Evaluation of the Upgraded Version 2.0 of the Roche COBAS® AmpliPrep/COBAS® TaqMan HIV-1 Qualitative Assay in Central African Children

Background:

Several commercially available molecular techniques were developed based on subtype B of HIV-1, which represents only 10% of HIV strains worldwide. Indeed, in sub-Saharan Africa, non-B subtypes of HIV-1 are predominant. The aim of this study was to evaluate the performances of the COBAS^® AmpliPrep/COBAS^® (CAP/CTM) HIV-1 Qualitative assays to detect the broad range of HIV-1 variants circulating in Central Africa and compare to the outgoing CAP/CTM HIV-1 Quantitative test v2.0 (Roche Molecular Systems), chosen as reference gold standard molecular assay.

Methods:

The CAP/CTM HIV-1 Qualitative tests versions 1.0 and 2.0 (Roche Molecular Systems, Inc., Branchburg, NJ, USA) were evaluated compared to CAP/CTM TaqMan HIV-1 Quantitative test v2.0 (Roche Molecular Systems) on 239 dried plasma spot (DPS) from 133 HIV-1-infected (with detectable plasma HIV RNA load) and 106 uninfected children, followed-up at Complexe Pédiatrique, Bangui, Central African Republic.

Results:

The version 1.0 showed low sensitivity (93.2%), with 9 (6.8%) false negative results, demonstrating under-detection of non-B HIV-1 subtypes. In contrast, the upgraded version 2.0 showed 100%-sensitivity, 100%-specificity and perfect agreement (κ coefficient, 1.0).

Conclusion:

Our evaluation in the Central African Republic demonstrates the clinical implications of the accuracy and reliability of the CAP/CTM HIV-1 Qualitative assay for early diagnosis of HIV-1 in Central African children.

Detection of Y chromosome DNA as evidence of semen in cervicovaginal secretions of sexually active women

The detection of traces of semen in cervicovaginal secretions (CVS) from sexually active women practicing unprotected sex is a prerequisite for the accurate study of cervicovaginal immunity. Two semen markers, the prostatic-specific antigen (PSA) and the Y chromosome, were detected in parallel in CVS obtained by a standardized vaginal washing of consecutive women attending the principal medical center for sexually transmitted diseases of Bangui, Central African Republic. PSA was detected by immunoenzymatic capture assay in the cell-free fraction of CVS, and the Y chromosome was detected by a single PCR assay of DNA extracted by silica from the cell fraction (Y PCR). Fifty (19%) cell-free fractions of the 264 beta-globin-positive CVS samples were positive for PSA, and 100 (38%) cell fractions of the CVS samples were positive for the Y chromosome. All the 50 (19%) PSA-containing CVS samples were also positive for the Y chromosome. Fifty (19%) CVS samples were positive only for the Y chromosome, with no detectable PSA. The remaining 164 (62%) CVS samples were both PSA and Y chromosome negative. These findings demonstrate that CVS from sexually active women may contain cell-associated semen residues unrecognized by conventional immunoenzymatic assays used to detect semen components. The detection of cell-associated male DNA with a highly sensitive and specific procedure such as Y PCR constitutes a method of choice to detect semen traces in female genital secretions.

Aetiology of urethral discharge in Bangui, Central African Republic

OBJECTIVES

To determine the aetiology of urethritis in Bangui, Central African Republic.

METHODS

410 men presenting with urethral discharge and 100 asymptomatic controls were enrolled. Urethral swabs were obtained and processed by gonococcal culture and polymerase chain reaction for the detection of Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium, Trichomonas vaginalis, and Ureaplasma urealyticum.

