Evaluating the role of human papillomaviruses in conjunctival neoplasia.

Mucosal, cutaneous and Epidermodysplasia verruciformis (EV)-related human papillomaviruses (HPVs) were searched by broad-spectrum PCR in 86 conjunctival neoplasia biopsies and 63 conjunctival non-neoplastic control tissue from Ugandan subjects. Seven different EV-related HPV types, including a putative new HPV, and two mucosal HPVs were detected in 25% (14 out of 56) of HIV-positive, in 10% (three out of 30) of HIV-negative conjunctival neoplasia samples, and rarely (0-1.6%) in control subjects. The absence of high-risk HPVs and the low detection frequency of EV-related HPV types in more advanced tumour stages (10%) raise doubts about their role in conjunctival carcinomas.

Induction of systemic and mucosal cross-clade neutralizing antibodies in BALB/c mice immunized with human immunodeficiency virus type 1 clade A virus-like particles administered by different routes of inoculation.

We have recently developed a candidate human immunodeficiency virus type 1 (HIV-1) vaccine model, based on virus-like particles (VLPs) expressing gp120 from a Ugandan HIV-1 isolate of clade A (HIV-VLP(A)s), which shows the induction of neutralizing antibodies as well as cytotoxic T lymphocytes (CTL) in BALB/c mice by intraperitoneal (i.p.) administration. In the present study, immunization experiments based on a multiple-dose regimen have been performed with BALB/c mice to compare different routes of administration. i.p. and intranasal (i.n.), but not oral, administration induce systemic as well as mucosal (vaginal and intestinal) immunoglobulin G (IgG) and IgA responses. These immune sera exhibit >50% ex vivo neutralizing activity against both autologous and heterologous primary isolates. Furthermore, the administration of HIV-VLP(A)s by the i.n. immunization route induces a specific CTL activity, although at lower efficiency than the i.p. route. The HIV-VLP(A)s represent an efficient strategy to stimulate both arms of immunity; furthermore, the induction of specific humoral immunity at mucosal sites, which nowadays represent the main port of entry for HIV-1 infection, is of great interest. All these properties, and the possible cross-clade in vivo protection, could make these HIV-VLP(A)s a good candidate for a mono- and multicomponent worldwide preventive vaccine approach not restricted to high-priority regions, such as sub-Saharan countries.

Intrauterine infection after delivery: a marker of HIV-1 seropositivity among puerperal women in Uganda?

A case controlled study about HIV seroprevalence among women with post-partum endometritis-myometritis (PPEM) matched with two controls. Each was performed in a non-governmental organization hospital in Kampala, Uganda. All participants were offered HIV pre- and post-test counselling. Personal and clinical information was obtained and HIV-1 ELISA tests performed on blood samples and discordant results resolved by Western blot test. HIV-1 seroprevalence was significantly higher among women with PPEM than controls, 26 (42.3%) and 26 (21.3%) respectively (P = 0.002). Women with PPEM were two-and-a-half times more likely to be HIV-positive than controls, odds ratio 2.74 (95% CI 1.34-5.65). Single or cohabiting women and low salaried women were also significantly more among PPEM cases than controls. In conclusion, PPEM cases had significantly higher seroprevalence of HIV-1 infection than controls and this needs further elucidation for purposes of management strategies.

Post-abortion endometritis-myometritis and HIV infection.

The objective was to explore if HIV-1 infection is a risk factor for post-abortion endometritis-myometritis (PAEM) in an urban hospital in Kampala, Uganda. HIV-1 seroprevalence in women with and without post-abortion infection was established using two standard enzyme-linked immunosorbent assays. Fifty-two women with PAEM and 106 without PAEM infection were recruited. The HIV-1 seroprevalence was 17 (32.7%) among women with PAEM and 38 (36.5%) among women without post-abortion infection. HIV infection was not found to correlate with the risk for PAEM. HIV-1 seroprevalence in both groups was double that among antenatal clients in the same hospital, 14.6% in 1997. Life-threatening infections such as septicaemia, peritonitis and pelvic abscesses were observed among 12 cases (23%). HIV-1 infection was not shown to be a risk factor for PAEM, but women with abortions with and without PAEM have a higher prevalence of HIV-1 than antenatal clients.

