretroviral therapy and human immunodeficiency virus (HIV) care is increasing in resource-limited settings. We evaluated clinical, behavioral, and demographic risk factors associated with virologic suppression in a public, urban clinic in Kampala, Uganda.

METHODS

We conducted a cross-sectional, observational study of 137 HIV-infected patients who were receiving antiretroviral therapy at the infectious diseases clinic at Mulago Hospital (Kampala). We measured the prevalence of viral suppression, evaluated risk factors associated with virologic failure, and documented phenotypic resistance patterns and genotypic mutations.

RESULTS

A total of 91 (66%) of 137 participants had an undetectable viral load (< 400 copies/mL) after a median duration of 38 weeks (interquartile range, 24-62 weeks) of antiretroviral therapy. Median CD4 cell count was 163 cells/mm3 (interquartile range, 95-260 cells/mm3). The majority of the patients (91%) were treated with nonnucleoside reverse-transcriptase inhibitor-based 3-drug regimens. In multivariate analysis, treatment with the first antiretroviral regimen was associated with viral suppression (odds ratio, 2.6; 95% confidence interval, 1.1-6.1). In contrast, a history of unplanned treatment interruption was associated with virologic treatment failure (odds ratio, 0.2; 95% confidence interval, 0.1-0.6). Of 124 participants treated with nonnucleoside reverse-transcriptase inhibitors, 27 (22%) were documented to have experienced virologic treatment failure. The most common mutation detected was K103N (found in 14 of 27 patients with virologic treatment failure).

CONCLUSIONS

Although many HIV-infected people treated in Kampala, Uganda, have advanced HIV disease, the majority of patients who received antiretroviral therapy experienced viral suppression and clinical benefit. Because of the frequent use of nonnucleoside reverse-transcriptase inhibitor-based therapy, the majority of resistance was against this drug class. In resource-limited settings, initiation of therapy with a potent, durable regimen, accompanied by stable drug supplies, will optimize the likelihood of viral suppression.

A new model to monitor the virological efficacy of antiretroviral treatment in resource-poor countries

Monitoring the efficacy of antiretroviral treatment in developing countries is difficult because these countries have few laboratory facilities to test viral load and drug resistance. Those that exist are faced with a shortage of trained staff, unreliable electricity supply, and costly reagents. Not only that, but most HIV patients in resource-poor countries do not have access to such testing. We propose a new model for monitoring antiretroviral treatment in resource-limited settings that uses patients' clinical and treatment history, adherence to treatment, and laboratory indices such as haemoglobin level and total lymphocyte count to identify virological treatment failure, and offers patients future treatment options. We believe that this model can make an accurate diagnosis of treatment failure in most patients. However, operational research is needed to assess whether this strategy works in practice.

Laboratory medicine in Africa: a barrier to effective health care

Providing health care in sub-Saharan Africa is a complex problem. Recent reports call for more resources to assist in the prevention and treatment of infectious diseases that affect this population, but policy makers, clinicians, and the public frequently fail to understand that diagnosis is essential to the prevention and treatment of disease. Access to reliable diagnostic testing is severely limited in this region, and misdiagnosis commonly occurs. Understandably, allocation of resources to diagnostic laboratory testing has not been a priority for resource-limited health care systems, but unreliable and inaccurate laboratory diagnostic testing leads to unnecessary expenditures in a region already plagued by resource shortages, promotes the perception that laboratory testing is unhelpful, and compromises patient care. We explore the barriers to implementing consistent testing within this region and illustrate the need for a more comprehensive approach to the diagnosis of infectious diseases, with an emphasis on making laboratory testing a higher priority.

Influence of HIV Infection on Changes in Circulating Leukocyte Counts during Measles in Zambian Children

Measles remains an important problem in Africa, where human immunodeficiency virus type 1 (HIV-1) infection is prevalent. To identify the consequences of coinfection, Zambian children hospitalized with measles were studied at entry, discharge, and 1 month after discharge. All children had low lymphocyte and eosinophil counts at entry and high leukocyte and monocyte counts during recovery. The death of cultured lymphocytes was more prolonged for HIV-positive children. CD38 and Fas were increased on CD4+ and CD8+ lymphocytes, and CD28 was decreased on CD8+ lymphocytes in all children. Abnormalities in CD4+ and CD8+ lymphocyte percentages and CD28 expression associated with HIV infection were preserved during measles. Therefore, the patterns of changes in leukocyte counts were similar, with little evidence that measles exacerbated HIV-associated lymphocyte abnormalities.

