Prevalence of serological ineligibility among blood donors of a Hemotherapy Center in Caxias do Sul, southern Brazil

Introduction: Blood donation should be voluntary, anonymous and altruistic, and the donor should not, directly or indirectly, receive any remuneration or benefit by virtue of donating blood. Like any other therapeutic method, transfusion procedures are not risk free and can expose the patient to a several complications. Serological screening is of great importance to ensure transfusion safety. The present study aimed to estimate the prevalence of serological ineligibility among blood donors from a Hemotherapy Center in Caxias do Sul (RS). Method: An exploratory, descriptive and quantitative study was conducted on data from July 2010 to December 2015 collected at a Hemotherapy Center in Caxias do Sul (RS). Results: During the study period, 14,267 blood donors attended the Hemotherapy Center, of which 9,332 (65.40%) were males and 4,935 (34.60%) were female. Considering only the suitable donors, 12,702 blood donations were performed, 144 (1.13%) presented positive serological tests. The most prevalent positive serology was for hepatitis B (anti-HBc) with 98 cases (0.77%), followed by syphilis with 19 cases (0.15%); Chagas disease, with 10 (0.08%); hepatitis C, with nine (0.07%); and HIV and HTLV, with four (0.03%) reactive samples each. Conclusion: The results presented are important for health surveillance and make it possible to take measures to ensure safe blood stocks (AU)

An in-house real-time polymerase chain reaction: standardisation and comparison with the Cobas Amplicor HBV monitor and Cobas AmpliPrep/Cobas TaqMan HBV tests for the quantification of hepatitis B virus DNA

This study aimed to standardise an in-house real-time polymerase chain reaction (rtPCR) to allow quantification of hepatitis B virus (HBV) DNA in serum or plasma samples, and to compare this method with two commercial assays, the Cobas Amplicor HBV monitor and the Cobas AmpliPrep/Cobas TaqMan HBV test. Samples from 397 patients from the state of São Paulo were analysed by all three methods. Fifty-two samples were from patients who were human immunodeficiency virus and hepatitis C virus positive, but HBV negative. Genotypes were characterised, and the viral load was measure in each sample. The in-house rtPCR showed an excellent success rate compared with commercial tests; inter-assay and intra-assay coefficients correlated with commercial tests (r = 0.96 and r = 0.913, p < 0.001) and the in-house test showed no genotype-dependent differences in detection and quantification rates. The in-house assay tested in this study could be used for screening and quantifying HBV DNA in order to monitor patients during therapy.

The use of nested Polymerase Chain Reaction (nested PCR) for the early diagnosis of Histoplasma capsulatum infection in serum and whole blood of HIV-positive patients* / Uso da Reação em Cadeia da Polimerase aninhada (PCR aninhada) para o diagnóstico precoce da infecção pelo Histoplasma capsulatum no soro e no sangue total de pacientes HIV positivos

The aim of the study was to detect the rDNA sequences and their regions in Histoplasma capsulatum, which could be considered species-specific and used as a molecular method for this diagnosis by the technique of nested polymerase chain reaction (nested PCR), employing specific sequences (primers) for H. capsulatum: 18S rDNA region (HC18), 100 kDa (HC100) and the sequence 5.8 S-ITS rDNA (HC5.8). The PCR sequences HC18, HC100 and HC5.8 resulted in a specificity of 100%. The molecular assays may increase the specificity, sensitivity and speed in the diagnosis of Histoplasmosis.

O objetivo do estudo consistiu em detectar seqüências no ADNr e as suas regiões no Histoplasma capsulatum, que pudessem ser consideradas espécie-específicas e usadas como método molecular para o diagnóstico pela técnica da reação em cadeia da polimerase aninhada ("nested PCR") com seqüências específicas ("primers") para H. capsulatum: regiões 18S ADNr (HC18), 100kDa (HC100) e a seqüência 5.8 S ADNr-ITS (HC5.8). A "nested PCR" com as seqüências HC18, HC100 e HC5.8 resultaram em 100% de especificidade. Os ensaios moleculares podem aumentar a especificidade, sensibilidade e rapidez na diagnose da Histoplasmose.

