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Biomedical subjects

G Biberfeld

Publications and source records attributed to G Biberfeld.

At least 55 records · Page 3Linked to original sources
PubMed1999

Comparative evaluation of 14 immunoassays for detection of antibodies to the human T-lymphotropic virus types I and II using panels of sera from Sweden and West Africa.

BACKGROUND: A new generation of assays for the detection of human T-lymphotropic virus types I and II (HTLV-I/II) antibodies has been released. These assays incorporate HTLV-I- and HTLV-II-specific antigens, and some are based on new assay principles. Comparative evaluation data that include these new as well as previous assays are limited. STUDY DESIGN AND METHODS: Fourteen HTLV antibody assays were evaluated by using well-characterized panels of sera from Guinea-Bissau, West Africa, and Sweden. The sera included 127 HTLV-I-positive and 62 HTLV-II-positive specimens, as well as 919 consecutive negative samples. RESULTS: The sensitivity for HTLV-I was 100 percent for all assays, except one, which repeatedly missed one sample. The sensitivity for HTLV-II varied between 86 percent and 100 percent. In general, new-generation assays incorporating HTLV-II-specific antigens, and some of which are based on new assay principles, had a higher sensitivity for HTLV-II than previous assays, which mainly are based on HTLV-I antigens. The specificity was generally higher for new assays than for the previous versions. Testing of Swedish blood donor sera gave higher specificities (94-100%) than did that of African specimens (90-99.7%). Most assays had low delta values (DVs), although there was a tendency toward increased DVs for the new generation of assays. Only two of the new generation of assays came close to a combination of high sensitivity for both HTLV-I and HTLV-II, high specificity, positive and negative predictive values, and high DVs. CONCLUSION: The sensitivity for HTLV-I was generally high and appears to have improved for HTLV-II with the introduction of a new generation of assays incorporating HTLV-II-specific antigens. However, some assays still give false-negative results on HTLV-II-positive specimens. The specificities and the DVs were generally higher for the new assays than for the previous versions.

Africa, Western↗
PubMed1999

Prevalence of HIV infection among hospital patients in north west Tanzania.

In order to estimate hospital HIV prevalence, the economic impact of AIDS on health care and to assess the implications of HIV testing on clinical suspicion of AIDS this hospital based study was done at the government regional hospital of Kagera, Tanzania. Consecutive admissions were recruited into the study, and those consenting had a blood specimen taken, one portion of which was used to aid clinical diagnosis, while the other was tested anonymously for HIV antibodies using two ELISA systems. A short questionnaire was used to specify demographic characteristics, hospital ward of admission and diagnosis of each study subject. The overall age adjusted HIV-1 prevalence was 32.8% (N = 1422) and there was no significant difference in the age adjusted sex specific prevalence. The highest prevalence (53.3%) was found in the 25-34 years age group as well as in the gynaecological and medical wards (41.2% and 40.4%, respectively). The diagnostic category of clinical AIDS had a sensitivity of 11.3% and a specificity of 99.3%, indicating that only 11.3% of the HIV seropositives would have been HIV tested on clinical suspicion of AIDS. Similarly, the HIV-1 antibody sensitivity and specificity for tuberculosis were 5.9% and 97.9%, respectively. Patients who were HIV-1 infected were more likely to have a history of previous hospital admissions, RR = 1.34 (95% CI = 1.16-1.56), and were at an increased risk of developing tuberculosis, RR = 2.02 (95% CI = 1.50-2.70). The diagnostic categories with the highest HIV-1 infection prevalence were clinical AIDS (88.5%), herpes zoster and other HIV-1 skin manifestations combined (85.7%) and pulmonary tuberculosis (58.3%). In conclusion, the prevalence of HIV-1 infection was high among hospitalized patients in Bukoba hospital indicating that the major cause of illness leading to admission to the hospital may have been underlying HIV-1 infection. The findings also indicate that in a high HIV-1 prevalence area, testing for HIV infection on the basis of clinical suspicion of AIDS alone is not sufficient to provide rational care to the majority of HIV infected patients.

AIDS-Related Opportunistic Infections↗
PubMed1999

Beta-chemokine production in macaques vaccinated with live attenuated virus correlates with protection against simian immunodeficiency virus (SIVsm) challenge.