Screening of Chlamydia trachomatis urogenital infections among the male and female population of the Republic of Macedonia

BACKGROUND

Noninvasive urine screening for Chlamydia trachomatis infections offers a valuable public health tool, that could be of vast importance in Chlamydia control programs.

OBJECTIVE

The goal was to determine the prevalence of C. trachomatis infections among a sexually active population, to define the epidemiological factors associated with it, and to develop potential selective screening strategies among asymptomatic individuals in the Republic of Macedonia, using a highly sensitive and specific DNA amplification method for C. trachomatis.

STUDY DESIGN

A total of 1435 urine samples, divided into two main groups: asymptomatic individuals (n = 1210) and symptomatic patients (n = 225), were tested. Samples from the asymptomatic group were collected during routine screening programs, while the symptomatic group consisted of patients with symptoms of urogenital tract infection, attending sexually transmitted diseases (STD) clinics. The presence of C. trachomatis was determined using commercial AMPLICOR C. trachomatis Assay (Roche Diagnostic Systems, Inc., Branchburg, NJ, USA).

RESULTS

The prevalence of C. trachomatis infections among different groups was: recruits 0%, soldiers 0.4%, policemen 3.5%, clerks 4.6%, pregnant women 4%, and students 4.4%. The average prevalence for both groups (asymptomatic and symptomatic) was 2.3%[95% confidence interval (CI): 1.5-3.1%]. The average prevalence for the asymptomatic group was 1.6% (95% CI: 0.8-2.4%), while the average prevalence for the symptomatic group was 6.2% (95% CI: 3.1-9.3%) which were significantly different (P = 0.00003).

CONCLUSION

Testing first void urine specimens by AMPLICOR C. trachomatis assay is a highly sensitive and specific method for diagnosing C. trachomatis infections in men and women. This method provides health care workers and public health officials with a new molecular amplification assay that uses noninvasive urine specimens for population-based screening purposes. The prevalence of C. trachomatis was relatively low among asymptomatic individuals. However, selective screening strategies are highly recommended for testing the student population in the Republic of Macedonia.

Increased risk of incident HIV during pregnancy in Rakai, Uganda: a prospective study

BACKGROUND

HIV acquisition is significantly higher during pregnancy than in the postpartum period. We did a prospective study to estimate HIV incidence rates during pregnancy and lactation.

METHODS

We assessed 2188 HIV-negative sexually active women with 2625 exposure intervals during pregnancy and 2887 intervals during breastfeeding, and 8473 non-pregnant and non-lactating women with 24,258 exposure intervals. Outcomes were HIV incidence rates per 100 person years and incidence rate ratios estimated by Poisson multivariate regression, with the non-pregnant or non-lactating women as the reference group. We also assessed the husbands of the married women to study male risk behaviours.

FINDINGS

HIV incidence rates were 2.3 per 100 person years during pregnancy, 1.3 per 100 person years during breastfeeding, and 1.1 per 100 person years in the non-pregnant and non-lactating women. The adjusted incidence rate ratios were 2.16 (95% CI 1.39-3.37) during pregnancy and 1.16 (0.82-1.63) during breastfeeding. Pregnant women and their male partners reported significantly fewer external sexual partners than did the other groups. In married pregnant women who had a sexual relationship with their male spouses, the HIV incidence rate ratio was 1.36 (0.63-2.93). In married pregnant women in HIV-discordant relationships (ie, with HIV-positive men) the incidence rate ratio was 1.76 (0.62-4.03).

INTERPRETATION

The risk of HIV acquisition rises during pregnancy. This change is unlikely to be due to sexual risk behaviours, but might be attributable to hormonal changes affecting the genital tract mucosa or immune responses. HIV prevention efforts are needed during pregnancy to protect mothers and their infants.