Extrinsic and intrinsic coagulation pathway, fibrinogen serum level and platelet count in HIV positive patients

Infection with human immunodeficiency virus [HIV] is a progressive condition which may cause endothelial dysfunction and liver damage leading to coagulopathy. With adventure of highly active antiretroviral therapy [HAART], life expectancy has prolonged in HIV positive patients but several acquired immunodeficiency syndrome [AIDS]-related conditions such as coagulopathies are responsible for associated morbidity and mortality. This study aimed to evaluate the extrinsic and intrinsic pathways of coagulation, serum level of fibrinogen and platelet count in HIV positive patients and compare it with negative healthy individuals. Through a case-control study, 114 HIV seropositive patients were compared with 114 seronegative samples in terms of hematological and other coagulation parameters. Mean age of study patients was 37.48 years. Intra venous drug abuse was the most common route of infection transmission with a prevalence of more than 50%. HIV route of transmission had a direct relationship with PTT abnormal levels [P<0.0001]. However, this relationship was not significant for PT values. Stages of HIV disease and administration of HAART did not reveal any significant relationship with PT and PTT. There was also a statistically significant correlation between CD4[+]< 200 and PT in case group [P=0.008]. On the other hands, in control group, CD4[+] had a weak relationship with PTT [P=0.02] and an inverse correlation with serum fibrinogen [P=0.013]. Hematological parameters and serum fibrinogen are decreased in HIV positive patients especially in direct relation with CD4[+] cell count<200 cell/ micro l. PT and PTT abnormal values are also more prevalent in this population

Time series cross-correlation analysis of HIV seropositivity and pulmonary tuberculosis among migrants entering Kuwait

There is a paucity of published data on burden and pattern of dual infection with Mycobacterium tuberculosis and HIV among migrants from South Asia, South-east Asia and sub-Saharan Africa entering the Middle-East, particularly Kuwait. Therefore, this study assessed the overall prevalence of HIV infection and pulmonary tuberculosis [TB] and evaluated the ecological relationship between them. Time series cross-correlation analysis was used to determine the ecological time-lagged relationship between the monthly proportions [per 100,000] of HIV seropositive and pulmonary TB cases among migrant workers that entered Kuwait between January 1, 1997 and December 31, 2006. During the study period, overall prevalence [per 100,000] of HIV seropositivity and pulmonary TB among the migrants was 21 [494/23,28,582] [95% CI: 19-23], and 198 [4608/23,28,582] [95% CI: 192-204], respectively. Estimated cross-correlation function revealed a significant positive correlation [0.292 +/- 0.093] at lag -3 representing a positive relationship between the proportions of HIV seropositive [per 100,000] migrants tested 3 months earlier and the proportion of pulmonary TB [per 100,000] cases detected among migrants in a given month. Thus, the peak in proportion of pulmonary TB cases preceded the peak in proportion of HIV seropositive migrants indicating a direct time-lagged association between HIV seropositivity and the prevalence of pulmonary TB among migrants. HIV infection seemed to have played a significant role in the re-activation of latent M. tuberculosis infection in this migrant population. While currently less evident, in near future, however, TB and HIV/AIDS control programmes in the countries of origin of migrants may face a crucial challenge. Knowledge of serious consequences of association between HIV infection and pulmonary TB allows the promotion of public heath education to reduce the exposure to these infections. Future studies may focus on evaluating the impact of public health education programs on this dual burden of HIV infection and pulmonary TB in migrants

HIV prevalence and risk factors in a Brazilian penitentiary

A infecção pelo HIV em presidiários alcança uma das maiores prevalências entre subgrupos populacionais específicos, com taxas de até 17 por cento, já tendo sido descritas no Brasil e no mundo. Esta pesquisa objetivou estimar a prevalência do marcador do HIV e fatores de risco para essa infecção na população masculina carcerária da Penitenciária de Ribeirão Preto, São Paulo, Brasil, no período de maio a agosto de 2003. Do total de 1.030 presidiários, foram sorteados 333 participantes por amostragem aleatória simples, os quais foram submetidos à aplicação de um questionário padronizado e coleta de sangue. Para diagnóstico sorológico do HIV foi utilizado o ensaio imunoenzimático (ELISA) e reação de imunofluorescência indireta. A prevalência global do HIV nos presidiários foi de 5,7 por cento (IC95 por cento: 3,2-8,2). Todas as variáveis que mostraram associação com presença do anti-HIV, por meio de análise univariada, foram submetidas a modelo multivariado de regressão logística não condicional. As variáveis que se mostraram preditoras de forma independente da infecção pelo HIV foram: tempo total da pena a ser cumprida inferior a cinco anos e compartilhamento de agulhas e seringas.