Induction of neutralizing antibodies and cytotoxic T lymphocytes in Balb/c mice immunized with virus-like particles presenting a gp120 molecule from a HIV-1 isolate of clade A.

We have recently developed a candidate HIV-1 vaccine based on virus-like particles (VLPs) expressing a gp120 from an Ugandan HIV-1 isolate of the clade A (HIV-VLP(A)s). In vivo immunogenicity experiments were performed in Balb/c mice, with an immunization schedule based on a multiple-dose regimen of HIV-VLP(A)s without adjuvants, showing a significant induction of both humoral and cellular immunity. The Env-specific cellular response was investigated in vitro, scoring for both the proliferative response of T helper cells and the cytolytic activity of cytotoxic T lymphocytes (CTLs). Furthermore, immune sera showed >50% neutralization activity against both the autologous field isolate and the heterologous T cell adapted B-clade HIV-1(IIIB) viral strain. This is one of the first examples of HIV-1 vaccines based on antigens derived from the A clade, which represents >25% of all isolates identified world wide. In particular, the A clade is predominant in sub-Saharan countries, where 70% of the global HIV-1 infections occur, and where vaccination is the only rational strategy for an affordable prevention against HIV-1 infection.

Relationship between HIV-1 Env subtypes A and D and disease progression in a rural Ugandan cohort.

OBJECTIVE: To investigate the role of HIV-1 envelope subtypes on disease progression in a rural cohort of Ugandan adults where two major HIV-1 subtypes (A and D) exist. METHODS: Participants of a clinical cohort seen between December 1995 and December 1998 had blood collected for HIV-1 subtyping. These included prevalent cases (people already infected with HIV at the start of the study in 1990) and incident cases (those who seroconverted between 1990 and December 1998). HIV-1 subtyping was carried out by heteroduplex mobility assay and DNA sequencing in the V3 env region. Disease progression was measured by the rate of CD4 lymphocyte count decline, clinical progression for the incident cases as time from seroconversion to AIDS or death, to first CD4 lymphocyte count < 200 x 10(6)/l and to the World Health Organization clinical stage 3. All analyses were adjusted for age and sex. RESULTS: One hundred and sixty-four individuals, including 47 prevalent and 117 incident cases, had V3 env subtype data of which 65 (40%) were subtyped as A and 99 as D. In the incident cases, 44 (38%) were subtyped as A and 73 as D. There was a suggestion that for most end-points A had a slower progression than D. The cumulative probability of remaining free from AIDS or death at 6 years post-seroconversion was 0.72 [95% confidence interval (CI), 0.50 to 0.85] for A and 0.58 (95% CI, 0.42 to 0.71) for D, and the adjusted hazard ratio of subtype D compared to A was estimated to be 1.39 (95% CI, 0.66 to 2.94; P = 0.39). The estimated difference in rates of decline in square root CD4 lymphocyte counts was -0.41 per year (95% CI, -0.98 to 0.15; P = 0.15). CONCLUSION: This study suggests that although subtype A may have a slower progression than D, HIV-1 envelope subtype is not a major factor in determining the progression of HIV-1 disease in a rural population in Uganda.

The uganda study on HPV variants and genital cancers.

BACKGROUND: Genital cancers in Uganda have been the most frequently diagnosed cancer in men as well as in women since the 1950s. Genetic studies have detected HPV-16 variants of Af1 class and identified a new sub-class designated Af1-u. OBJECTIVES: The main goal of this study is to analyze the prevalence of HPV strains and HPV variants in anogenital lesions of Ugandan male and female subjects in order to possibly determine their role in the pathogenesis of such lesions and to develop an Ugandan preventive HPV vaccine program. STUDY DESIGN: The study is planning to enroll male and female subjects affected by genital lesions, in particular to collect 200 scrapes/biopsies from women with normal ectocervical epithelium as well as with all different degrees of ectocervical lesions (from CIN 1/LSIL to cervical carcinoma). All samples are analyzed by PCR amplification of the L1 conserved region (nt 6584-7035) and the E6/E7 genes (nt 34-880), nucleotide sequence analysis, homology and phylogenetic studies. Variant distribution studies will be followed by serological studies of prevalence and incidence in 1000 women. PRELIMINARY RESULTS AND CONCLUSIONS: Penile cancers from the Kyadondo County have been analyzed for the presence of HPV sequences. More recently 16 ectocervical scrapes and three biopsies have been received from women attending the Nsambya Hospital and analyzed for the presence and type of HPVs. Our results, obtained by PCR and sequencing analysis, allowed the identification of HPV-16 Af1 sequences in 100% of tumor tissue and in 6.25% of scrapes. HPV 45 was identified only in one tumor together with HPV 16 infection. HPV 33 and HPV 58 were present in 20% and 40%, respectively of HPV positive benign samples. The results are showing a narrowing of the HPV pattern in more advanced lesions, suggesting that mainly HPV-16 Af1 patients are progressing to cancer.

