[The challenges of training in medical laboratories in Africa]. / Le défi de la formation dans le domaine du laboratoire de biologie clinique en Afrique.

Sub-Saharan Africa has a considerable deficit in laboratory facilities. For a decade, international and national public and private initiatives have multiplied to expand both the supply and quality of medical laboratories in Africa. By 2020, the World Health Organization, with as its main operator the African Society for Laboratory Medicine, will have provided training for 30,000 laboratory personnel and encouraged 2,500 laboratories to begin the accreditation process. In addition, the World Health Organization recommendations for treatment and care of HIV-infected individuals in resource-limited settings, revised in 2013, emphasize the need for laboratory monitoring to guide antiretroviral therapy. The University Diploma in Biological Retrovirology at the Cheikh Anta Diop University in Dakar, Senegal, offers multidisciplinary training in French at the postgraduate level in the complex and diverse field of biological monitoring of HIV infection in Africa. In nearly 10 years, more than 200 African biologists have been trained.

Role of the laboratory in ensuring global access to ARV treatment for HIV-infected children: consensus statement on the performance of laboratory assays for early infant diagnosis.

A two day meeting hosted by the World Health Organization (WHO) and the U.S. Centers for Disease Control and Prevention (CDC) was held in May 2006 in Entebbe, Uganda to review the laboratory performance of virologic molecular methods, particularly the Roche Amplicor DNA PCR version 1.5 assay, in the diagnosis of HIV-1 infection in infants. The meeting was attended by approximately 60 participants from 17 countries. Data on the performance and limitations of the HIV-1 DNA PCR assay from 9 African countries with high-burdens of HIV/AIDS were shared with respect to different settings and HIV- subtypes. A consensus statement on the use of the assay for early infant diagnosis was developed and areas of needed operational research were identified. In addition, consensus was reached on the usefulness of dried blood spot (DBS) specimens in childhood as a means for ensuring greater accessibility to serologic and virologic HIV testing for the paediatric population.

Evaluation of a quantitative double ELISA strategy for confirmation and differentiation of HIV infection.

The current HIV pandemic is complicated by the spread of distinct types and subtypes of HIV. The currently used conventional diagnostic tests have shown limitations in the detection of antibodies against all HIV-1 subtypes, as demonstrated by recent identification of HIV-1 subtype O. To evaluate quantitatively the diagnostic potential of a double ELISA strategy for the detection and partial differentiation of HIV-1, HIV-1 subtype O and HIV-2 infections blood samples were examined at five different test centers: Blantyre, Malawi; Abidjan and Daloa, Ivory Coast; Yaoundé, Cameroon; Munich, Germany. All tests results, including ELISA extinction values and Western blot profiles, were forwarded to Munich for final interpretation. An indirect anti-HIV-1/2 ELISA and a competitive anti-HIV-1 ELISA were used in combination for the initial screening of blood specimens. All anti-HIV positive and anti-HIV negative samples were subjected to immunoblot analysis. Independent of the diversity of the extinction profiles, and of the test manufacturer, the quantitative evaluation of the ELISA extinction values could define two extinction areas with a 100% predictive value for HIV-1 seropositivity and HIV seronegativity; extinction values > 2 by the indirect ELISA and < 0.2 by the competitive ELISA for an anti-HIV-1 subtype A to I positive result; extinction values < 0.2 by the indirect ELISA and > 1.0 by the competitive ELISA for an anti-HIV negative result. Additionally, the quantitative evaluation of the extinction profile provides partial information on the HIV-1 subtype as far as the distinction in group M and group O is concerned. In conclusion, the quantitative evaluation of this double ELISA strategy can reduce the number of blood specimens that require additional confirmatory testing in developing countries and can be superior to the immunoblot method during early seroconversion.