HIV infection among prison inmates shows one of the highest prevalence rates for specific population subgroups, reaching as high as 17 percent in Brazil and elsewhere in the world. The present study aimed to estimate HIV antibody prevalence and risk factors for infection in male inmates at the Ribeirão Preto Penitentiary, São Paulo State, Brazil, from May to August 2003. Using simple random sampling, 333 participants were selected, answered a standardized questionnaire, and had blood samples collected. Enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence were used for HIV serological diagnosis. Overall HIV prevalence among inmates was 5.7 percent (95 percentCI: 3.2-8.2). All variables associated with HIV antibodies in the univariate analysis were submitted to unconditional multivariate logistic regression. Independent predictors of HIV infection were: total prison sentence less than five years and sharing needles and syringes.

Glycaemic consequences of HIV and highly active antiretroviral therapy: a pilot study and review of literature.

The metabolic consequences of HIV and AIDS are accentuated in the setting of highly active antiretroviral therapy. Peripheral lipodystrophy, central adiposity, hyperlipidaemia, insulin resistance and diabetes mellitus are frequent associations of protease inhibitor containing highly active antiretroviral therapy regimens. Ninety patients aged 25-50 years (males 52, females 38), seropositive for HIV 1 and 2 or both were selected to see the glycaemic profiles in asymptomatic early HIV disease with CD4 counts > 100/microl and to compare this with the glycaemic profile of (a) advanced HIV disease (CD4 counts < 200/microl), not on highly active antiretroviral therapy and (b) advanced HIV disease (CD4 counts < 200/microl), on uninterrupted non-protease inhibitor highly active antiretroviral therapy > 6 months. All the patients were grouped into 3: (1) Group A: CD4 counts > 500/microl (n=37), highly active antiretroviral therapy naive, (2) group B: CD4 counts < 200/microl (n=21), not on highly active antiretroviral therapy, and (3) group C: CD4 counts < 200/microl, receiving uninterrupted non-protease inhibitor based highly active antiretroviral therapy for > 6 months (n=32). The fasting blood glucose, glycosylated Hb (HbA1c) levels, were measured in all the patients in 3 groups and significance of difference between means was calculated among various groups. Body weight and waist-hip ratio were also measured. The results were analysed and compared with other studies.

Vertical transmission of hepatitis C virus in a hospital in southern Brazil

RACIONAL: Ainda existem controvérsias em relação à transmissão vertical do vírus da hepatite C (VHC). OBJETIVO: Avaliar a prevalência dos anticorpos contra o VHC (anti-VHC) em mulheres grávidas, bem como a percentagem de transmissão vertical observada. PACIENTES E MÉTODOS: Entre agosto de 1998 e novembro de 1999, 1.090 mulheres grávidas consecutivas realizaram a determinação do anti-VHC. A confirmação do teste foi feita pela reação em cadeia da polimerase. A carga viral foi determinada pelo b-DNA e o genótipo por seqüenciamento. Os mesmos testes foram realizados no 1º e 6º mês de vida, nas crianças nascidas de mães infectadas. RESULTADOS: Das 1.090 mães estudadas, 29 apresentaram positividade para o anti-VHC (prevalência de 2,66%). Em 25 pacientes foi demonstrado o RNA do VHC, sendo que a carga viral média foi de 3,132 ± 5,891 MEq/mL. Vinte e duas pacientes (6 co-infectadas com o vírus da imunodeficiência humana) foram seguidas e deram à luz a 23 crianças, das quais 18 tiveram seu sangue testado no 1º mês e 22 no 6º mês. Foi observada transmissão vertical em 5,56% dos casos. Assim, em uma criança do sexo feminino foi detectado o RNA do VHC (41,570 MEq/mL). A mãe desta criança estava co-infectada pelo vírus da imunodeficiência humana e apresentava carga viral de 3,765 MEq/mL, com 100% de homologia no genótipo viral. CONCLUSAO: Estes resultados sugerem que a prevalência da infecção pelo VHC em gestantes não deve ser negligenciada e que um diagnóstico precoce e o seguimento das crianças infectadas deve ser preconizado.

Hematological profile of HIV positive patients.