Simian immunodeficiency virus (SIV) uses the CCR5 chemokine receptor as the main co-receptor to enter CD4+ cells. RANTES, MIP-1alpha and MIP-1beta have been suggested as the major human immunodeficiency virus-suppressor factors produced by CD8+ T-cells. The aim of this study was to investigate the CD8+ T-cell production of anti-viral factors and of beta-chemokines in six cynomolgus macaques vaccinated with live attenuated SIVmacC8 in relation to protection against infectious intrarectal SIVsm challenge. Three of the vaccinated animals were completely protected and one was partially protected against the challenge virus. Interestingly, these monkeys showed higher in vitro anti-viral CD8+ cell suppressor activity and beta-chemokine production both before and after vaccination as compared to the infected monkeys. The results indicate that beta-chemokines may play a role in protective immunity but also that genetic and/or environmental factors may influence their production.

Animals↗
PubMed1998

Live attenuated simian immunodeficiency virus (SIV)mac in macaques can induce protection against mucosal infection with SIVsm.

OBJECTIVE: To investigate whether vaccination of macaques with attenuated simian immunodeficiency virus (SIV)macC8 could induce long-term protective immunity against rectal exposure to SIVsm and intravenous exposure to the more divergent HIV-2. DESIGN AND METHODS: Eight months after vaccination with live attenuated SIVmacC8, four cynomolgus monkeys were challenged with SIVsm intrarectally and another four vaccinated monkeys were challenged with HIV-2 intravenously. Sixteen months after SIVmacC8 vaccination, another two monkeys were challenged with SIVsm across the rectal mucosa. Two vaccinees shown to be protected against SIVsm were rechallenged 8 months after the first challenge. Ten naive animals were used as controls. Serum antigenaemia, virus isolation, antibody responses, cell-mediated immunity and CD4+ and CD8+ T-cell subpopulations were monitored. PCR-based assays were used to distinguish between virus populations. RESULTS: At the time of challenge, eight out of 10 vaccinees were PCR-positive for SIVmacC8 DNA but no virus could be isolated from peripheral blood mononuclear cells. After SIVsm challenge, three out of six vaccinees were repeatedly SIVsm PCR-negative. In one of the three infected monkeys, the challenge virus was initially suppressed but the monkey ultimately developed AIDS after increased replication of the pathogenic virus. Rechallenged monkeys remained protected. All HIV-2-challenged vaccinees became superinfected. All controls became infected with either SIVsm or HIV-2. At the time of challenge the vaccinees had neutralizing antibodies to SIVmac but no demonstrable cross-neutralizing antibodies to SIVsm or HIV-2. Titres of antigen-binding or neutralizing antibodies did not correlate with protection. Cytotoxic T-cell responses to SIV Gag/Pol and virus-specific T-cell proliferative responses were low. CONCLUSION: The live attenuated SIVmacC8 vaccine was able to induce long-term protection against heterologous intrarectal SIVsm challenge in a proportion of macaques but not against the more divergent HIV-2, which was given intravenously.

Animals↗
PubMed1998

Optimization of polymerase chain reaction for detection of HIV type 2 DNA.

The aim of this study was to increase the sensitivity of an earlier version of an HIV-2 nested PCR assay based on primers in the gag, pol, LTR, and env regions. The assay was first optimized with regard to concentrations of dNTP, MgCl2, and primers, using a method that allowed optimization of all three parameters in only two test runs. We then designed and optimized new primer sets in the LTR, gag, and gag/pol regions that were based on more isolates than were the former (old) primer sets. Samples from 57 HIV-2 antibody-positive individuals were tested with the four old primer sets as well as with the three new primer sets. Five primer sets from this run (new gag, new gag/pol, old LTR, old env, and new LTR) were then tested with 35 more samples, giving a total number of 92 tested samples from HIV-2-infected individuals. At initial testing of the 92 samples a combination of primer sets from two different regions yielded a sensitivity ranging from 93.5 to 98.9%. After repeated testing the sensitivity ranged from 96.7 to 100% for the different primer combinations. The specificity was 100% for all primer sets except old LTR, which had a specificity of 97%. In conclusion, it is possible to create a more sensitive PCR assay by optimizing the different PCR parameters as well as by including primer sets based on more isolates.

DNA Primers↗
PubMed1998

Decline in the prevalence of HIV-1 infection in young women in the Kagera region of Tanzania.