The effects of herpes simplex virus-2 on HIV-1 acquisition and transmission: a review of two overlapping epidemics

Increasing evidence demonstrates a substantial link between the epidemics of sexually transmitted HIV-1 and herpes simplex virus (HSV)-2 infection. More than 30 epidemiologic studies have demonstrated that prevalent HSV-2 is associated with a 2- to 4-fold increased risk of HIV-1 acquisition. Per-sexual contact transmission rates among couples from Rakai, Uganda indicate that at all levels of plasma HIV-1 RNA in the source partner, HSV-2-seropositive HIV-1-susceptible persons have a 5-fold greater risk of acquiring HIV-1 compared with HSV-2-negative persons. In vitro and in vivo studies suggest that mucosal HIV-1 shedding is more frequent and in greater amounts during mucocutaneous HSV-2 replication, including subclinical mucosal reactivations. Most HIV-1-infected persons are coinfected with HSV-2, and most experience frequent subclinical and clinical reactivations of HSV-2. Subclinical HSV reactivation elevates serum HIV-1 RNA levels, and daily therapy with acyclovir appears to reduce plasma HIV-1 RNA. These data show that greater attention to the diagnosis and treatment of HSV-2 among HIV-1-infected persons is warranted, especially those who continue to be sexually active, those not on antiretroviral therapy, or those whose disease is not well suppressed by antiretrovirals.

Which patients first? Setting priorities for antiretroviral therapy where resources are limited

The availability of limited funds from international agencies for the purchase of antiretroviral (ARV) treatment in developing countries presents challenges, especially in prioritizing who should receive therapy. Public input and the protection of human rights are crucial in making treatment programs equitable and accountable. By examining historical precedents of resource allocation, we aim to provoke and inform debate about current ARV programs. Through a critical review of the published literature, we evaluate 4 precedents for key lessons: the discovery of insulin for diabetes in 1922, the release of penicillin for civilian use in 1943, the development of chronic hemodialysis programs in 1961, and current allocation of liver transplants. We then describe current rationing mechanisms for ARVs.

Genetic diversification and recombination of HIV type 1 group M in Kinshasa, Democratic Republic of Congo

As the HIV-1 pandemic becomes increasingly complex, the genetic characterization of HIV strains bears important implications for vaccine research. To better understand the molecular evolution of HIV-1 viral diversity, we performed a comparative molecular analysis of HIV strains collected from high-risk persons in Kinshasa, Democratic Republic of Congo (DRC). Analysis of the gag-p24, env-C2V3 and -gp41 regions from 83 specimens collected in 1999-2000 revealed that 44 (53%) had concordant subtypes in the three regions (14 subsubtype A1, 10 subtype G, 8 subtype D, 5 subtype C, 2 each subsubtype F1 and CRF01_AE, and one each of subtypes H and J, and subsubtype A2, while the remaining 39 (47%) had mosaic genomes comprising multiple subtype combinations. Similar multisubtype patterns were also observed in 24 specimens collected in 1985. Sequence analysis of the gag-pol region (2.1 kb) from 21 discordant specimens in the gag-p24, env-C2V3 and -gp41 regions in 1985 and 1999-2000 further confirmed the complex recombinant patterns. Despite the remarkable similarity in overall subtype distribution, the intra- and intersubtype distances of major subtypes A1 and G increased significantly from 1985 to 1999-2000 (p=0.018 and p=0.0016, respectively). Given the complexity of HIV-1 viruses circulating in DRC, efforts should focus on the development of vaccines that result in cross-clade immunity.

HIV/AIDS in women: an expanding epidemic

More than 20 years into the human immunodeficiency virus-type 1 (HIV-1) epidemic, women account for nearly half of the 40 million people living with HIV-1 worldwide, with an even higher proportion existing in developing countries. Social determinants of female vulnerability to HIV-1 include gender disparities, poverty, cultural and sexual norms, lack of education, and violence. Women are also more susceptible to HIV-1 because of hormonal changes, vaginal microbial ecology and physiology, and a higher prevalence of sexually transmitted diseases. Prevention strategies must address the wide range of gender inequalities that promote the dissemination of HIV-1.

Developments in STD/HIV Interactions: The Intertwining Epidemics of HIV and HSV-2

Antiviral agents aimed at treating HSV-2 chronically infected individuals have proven to be effective in the prevention of symptomatic genital herpes and the reduction of viral shedding. These agents play a key role in current HIV prevention trials that will assess the role of suppression of HSV-2 infection on the risk for HIV acquisition and transmission. An added clinical benefit of treating HSV-2/HIV-coinfected individuals is the potential survival benefit, as suggested by earlier studies and by the recent findings that HSV-2/HIV dually infected individuals have higher viral loads. The results of the current HSV-2 suppression trials may provide additional tools to fight the global spread of HIV infection. Treatment of HSV-2/HIV dually infected individuals may prove to be a low-cost intervention to improve clinical outcomes and delay the need for antiretroviral therapy.