Valeur predictive du dosage simultane de la beta2 - microglobuline et de la ferritine seriques au cours de l'infection a VIH

L'Etude a porte sur le dosage serique de la beta2-microglobiline (B2-m) et de la ferritine (Ft) chez 60 patients souffrant du syndrome d'immuno deficience acquise (SIDA) repartis en fonction des affections associees. Les resultats obtenus montrent que la B2-m est precocement augmentee dans l'infection a VIH alors que l'elevation de la Ft n'apparait que dans le SIDA maladie. Ceci suggere que ces deux parametres biologiques devraient faire partie du bilan biologique de l'infection a VIH et constitueraient ainsi un mini-profil proteique de la surveillance des sujets asymptomatiques seropositifs aux anticorps anti-VIH

Biological phenotypes of HIV-1 subtypes A and B strains of diverse origins.

The identification of specific biologic phenotypic traits that can be correlated with different HIV-1 genetic subtypes was sought. The genetic subtypes were determined by either sequencing (Cameroonian strains, n = 18) or by the heteroduplex mobility assay (HMA) (Belgian strains, n = 21 and Ivorian strains, n = 25). Seventeen (81%) of the 21 Belgian isolates belonged to subtype B and 4 (17%) were subtype A strains. Subtype A variants were predominant in the two African countries studied; 11 (61%) of 18 strains from Cameroon and 23 (92%) of 25 strains from the Ivory Coast. Of the 64 isolates, 38 (58%) and 19 (29%) belonged to subtypes A and B, respectively. No significant difference was observed for biological phenotypes (slow/low and rapid/high) of both genetic subtypes. In symptomatic individuals, however, a significantly higher number of subtype B isolates were of rapid/high phenotype, compared with subtype A (5 of 10; 50%) vs. 2 of 22; 9%), respectively; X2 = 6.7, P = 0.02). The findings suggest that overall HIV-1 isolates belonging to genetic subtype B are not distinguishable from subtype A variants on the basis of their biological phenotypes. Syncytium-inducing variants were less prevalent regardless of the geographic origin of the isolates.

Isolation of simian immunodeficiency viruses from two sooty mangabeys in Côte d'Ivoire: virological and genetic characterization and relationship to other HIV type 2 and SIVsm/mac strains.

OBJECTIVE: To search for the presence of SIV in sooty mangabeys and other monkey species in Côte d'Ivoire, West Africa, and to compare viral isolates with HIV-2 strains from the same region. METHODS: Forty-three captive housed monkeys (28 African green monkeys, 6 sooty mangabeys, 6 baboons, and 6 patas monkeys) were tested for the presence of HIV and SIV antibodies. Virus was isolated from the peripheral blood lymphocytes of seropositive animals and from HIV-2 antibody-positive patients originating from Côte d'Ivoire, Ghana, Senegal, and Belgium. Viruses were characterized by Western blot and radioimmunoprecipitation assay. Proviral DNA was amplified by PCR, cloned, and sequenced to construct a phylogenetic tree. RESULTS: One African green monkey and three sooty mangabeys had antibodies that cross-reacted with HIV-2. From two mangabeys lentiviruses were isolated and designated as SIVsmCI2 and SIVsmCI8. Serological, virological, and sequence data showed that these isolates are members of the HIV-2/SIVsm/SIVmac group of primate lentiviruses. Furthermore, in the phylogenetic tree, these two new viruses form a distinct subgroup that is equidistant to the HIV-2 strains and the previously described SIVsm/SIVmac viruses. CONCLUSION: This study provides additional evidence that sooty mangabey monkeys can be infected with a lentivirus in their natural habitat. Within the SIVsm and SIVmac viruses extensive genetic variation is observed.

Effect of methodology on detection of HIV-1/HIV-2 dual infections in Côte d'Ivoire.

Dual seroreactivity to the human immunodeficiency virus (HIV) types 1 and 2 is common in Côte d'Ivoire. To assess whether dual infection is the reason for dual seroreactivity, different methods for detection of HIV-1 and HIV-2 viruses were compared. PCR on primary uncultured lymphocytes of 56 dually seropositive samples revealed the presence of both HIV-1 and HIV-2 proviral DNA in 23 (41%) cases. In 7 other dual seropositive persons, PCR was carried out on the primary lymphocytes as well as on lymphocytes after 3 and 6 weeks of cocultivation. More cultures, 5/7 (71%), were positive for both viruses at 3 weeks compared to 0/7 at 6 weeks post cultivation. Moreover, 2 out of 3 samples, where only HIV-1 was detected in uncultured cells, were positive for both viruses after 3 weeks of cultivation. These data indicate that the sensitivity of HIV-2 detection can be increased by stimulation of patients' lymphocytes. A higher number of dual seropositive individuals (10/23 (48%)) had antibodies able to neutralize simultaneously both HIV-1 and HIV-2 prototype viruses than did HIV-1 antibody-positive sera (5/21 (24%)) or HIV-2 antibody positive sera (3/18 (17%)). The prevalence of dual seropositives being infected with both viruses is highly dependent on the method used to detect infection. There is a need to standardize virological markers in order to gain a better insight into the relative proportions of HIV-1, HIV-2 and HIV-1/HIV-2 dually infected persons.