RESULTS

In multivariate analyses, M genitalium and C trachomatis were significantly associated with urethral discharge when comparing cases of non-gonococcal urethritis (NGU) with controls. T vaginalis was also more common in cases than in controls, but this reached statistical significance only among cases in whom N gonorrhoeae was also detected. U urealyticum was not associated with urethritis. The gonococcus was found in 69% of cases of urethral discharge. M genitalium was the predominant pathogen in patients with NGU, being found in 42% (53/127) of such patients while C trachomatis was found in only 17% (22/127). T vaginalis was found in 18% (23/127) of patients with NGU, but also in 15% (43/283) of patients with gonococcal urethritis, and two thirds of patients with T vaginalis also had the gonococcus. Multiple infections were common. M genitalium caused a syndrome similar to chlamydial urethritis, with a less severe inflammation than in gonococcal infection. No behavioural or clinical characteristic could discriminate between the various aetiological agents.

CONCLUSIONS

M genitalium is more prevalent than C trachomatis and is the most common cause of NGU in BANGUI: It causes a syndrome similar to chlamydial urethritis. T vaginalis is weakly associated with urethritis, and is often found along with other pathogens.

Interactions between herpes simplex virus type 2 and human immunodeficiency virus type 1 infection in African women: opportunities for intervention

Sexually transmitted diseases (STDs) are cofactors for human immunodeficiency virus (HIV) transmission, but the specific role of herpes simplex virus type 2 (HSV-2) is unclear. This study aimed to examine the in vivo relationships between HSV-2 and HIV-1 in 300 women in Bangui, Central African Republic. Sera were tested for syphilis, HIV-1, HSV-2 antibody, and levels of vitamins A and E. Genital specimens were tested for other STDs. HSV-2 DNA and HIV-1 RNA were quantified in cervicovaginal lavage. The prevalences of HSV-2 antibody (91% vs. 78%, P=.02), HSV-2 shedding (43% vs. 22%, P=. 003), and levels of HSV-2 DNA (P=.01) were all significantly higher among HIV-1-seropositive than among HIV-1-seronegative women. There was a significant correlation between genital HIV-1 RNA and HSV-2 DNA levels (P=.02) among the 23 women who were shedding HSV-2 DNA. If confirmed, such associations highlight the urgent need for HSV-2 control measures in populations at high risk of both infections.

Quality of sexually transmitted disease treatments in the formal and informal sectors of Bangui, Central African Republic

BACKGROUND

Interventions for upgrading sexually transmitted disease (STD) management in sub-Saharan Africa have focused on the public sector, and to a much lower extent on private medical practitioners and pharmacies. However, in most African cities there is a large informal sector that provides care to many patients with STD symptoms.

GOAL

To compare the quality of treatments offered to patients with major STD syndromes in the public sector, pharmacies, and the informal sector of the same city.

STUDY DESIGN

Healthcare providers in health centers, pharmacies, private laboratories, and market drug peddlers in Bangui, Central African Republic, were asked to complete a short form for every patient consulting them with genital complaints. The treatments they ordered were evaluated for their potential efficacy against the major etiologic agents of the syndrome for which the patient consulted.

RESULTS

The majority of male patients with STDs preferred to seek care in pharmacies and in the informal sector. The STD treatments offered to patients with urethral discharge or genital ulcers in pharmacies and in the informal sector tended to focus on a single etiologic agent. The quality of STD treatments offered by drug peddlers and private laboratories was poor, apart from adequate coverage of syphilis in patients with genital ulcers and of candidiasis in women with vaginal discharge. For instance, 41% and 34% of patients with urethral discharge managed by drug peddlers and private laboratories did not receive a drug active against either Neisseria gonorrhoeae or Chlamydia trachomatis, whereas this proportion was 22% in pharmacies and 14% in health centers. For patients with genital ulcers, the proportion offered a drug active against Haemophilus ducreyi was 2% if seen by drug peddlers, 0% in laboratories, 10% in pharmacies, and 25% in health centers. For each syndrome and each category of provider, between one fourth and two thirds of patients had already received another ineffective treatment elsewhere.

CONCLUSION

National STD and HIV control programs will have to improve STD management in pharmacies and in the informal sector if they are to have any impact on the dynamics of HIV infection in urban centers.