A novel assay allows genotyping of the latent reservoir for human immunodeficiency virus type 1 in the resting CD4+ T cells of viremic patients

A latent reservoir for human immunodeficiency virus type 1 (HIV-1) consisting of integrated provirus in resting memory CD4+ T cells prevents viral eradication in patients on highly active antiretroviral therapy (HAART). It is difficult to analyze the nature and dynamics of this reservoir in untreated patients and in patients failing therapy, because it is obscured by an excess of unintegrated viral DNA that constitutes the majority of viral species in resting CD4+ T cells from viremic patients. Therefore, we developed a novel culture assay that stimulates virus production from latent, integrated HIV-1 in resting CD4+ T cells in the presence of antiretroviral drugs that prevent the replication of unintegrated virus. Following activation, resting CD4+ T cells with integrated HIV-1 DNA produced virus particles for several days, with peak production at day 5. Using this assay, HIV-1 pol sequences from the resting CD4+ T cells of viremic patients were found to be genetically distinct from contemporaneous plasma virus. Despite the predominance of a relatively homogeneous population of drug-resistant viruses in the plasma of patients failing HAART, resting CD4+ T cells harbored a diverse array of wild-type and archival drug-resistant viruses that were less fit than plasma virus in the context of current therapy. These results provide the first direct evidence that resting CD4+ T cells serve as a stable reservoir for HIV-1 even in the setting of high levels of viremia. The ability to analyze archival species in viremic patients may have clinical utility in detecting drug-resistant variants not present in the plasma.

Performance of urine leukocyte esterase in asymptomatic male youth: another look with nucleic acid amplification testing as the gold standard for Chlamydia detection

PURPOSE

To re-evaluate the sensitivity and specificity of leukocyte esterase (LE) for screening adolescent and young adult males for Chlamydia trachomatis using a nucleic acid amplification test (NAAT) as the gold standard.

METHODS

This study was conducted at two Massachusetts Department of Youth Services sites and one Job Corps site. Recently admitted asymptomatic sexually active male youth aged 14 to 25 years (mean 16.6 years) were recruited between January 2001 and July 2003 (N = 1008). Participants provided first part voided urine specimens for testing with LE and Chlamydia NAAT. The sensitivity, specificity, and positive and negative predictive value of urine LE for identification of Chlamydia infection were determined using NAAT as the gold standard.

RESULTS

Fifty-seven (5.7%) participants were infected with Chlamydia as defined by a positive NAAT. Defining trace + as the LE cut point resulted in sensitivity and specificity of 57.9% and 78.3%, respectively. Defining 1+ as the cut point resulted in sensitivity and specificity of 47.4% and 96.1%, respectively.

CONCLUSIONS

Urine leukocyte esterase is a moderately sensitive method to screen for Chlamydia. Nevertheless, a substantial proportion of infections are not detected with LE screening. When feasible, urine NAAT provides a much more sensitive and equally noninvasive method of detecting Chlamydia. However, if LE is used as an initial screen followed by NAAT confirmation of LE positive samples, we recommend using trace LE as the cut point for positive results.

Rates of HIV-1 transmission per coital act, by stage of HIV-1 infection, in Rakai, Uganda

BACKGROUND

We estimated rates of human immunodeficiency virus (HIV)-1 transmission per coital act in HIV-discordant couples by stage of infection in the index partner.

METHODS

We retrospectively identified 235 monogamous, HIV-discordant couples in a Ugandan population-based cohort. HIV transmission within pairs was confirmed by sequence analysis. Rates of transmission per coital act were estimated by the index partner's stage of infection (recent seroconversion or prevalent or late-stage infection). The adjusted rate ratio of transmission per coital act was estimated by multivariate Poisson regression.

RESULTS

The average rate of HIV transmission was 0.0082/coital act (95% confidence interval [CI], 0.0039-0.0150) within approximately 2.5 months after seroconversion of the index partner; 0.0015/coital act within 6-15 months after seroconversion of the index partner (95% CI, 0.0002-0.0055); 0.0007/coital act (95% CI, 0.0005-0.0010) among HIV-prevalent index partners; and 0.0028/coital act (95% CI, 0.0015-0.0041) 6-25 months before the death of the index partner. In adjusted models, early- and late-stage infection, higher HIV load, genital ulcer disease, and younger age of the index partner were significantly associated with higher rates of transmission.

