Quantitation of human immunodeficiency virus type 2 DNA in peripheral blood mononuclear cells by using a quantitative-competitive PCR assay.

A new quantitative-competitive PCR-based human immunodeficiency virus type 2 (HIV-2) proviral DNA assay (QC-PCR) was developed and used to determine the proviral load in HIV-2-infected individuals. Proviral load varied considerably, with means of 1,831 copies per 10(6) peripheral blood mononuclear cells for asymptomatic subjects (n = 19) and 2,587 for AIDS patients (n = 2). HIV-2 viral and proviral loads also varied significantly over time in asymptomatic patients. These data suggest that a high level of virus replication occurs throughout the asymptomatic phase of HIV-2 infection.

Virological and molecular demonstration of human immunodeficiency virus type 2 vertical transmission.

To demonstrate that human immunodeficiency virus type 2 (HIV-2) mother-to-child transmission exists, HIV-2 isolates were obtained from both an asymptomatic mother (HIV-2 strain ARM), and her child (HIV-2 strain SAR), who had a diagnosis of AIDS. To determine their biological phenotype, primary isolates were used to infect various primary mononuclear cells and cell lines. HIV-2 ARM replicates in primary cells and Jurkat-tat, while HIV-2 SAR infects these cells plus SupT1, which led us to classify HIV-2 ARM as a slow/low virus and HIV-2 SAR as having an intermediate (slow/low-3) phenotype. Molecular analysis of the env region corresponding to gp125 was performed. Viral DNA was cloned, sequenced, and used to construct phylogenetic trees. The DNA sequence analysis demonstrated an overall nucleotide diversity of 7.6%. The results present evidence that the child's strain is more virulent than the mother's strain, which is in agreement with the immunodeficiency of the child. The phylogenetic trees that were constructed demonstrate that the two isolates cluster together, being closer to each other than to any other isolate described until now.

Multicenter evaluation of a fully automated screening test, VIDAS HIV 1 + 2, for antibodies to human immunodeficiency virus types 1 and 2.

A multicenter study was done to evaluate the sensitivity, specificity, and efficiency of a new screening test for the simultaneous detection of human immunodeficiency virus type 1 and 2 (HIV-1 and HIV-2) antibodies. The VIDAS HIV 1 + 2 (bioMérieux, Marcy l'Etoile, France) is a fully automated enzyme-linked fluorescent immunoassay that uses synthetic peptides from immunodominant regions of gp41 of HIV-1 and gp36 of HIV-2 as antigens. A total of 2,984 samples were evaluated with this system in six different laboratories, and the results were compared to those obtained with other enzyme-linked immunosorbent assays. The VIDAS HIV 1 + 2 assay showed a very good performance in terms of sensitivity (100%) and specificity (99.6%), requiring minimal manipulation and short incubation time (32 min) to give results similar to or better than those of the other enzyme-linked immunosorbent assays used for screening.

Diagnosis of human immunodeficiency virus (HIV) infection: multicenter evaluation of a newly developed anti-HIV 1 and 2 enzyme immunoassay.

A new anti-human immunodeficiency virus type 1 and 2 (anti-HIV 1 and 2) test is described. It uses recombinant p24 and peptides covering gp32, gp41, and gp120 to identify HIV-1 and HIV-2 infections. This test has been shown to be specific (99.5%) and sensitive (99.8%). In this respect, the assay was equal or superior to anti-HIV 1 and 2 tests run as references. The test was able to discriminate sera from patients with HIV infections from those from uninfected individuals with excellence; it also exerted high intra- and interassay precisions. The "modular" concept of the test allows the use of single components (gp32 or gp41) to separate between HIV-2 and HIV-1 infections, respectively.

Prevalence of HIV-2 infection in a family planning clinic in Lisbon.