Screening blood donations for hepatitis C in Central Africa: analysis of a risk- and cost-based decision tree

Four screening strategies (no testing, HC Abbott, HC Pasteur, and a combined test) for the detection of hepatitis C virus (HCV) antibody in donated blood were considered in a formal decision tree. Decision criteria included residual risk of infection and overall monetary cost. Tree parameters were determined using data from the Central African Republic. The prevalences observed among blood donors for HIV infection, hepatitis B, syphilis, and hepatitis C varied between 6% and 15%. The current residual risk of transfusion-transmitted infections is very high (8.4%). Screening for HCV would bring that risk down to about 3% with either the HC Pasteur, the HC Abbott, or the combined test. Even though baseline analysis gives preference to the HC Abbott test (the combined test coming out last), Monte Carlo sensitivity and uncertainty analyses showed that Abbott's and Pasteur's tests are interchangeable, on the basis or either risk or cost considerations.

High prevalence in Central Africa of blood donors who are potentially infectious for human herpesvirus 8

BACKGROUND

In western countries, the transmission of human herpesvirus 8 (HHV-8) via blood transfusion has been recently postulated. In sub-Saharan African, the incidence of HHV-8-associated Kaposi's sarcoma and the seroprevalence for HHV-8 in autochthonous populations are high.

STUDY DESIGN AND METHODS

The aim of this study was to estimate the prevalence of blood donations potentially infectious for HHV-8 in the general adult population of Central Africa. Forty-nine blood donors at the Centre de Transfusion Sanguine in Bangui, the capital of the Central African Republic, were selected. Forty-five inpatients of Broussais Hospital, Paris, France, who were known to be seronegative for HIV and hepatitis B and C viruses and who had not received heart or kidney transplants, were chosen as a European "control" group for comparison. HHV-8 DNA sequences were detected in peripheral blood mononuclear cells by nested polymerase chain reaction using primer sets located in the HHV-8 open reading frame 26.

RESULTS

Eleven (22.5%; 95% CI: 12%-37%) of 49 blood donors were positive for HHV-8. Three (6%) were HIV-1 seropositive. Two (67%) of the 3 HIV-infected blood donors were also positive for HHV-8. All blood donors were apparently healthy; none was known to suffer from Kaposi's sarcoma. Only one (2.2%) control was carrying HHV-8 DNA on the peripheral blood mononuclear cells. The prevalence of HHV-8 was higher in blood donors from Bangui than in patients from Broussais Hospital.

CONCLUSIONS

HHV-8 infection is highly prevalent in an apparently healthy adult population from Central Africa, which raises concerns about HHV-8 transmission through transfusion in this setting.

Typing of urinary JC virus DNA offers a novel means of tracing human migrations

Although polyomavirus JC (JCV) is the proven pathogen of progressive multifocal leukoencephalopathy, the fatal demyelinating disease, this virus is ubiquitous as a usually harmless symbiote among human beings. JCV propagates in the adult kidney and excretes its progeny in urine, from which JCV DNA can readily be recovered. The main mode of transmission of JCV is from parents to children through long cohabitation. In this study, we collected a substantial number of urine samples from native inhabitants of 34 countries in Europe, Africa, and Asia. A 610-bp segment of JCV DNA was amplified from each urine sample, and its DNA sequence was determined. A worldwide phylogenetic tree subsequently constructed revealed the presence of nine subtypes including minor ones. Five subtypes (EU, Af2, B1, SC, and CY) occupied rather large territories that overlapped with each other at their boundaries. The entire Europe, northern Africa, and western Asia were the domain of EU, whereas the domain of Af2 included nearly all of Africa and southwestern Asia all the way to the northeastern edge of India. Partially overlapping domains in Asia were occupied by subtypes B1, SC, and CY. Of particular interest was the recovery of JCV subtypes in a pocket or pockets that were separated by great geographic distances from the main domains of those subtypes. Certain of these pockets can readily be explained by recent migrations of human populations carrying these subtypes. Overall, it appears that JCV genotyping promises to reveal previously unknown human migration routes: ancient as well as recent.