Predominance of HIV-1 subtype A and D infections in Uganda.

To better characterize the virus isolates associated with the HIV-1 epidemic in Uganda, 100 specimens from HIV-1-infected persons were randomly selected from each of two periods from late 1994 to late 1997. The 200 specimens were classified into HIV-1 subtypes by sequence- based phylogenetic analysis of the envelope (env) gp41 region; 98 (49%) were classified as env subtype A, 96 (48%) as D, 5 (2.5%) as C, and 1 was not classified as a known env subtype. Demographic characteristics of persons infected with the two principal HIV-1 subtypes, A and D, were very similar, and the proportion of either subtype did not differ significantly between early and later periods. Our systematic characterization of the HIV-1 epidemic in Uganda over an almost 3-year period documented that the distribution and degree of genetic diversity of the HIV subtypes A and D are very similar and did not change appreciably over that time.

Protease sequences from HIV-1 group M subtypes A-H reveal distinct amino acid mutation patterns associated with protease resistance in protease inhibitor-naive individuals worldwide. HIV Variant Working Group.

BACKGROUND: Although numerous mutations that confer resistance to protease inhibitors (PRI) have been mapped for HIV-1 subtype B, little is known about such substitutions for the non-B viruses, which globally cause the most infections. OBJECTIVES: To determine the prevalence of PRI-associated mutations in PRI-naive individuals worldwide. DESIGN: Using the polymerase chain reaction, protease sequences were amplified from 301 individuals infected with HIV-1 subtypes A (79), B (95), B' (19), C (12), D (26), A/E (23), F (26), A/G (11), and H (3) and unclassifiable HIV-1 (7). Amplified DNA was directly sequenced and translated to amino acids to analyze PRI-associated major and accessory mutations. RESULTS: Of the 301 sequences, 85% contained at least one codon change giving substitution at 10, 20, 30, 36, 46, 63, 71, 77, or 82 associated with PRI resistance; the frequency of these substitutions was higher among non-B (91%) than B (75%) viruses (P < 0.0005). Of these, 25% carried dual and triple substitutions. Two major drug resistance-conferring mutations, either 20M or 30N, were identified in only three specimens, whereas drug resistance accessory mutations were found in 252 isolates. These mutations gave distinct prevalence patterns for subtype B, 63P (62%) > 77I (19%) > 10I/V/R (6%) = 361 (6%) = 71T/V (6%) > 20R (2%), and non-B strains, 36I (83%) > 63P (17%) > 10I/V/R (13%) > 20R (10%) > 77I (2%), which differed statistically at positions 20, 36, 63, 71, and 77. CONCLUSIONS: The high prevalence of PRI-associated substitutions represent natural polymorphisms occurring in PRI-naive patients infected with HIV-1 strains of subtypes A-H. The significance of distinct mutation patterns identified for subtype B and non-B strains warrants further clinical evaluation. A global HIV-1 protease database is fundamental for the investigation of novel PRI.

An improved algorithm for determining HIV type 1 subtypes in a primary laboratory in Uganda.

