[Long-term impact of antiretroviral therapy in Africa: current knowledge]. / Impact à long terme des traitements antirétroviraux en Afrique, état des connaissances.

By the end of 2013, 11 million PLHIV were taking ARVs in Africa; application of the WHO recommendation to initiate treatment earlier (at CD4 count of 500 cells/mm3 or less) should further increase this number. Currently, twothirds of patients in Africa have been on treatment for less than five years, and less than 10% have received treatment for eight years or more. Given the historical perspective is in its early stages, the long-term impact of ARV therapy is still unclear. This article reviews the knowledge gained over the period marking the first ten years of implementation of the universal access strategy (2003-2013) in Africa, through a review of the literature documenting the long-term consequence of ARV treatment, focusing on medical care for adults with an emphasis on the patient-centered approach. The goal is to understand the interrelationships between biological and social factors and individual and collective aspects that affect the lives of PLHIV and determine the impacts of ARV treatment over the long term. The biomedical and social factors are addressed successively, based on the most significant results. Key knowledge on the long-term outcomes for PLHIVon ARV treatment offers vital information on the necessary conditions and adaptations for care systems needed to ensure the benefits of treatment endure over time.

Twelve years of follow-up for patients treated with ARVs in Senegal (ANRS Cohort 1215): description of population and methodology.

The ANRS Cohort 1215 brought together the first 400 patients receiving antiretroviral treatments through the government program for ARV treatment in Senegal. These people, infected with HIV-1, began their treatment between 1998 and 2002; they were treated with 2 NRTI + 1 PI or NNRTI. This prospective observational cohort received follow-up over the course of 12 years, from 1999 to 2010, and was one of the earliest established cohorts in Africa and providing the longest duration of ART follow-up. A series of interdisciplinary studies was conducted among these patients to assess the medical and social as well as the individual and collective impact of these treatments over the long term. This article presents the cohort's key methodological characteristics.

Phylogenetic analyses of symbiotic genes and characterization of functional traits of Mesorhizobium spp. strains associated with the promiscuous species Acacia seyal Del.

AIMS: To assess the phenotypic, symbiotic and genotypic diversity scope of Mesorhizobium spp. strains associated with Acacia seyal (Del.) isolated from different agro-ecological zones in Senegal, and uses of susceptible microbial inoculum in a reafforestation process. METHODS AND RESULTS: A polyphasic approach including phenotypic and genotypic techniques was used to study the diversity and their relationships with other biovars and species of rhizobia. The geographical origins of the strains have limited effect on their phylogenetic and phenotypic classification. Nodulation tests indicated promiscuity of the strains studied, because they were capable of nodulating six woody legume species (Acacia auriculiformis, Acacia senegal, A. seyal, Acacia tortilis ssp. raddiana, Leucaena leucocephala and Prosopis juliflora). Sequencing and phylogenetic analyses of nodA, nodC and nifH genes pointed out that in contrast to nodA gene, the phylogenies of nodC and nifH genes were not consistent with that of 16S rRNA, indicating that these genes of the A. seyal-nodulating rhizobia might have different origins. Microbial inoculation on nonsterile soil had significant effect on the nodules number and the growth of the seedlings, indicating that these strains of rhizobia might be used as inoculum. CONCLUSIONS: The results indicated that A. seyal is a nonselective host that can establish effective symbiosis with Mesorhizobium spp. strains from diverse genomic backgrounds and that the selected A. seyal-nodulating rhizobia could enhance plant growth. SIGNIFICANCE AND IMPACT OF THE STUDY: These results showed the important role that A. seyal could play in the improvement of reafforestation process as a promiscuous host, which can establish effective symbiosis with rhizobia from diverse genomic backgrounds.

Genetic diversity and distribution of Bradyrhizobium and Azorhizobium strains associated with the herb legume Zornia glochidiata sampled from across Senegal.