In northwestern Tanzania, a population-based survey of HIV-1 infection in the Kagera region in 1987 demonstrated a high prevalence (24.2%) in adults of Bukoba town, whereas it was lower (10.0%) in the surrounding rural district of Bukoba. In 1993 and 1996, population-based cross-sectional studies were carried out in urban and rural Bukoba districts, respectively, to monitor the time trend in the prevalence of HIV-1 infection in the region. In both studies, a multistage cluster sampling technique was adopted in selecting study individuals. Consenting individuals between 15 and 54 years of age were interviewed using a structured questionnaire. Following individual counseling, blood samples were drawn and tested for HIV infection using enzyme-linked immunosorbent assay (ELISA) antibody detection tests. The overall age-adjusted HIV-1 seroprevalence in urban Bukoba decreased from 24.2% (134 of 553) in 1987 to 18.3% (118 of 653) in 1993 (p = .008). The age-adjusted gender-specific prevalence declined significantly in women, from 29.1% (95 of 325) to 18.7% (74 of 395; p = .0009). Except for men > or = 35 years of age, whose prevalence appeared to have an upward trend between the two studies, all other age groups in both genders had a downward trend; this finding was most significant in women between 15 and 24 years of age (from 27.6% to 11.2%; p = .0004). For the rural population, the overall prevalence decreased from 10.0% (54 of 538) in 1987 to 6.8% (118 of 1728) in 1996 (p = .01). Except for rural women between 15 and 24 years of age whose prevalence decreased from 9.7% (12 of 124) to 3.1% (12 of 383; p = .002), other age groups in the rural populations showed no change in prevalence. Ongoing interventions in this area leading to behavioral change may have contributed to this observation. An incidence study is under way to confirm this observation and to investigate the factors that are responsible for the decline in the HIV-1 prevalence.

Adolescent↗
PubMed1998

Evaluation of 14 commercial HIV-1/HIV-2 antibody assays using serum panels of different geographical origin and clinical stage including a unique seroconversion panel.

The performance of 14 commercially available HIV-1/2 antibody assays were compared using well-characterized serum panels containing in total 1500 1800 sera. The panels included consecutive HIV-negative blood donor sera from Sweden, unselected blood donor and patient sera from Tanzania and unselected sera from outpatient clinics in Guinea-Bissau. Furthermore selected HIV-1 antibody positive sera from Sweden and Tanzania and HIV-2 antibody positive sera from Guinea-Bissau were included in the panels. The HIV-1 antibody positive sera were from individuals at various stages of HIV infection, from primary infection, to asymptomatic phase and late stage disease. 12 of the 14 assays identified correctly all HIV-1 and HIV-2 antibody positive sera. One Tanzanian HIV-1 antibody positive sample with complete banding pattern on Western blot was not detected by two of the ELISAs employing synthetic peptides. There were small differences in sensitivity between the assays when used for analysis of seroconversion panels. The most sensitive assay, Abbott IMx HIV-1/HIV-2 III Plus detected antibodies in all nine samples collected from four individuals during the first week after onset of symptoms of primary HIV-1 infection. Most of the assays became reactive during the second week after onset of symptoms and the least sensitive assays were reactive from the third week. The assays showed a high specificity ranging from 99.2 to 100% when used for analysis of Swedish blood donor sera, while most of the assays showed a significantly lower specificity, 91.9-99.6%, when used for testing African specimens.

AIDS Serodiagnosis↗
PubMed1998

Clinical features, immunological changes and mortality in a cohort of HIV-2-infected individuals in Bissau, Guinea-Bissau.

Clinical symptoms and immunological changes associated with HIV-2 infection were studied in a cohort of police officers in Guinea-Bissau. HIV-related symptoms were classified according to the WHO clinical staging system. The inclusion period was from January 1990 to January 1997, and among 2637 subjects included (90.7%M, 9.3%F), the prevalence of HIV-1, HIV-2 and dual reactivity to both HIV-1 and HIV-2 was 0.9%, 9.7% and 0.5%, respectively. Weight loss > 10%, diarrhoea or fever > 1 month, generalized lymphadenopathy and generalized pruritic dermatitis were significantly associated with HIV-2 infection as well as suppression of CD4 cells as compared with HIV-negative controls. Females had significantly higher CD4 cell counts than males, both among HIV-negative and HIV-2-positive asymptomatic individuals. The mortality rates/100 person-years (p.y.) were 0.4 in HIV-negative and 2.6 in HIV-2-positive subjects, giving an age-adjusted mortality rate ratio of 6.6 (95% CI, 4.0-10.9; p < 0.001). The mortality rate among HIV-2-infected individuals varied considerably in different stages of the WHO clinical staging system; 1.7 and 8.0/100 p.y. in stage 1 and 3, respectively.