A pilot study was undertaken with the objective of developing a simple, economical, and efficient algorithm through which to subtype HIV-1 in a large epidemiological cohort study in Uganda. A peptide enzyme immunoassay (PEIA) employing both V3 and gp41 regions and a heteroduplex mobility assay (HMA) were evaluated in comparison with DNA sequencing. Of 146 samples selected, 115 (79%) were successfully sequenced. Taking sequence data as the "gold standard," other assays were compared with these data. The HMA correctly identified 95 (83%) of the samples, and only 1 sample was wrongly identified. The V3 PEIA alone and in combination with gp41 peptides correctly identified 76 and 78% of the samples, respectively; however, the number of wrongly identified samples was four times less with the combination compared with V3 peptides alone (4 versus 16%). The sensitivity, specificity, and positive and negative predictive values for serotype A and D samples were greater for the combination than V3 peptides alone. We have described a new algorithm to segregate subtypes A and D. This algorithm uses the two peptide assays followed by HMA and then DNA sequencing for untypable samples, giving an accuracy of 95% at a cost of 37 and 21% for consumables compared with subtyping all the samples by HMA or DNA sequencing, respectively. This proposed approach is suitable for epidemiological studies in Uganda and other regions with a predominance of A and D subtypes.

Genetic characterization and phylogenetic analysis of HIV-1 subtype C from Uganda.

To better understand the emergence of subtype C and its potential impact on vaccine efforts in Uganda, we have characterized subtype C sequences from Uganda (n = 13), Zimbabwe (n = 11), Mozambique (n = 5), South Africa (n = 4), and India (n = 3). Phylogenetic analysis of subtype C sequences in the env gp41 gene region revealed multiple subclusters within subtype C. Further, while most Ugandan specimen subclustered together, other subclusters did not reflect a clear geographic location. The nucleotide divergence within the Ugandan subset was 8.2% (6.1-9.8%) compared with 9.5% (2.5-15%) for the other subtype C gp41 sequences. The protein sequence alignment revealed marked sequence conservation of major immunodominant epitopes within the gp41 region.

Molecular epidemiology of HIV type 1 in a rural community in southwest Uganda.

The molecular epidemiology of a population-based cohort in a cluster of 15 villages in southwestern Uganda was investigated by sequencing part of the p24 gag gene and performing heteroduplex mobility assays (HMAs) of the V3 region of the env gene. Sequence and HMA data, obtained for 69 and 88 proviruses, respectively, showed that the clade A and D viruses were present at a ratio of about 0.67:1. No other clades were detected. Thirteen (22%) of 59 proviruses for which both gag and env data were obtained appeared to be recombinants. Although both clade A and D viruses were present in 13 of the villages, their distribution was unequal: for example, from env data 59% of clade A viruses were found in the eastern villages, compared with only 27% of clade D viruses. Phylogenetic (maximum likelihood) analysis of the p24 gag sequences showed a total of five clusters supported by bootstrap resampling values above or close to 75%. Four clusters were sexual partners, but there was no known sexual contact between the persons in the other cluster. The DNA sequences showed between 0.5 and 8.3% divergence from the cohort clade A or D consensus sequences. The sequences were not closely related to those published for other clade A or D proviruses.

Analysis of genetic variability within the immunodominant epitopes of envelope gp41 from human immunodeficiency virus type 1 (HIV-1) group M and its impact on HIV-1 antibody detection.

The serodiagnosis of human immunodeficiency virus type 1 (HIV-1) infection primarily relies on the detection of antibodies, most of which are directed against the immunodominant regions (IDR) of HIV-1 structural proteins. Among these, the N-terminal region of gp41 contains cluster I (amino acids [aa] 580 to 623), comprising the cytotoxic T-lymphocyte epitope (AVERYLKDQQLL) and the cysteine loop (CSGKLIC), and cluster II (aa 646 to 682), comprising an ectodomain region (ELDKWA). To delineate the epitope diversity within clusters I and II and to determine whether the diversity affects serologic detection by U.S. Food and Drug Administration (FDA)-licensed enzyme immunoassay (EIA) kits, gp41 Env sequences from 247 seropositive persons infected with HIV-1 group M, subtypes A (n = 42), B (n = 62), B' (n = 13), C (n = 38), D (n = 41), E (n = 18), F (n = 27), and G (n = 6), and 6 HIV-1-infected but persistently seronegative (HIPS) persons were analyzed. While all IDR were highly conserved among both seropositive and HIPS persons, minor amino acid substitutions (<20% for any one residue, mostly conservative) were observed for all subtypes, except for B', in comparison with the consensus sequence for each subtype. Most importantly, none of the observed substitutions among the group M plasma specimens affected antibody detection, since all specimens (n = 152) tested positive with all five FDA-licensed EIA kits. Furthermore, all specimens reacted with a group M consensus gp41 peptide (WGIKQLQARVLAVERYLKDQQLLGIWGCSGKLICTTAVPWNASW), and high degrees of cross-reactivity (>80%) were observed with an HIV-1 group N peptide, an HIV-1 group O peptide, and a peptide derived from the homologous region of gp41 from simian immunodeficiency virus from chimpanzee (SIVcpz). Taken together, these data indicate that the minor substitutions observed within the IDR of gp41 of HIV-1 group M subtypes do not affect antibody recognition and that all HIV-1-seropositive specimens containing the observed substitutions react with the FDA-licensed EIA kits regardless of viral genotype and geographic origin.