A series of 500 HIV positive patients referred to our centre for CD4 and CD8 cell enumeration are included in this study. The following parameters were studied in each of these patients: Hb, RBC indicates, WBC count, platelet count, three part differential count, absolute CD4 and CD8 counts. Male:Female ratio of 4.9:1 was noted 30.8% patients has anemia (Hb<10 gm%), with an average Hb value of 8.1 gm%. The anemia was normochromic, normocytic in 61% of patients, microcytic in 33% and macrocytic in 6% patients. The absolute CD4 count was less than 200 ul in 50.2% patients with an average value of 92/ul. Thrombocytopenia was seen in 13% patients with average platelet count 0.92x10(3)/ul.

Anti-HIV-1 antibody testing using modified gelatin particle agglutination: a large field study.

Anti-HIV testing using gelatin particle agglutination (GPA) assay was investigated in parallel with ELISAs from routine service at Siriraj Hospital. In the first strategy, 174,032 sera from a patient population with an HIV-1 seroprevalence of 13.72 per cent were assayed using reduced volumes of GPA reagents, giving a cost reduction of 40 per cent. In the second strategy, 90,560 pregnant women and 48,936 emigrant workers with an HIV-1 seroprevalence of 2.2 per cent and 0.3 per cent, respectively, were tested in pools of 4 sera using the manufacturer's recommended volumes, giving a cost saving of 67 per cent. Overall, the sensitivity and specificity were almost identical with standard methods. Thus, parallel use of either modified GPA might be considered appropriate when testing large numbers of samples. However, both modified versions of GPA are not recommended as the first assay for diagnostic or blood bank screening especially in high prevalence of HIV infection.

Unidad de sangre excluida confidencialmente y prevalencia de marcadores serológicos / Confidential exclusion of a blood unit: importance of serological markers

La unidad de sangre excluida confidencial (USEC) es recomendada por la Administración de Drogas y Alimentos de los Estados Unidos de América con el fin de reducir el riesgo de enfermedades infecciosas transmitidas por la sangre durante el período de incubación o "ventana"; sin embargo se encuentran en la literatura médica especializada detractores y defensores del procedimiento. El objetivo de este artículo es analizar los resultados de la aplicación de USEC en 17.229 donantes seleccionados. Se clasificaron como USEC-, cuando no fue excluida, 16.763 (97,3 por ciento), y como USEC las excluidas (466, 2,7 por ciento), donde se incluyeron además los protocolos dejados en blanco y los anulados o dudosos. En todos los casos se estudiaron los marcadores serológicos (MS) habituales con los siguientes resultados: anti-HIV-1,2, 68 (0,39 por ciento), HBsAg 216 (1,25 por ciento), anti-HVC 206 (1,23 por ciento), VDRL 208 (1,21 por ciento). El total de MS positivos fue de 778 (4,5 por ciento). En los clasificados como USEC-: 66 (0,45 por ciento) para anti-HIV-1,2, 216 (1,28 por ciento) para HBsAg, 279 (1,66 por ciento) anti-HVC, 206 (1,23 por ciento) VDRL. El total de MS en este grupo fue de 767 (4,58 por ciento). Los USEC+:2(0,45 por ciento) anti-HIV-1,2, ninguno en el HBsAg, 7 (1,50 por ciento) para el HVC, 2 (0,43 por ciento) VDRL y el total de MS 11 (2,3 por ciento). La positividad del total de MS fue semejante a otras publicacioes y se encuentra dentro del rango encontrado en América Central y América del Sur. Se plantea que la implementación de la USEC no tiene el impacto esperado en la seguridad de la transfusión en nuestro medio, lo que estaría relacionado con la educación sanitaria de los donantes altruistas, la vigilancia epidemiológica y sus acciones con las poblaciones de riesgo, que persuadirían a los posibles donantes que pueden clasificarse como USEC+ a diferir su donación; no obstante, se recomienda mantener y perfeccionar en todos sus aspectos la aplicación de la USEC y evaluar periódicamente los resultados, además del seguimiento de los donantes con protocolos USEC+, con el fin de detectar su seroconversión en algunos de los MS utilizados.