Molecular phylogeny of part of the env gene of HIV-1 strains isolated in Côte d'Ivoire.

OBJECTIVES: To examine the genetic variation of HIV-1 isolates in Abidjan, Côte d'Ivoire, and to determine the extent to which phylogenetic trees based on sequence information of part of the env gene containing the principal neutralizing domain are representative for documenting genetic variability. DESIGN: Phylogenetic comparison of 13 HIV-1 strains isolated from patients in Abidjan with previously documented HIV-1 strains of different geographic origin. METHODS: To sequence a 900 base-pair fragment of the env gene containing V3, V4, V5 and the beginning of gp41 of three to four clones per isolate. Phylogenetic tree analysis was performed with the software package TREECON. RESULTS: Eleven HIV-1 isolates of Abidjan were classified as genotype A, while two were classed as genotypes B and D. Intra-genotype A distances at the nucleotide level were a maximum of 14.1%. Inter-genotype distances between genotype A and genotypes B, C, and D varied from 16.0 to 22.6%. Phylogenetic trees, based on sequence data of a 300 base-pair fragment containing the V3 loop, showed significant differences in tree topology and statistical confidence with phylogenetic trees based on sequence data of the 900 base-pair env fragment. CONCLUSIONS: Genotype A Côte d'Ivoire HIV-1 strains, which comprise 11 out of 13 isolates, predominate in Abidjan, which may indicate a local burst of particular variants. Phylogenetic trees should be interpreted with caution when based on a more limited number of nucleotides, such as the V3 region.

Phylogenetic analysis of gag genes from 70 international HIV-1 isolates provides evidence for multiple genotypes.

OBJECTIVE: To determine the extent of genetic variation among internationally collected HIV-1 isolates, to analyse phylogenetic relationships and the geographic distribution of different variants. DESIGN: Phylogenetic comparison of 70 HIV-1 isolates collected in 15 countries on four continents. METHODS: To sequence the complete gag genome of HIV-1 isolates, build multiple sequence alignments and construct phylogenetic trees using distance matrix methods and maximum parsimony algorithms. RESULTS: Phylogenetic tree analysis identified seven distinct genotypes. The seven genotypes were evident by both distance matrix methods and maximum parsimony analysis, and were strongly supported by bootstrap resampling of the data. The intra-genotypic gag distances averaged 7%, whereas the inter-genotypic distances averaged 14%. The geographic distribution of variants was complex. Some genotypes have apparently migrated to several continents and many areas harbor a mixture of genotypes. Related variants may cluster in certain areas, particularly isolates from a single city collected over a short time. CONCLUSIONS: The genetic variation among HIV-1 isolates is more extensive than previously appreciated. At least seven distinct HIV-1 genotypes can be identified. Diversification, migration and establishment of local, temporal 'blooms' of particular variants may all occur concomitantly.

[The pathogenicity of the human immunodeficiency virus HIV-2 as seen by epidemiologists]. / La pathogenicite du virus de l'immunodeficience humaine VIH2 vue par des epidemiologistes.

The purpose of this study is an evaluation of HIV-2 pathogenicity through an epidemiological analysis, specially in Africa. It is acknowledged that the incubation, or more specially the lapse of time between the infection and the AIDS disease, is longer with HIV-2 than with HIV-1. More over, a certain number of surveys done in Africa show that the average age is higher with HIV-2 than with HIV-1; this is a regular sign of lower pathogenicity. It appears that the sexual transmission of the virus is the same for the HIV-2 and the HIV-1, but it is less effective from mother to baby. Furthermore this type of virus is less prevalent with AIDS patients or AIDS suspects than the HIV-1; and the follow-up of HIV-2 seropositives show that fewer people fall ill than with the HIV-1. A few signs of AIDS standard diagnosis are less frequent among HIV-2 infected patients than among HIV-1 infected patients. Opportunist or associated infections, like tuberculosis or malnutrition, are less often found in HIV-2 patients.