The immune response to Mycobacterium tuberculosis in HIV-infected and uninfected adults in Uganda: application of a whole blood cytokine assay in an epidemiological study.

SETTING: Out-patient clinic, Entebbe, Uganda. BACKGROUND: It has been proposed that 'type 1' cytokines are essential in protective immunity to Mycobacterium tuberculosis and that suppression of 'type 1' or a switch to a 'type 2' profile is deleterious. We employed a simple assay to examine whether the dependence of the immunological responses to mycobacterial antigens on a range of explanatory factors could be determined in a population where tuberculosis is endemic. OBJECTIVE: To determine the relationship between the tuberculin skin test response and cytokine profile, and the effect of human immunodeficiency virus (HIV) infection. DESIGN: A cross-sectional study of 97 Ugandan adults (22 HIV-positive, 75 HIV-negative). Whole blood was stimulated in vitro using mycobacterial antigens (purified protein derivative [PPD] and culture filtrate proteins [CFP]). 'Type 1' cytokines (gamma interferon [IFN-gamma] and interleukin-2 [IL-2]), 'type 2' cytokines (IL-5 and IL-10) and tumour necrosis factor alpha (TNF-alpha) were measured in culture supernatants. RESULTS: Among HIV-negative subjects, a positive tuberculin skin test was associated with type 1 or mixed (type 1 + type 2) cytokine production, but a positive IFN-gamma response also occurred in a proportion of tuberculin skin test negative subjects (36% for PPD, 17% for CFP). In association with HIV infection, IFN-gamma responses to mycobacterial antigens were profoundly impaired (odds ratio [OR] 0.10 for PPD, 0.06 for CFP, P< or =0.001), but production of IL-2, IL-5 and TNF-alpha was relatively sustained, and IL-10 increased or sustained (OR 3.97 for PPD, P = 0.01, 1.14 for CFP, P = 0.99). CONCLUSION: The type 1/type 2 cytokine balance was not defined by the tuberculin skin test response, and may have a closer relation to protective immunity. IFN-gamma production was strikingly impaired in association with HIV infection, while production of type 2 cytokines was sustained or increased. Use of a simple assay allowed a large sample of subjects to be examined, producing epidemiologically meaningful results.

HLA-A, -B, -C, -DRB1, DRB3, DRB4, DRB5 and DQB1 polymorphism detected by PCR-SSP in a semi-urban HIV-positive Ugandan population.

PCR-SSP was used to HLA-type a cohort of Ugandan HIV-positive individuals. The results represent a more comprehensive description of HLA in an African population than previously described and are in concordance with data from a general Black population. Substantial differences exist between this population and Caucasoid populations in which immunological responses to HIV have been investigated; this emphasises that the main HLA-restrictive elements for HIV-specific cytotoxic T lymphocytes will most likely be different for each population.

Optimizing the delivery of HIV counseling and testing services: the Uganda experience using rapid HIV antibody test algorithms.