Infección por virus de inmunodeficiencia humana en la mujer / HIV infection in the women

La mujer constituye uno de los puntos más vulnerables en la cadena epidemiológica en la Infección por Virus de Inmunodeficiencia Humana (HIV). Dicha vulnerabilidad está determinada por factores sociopolíticos, económicos y culturales de cada país en particular, lo cual se traduce en un incremento cada vez mayor del número de casos de Infección por VIH en este sexo. Los aspectos más dramáticos de la Infección por VIH en este segmento tan especial de la población susceptible, corresponden a: 1. el mayor número de casos se observa en mujeres jóvenes con vida sexual activa. 2. el Síndrome de Inmunodeficiencia Adquirida (SIDA) es la tercera causa de muerte en mujeres con edad comprendida entre 25 y 44 años, lo cual coloca en situación de orfandad a miles de niños a nivel mundial, con un total actual de 8.2 millones de niños huérfanos por esta causa. 3. aún cuando el porcentaje de mujeres con Infección por VIH que consultan por sintomatología primaria de enfermedad ginecológica es relativamente bajo (aproximadamente 9 por ciento), una evaluación ginecológica exhaustiva, puede demostrar patología ginecológica hasta en un 83 por ciento de los casos. 4. en relación a la transmisión vertical, en algunas regiones del mundo, el hecho de saberse infectada con el HIV no cambia en la mujer la conducta ante la concepción, por lo tanto considerando que más del 86 por ciento de la Infección por VIH en niños es adquirida de madre a hijo, es la mujer uno de los elementos claves de la cadena epidemiológica donde se deben fundamentar programas integrales de prevención y tratamiento antiretroviral efectivo para garantizar de esta forma no solo una mejor calidad de vida a la mujer infectada, sino la posibilidad de disminuir la incidencia de Infección por VIH en los niños

Evaluation of monoclonal antibody reagents from three different manufacturers using flow cytometric two-color immunophenotyping.

We evaluated a flow cytometric (FCM) two-color immunophenotyping of CD3+/CD4+ T-helper and CD3+/CD8+ T-suppressor lymphocytes in whole blood samples from HIV-infected individuals using monoclonal antibody reagents from three different manufacturers. Lymphocytes were firstly determined using CD45/CD14 in association with a forward scatter/side scatter gating strategy. CD3+/CD4+ and CD3+/CD8+ were then determined and compared. Reagents from all manufacturers showed good separation of lymphocytes, monocytes and granulocytes with high purity and recovery. There was a good correlation of the percentage of CD3+/CD4+ and CD3+/CD8+ lymphocytes amongst each of the manufacturer's reagents, but the fluorescent intensities of positive cells were not the same. This difference can result in poor discrimination of positive and negative non CD3 cells leading to erroneous results.

HIV infection among the high risk groups of Upper Assam.

Serum samples of 9350 individuals belonging to different high risk groups were tested for HIV Infection by ELISA and western blot technique. 9 samples were found to be positive. Two of them belonged to indigenous people of Assam and the infection was transfusion/transplant associated and acquired outside the state during the course of medical treatment. Two were IDUs from Nagaland requiring treatment in a local hospital at Dibrugarh, Assam. Five were from floating population temporarily residing in Assam with history of heterosexual promiscuity. Overall seropositivity rate was 0.97/1000. It is felt that HIV infection in Upper Assam has not penetrated deeply and is at a manageable level and the spread of infection can be prevented through IEC programmes.

Flow cytometric three-color determination of CD4 T-lymphocytes on blood specimens from AIDS patients who have a large number of contaminating non-lymphocytes.

A three-color flow cytometric determination of CD4 T-lymphocytes on whole blood specimens from AIDS patients which contain a high proportion of non-lymphocyte elements is described. Peripheral blood cells were stained by a three-color method using monoclonal antibodies conjugated respectively with fluorescein isothiocyanate (FITC)-CD3, phycoerythrin (PE)-CD4 and peridinin chlorophyll protein (PerCP)-CD45. CD45 stains all leukocytes with the highest fluorescence expression of CD45 antigen in lymphocytes. By combining light scatter with CD45 in the fluorescence 3 (FL3) channel, a light scattering window can be drawn to include almost all bright CD45 lymphocytes. This live gate of lymphocytes was then acquired and analysed simultaneously using other irrelevant two-color (FITC/PE) antibodies of CD3 and CD4 in the FITC and PE channels, respectively. This method is easy and straightforward, and gives successful analysis of CD4 T-lymphocytes in AIDS blood specimens contaminated with an unusually large number of non-lymphocytic cells.