Salivary and urinary diagnosis of human immunodeficiency viruses 1 and 2 infection in Côte d'Ivoire, using two assays.

This investigation, done at the Institut Pasteur de Cote d'Ivoire 'blind' of the previous serological findings, suggests that GACELISA, a commercial immunoglobulin G capture enzyme immunoassay for anti-human immunodeficiency virus antibody, can be successfully applied to unprocessed saliva and urine specimens. Its accuracy may be as high as that of conventional enzyme assays on serum tested under similar conditions. However, the role of GACPAT, a similar assay, as a cheap alternative screening test for urine remains in doubt unless its non-specificity can be controlled.

Virological and polymerase chain reaction studies of HIV-1/HIV-2 dual infection in Côte d'Ivoire.

Dual serological reactivity to the human immunodeficiency virus (HIV) types 1 and 2 is common in Côte d'Ivoire. To assess whether dual infection is the reason for dual seropositivity we sought HIV-1 and HIV-2 proviral DNA in primary uncultured peripheral blood mononuclear cells from selected seropositive patients in Côte d'Ivoire with the polymerase chain reaction (PCR). PCR on primary lymphocytes in 36 dually seropositive samples revealed the presence of both HIV-1 and HIV-2 proviral DNA in 12 cases and the presence of HIV-1 only in 24 cases. In 18 of these 36 samples a virus was isolated and identified by PCR. HIV-1 was isolated from the 9 specimens with only HIV-1 proviral DNA in the primary lymphocytes. Among dually PCR-positive samples, 2 viral isolates reacted with both HIV-1 and HIV-2 primers; and only HIV-2 (n = 1) or HIV-1 (n = 6) strains were isolated from the other samples. The findings show that surveys based on serology may overestimate the prevalence of mixed infections in areas where both HIV-1 and HIV-2 occur.

Genetic comparison of HIV-1 isolates from Africa, Europe, and North America.

PIP: Laboratory scientists used anchored polymerase chain reaction (PCR) and DNA sequencing to compare HIV-1 isolates from countries in Africa (Ivory Coast, Gabon, Zaire, Kenya, and others), Europe (Belgium and other countries), and the US. The US isolates had the most homogenous PCR profile followed by the European pattern. There was considerable PCR primer mispairing for the African isolates, especially those from Kenya, indicating that the range of HIV-1 variation could have been rather extensive. This virus diversity could greatly affect therapy or intervention in sites in Africa with such a complex mix of variants. Nevertheless, the genetic information of these diverse isolates could bring about research leading to an anti-HIV-1 vaccine. For example, the expanded DNA sequence data base could record phylogenetic relationships, thereby, helping researchers choose prototypic variants for vaccine development. More information would allow researchers to generate new PCR primers for better discrimination of variants. They could apply PCR typing to huge sample sizes to adequately document HIV-1 variation in Africa. It could also prove invaluable as a means to determine incidence and prevalence of local variants during vaccine field trials. It can also discern the limiting criteria for HIV-1 genetic variation.^ieng

Isolation and characterization of a new chimpanzee lentivirus (simian immunodeficiency virus isolate cpz-ant) from a wild-captured chimpanzee.