A significant proportion (10%) of notified AIDS cases in Portugal are due to HIV-2 infection as a result of the close connections of Portugal with Western African Countries (ex-Portuguese colonies) where there is a high HIV-2 seroprevalence. We conducted a seroepidemiological study of HIV-1 and HIV-2 infection in 1400 women attending family planning and antenatal clinics in a health centre in Lisbon with the objective of analysing whether there was evidence of HIV-2 spread in this population. The seroprevalence for HIV, as determined by ELISA and confirmed by Western Blot, was 0.42% (6 cases) and 50% of these were of HIV-2 infection. Analysis of the epidemiological inquiries reveals that out of the 6 seropositive cases, only one was a drug addict (HIV-1) and another a western African black woman (HIV-2). The other 4 cases (2 HIV-2 and 2 HIV-1) were white Portuguese women with no history of travelling to Africa or previous blood transfusions, and the only risk factor was a history of multiple sexual partners (in 3 out of 4).

[Prevalence of HIV1 and HIV2 infection in women living in an area of Lisboa City]. / Análise da seroprevalência da infecção pelo HIV1 e HIV2 em mulheres residentes numa área da cidade de Lisboa.

A seroprevalence study of HIV1 and HIV2 infection in women attending a Family Planning and an Antenatal Clinic was done in an area of the city of Lisbon where 7% of the population is of African origin. The protocol of study was of non linked type although with the possibility of collecting a second sample of blood for confirmation of results. Epidemiological, social and clinical data were collected from 1390 women and this was followed by the collection of a blood sample for the seroepidemiological study of HIV1 and HIV2. The population that was submitted to blood tests (75%) was compared to the one that missed the test and it was found that no important differences were present between the two. The criteria for HIV1 or HIV2 positive results were the presence of a positive ELISA test confirmed by an Western Blot revealing antibodies against the three proteins env, core and gag. For a test to be considered positive results by both methods had to be found in a second sample collected later. The prevalences of infection were of 0.29% for HIV1 and 0.29% for HIV2 although the prevalence of HIV2 in the population of African origin was higher (1.45%). The six seropositive cases detected included a drug addict, one prostitute, one case of African origin and two cases with multiple sexual partners. The clinical, epidemiological and immunological features of the seropositive cases are presented and the prevalence found is discussed in the context of other portuguese data.(ABSTRACT TRUNCATED AT 250 WORDS)

A study of seroprevalence of HIV-1 and HIV-2 in six provinces of People's Republic of Angola: clues to the spread of HIV infection.

A seroepidemiological study was carried out to determine the distribution of the human immunodeficiency viruses type 1 (HIV-1) and type 2 (HIV-2) in the People's Republic of Angola, where HIV-2 existence was previously unknown and HIV-1 seropositivity was only reported to be present in Luanda and Cabinda. A total of 1,695 serum samples were obtained from healthy persons (control group) and from a group of patients in the provinces of Zaire (13), Lunda-Norte (L.N.) (749), Luanda (556), Huambo (154), Kuando-Kubango (K.-K.) (49), and Namibe (119). All samples were tested for HIV-1 and HIV-2 antibodies by enzyme-linked immunosorbent assay and an indirect immunofluorescence assay using MOLT-T4 cells. Positive samples were confirmed by the Western-blot technique. Sera giving cross reactivity at the level of HIV-1 and HIV-2 large glycoproteins were further tested by radioimmunoprecipitation assay and by reactivity against a peptide corresponding to the dominant epitope of the transmembrane protein. The overall seroprevalance was 14.2%, with significantly higher values in the patient group [19.4% (HIV-1 = 8.8%; HIV-2 = 8.4%; HIV-1 + HIV-2 = 2.2%)] than the control group [9.3% (HIV-1 = 3.3%; HIV-2 = 5.3%; HIV-1 + HIV-2 = 0.7%)]. HIV-2 as well as HIV-1 infection is actually present in Angola in all studied provinces. Higher seroprevalence was seen in the provinces of Zaire, Lunda Norte, and Huambo. People displacements, mainly as a consequence of the war, certainly play an important role in spreading HIV infection from the northern frontier areas of the country to the central and southern regions.