The AIDS Information Center (AIC) was established in Kampala, Uganda in 1990 in response to increasing interest by members of the general public who wished to know their HIV serostatus. By 1996, >300,000 clients had been seen. HIV serologic testing was performed at a central laboratory and results reported back to AIC after 2 weeks. Approximately 25% of clients failed to learn their HIV serostatus as a result of failure to return or late arrival of results. To address these issues, AIC carried out an evaluation of 3 rapid HIV assays, Sero-Strip, SeroCard, and Capillus, against a standard criterion to identify a testing algorithm that could be used as an on-site confirmatory testing strategy. The study was carried out over a period of 5 working days and 325 clients were seen. An algorithm was identified, which gave no indeterminate results with unambiguously positive or negative specimens, which was 100% sensitive and specific, and which could be integrated with minimal disruption into existing counseling procedures. All clients left AIC knowing their HIV serostatus and having spent <2 hours at the Center. The results of this evaluation demonstrate that "same-day" results can be provided in counseling and testing settings without compromising the quality of counseling or the accuracy of HIV testing.

PIP: An evaluation conducted at the AIDS Information Center in Kampala, Uganda, demonstrated that same-day HIV results can be provided in counseling and testing centers without compromising service quality. The Center was established in 1990 in response to widespread public interest in HIV serodiagnosis. By 1996, more than 300,000 clients had been tested. However, 25% of these clients never received their result because of failure to report back to the Center after 2 weeks (the time required for results to be returned from an off-site laboratory) or late arrival of results. To address this problem, the Center evaluated three rapid HIV assays (Sero-Strip, SeroCard, and Capillus) against a standard criterion to identify a testing algorithm that could be used as an on-site confirmatory testing strategy. 325 clients were enrolled in the 5-day evaluation. Individually, all three rapid tests performed well when compared with the standard criterion result. The resulting algorithm (a combination of Capillus as the screening assay and SeroCard as a supplementary assay for initially positive specimens and Multispot as a tie-breaker assay) gave no indeterminate results, was 100% sensitive and specific, and could be integrated easily into existing counseling protocols. The entire process (registration, test decision counseling, phlebotomy, laboratory testing, prevention counseling, and post-test counseling) took an average of 2 hours to complete.

The development and evaluation of a probe hybridization method for subtyping HIV type 1 infection in Uganda.

We developed a method for large-scale screening of HIV-1 genotypic variation based on DNA probe hybridization. Nested PCR amplifications were performed to generate fragments in the env C2-V3 region and also in the gp41 region, which encompasses the immunodominant domain. The proviral DNA sequences were derived from 68 samples and phylogenetically analyzed. For comparison, the C2-V3 fragment was used in DNA probe hybridization to rapidly determine the infecting HIV subtype. The hybridizing probes were designed on the basis of the two most prevalent subtypes in Uganda, A and D. The results were compared to evaluate the feasibility of using this hybridization method for large-scale genotypic screening. Sequence analysis of the 68 amplified PCR fragments showed that 39 were subtype A and 29 were subtype D. The results of DNA hybridization to the amplified products with A and D subtype-specific probes were more than 90% concordant with the subtypes determined by sequence analysis. Our findings suggest that probe hybridization with subtype-specific probes is effective for large-scale screening of HIV-infected populations. Application of this method will significantly reduce the time needed for large, population-based investigations.

A molecular epidemiologic survey of HIV in Uganda. HIV Variant Working Group.

OBJECTIVE: Previous data, based on a small sampling of convenience, reported subtypes A, B, C, D, and G in Uganda, but neither the extent nor the proportion of these subtypes could be evaluated. To establish correctly the prevalence and distribution of HIV-1 subtypes, we analysed viral clades in 739 HIV-1-seropositive specimens from different areas of Uganda. METHODS: Blood specimens from 1100 patients were collected in five districts of Uganda. Within this collection, 929 HIV-1-seroreactive samples underwent analysis of viral DNA, and 739 were selected for further subtyping in env or pol regions. RESULTS: Using a combination of subtype A- and D-specific probes to C2-V3 region and DNA sequencing, HIV-1 env subtypes were determined in 594 specimens: 341 were of subtype A (57.4%), 250 of subtype D (42.1%), and three of subtype C (0.5%). Sixty-two samples showed reactivity with both probes, suggesting potential mixed infections, cross-reactivity to probes, or possibly other subtypes. Subsequent sequence analysis of 19 randomly selected specimens revealed subtypes A (n = 4), D (n = 12), and C (n = 3). Sequence analysis of the 27 samples chosen from the remaining 83 samples, which could be amplified only with viral gp41 or protease gene primers, classified them as subtypes A (n = 13) and D (n = 14). No significant clinical, demographic, or geographic differences were found between HIV-1 infections with viruses of subtypes A and D, despite considerable genetic diversity within these clades. CONCLUSIONS: This is the first major population-based study of the prevalent HIV-1 strains in an African country selected for vaccine trials. The subtyping methods we describe should be of use to investigators seeking to conduct large-scale screening for HIV variants in other populations.