Adolescent↗
PubMed1998

Acceptability of voluntary HIV testing with counselling in a rural village in Kagera, Tanzania.

A pilot study on acceptability of voluntary HIV testing with counselling was performed in a rural village in Kagera, Tanzania as a potential intervention against HIV transmission. Village residents were prepared by their leaders and subsequently invited to health education group meetings to volunteer for the test. Consenting individuals were interviewed to determine awareness and acceptance of the offer followed by pre-test counselling and taking of a blood sample for subsequent HIV testing. Two months later, the results of the test were returned with post-test counselling coupled with a short interview of a random sample of adults in the village. Of the 245 adults responding to the call, 137 (55.9%) subsequently volunteered. The main reason for volunteering was to know the HIV status (96%). Among those who were aware of the offer, the main reason for not volunteering was that they felt unlikely to catch AIDS, implying that they had a false perception of being at low risk. In this study a significant proportion were willing to volunteer for the HIV test and to receive the results, indicating a moderate level of acceptability. The results also indicate the need for developing innovative ways of enhancing acceptability of voluntary HIV testing with counselling. However, the relationship between knowledge of HIV status and behavioural change is complex and therefore several potential mechanisms may exist by which HIV testing in combination with counselling can influence behaviour. For this reason, people should be given the choice of knowing their HIV status since it may constitute a potential mechanism for influencing behaviour towards reduction of HIV transmission.

Adolescent↗
PubMed1998

Immunological profile of endemic and epidemic Kaposi's sarcoma patients in Dar-es-Salaam, Tanzania.

Kaposi's sarcoma (KS) presents in four clinicopathological types namely classical/sporadic (CKS), endemic African (EKS), iatrogenic (IKS) and that associated with AIDS (AKS). Recently a putative herpes virus (HHV-8) was described and shown to be present in all four types of KS. The immunological status of patients with EKS has been conflicting. In this study total leucocyte counts, total lymphocyte counts and lymphocyte subsets of patients with EKS and AKS were determined by flow cytometry and compared to those of healthy HIV-1 seronegative controls. Results show that 50% of EKS lesions were of nodular type. Patients with EKS had significantly lower levels of CD4+ T- lymphocytes and CD4:CD8 ratio but significantly higher CD8+ T-lymphocytes compared to controls. Patients with AKS had significantly lower levels of CD4+ T-lymphocytes and also CD4:CD8 ratios but significantly higher percentage of CD8+ T-lymphocytes when compared with EKS patients. These findings indicate that in both forms of KS there is a certain degree of immunological disturbance which is more conspicuous in AKS because of HIV infection and suggests that HIV-1 acts synergistically with the aetiological agent (HHV-8) to cause a more aggressive type of KS.

AIDS-Related Opportunistic Infections↗
PubMed1997

Outcome of immunization of cynomolgus monkeys with recombinant Semliki Forest virus encoding human immunodeficiency virus type 1 envelope protein and challenge with a high dose of SHIV-4 virus.

Infection of macaques with chimeric simian-human immunodeficiency viruses (SHIVs) allows evaluation of HIV-1 envelope vaccines. SHIV-4 is based on SIVmac239 but carries the env, tat, and rev genes of HIV-1IIIB. In this study we used Semliki Forest virus (SFV) RNA vectors to express the envelope protein gp160 of HIV-1IIIB in cynomolgus macaques. Monkeys were immunized four times with recombinant suicide SFV. Whereas two of four monkeys showed T cell-proliferative responses, only one monkey had demonstrable levels of antibodies to HIV-1 gp41 and gp120 as shown by enzyme-linked immunosorbent assay (ELISA) and Western blot. The vaccinated monkeys and four control animals were challenged with 10,000 MID100 (100% minimum infectious doses) of cell-free monkey cell-grown SHIV-4 virus. As demonstrated by virus isolation, all macaques became infected after challenge. All vaccinated monkeys showed an HIV-1-specific anamnestic T cell-proliferative response. Three of four vaccines had developed HIV-1-Env-specific antibodies 2 weeks after challenge whereas none of the four controls showed any detectable immune response at this time point. Furthermore, three of four vaccinated monkeys had no demonstrable viral antigenemia and low viral load as opposed to one of the four naive control animals.

AIDS Vaccines↗
PubMed1997

Prevalence and risk factors for HTLV-II infection in 913 injecting drug users in Stockholm, 1994.