Calor versus dissociaçåo acida de imunocomplexos para a detecçåo da antigemia P24 / Heat versus acid dissociation of immune complexes for the detection of p24 antigemia

INTRODUÇÄO - A antigemia P24 é amplamente utilizada como marcador substitutivo de progresso da infecçåo pelo HIV e da eficácia da terapêutica. A dissociaçåo ácida de imunocomplexos, por aumentar a sensibilidade dos testes para a detecçåo do P24, tornou-se a técnica padråo. OBJETIVO - Comparar a dissociaçåo pelo calor (HD) com a dissociaçåo ácida (AD) dos imunocomplexos nos testes de captura para antígeno P24. MÉTODOS - Soros de pacientes infectados pelo HIV previamente conhecidos por serem P24 negativos por AD, foram ensaiadas paralelamente depois da AD e HD, usando um tampåo de Glicina seguido por neutralizaçåo com um tampåo tris. A HD foi realizada diluindo-se o soro 1:3 em água destilada seguido pela imersåo dos tubos em banho de água fervente por 5 minutos. Os títulos de P24 foram quantificados pela comparaçåo da densidade óptica do soro com uma curva padråo de espécimes positivos. RESULTADOS - Das 39 amostras testadas, todas permaneceram negativas por AD e 3(7,7 por cento; 95 CI= 0-16 por cento) tornaram-se positivas depois do HD. CONCLUSÄO - A HD de imunocomplexos é de execuçåo mais barata, simples e rápida do que a AD, aumentando ainda a sensibilidade das técnicas de detecçåo do antígeno P24

Isolation of HIV-1 from Filipino commercial sex workers (CSWs).

Peripheral blood mononuclear cells (PBMC) from 36 HIV-1 antibody positive Filipino female commercial sex workers (CSWs) were co-cultivated at a 1:1 ratio with phytohemagglutinin-P activated PBMC from healthy, HIV-1 antibody negative donors. After 3-18 (mean 7.2) days of incubation at 37 degrees C in 5% CO2, 29 cultures showed evidence of replication of HIV-1: increasing concentrations of p24 antigen in the growth medium and the appearance of multinucleated giant cells. Although the length of incubation required for the appearance of cytopathogenic effect for each particular isolate was essentially the same when either 6 microwell plates were seeded with 3.0 x 10(6) cells/well or 24 well plates were seeded with 1.5 x 10(6) cells/well, the 24 well format was more sensitive. The ability to isolate HIV-1 from PBMC did not appear to be associated with the progression of disease or the presence or absence of any specific clinical findings. However, if the PBMC were from individuals with a concomitant p24 antigenemia, the incubation time required for isolation was significantly shorter (mean 3.8 days). The absolute CD4+ lymphocyte count was also slightly reduced in the culture positive, p24 antigenemic patients (range 302-813 cells/mm3, mean 502 cells/mm3) compared to the culture positive, p24 serum negative cases (range 311-1,511 cells/mm3, mean 830 cells/mm3). The p24 serum negative cases with CD4+ counts of < 500 cells/mm3 had positive PBMC cultures by 6 days of incubation.(ABSTRACT TRUNCATED AT 250 WORDS)

Human immunodeficiency virus-1 infection in spouses of seropositive individuals.

BACKGROUND. Unprotected sex can lead to transmission of the human immunodeficiency virus-1 (HIV-1) to the spouse of an infected individual. We studied the incidence of HIV-1 infection in the spouses of cases diagnosed to have HIV-1 infection by serology and the polymerase chain reaction (PCR). METHODS. Blood samples collected from 9 index cases and their respective spouses were tested for HIV-1 infection by ELISA, Western blot (WB) and PCR as well as from 10 healthy individuals with no high-risk behaviour. DNA extracted from both plasma and peripheral blood mononuclear cells was amplified by PCR, using multiple primer pairs for distinct regions of the HIV-1 genome. Specificity of the PCR product was demonstrated by hybridization to an oligonucleotide probe. RESULTS. All the index cases which were seropositive by ELISA and WB were also positive by PCR of plasma extracted DNA. Eight of the spouses were seronegative. Of these seven were positive by PCR--one spouse was negative by ELISA but showed a p55 band on WB and was positive by PCR. One spouse was negative by serology and PCR. The spouse belonging to the lone concordant couple was positive by serology and PCR. Except for one index case, PCR signals were obtainable only from DNA extracted from plasma but not from the DNA extracted from peripheral blood mononuclear cells. The control samples were negative by serology and PCR. CONCLUSION. It is possible to detect HIV-1 infection by PCR using DNA extracted from plasma even when the individuals are negative by ELISA and WB. It can help in the early counselling of HIV infected persons and their spouses.