Herb legumes have great potential for rehabilitation of semi-arid degraded soils in Sahelian ecosystems as they establish mutualistic symbiosis with N(2)-fixing rhizobia. A phylogenetic analysis was performed for 78 root nodule bacteria associated with the common Sahelian herb legume Zornia glochidiata Reichb ex DC in Senegal. Based on ITS (rDNA16S-23S) and recA sequences, these strains were shown to belong to the two genera Bradyrhizobium and Azorhizobium. Strains of this latter, although frequent, formed small and ineffective nodules and suggested a parasitism rather than a symbiotic association. A potential negative effect of Azorhizobium on Zornia growth was tested for when inoculated alone or in association with a Bradyrhizobium strain. Bradyrhizobium isolates were distributed in four groups. Groups A and B were two sister clades in a larger monophyletic group also including Bradyrhizobium liaoningense, Bradyrhizobium yuanmingense, and Bradyrhizobium japonicum. Strains of cluster D fell in a sister clade of the photosynthetic Bradyrhizobium sp. group, including ORS278, whereas group C appeared to be divergent from all known Bradyrhizobium clusters. Amplified fragment length polymorphism (AFLP) clustering was congruent with ITS and recA phylogenies, but displayed much more variability. However, within the main Bradyrhizobium clades, no obvious relationship could be detected between clustering and geographical origin of the strains. Each sub-cluster included strains sampled from different locations. Conversely, Azorhizobium strains showed a tendency in the phylogeny to group together according to the site of sampling. The predominance of ineffective Azorhizobium strains in the nodules of Zornia roots, the large Bradyrhizobium genetic diversity and the geographical genetic diversity pattern are explored.

[Enhancing the anthelminthic activity roots of Annona sengalensis]. / Mise en evidence de l'activite antihelminthique des racines d'Annona senegalensis.

INTRODUCTION: Annona senegalensis is a plant largely used in traditional medicine in Africa. The roots showed an antiparsitic activity. The purpose of this work is to determine through bioassay on Rhabditis pseudoelongata the activity of the roots of Annona senegalensis and characterise if any substances responsible for this activity. MATERIAL AND METHODS: The vegetable material consists of roots of Annona senegalensis collected in Casamance at 1999. The tests of activity are carried out on Rhabditis pseudoelongata, stock L. Lamy, Institut Pasteur, Paris. Powder of roots (1070 g) was extracted with methanol. From this rough extract, we carried out two extractions with the dichloromethane of which one after passages in alkaline and acid medium. Various extracts were subjected to a chromatography on column of silica gel or from alumina gel; some compounds were isolated by high performance liquid chromatography . The identification of compounds was deed using spectrometric techniques (mass, Ultraviolet, Infrared) and nuclear magnetic resonance. The tests of activity related to three extracts and seven molecules isolated from the roots. The percentage of dead worm is determined after two hours of contact with demineralised water containing the sample to be tested. RESULTS: The neutral extract chloromethylenic showed an important activity on Rhabditis pseudoelongata. Five acetogenines were insulated starting from this extract chloromethylenic (gigantetronenine, squamocine, glaucanisine, glaucanetine, goniothalamicine) and two alkaloids starting from the alkaline extract chloromethylenic (liriodenine and norolivéroline). The tests on Rhabditis pseudoelongata of these compounds showed an activity of the squamocine with a IC50 of 0.1 microg/ml and IC90 0.3 microg/ ml more powerful than that of the levamisole, reference substance (IC50 of 0.8 microg/ml and IC90 13 microg/ml). CONCLUSION: The study of the biological activity of the roots of Annona senegalensis made it possible to determine the anthelminthic activity of the extract chloromethylenic from where the squamocine was isolated. The presence of this molecule could explain the anthelminthic activity of this plant.

HIV prevalence, previous HIV testing, and condom use with clients and regular partners among Senegalese commercial sex workers.