CONCLUSIONS

The rate of HIV transmission per coital act was highest during early-stage infection. This has implications for HIV prevention and for projecting the effects of antiretroviral treatment on HIV transmission.

Molecular epidemiology of HIV-1 subtypes in southern China

The driving forces of the HIV-1 epidemic in Guangxi, China were assessed by investigating virologic and epidemiologic data from a cohort of longitudinally followed injection drug users (IDUs) in Binyang and Pingxiang, major urban areas along 2 separate drug routes in the province. Sera and interview data were obtained in September and October of 2000. Sequence analysis of HIV-1 was performed on the gag-pol region (HXB2 nt 1850-3005) and C2 to V4 env (HXB2 nt 6704-7626). Sequence data demonstrated that 88% of the infections in Pingxiang were CRF01_AE, whereas 96% in Bin-yang were CRF08_BC. Three recently infected subjects in Pingxiang were infected with CRF08_BC, and 1 chronically infected subject had evidence of a recombinant virus. Intersubject distances were statistically greater for CRF01_AE-infected subjects than CRF08_BC-infected subjects for all regions except V4. The epidemic in Binyang is similar to previously described IDU-based epidemics, with a strong founder effect with little variation in V3. The epidemic in Pingxiang may have had multiple introductions of the CRF01_AE epidemic into the city and greater spread through sexual transmission, resulting in greater variation in V3 than typically seen in purely parenterally based epidemics.

Intermittent HIV-1 viremia (Blips) and drug resistance in patients receiving HAART

CONTEXT

Many patients infected with human immunodeficiency virus type 1 (HIV-1) and receiving highly active antiretroviral therapy experience intermittent episodes of detectable viremia ("blips"), which may raise concerns about drug resistance, lead to costly repeat measurements of viral RNA, and sometimes trigger alterations in therapy.

OBJECTIVE

To test the hypothesis that blips represent random biological and statistical variation around mean steady-state HIV-1 RNA levels slightly below 50 copies/mL rather than biologically significant elevations in viremia.

DESIGN, SETTING, AND PATIENTS

Between June 19, 2003, and February 9, 2004, patients receiving therapy underwent intensive sampling (every 2-3 days) over 3 to 4 months to define the frequency, magnitude, and duration of blips and their association with drug levels and other clinical variables. Blips were defined as HIV-1 RNA measurements greater than or equal to 50 copies/mL preceded and followed by measurements less than 50 copies/mL without a change in treatment. To determine whether blips result from or lead to drug resistance, an ultrasensitive genotyping assay was used to detect drug resistance mutations before, during, and after blips. Patients were 10 HIV-1-infected asymptomatic adults recruited by clinicians and followed up in the Moore Clinic at the Johns Hopkins Hospital. Patients had suppression of viremia to below 50 copies/mL while receiving a stable antiretroviral regimen for 6 months or longer.

MAIN OUTCOME MEASURES

At each time point, plasma HIV-1 RNA levels were measured in 2 independent laboratories and drug resistance mutations were analyzed by clonal sequencing.

RESULTS

With the intensive sampling, blips were detected in 9 of 10 patients. Statistical analysis was consistent with random assay variation around a mean viral load below 50 copies/mL. Blips were not concordant on independent testing and had a short duration (median, <3 days) and low magnitude (median, 79 copies/mL). Blip frequency was not associated with demographic, clinical, or treatment variables. Blips did not occur in relation to illness, vaccination, or directly measured antiretroviral drug concentrations. Blips were marginally associated (P = .08) with reported episodes of nonadherence. Most importantly, in approximately 1000 independent clones sequenced for both protease and reverse transcriptase, no new resistance mutations were seen before, during, or shortly after blips.

CONCLUSION

Most blips in this population appear to represent random biological and statistical variation around mean HIV-1 levels below 50 copies/mL rather than clinically significant elevations in viremia.

Effectiveness of syphilis treatment using azithromycin and/or benzathine penicillin in Rakai, Uganda

OBJECTIVE

The goal of this study was to assess azithromycin and/or benzathine penicillin for treatment of syphilis.