In vivo semen-associated pH neutralization of cervicovaginal secretions

Physiological cervicovaginal acidity can partly inactivate human immunodeficiency virus (HIV). Basic semen components should be able to partially neutralize in vivo cervicovaginal pH. The goals of the study were to evaluate the relationship between cervicovaginal pH and presence of semen components in sexually active African women and to assess whether vaginal douching with water performed just after sexual intercourse could significantly reduce semen components and restore physiological cervicovaginal pH. Cervicovaginal secretion (CVS) from 56 heterosexual African women (19 to 45 years old), living in Bangui, Central African Republic, were evaluated for pH, semen components (prostatic acid phosphatase [PAP] and prostatic specific antigen [PSA]), cellularity, and hemoglobin at inclusion and after vaginal douching with 100 ml of water by using a bock. Before douching, semen components were found in 46 of 56 CVS (82%). The mean vaginal pH was 5.2 (range, 3.6 to 7.7), and concentrations of both PAP and PSA correlated positively and strongly with cervicovaginal pH (P < 0.001). After douching, semen components were found in 35 of 56 CVS (62%) (P = 0.03). Cervicovaginal PAP and PSA levels were significantly decreased (respectively, P < 0.0001 and P < 0.01; PAP, -72%; PSA, -87%), as was the total cell count (-60%; P < 0.0001). Furthermore, in CVS previously positive for both PAP and PSA, the mean vaginal pH was significantly decreased (6.5 versus 5.3, P < 0.01); no genital bleeding was observed. Frequent persistence of semen in CVS from heterosexually active African women leads to a shift from acidity to neutrality that could favor male to female HIV transmission. Vaginal douching provides significant elimination of semen after sexual intercourse; it should be considered for study as a supplementary means for the prevention of heterosexual HIV transmission.

[In vivo neutralization of physiological cervicovaginal acidity by sperm nitrogen bases]

Cervicovaginal secretions (CVS) from 46 heterosexual African women, attending the National Reference Center for Sexually Transmitted Diseases and AIDS of Bangui, Central African Republic, were investigated, at inclusion and after vaginal douching with water, in order, i) to determine the relationship between cervicovaginal pH and the presence of semen components [prostatic acid phosphatase (PAP) and prostatic specific antigen (PSA)] in sexually active African women; ii) to assess whether vaginal douching performed after sexual intercourse could efficiently eliminate semen components and restore cervicovaginal acid pH. At inclusion, semen components were found in 41 CVS (89%); the mean cervicovaginal pH was 6.12 (range, 3.86 to 8.33); concentrations of both PAP and PSA correlated positively and strongly with cervicovaginal pH (p < 0.001). After douching, semen components were found in only 31 CVS (67%) (p < 0.03); vaginal PAP and PSA levels were significantly decreased (p < 0.0001); PAP: -21%; PSA: -36%). Frequent persistence of semen in cervicovaginal secretions from heterosexually active African women leads to a shift from acidity to neutrality, that could favor male-to-female HIV transmission.

High prevalence of hepatitis B, C, and E markers in young sexually active adults from the Central African Republic