OBJECTIVES: To assess HIV prevalence and risk factors for HIV infection, to investigate condom use among registered female commercial sex workers (CSWs) in Senegal, West Africa, and to examine the association between previous HIV testing, knowledge of HIV serostatus and condom use with both regular sex partners and clients within this population. METHODS: A cross-sectional study was conducted at three sexually transmitted disease clinics among 1052 Senegalese registered CSWs between 2000 and 2004. Inperson interviews soliciting information concerning demographic characteristics, medical history, sexual behaviour with clients and regular partners, and previous HIV testing history were performed. Blood samples were collected for determination of HIV-1 and/or HIV-2 serostatus. Multivariable, Poisson and log-binomial models were used to calculate prevalence ratios. RESULTS: The overall HIV prevalence was 19.8%. Over 95% of CSWs reported always using a condom with clients, but only 18% reported always using a condom with their regular partners. A history of previous HIV testing was not associated with condom use with clients (adjusted prevalence ratio (APR) = 0.98, 95% confidence intervals, CI: 0.90 to 1.06). However, prior HIV testing was associated with decreased condom use with their regular partners (APR = 0.44, 95% CI: 0.28 to 0.69), especially in women who tested HIV negative (APR = 0.17, 95% CI: 0.08 to 0.36). CONCLUSIONS: CSWs in Senegal have a high HIV prevalence; therefore preventing HIV transmission from this population to the general population is important. Condom use with regular partners is low among registered CSWs in Senegal, and a prior HIV negative test is associated with even less condom use with regular partners. Intervention efforts to increase condom use with regular sexual partners are needed.

[Cytotoxic activity of two cyclic peptides from the latex of Jatropha integerrima Euphorbiaceae]. / Etude de l'activite cytotoxique de deux cyclopeptides isoles du latex de jatropha integerrima euphorbiaceae.

Activity-guided fractionation of the ethyl acetate extract of the latex of Jatropha integerrima Euphorbiaceae combinated with cytotoxic assay against the KB human nasopharyngeal carcinoma cells, resulted to the isolation by chromatographic methods including HPLC of two new cyclopeptides: integerrimacyclopeptide4 and integerrima cyclopeptide B. The amino acid composition was established after hydrolysis and derivatization. All chiral amino acids were L configuration and were hydrophobic. Their sequences were determined by MS fragmentations (ESI-q-TOF, MS/MS) and confirmed by 2D NMR homo- and heteronuclear studies. Integerrimacyclopeptide A was a cyclooctapeptide with m/z 766 corresponding to the molecular formula C37H66N8O9. Analysis of mass spectra gave b(n) and a(n) acylium ion series which the sequence could be deduced: cyclo(Leu-Gly-Ser-Ile-Ile-Leu-Gly-lle). This structure was confirmed by interpretation of HMBC and ROESY spectra. Likewise, integerrimacyclopeptide B was a cycloheptapeptide with m/z 651 and C31H53N7O8 as molecular formula containing one proline residue: cyclo(Pro-Gly-Thr-Ile-Gly-Ile-Leu). These two cyclic peptides exhibited significant cytotoxic activityin vitro against KB tumorales cells with respective IC50 values of 0.46 +/- 0.04 and 0.66 +/-0.08 microg/ml.

The early-stage ectomycorrhizal Thelephoroid fungal sp. is competitive and effective on Afzelia africana Sm. in nursery conditions in Senegal.

This study was conducted to evaluate the competitiveness and effectiveness of Thelephoroid fungal sp. ORS.XM002 against native ectomycorrhizal fungal species colonizing potted Afzelia africana seedlings during 3 months of growth in different forest soils collected from under mature trees. Using morphotyping and restriction fragment length polymorphism (RFLP) analysis of the nuclear rDNA internal transcribed spacer (ITS), we were able to distinguish the introduced Thelephoroid fungal sp. ORS.XM002 among native ectomycorrhizal fungal species that form ectomycorrhizae in A. africana seedlings. The morphotype (MT) of the introduced fungus showed some color variation, with a shift from light- to dark-brown observed from younger to older mycorrhizal tips. We were able to differentiate the ITS type xm002 of the introduced fungus from the 14 ITS-RFLP types characterizing the 9 native MT that occurred in forest soils. The frequency of ITS type xm002 ranged from 40% to 49% depending on the forest soil used, and was always higher than those of ITS types from native dark-brown MT that occurred in inoculated seedlings 3 months after inoculation. We considered Thelephoroid fungal sp. ORS.XM002 to be responsible for stimulation of mycorrhizal colonization of inoculated A. africana seedlings when compared with control seedlings in forest soils. This fungus appeared to be more effective in increasing the root dry weight of A. africana seedlings. To identify the unknown introduced fungal species and native MT, we sequenced the ML5/ML6 region of the mitochondrial large subunit rRNA. Sequence analysis showed that these fungi belong to three ML5/ML6 groups closely related to the Cortinarioid, Thelephoroid, and Sclerodermataceous taxa. The molecular evidence for the persistence of Thelephoroid fungal sp. ORS.XM002 despite competition from native fungi argues in favor of using this fungus with A. africana in nursery soil conditions in Senegal.