METHODS

In a population-based study, participants with serologic syphilis (TRUST with TPHA confirmation) were offered 2.4 MU benzathine penicillin intramuscularly. Intervention arm participants received 1 g presumptive oral azithromycin. We assessed cure rates with penicillin or azithromycin given alone and in combination. Cure assessed after 10 months was defined as seroreversion or a 4-fold decrease in titer. The rate ratio (RR) of cure and 95% confidence intervals (95% CIs) were estimated by log binomial regression.

RESULTS

Among 952 cases with syphilis, 18% received penicillin alone, 17% azithromycin only, and 65% dual treatment. The overall cure rate was 61%. Cure rates were lower in males compared with females (RR, 0.89; 95% CI, 0.80-0.99) and in subjects with initial titers > or =1:4 compared with < or =1:2 (RR, 0.77; 95% CI, 0.69-0.86). There was no significant differences in cure rates among HIV-positive and HIV-negative persons. With initial titers < or =1:2, there were no differences in cure rates by treatment regimen. However, with initial titers > or =1:4, significantly higher cure rates were observed with azithromycin alone (adjusted RR, 1.38; 95% CI, 0.97-1.96), and with dual treatment of azithromycin and benzathine penicillin (RR, 1.38; 95% CI, 1.03-1.87) compared with penicillin alone.

CONCLUSION

Azithromycin alone or in combination with penicillin achieved higher cure rates than penicillin alone in cases with a high initial TRUST titer. In low-titer infections, the 3 drug combinations were equally effective. HIV status did not affect cure rates.

Urine nucleic acid amplification tests for the diagnosis of sexually transmitted infections in clinical practice

PURPOSE OF REVIEW

With the advent of highly sensitive and specific nucleic acid amplification assays, this report will demonstrate that self-collected genital specimens, such as urine or even vaginal swabs can be accurately used to diagnose sexually transmitted infections.

RECENT FINDINGS

Use of self collected samples can eliminate the necessity of a clinician to perform a pelvic examination for women or collect a urethral swab for men, thus extending the diagnostic capability for sexually transmitted infections to non-clinic screening venues. As many sexually transmitted infections are asymptomatic, this ability to use self-sampling greatly increases the numbers of patients that can be screened, and has the potential to augment public health programs designed to control the epidemic of sexually transmitted infections in the community. Patient collected samples are highly acceptable, highly accurate, and are becoming widely used. Self-sampling also allows clinicians to easily screen patients in the clinic, who are not presenting for pelvic or urogenital examinations, for sexually transmitted infections.

SUMMARY

Highly accurate molecular tests and easily obtained self-collected urogenital samples represent the ideal combination for obtaining the public health goal of decreasing the sexually transmitted infection epidemic among sexually active persons in the United States today.

Use of multiple nucleic acid amplification tests to define the infected-patient "gold standard" in clinical trials of new diagnostic tests for Chlamydia trachomatis infections

Nucleic acid amplification tests (NAATs) can be used to define the infected-patient "gold standard" for the purpose of designing studies of the performance of Chlamydia trachomatis diagnostic tests. It is unclear how many test results run by different NAATs and what combinations of specimens comprise the best infected-patient gold standard. We approached this question with data from a large study of the performance of a new NAAT. Data were available from three endocervical swabs and a urine specimen collected from each of 1,412 women and tested by three different NAATs. Results from all three assays were used equally in a rotating fashion to define the infected-patient gold standard. Multiple different infected-patient gold standards for estimating swab and urine specimen sensitivity and specificity for one NAAT method were created by varying the number and combinations of swab and urine comparator results with two different NAATs, The effect of changing the infected-patient gold standard definition was determined by constructing receiver-operator-like curves with calculated sensitivities and specificities for each test. The one-positive-of-two-results or two-positive-of-two-results (same or two different assays) infected-patient gold standard definitions produced low sensitivity and low specificity estimates, respectively. If four comparator NAAT results were used, the any-three-positive-of-four-results definition or the at-least-one-specimen-positive-by-each-of-two-comparator-assays definition appeared to provide better combinations of sensitivity and specificity estimates. The any-two-positive-out-of-three-results definition resulted in estimates that were as good as produced with the former two definitions. This analytic approach provides a means of clearly visualizing the effects of changing NAAT-based infected-patient gold standards and should be helpful in designing future studies of new C. trachomatis diagnostic tests.