Epidemiologic and genomic study of rotavirus strains infecting young children and calves in the same rural environment.

The epidemiological profile of rotavirus infection in young calves and young children form the same rural environment in France was studied during autumn-winter 1983-1984. Viruses were isolated from calves on each farm and were identified by their electropherotype for 8 out of the 9 farms under study. Among 13 children regularly checked on 9 farms for 25 weeks, 7 were found to be rotavirus positive. Nevertheless, no transfer of virus between child and bovine was documented by the electropherotype migration. In the case of the calves, the predominance of the Ib IIa IIIe IVa electropherotype at 5 of the 9 farms is similar to the epidemiological situation observed among newborn in some maternity wards.

Rotavirus electrophoretypes in infantile gastro-enteritis. An epidemiological study.

From January first 1978 to September 30, 1981, 93 fecal samples from children hospitalized with a rotavirus gastro-enteritis were tested after RNA extraction and polyacrylamide gel electrophoresis. 14 electrophoretypes (TI--T14) were identified by this technique. They were studied in relation with epidemiological as well as clinical symptoms. No electrophoretype correlated well with age or living area. The electrophoretype T3 was found only in male infants and the electrophoretype T7 was 3 times more frequent in boys than in girls. The electrophoretype T4 was prevailing during the winter 1980-1981 and the electrophoretype T5 prevailed during the summer 1981. 19 infants were probably contaminated during their stay in the hospital, 9 of them with the electrophoretype T4 prevailing at that time. The prevalence of associated otitis and rash was significantly higher with the electrophoretype T3. The polyacrylamide gel electrophoresis technique appears to be a simple, and reliable epidemiological tool to evaluate rotavirus infection in communities.

Survey of human rotavirus propagation as studied by electrophoresis of genomic RNA.

Rotavirus RNA isolated from three different environmental sources during the winter of 1981-1982 was analyzed by polyacrylamide gel electrophoresis. Our results demonstrate the presence of novel RNA patterns, the coexistence of multiple electrophoretic patterns in rotavirus isolated from samples from a given ward, and that spread of a given electropherotype is limited.

Isolation of a human pararotavirus.

During a survey of 350 different isolates of human rotaviruses, a single isolate with unique properties was obtained. Unlike all rotaviruses tested this unique isolate failed to react in an ELISA test with antibody directed against the group-specific rotavirus antigen. The morphology of this unusual virus isolate was identical in electron micrographs with other rotaviruses and the virus also contained 11 double-stranded RNA segments characteristic of this virus group. The electrophoretic migration of these RNAs (electrophoretype) in polyacrylamide gels did not coincide with the typical pattern of distinct size classes observed with all human rotaviruses. The unique isolate thus had two distinct properties that distinguish it from human rotaviruses, lack of a group-specific antigen and an atypical electrophoretype of the RNA segments. Based upon this, the new human isolate is given the name pararotavirus to distinguish this new type of virus group. Porcine and chicken pararotaviruses have recently been described with similar properties.

Renal transplantation and viral infections. II. Results of follow-up studies.

13 renal transplant recipeints were submitted to virological survey over a period of about 10 months following transplantation. They were compared to a group of individuals who underwent no transplantation : 7 patients on chronic hemodialysis and 10 healthy blood donors. The renal transplant recipients, showed rises in titer of antibodies against various viral antigens. Nevertheless, no other viral elimination but that of cytomegalovirus and herpes simplex virus was detected in them. Renal trnasplant recipients show significantly more often rises in virus antibody titers than the other individuals, when time of survey is taken into account. Some of these rises appeared to be simultaneous. Their mechanism is under debate : analysis of special cases and observation of associated immunohematological abnormalities are strongly suggesting that in some situations, rises in titer of viral antibodies may occur without infection.