Mobility and the spread of human immunodeficiency virus into rural areas of West Africa.

BACKGROUND: In eastern and southern Africa, the human immunodeficiency virus (HIV) epidemic appeared first in urban centres and then spread to rural areas. Its overall prevalence is lower in West Africa, with the highest levels still found in cities. Rural areas are also threatened, however, because of the population's high mobility. We conducted a study in three different communities with contrasting infection levels to understand the epidemiology of HIV infection in rural West Africa. METHOD: A comparative cross-sectional study using a standardized questionnaire and biological tests was conducted among samples in two rural communities of Senegal (Niakhar and Bandafassi, 866 and 952 adults, respectively) and a rural community of Guinea-Bissau (Caio, 1416 adults). We compared the distribution of population characteristics and analysed risk factors for HIV infection in Caio at the individual level. RESULTS: The level of HIV infection was very low in Niakhar (0.3%) and Bandafassi (0.0%), but 10.5% of the adults in Caio were infected, mostly with HIV type 2 (HIV-2). Mobility was very prevalent in all sites. Short-term mobility was found to be a risk factor for HIV infection among men in Caio (adjusted odds ratio (aOR) = 2.06; 95% CI: 1.06-3.99). Women from Caio who reported casual sex in a city during the past 12 months were much more likely to be infected with HIV (aOR = 5.61 95% CI: 1.56-20.15). Short-term mobility was associated with risk behaviours at all sites. CONCLUSIONS: Mobility appears to be a key factor for HIV spread in rural areas of West Africa, because population movement enables the virus to disseminate and also because of the particularly risky behaviours of those who are mobile. More prevention efforts should be directed at migrants from rural areas who travel to cities with substantial levels of HIV infection.

Full-length genome sequencing of HIV type 1 group O viruses isolated from a heterosexual transmission cluster in Senegal.

In a polygamous marriage in Senegal, the husband and his two spouses were infected with HIV-1 group O. This study provides new full-length genome sequences for the two spouses (99SE-MP1299 and 99SE-MP1300) and the 3'-end LTR-tat fragment (6084 bp) for the husband (98SE-42HALD). Phylogenetic tree and diversity plot analysis revealed that the new viruses belong to HIV-1 group O and that they are closely related to each other in a cluster around ANT-70. The intrafamilial transmission occurred at most 6 years ago. The interpatient variability was highest in the envelope region, and in some regions of the envelope the strains from the two spouses do not cluster together anymore. The source of infection was in Cameroon and confirms a slow but continuous spread of HIV-1 group O viruses.

Prevalence and risk factors of cervicovaginal HIV shedding among HIV-1 and HIV-2 infected women in Dakar, Senegal.

OBJECTIVES: To assess the risk determinants and prevalence of cervicovaginal shedding of HIV-1 and HIV-2 among women in Dakar, Senegal. METHODS: We conducted a cross sectional study of 153 HIV seropositive female sex workers (FSW) and another 142 HIV seropositive women attending an infectious diseases unit, based on an interview, physical examination, and laboratory screening for major sexually transmitted infections (STI). Cervicovaginal lavage fluid was tested for HIV-RNA by means of nested PCR. Links between cervicovaginal shedding of HIV-1 and HIV-2 and sociodemographic, clinical, and laboratory variables were identified by using odd ratios and 95% confidence intervals. Logistic regression analysis was used to identify independent links with HIV shedding. RESULTS: The detection rate of HIV-RNA in cervicovaginal lavage fluid was low among FSW, with no difference between HIV-1 (7/90: 8%) and HIV-2 (3/48: 6%). The rate was far higher among the other women (41%, 48/117; 33%, 7/21 for HIV-1 and HIV-2, respectively). In multivariate analysis, high plasma viral load (>40 000 copies/ml) (AOR = 2.4 (1.0-5.6) p = 0.04) and basic vaginal pH (AOR = 2.2 (1.3-3.7) p = 0.002) were independently associated with HIV-1 shedding. For HIV-2 a CD4 count < 200 cells x 10(6)/l was the only factor associated with the shedding of HIV-2 (AOR = 9.0 (0.9-93)). The genital shedding rate was higher with HIV-1 than with HIV-2 (OR = 2.1 (0.9-4.8), but this difference disappeared after adjustment for the CD4+ cell count (AOR = 1.2 (0.5-2.9)). CONCLUSION: Advanced disease stage and immunosuppression are the major risk determinants for shedding of both HIV-1 and HIV-2. Basic vaginal pH is also a risk determinant for HIV-1 shedding.