OBJECTIVE: To assess the prevalence of infection with simian immunodeficiency virus (SIV) isolate cpz, a lentivirus closely related to HIV-1, in chimpanzees, and to obtain new SIVcpz isolates. METHODS: Forty-four wild-captured chimpanzees in Belgium and Côte d'Ivoire were tested for HIV and SIV antibodies. Virus was isolated from the peripheral blood lymphocytes of positive animals and characterized by electron microscopy, Western blot and radioimmunoprecipitation assay. RESULTS: One animal had antibodies that cross-reacted with HIV-1. A lentivirus was isolated and referred to as SIVcpz-ant. With regard to molecular weight patterns, SIVcpz-ant differs from SIVcpz-gab' an HIV-1-related virus isolated from a wild-captured chimpanzee in Gabon. The major core protein, the transmembrane and outer membrane glycoproteins of the SIVcpz-ant strain consistently had higher molecular weights. Significantly more HIV-1-positive sera reacted with the envelope proteins of the Gabonese SIVcpz-gab strain than with the SIVcpz-ant strain. CONCLUSIONS: This study shows that natural infection of wild-captured chimpanzees with an HIV-related virus may not be uncommon. The diversity of the two chimpanzee isolates, the different geographical origin and the absence of disease suggest that chimpanzees have not recently become SIVcpz-infected.

[Prevalence of Chlamydia trachomatis in genital samples from Abidjan]. / Prévalence de Chlamydia trachomatis dans des prélèvements génitaux à Abidjan.

A study of direct genital swabs achieved in Abidjan, on 116 men and 131 women consulting for urogenital complaints, has revealed that the men show a prevalence of 28.4% Chlamydia trachomatis, and of 18.1% Neisseria gonorrhoeae. Concerning the women the prevalence of the same germs are 13.7% for Chlamydia trachomatis, and 4.6% for Neisseria gonorrhoeae. These results show the importance of Chlamydia trachomatis as a sexually transmitted disease in Abidjan (Côte-d'Ivoire). No differences were observed according to age in the two groups.

The present and future course of the AIDS epidemic in Côte d'Ivoire.

An assessment of the current and future mortality and morbidity from acquired immunodeficiency syndrome (AIDS) in Côte d'Ivoire was made using the results of the 1989 national survey of the prevalence of human immunodeficiency (HIV) infection in the country and the AIDS projection model developed by WHO. For 1989 it was estimated that about 25,000 AIDS cases in adults and children had occurred, although the total number of cases reported for 1989 (up to 1 July 1991) was about 13% (1:6.9) of this estimated total. It is projected that by 1994 in Côte d'Ivoire the cumulative number of cases of AIDS in adults will be 89,000, and that for infants and children the corresponding number will be 41,000. It was also projected that about 371,000 uninfected children will have been born to HIV-infected mothers in Côte d'Ivoire by 1994 and that many of these children will have been orphaned by the deaths of their mothers from AIDS.

[Analysis of new criteria for increasing the specificity of commercial Western blots]. / Analyse de nouveaux critères pouvant accroître la spécificité des western blots commerciaux.

We examined the frequency of serum cross-reactivity on Western blot for HIV1 and HIV2. 661 patients with tuberculosis in Abidjan, and 4,899 asymptomatic persons for HIV1 and HIV2 infections were tested. All specimens positive on ELISA for HIV1 or HIV2 were further characterized by synthetic peptide based tests. Confirmed positive samples were tested by HIV1 and HIV2 specific Western blot criteres utilisis. Dual serologic reactivity on synthetic peptide tests was significantly more frequent in HIV positive patients with tuberculosis than asymptomatic subjects. Positive HIV1 Western blots were seen in 61%-86% of specimens positive for HIV2 only on synthetic peptide tests. [Cross-reactivity, to HIV2 Western blots by HIV1 positive specimens was significantly more frequent in patients with tuberculosis than in asymptomatic subjects.] Using recently recommended criteria for HIV1 and HIV2 Western blot interpretation (presence of 2 env bands) reduced the overall proportion of HIV1 positive specimens having a positive HIV2 Western blot from 39% to 14% and HIV2 positive specimens having a positive HIV1 Western blot from 31% to 8%.

[Cryptosporidiosis in Ivorian children form Yopougon]. / La cryptosporidiose chez les enfants ivoiriens de Yopougon.

Coprological survey involving 250 ivorian children with diarrhoea was done to evaluate the incidence of cryptosporidiosis. Crypstosporidium sp. was found in 10.4% of subjects. 76.9, 57.7 and 19.2% Cryptosporidium positive children had profuse diarrhoea, fever and pulmonary symptoms respectively. In Ivory Coast, children diarrhoeas due to cryptosporidiosis are quantitatively important.