The prevalence and risk factors for acquisition of human T-cell lymphotropic virus type I and II (HTLV-I and II) were investigated in a prospective study of 913 injecting drug users (IDUs) in Stockholm in 1994. Epidemiologic data were recorded, and blood samples were tested for antibodies against HTLV-I and HTLV-II; human immunodeficiency virus (HIV) types 1 and 2; and hepatitis A (HAV), B (HBV), C (HCV), and D (HDV). Positive serologic results for HTLV were confirmed by Western blot (WB) and polymerase chain reaction (PCR). Of the 905 participants with conclusive HTLV-II status, 29 (3.2%) were HTLV-II positive, and all but three were of Nordic descent. None was HTLV-I infected. One person was infected as early as 1981, before HIV had reached the IDU population in Sweden. The prevalence of HTLV-II infection was 12% among HIV-1-seropositive and 1.8% among HIV-1-seronegative participants. The overall seroprevalences were 14% for HIV-1, 0% for HIV-2, 41% for HAV, 75% for HBV, 92% for HCV, and 8% for HDV. Although amphetamine has been the main injecting drug in Sweden for several decades, heroin abuse combined with a debut of injecting drugs before 1975 was identified as the most important risk factor associated with HTLV-II infection. HAV and HIV seropositivity were also independent risk factors.

Adult↗
PubMed1997

Evaluation of T cell subsets by an immunocytochemical method compared to flow cytometry in four countries.

The authors tested an alternative method for CD4 and CD8 T lymphocytes enumeration, the immunoalkaline phosphatase method (IA), in three African countries and in Denmark. The IA determinations from 136 HIV antibody positive and 105 HIV antibody negative individuals were compared to the corresponding results obtained by flow cytometry (FC) performed in the respective countries. The authors found good correspondence between the two methods for measurements of CD4 and CD8 T lymphocytes independent of serological status and geographical site. However, the CD4 and CD8 T lymphocytes values obtained by the two methods are not interchangeable as IA compared to FC consistently gives higher percentage of CD4 T lymphocytes, and lower percentage of CD8 T lymphocytes. Mean differences between the two methods did not differ between the three African countries indicating that the IA method provides systematic results. Replicate measurements suggested good correspondence between results obtained by IA. By using an IA level of < 300 CD4 T lymphocytes/microliter, the sensitivity was 81% and specificity 96% for detecting an FC level of < 200 CD4 T lymphocytes/microliter. Using an IA level of < 20% CD4 T lymphocytes, the sensitivity was 89% and specificity 95% for detecting an FC level of < 14% CD4 T lymphocytes. The FC and IA methods had the same internal correspondence between low absolute CD4 T cell count and low CD4 percentages; the sensitivity and specificity for detecting a low absolute CD4 T cell counts with a low CD4 percentage was 92% and 68% for FC and 91% and 73% for IA, respectively. The IA method is 10-fold cheaper than FC, is independent of advanced laboratory facilities, and does not need immediate processing of samples as blood smears can be stored for long periods. The IA method is therefore suitable for use in areas with limited resources and laboratory facilities where there is a need for immunological surveillance in hospital or community studies.

Alkaline Phosphatase↗
PubMed1997

Field evaluation of alternative testing strategies for diagnosis and differentiation of HIV-1 and HIV-2 infections in an HIV-1 and HIV-2-prevalent area.