The Central African Republic is located in tropical Africa, where both the human immunodeficiency virus (HIV) and hepatitis B virus (HBV) are highly endemic. The exact prevalence of hepatitis C virus (HCV) and hepatitis E virus (HEV) markers in this country is unknown. The aim of the study was to determine, according to HIV and HBV serostatus, the prevalence of these markers in young sexually active adults in the Central African Republic. One hundred and fifty-seven consecutive patients attending the National Centre for Sexually Transmitted Diseases in Bangui were included. The following serological markers were examined: (i) anti-HIV1 and anti-HIV2 antibodies; (ii) markers of HBV infection; (iii) anti-HCV antibodies; (iv) anti-HEV antibodies. Anti-HIV1 antibodies were found in 31 of the 157 patients (20%). The prevalence of anti-HBc antibodies, reflecting exposure to HBV, was 140/157 (89%) and 45 had detectable anti-HBs antibodies. Twenty-two patients (14%) were chronic carriers of hepatitis B surface antigen (HBsAg), but only one was HBe antigen-positive. Anti-HCV antibodies were found in 8 persons (5%) and anti-HEV antibodies in 38 (24%). No difference was found in the prevalence of these markers according to the presence or absence of anti-HIV antibodies. This study confirms the high rate of HIV infection, HBV exposure and chronic carriage of HBsAg in sexually active young adults in the Central African Republic. A high prevalence of HCV markers was found in this population, similar to that reported in neighbouring countries, together with a high rate of HEV markers, suggesting that HEV is endemic in this region.

Human immunodeficiency virus type 1 p24 antigen in cervicovaginal secretions

The failure to detect human immunodeficiency virus (HIV) antigen in cervicovaginal secretions (CVS) from HIV-infected women could be due in part to an in situ formation of immune complexes involving HIV antigens and cervicovaginal anti-HIV antibodies. CVS from 30 HIV-1-infected heterosexual women were assayed for p24 antigen detection by ELISA before and after acid disruption of immune complexes. Before acid treatment, free p24 antigen was detected in only 1 sample of CVS, whereas after acid dissociation, 4 (13.5%) of 30 samples had detectable and neutralizable p24 antigen. Adsorbent capacities of the CVS for recombinant p24 antigen, evaluated in an in vitro model, depended on both titer and avidity of cervicovaginal antibodies to HIV. In conclusion, local antibodies to HIV are able in vivo to bind HIV antigen within CVS and to participate in the immune exclusion of free virus particles or proteins.

Detection of antibodies to human immunodeficiency virus in vaginal secretions by immunoglobulin G antibody capture enzyme-linked immunosorbent assay: application to detection of seminal antibodies after sexual intercourse

In order to evaluate a commercial immunoglobulin G (IgG) antibody capture enzyme-linked immunoassay (ELISA) (Wellcozyme HIV1 + 2 Gacelisa; Murex Diagnostics Limited, Dartford, United Kingdom) for the detection of antibodies to human immunodeficiency virus (HIV) in vaginal secretion samples (VS) from HIV-seropositive and -seronegative women, serum samples (S) and VS were obtained from 129 African women living in the Central African Republic, a country of high HIV prevalence. Sera were tested for HIV by routine second-generation ELISA with confirmatory Western blot (immunoblot) (WB). By the Gacelisa IgG immuno-capture assay, 45 VS were positive and 84 were negative, whereas by WB, 44 VS were confirmed positive and 85 were confirmed negative. Considering WB as a reference, the IgG immunocapture assay in VS was 97.7% sensitive (43 of 44 positive samples) and 97.6% specific (83 of 85 negative samples). Of 42 HIV-seropositive women, 41 (97.6%) had S and VS that both were HIV positive (S+ VS+), and of 87 HIV-seronegative women, 83 (95.4%) had S and VS that both were HIV negative (S- VS-). Five women had discordant results for S and VS. One (S+ VS-) possibly had a false-negative VS result. Two (S- VS+) had similar indeterminate patterns for S and VS in WB. Two (S- VS+) had a typical HIV-positive pattern on WB of VS, whereas S results in WB were indeterminate in one case and negative in the other case; for both women, detection of prostatic acid-phosphatase was positive in VS, strongly suggesting recent sexual intercourse with an HIV-positive man. Because all HIV-infected men have detectable IgG antibodies to HIV in the seminal fluid, an HIV-seronegative rape victim with HIV-positive VS (S- VS+) should receive short-term antiviral therapy to prevent possible HIV transmission.