Recombinant viruses and early global HIV-1 epidemic

Central Africa was the epicenter of the HIV type 1 (HIV-1) pandemic. Understanding the early epidemic in the Democratic Republic of the Congo, formerly Zaire, could provide insight into how HIV evolved and assist vaccine design and intervention efforts. Using enzyme immunosorbent assays, we tested 3,988 serum samples collected in Kinshasa in the mid-1980s and confirmed seroreactivity by Western blot. Polymerase chain reaction of gag p17, env C2V3C3, and/or gp41; DNA sequencing; and genetic analyses were performed. Gene regions representing all the HIV-1 group M clades and unclassifiable sequences were found. From two or three short gene regions, 37% of the strains represented recombinant viruses, multiple infections, or both, which suggests that if whole genome sequences were available, most of these strains would have mosaic genomes. We propose that the HIV epidemic was well established in central Africa by the early 1980s and that some recombinant viruses most likely seeded the early global epidemic.

International travel: Recommendations for the HIV-infected patient

In order to prevent travel-related diseases in patients infected with HIV, pretravel planning that includes vaccination, chemoprophylaxis, and behavioral modification is recommended. Many HIV-infected individuals successfully treated with highly active antiretroviral therapy may travel safely. However, patients with reduced CD4 lymphocyte counts are at increased risk for bacterial, mycobacterial, viral, fungal, and parasitic infections. Recommendations for vaccination and chemoprophylaxis are based on immune status and risk of infection. The efficacy of vaccination is dependant on CD4 lymphocyte count; inactivated and polysaccharide vaccines are considered safe in this population. Behavioral modifications to prevent food- and waterborne disease are an important component of disease prevention. A travel-health practitioner should review travel duration, destination, and activities, and assess the risk-benefit ratio of vaccination and chemoprophylaxis, in order to reduce the likelihood of travel-associated illness.

Performance of the MagNA pure LC robot for extraction of Chlamydia trachomatis and Neisseria gonorrhoeae DNA from urine and swab specimens

DNA from uncentrifuged urines (n = 195 and n = 202) and cervical swabs (n = 221 and n = 601) was extracted by the MagNA Pure LC robot and the Amplicor method to validate the robot's extraction for Chlamydia trachomatis and Neisseria gonorrhoeae testing by Roche PCR. The robot provided a highly sensitive and specific method of DNA extraction.

Total lymphocyte count of 1200 is not a sensitive predictor of CD4 lymphocyte count among patients with HIV disease in Kampala, Uganda

INTRODUCTION

Total Lymphocyte Count (TLC) has been found to be an inexpensive and useful marker for staging disease, predicting progression to AIDS and death and monitoring response to ART. However, the correlation between TLC and CD4 has not been consistent. Access to HAART is expanding in Kampala, Uganda, yet there are no published data evaluating the utility of TLC as inexpensive surrogate marker of CD4 cell count to help guide therapeutic decisions.

OBJECTIVE

To evaluate clinical illnesses and total lymphocyte count (TLC) as surrogate markers of the CD4 cell count in HIV infected persons being considered for ART.

METHODS

A total of 131 patients were enrolled and evaluated by clinical assessment, TLC and CD4 count. Clinical illnesses and TLC dichotomized at various cut-point values were used to determine the sensitivity, specificity, and positive and negative predictive values (PPV and NPV) for the diagnosis of CD4 count <200 cells/mm 3 among 100 participants fulfilling criteria for WHO clinical stage 2 and 3.

RESULTS

A strong correlation was observed between TLC and CD4 (r = 0.73, p<0.0001). For all clinical syndromes, except pulmonary tuberculosis, the positive predictive values (PPV) for a CD4 count <200 cells/mm 3 were high (>80%) but the negative predictive values (NPV) were low. Using the WHO recommended TLC cut-off of 1200 cells/mm 3 to diagnose a CD4 less than 200 cells/mm 3 , the PPV was 100%, and the NPV was 32%.

CONCLUSION

Our data showed a good correlation between TLC and CD4 cell count. However, the WHO recommended TLC cut-off of 1200 did not identify the majority of WHO stage 2 and 3 patients with CD4 counts less than 200 cells/mm 3 . A more rational use of TLC counts is to treat all patients with WHO stage 2 and 3 who have a TLC <1200 and to limit CD4 counts to patients who are symptomatic but have TLC of >1200.