Rapid HIV testing with same-day results: a field trial in Uganda.

Rapid, on-site HIV testing with same-day results may improve services and increase the number of clients who learn their serostatus in developing countries. To validate test performance under field conditions and assess the change in the proportion of clients who learn their serostatus, we conducted a field trial using the Capillus HIV-1/HIV-2 assay (Cambridge Diagnostics) at the AIDS Information Centre counselling and testing sites in Uganda. Compared to the standard 2-EIA testing algorithm, the sensitivity of Capillus was 99.6% (95% CI; 98.5%, 99.9%), the specificity was 98.8% (95% CI; 98.1%, 99.3%), the positive predictive value was 96.5% (95% CI; 94.5%, 97.8%), and the negative predictive value was 99.9% (95% CI; 99.5%, 100%). It took less than 5 min to perform a single test, and results were returned to clients in less than an hour, during which time clients were counselled. This resulted in a 27% increase in the proportion of clients who learned their serostatus and received counselling. We conclude that simple, rapid HIV tests can be performed accurately on-site within the time frame of a clinic visit, increasing the number of clients who learn their serostatus and receive post-test counselling.

PIP: The capability of rapid, on-site HIV testing with same-day results to improve HIV services in developing countries was evaluated through field studies conducted at AIDS Information Centers in Uganda. The screening test selected--Capillus HIV-1/HIV-2--is a direct latex agglutination assay performed on a plastic capillary agglutination slide. The rapid test protocol included anonymous registration, orientation and test decision counseling, phlebotomy, prevention counseling, and test result counseling. Clients received their result an average of 48 minutes after venipuncture, during which time they were counseled. When 2135 serum samples tested on-site in Kampala were compared with the standard 2-week enzyme immunoassay (EIA) testing algorithm used by the Nakasero Blood Bank, 520 samples were positive by both tests, 19 were Capillus-negative and EIA-positive, and 2 were Capillus-positive and EIA-negative. With an HIV prevalence of 24%, the negative predictive value of the Capillus test was 99.9% and the positive predictive value was 96.5%. The Capillus HIV test was associated with a 27% increase over the EIA in the proportion of clients who learned their serostatus and received counseling. Of concern, however, was the finding that only 16% of clients whose initial test was positive returned to the clinic for confirmatory results. Clients expressed a preference for same-day HIV results and, because of the reductions in time and expenses associated with a single visit, were willing to pay an average of US$3 for rapid testing. Overall, these findings suggest that rapid HIV testing is feasible under field conditions in developing countries with high HIV prevalence and can be completed within the time frame of a typical clinic visit.

Molecular epidemiological analysis of HIV in sexual networks in Uganda.

OBJECTIVE: To investigate the suitability of HIV sequence analysis, based on the p17 region of the gag gene, to characterize the sexual networks in and around a trading town in south-west Uganda. METHODS: Blood samples were obtained from 54 HIV-seropositive members of three distinct sexual networks and phylogenetic analysis carried out on proviral DNA sequences obtained from the p17 region of gag from 53 individuals. RESULTS: Despite documented evidence of very little sexual mixing between residents of the trading town, fishing village and surrounding rural area, there was no evidence of clustering of sequences associated with place of residence. More strikingly, known sexual partners failed to show significantly related sequences, and the two pairs of sequences that did show significant similarity came from individuals who had no known social or sexual contact. CONCLUSIONS: Sequence analyses such as those described here have proved effective in confirming or identifying epidemiological links not only following single transmission events but also within risk groups. However, the results from Uganda contrast markedly with those from Europe and the United States. The length of time that the community has been infected, the number of occasions when the virus has been introduced and the high degree of partner change may contribute to the lack of supportive evidence for sociological studies of sexual networks in Uganda.