OBJECTIVE: To identify cost-efficient alternative antibody testing strategies for screening, confirmation and discrimination of HIV-1 and HIV-2 infections, including rapid simple tests (RST) as well as enzyme-linked immunosorbent assays (ELISA), in a HIV-1 and HIV-2-prevalent area. DESIGN: Evaluation and comparison of anti-HIV-1/2 assays, adhering to the World Health Organization recommendations for alternative confirmatory strategies, using banked and prospectively collected specimens in Guinea-Bissau. METHODS: A total of 1110 consecutive sera from Bissau were included in the first phase, of which 198 (17.8%) were HIV-seropositive: 52 (4.7%) HIV-1, 120 (10.8%) HIV-2, and 26 (2.3%) HIV-1/HIV-2 dually reactive. In addition, 95 selected HIV-positive specimens were included for study of sensitivity and cross-reactivity between HIV-1 and HIV-2. Western blot was used as a gold standard for confirming the reactivity of the specimens. All specimens were screened by two assays. Enzygnost ELISA and Capillus RST. Samples reactive by any of the screening assays were further tested by assays chosen for confirmation: UBI ELISA, Innotest ELISA Recombigen RST, Multispot RST and Immunocomb RST. The confirmatory RST as well as Wellcozyme Recombinant HIV-1 ELISA, PEPTI-LAV and INNO-LIA were also used to study differentiation between HIV-1 and HIV-2. RESULTS: The sensitivities of all assays were 100%. The specificities of the screening assays at initial and repeated testing were 98.0 and 99.7%, respectively, for Enzygnost and 99.8 and 99.9%, respectively, for Capillus. The various combinations of two or three assays showed specificities of 99.2-100%. Several possible combinations of assays were identified where a specificity of 100% and good differentiation between HIV-1 and HIV-2 was achieved. Significant differences in the capacity to discriminate were noted; Immunocomb and PEPTI-LAV had the lowest number of dual-reactive results. A follow-up study of 1501 consecutive samples tested with the strategy chosen for routine use showed a sensitivity and specificity comparable to ELISA and Western blot. CONCLUSION: High sensitivities and specificities were obtained with various combinations of assays including RST as well as ELISA, and these procedures are well suited for field use in Africa. Serodiagnostic strategies for HIV can be based on RST alone and differentiation between HIV-1 and HIV-2 can be achieved as part of these strategies. Large differences in the capacity of individual assays to discriminate between HIV-1 and HIV-2 were observed.

Diagnosis, Differential↗
PubMed1997

Late postnatal transmission of human immunodeficiency virus type 1 infection from mothers to infants in Dar es Salaam, Tanzania.

OBJECTIVE: To study late postnatal transmission of human immunodeficiency virus type 1 in a cohort of children born to HIV-1-seropositive mothers who delivered at Muhimbili Medical Centre in Dar es Salaam, Tanzania. MATERIALS AND METHODS: Since 1991 a prospective cohort study of mother-to-child transmission of HIV-1 has been conducted at Muhimbili Medical Centre in Dar es Salaam. HIV-1-seropositive mothers and age-matched seronegative controls were recruited into the cohort at delivery together with their newborns. Diagnosis of HIV-1 infection in children was based on polymerase chain reaction, HIV-1 p24 antigen tests and HIV antibody tests. Late postnatal transmission was defined as HIV-1 infection occurring after 6 months of age in a child who was uninfected at 6 months of age and who had an HIV-1-seropositive mother. Children born to HIV-seronegative mothers were used as controls. Breast-feeding was universal in this cohort. CD4 and CD8 T lymphocytes were assayed by flow cytometry in the mothers. RESULTS: Among 139 children born to HIV-1-seropositive mothers and known to be HIV-uninfected at 6 months of age, 8 children became HIV-1-infected at the end of their first year of life or later. No conversions were observed in children younger than 11 months. The 8 conversions were observed during a follow-up covering 1555 child months between 6 and 27 months of age corresponding to a conversion rate of 6.2 per 100 child years. Among 260 children with HIV-seronegative mothers no child became HIV-infected during the follow-up. The percentage of CD4 T lymphocytes was similar in mothers with early and late transmission but was significantly lower in transmitting than in nontransmitting mothers. CONCLUSION: Because no HIV-1 infection occurred in children with HIV-seronegative mothers, we conclude that the observed infections at the end of the first year of life or later among children born to HIV-seropositive women were caused by late transmission from mother to child, most likely through breast-feeding.

AIDS Serodiagnosis↗
PubMed1997

Comparison of in-house and commercial sample preparation and PCR amplification systems for detection of human immunodeficiency virus type 1 DNA in blood samples from Tanzanian adults.

This study compared the performance of several in-house nested PCR systems and the Amplicor human immunodeficiency virus type 1 (HIV-1) PCR kit in the detection of HIV-1 DNA in Tanzanian samples prepared by two different methods. All six of the in-house primer sets evaluated had a higher sensitivity for HIV DNA detection in samples prepared by the Amplicor PCR sample preparation method than in those prepared by the Ficoll-Isopaque (FIP) density gradient centrifugation method. A sensitivity of 100% was achieved by combining two in-house primer sets. The sensitivity of the standard Amplicor HIV-1 PCR kit was only 59%, whereas a modified Amplicor HIV-1 PCR test had a sensitivity of 98%. Our data show that Tanzanian samples prepared by the Amplicor preparation method are more suitable for HIV-1 PCR testing than samples prepared by the FIP method. The modified, but not the standard, Amplicor HIV-1 PCR kit provides an alternative to the nested in-house PCR technique for the diagnosis of HIV infection.

Adult↗