Differential elevation of circulating interleukin-1 beta, tumor necrosis factor alpha, and interleukin-6 in AIDS-associated cachectic states

Elevation of serum interleukin-1 beta (IL-1 beta) levels, and to a lesser degree tumor necrosis factor alpha levels, was found in cachectic human immunodeficiency virus (HIV)-infected African patients without concurrent opportunistic infection or neoplasia (HIV wasting syndrome). A heterogeneous pattern of elevations of cytokine levels, including mild elevations of IL-1 beta and pronounced elevations of IL-6 levels, was found in other cachectic states.

Free and decomplexed human immunodeficiency virus p24 antigenaemia in black patients with AIDS and AIDS-related disorders

OBJECTIVES

To determine the clinical signification of free and decomplexed p24 antigenaemia in HIV1-infected black individuals.

PATIENTS AND METHODS

Sixty African patients with pre-AIDS (n = 12) and AIDS (n = 48), hospitalized in the Centre National Hospitalier Universitaire de Bangui, Central African Republic, were prospectively included. 15 HIV1-seronegative healthy African subjects served as controls. Serum p24 antigenaemia was detected using a polyclonal and a monoclonal sandwich enzyme immunoassay (EIA). All sera were tested again after acid pretreatment (45 mn incubation of serum with a 0.5 N solution of HCl at +37 degrees C).

RESULTS

The polyclonal EIA and the monoclonal EIA detected respectively four (7%) to six (10%) free p24 antigen positive samples from the HIV1-infected individuals, with a similar frequency in pre-AIDS and AIDS patients. None of the controls were found p24 antigen positive. After acid pretreatment, the rate of detectable p24 antigenaemia increased significantly, leading with the monoclonal EIA to a 47% positivity rate (p < 0.001), and the patients with AIDS became more frequently p24 antigen positive (54%), than the patients with pre-AIDS (17%) (p = 0.02).

CONCLUSION

Detectable p24 antigenaemia in HIV1-infected African subjects could be obtained in nearly half of cases by increasing the sensitivity of the assay using monoclonal EIA and acid hydrolysis of circulating immune complexes. Decomplexed p24 antigenaemia in HIV1-infected Black African patients could have predictive signification similar to free p24 antigenaemia in Caucasians.

Coxiella burnetii infection among subjects infected with HIV type 1 in the Central African Republic

Sixty-six sera from HIV-1-seropositive adult African subjects and 49 sera from HIV-seronegative age and sex matched healthy African controls living in Bangui, Central African Republic, were screened for Coxiella burnetii antibody by an indirect immunofluorescent antibody test. 16.7% of HIV-infected patients and 16.3% of the HIV-negative controls had positive IgG titres, with no significant difference between the two groups. Two of the seven HIV-infected patients seropositive for Coxiella burnetii for whom clinical data was available had a medical history compatible with symptomatic Q fever. These findings indicate that there is a high degree of exposure to Coxiella burnetii infection in Bangui. In individuals co-infected with HIV and Coxiella burnetii, cellular immunosuppression could favour symptomatic Q fever. Physicians should be aware of the possibility of symptomatic Coxiella burnetii infection among HIV-infected people, particularly in endemic regions for both infections such as in sub-saharan Africa.

Low prevalence of neuro-psychiatric clinical manifestations in central African patients with acquired immune deficiency syndrome

In order to evaluate the frequency of neurological and psychiatric disorders in central African patients with acquired immune deficiency syndrome (AIDS), 93 inpatients at the National Hospital Centre of Bangui were selected according to the World Health Organization (Bangui) clinical definition of AIDS and were confirmed to be serologically positive for human immunodeficiency virus (HIV) 1 (92/93) or HIV 2 (1/93) by Western blot. Neurological (11/15) and psychiatric (4/15) abnormalities were clinically detected in 16% (15/93) of African patients with AIDS. In this series, the prevalence of neuro-psychiatric disorders appeared to be lower than in Europe and North America.