Primary prevention with cotrimoxazole for HIV-1-infected adults: results of the pilot study in Dakar, Senegal.

OBJECTIVES: To assess the efficacy and tolerance of chemoprophylaxis with cotrimoxazole compared with placebo among HIV-1-infected adults. DESIGN: Randomized, double-blind, placebo-controlled clinical trial in the urban community of Dakar, Senegal. METHODS: Eligibility criteria were age greater than 15 years, HIV-1 or HIV-1 and HIV-2 dual seropositivity, CD4 cell count lower than 400 copies/mm3, no progressive infection, no previous history of intolerance to sulphonamide, lack of severe anemia or neutropenia, and renal or hepatic failure. Written informed consent was obtained. Recruited patients received 80 mg of trimethoprim and 400 mg of sulphamethoxazole daily or a matching placebo. The main outcomes were survival and the occurrence of clinical events defined as Pneumocystis carinii pneumonia, cerebral toxoplasmosis, bacterial pneumonia, infectious enteritis, bacterial meningitis, urinary tract infection, bacterial otitis and sinusitis, and pyomyositis. RESULTS: Between September 1996 and March 1998, 297 patients were screened, and 100 were randomized in the study. Demographic, clinical, and biological characteristics of the two groups were similar as was the mean length of follow-up (7.7 months for the cotrimoxazole group vs. 8.0 months for the placebo group). There was no significant difference between the two groups in survival (hazard ratio = 0.84; 95% confidence interval [CI]: 0.36-1.94) in the probability of severe event occurrence, defined as death or hospital admission (hazard ratio = 1.10; 95% CI: 0.57-2.13), or in the probability of clinical event occurrence (hazard ratio = 1.19; 95% CI: 0.55-2.59). Adjustment for initial CD4 cell count did not change these results. A low dose of cotrimoxazole was tolerated well clinically as well as biologically; only one treatment interruption occurred as the result of a moderate cutaneous eruption (grade 2). CONCLUSION: Our study does not show a beneficial effect of chemoprophylaxis with low-dose cotrimoxazole on survival or occurrence of opportunistic or nonopportunistic infections for HIV-1-infected patients in Dakar, Senegal.

Religion and protective behaviours towards AIDS in rural Senegal.

OBJECTIVES: To describe the association between religion and factors related to sexually transmitted diseases (STD)/AIDS in a country where religious leaders were involved early in prevention. DESIGN: A cross-sectional study conducted in a rural area in central Senegal. METHODS: Questionnaire-based interviews of a random sample of 858 adults from the general population aged 15-59 years and in-depth interviews of four religious leaders and 50 people. RESULTS: Seventy-six per cent of the respondents were Muslim, 24% Catholic, 1% Animist and 0.2% Protestant. A total of 86% of men and 87% of women reported religion to be very important to them. Important prevention-related variables were inversely associated with the importance of religion. Men who considered religion to be very important were less likely to cite AIDS as a major health problem [odds ratio (OR) 0.4, P = 0.008] and were less likely to feel at risk of getting HIV (OR 0.5, P = 0.0005). Women who considered religion to be very important were less likely to report an intention to change to protect themselves from AIDS (OR 0.2, P = 0.0001), less likely to report having discussed AIDS with others (OR 0.4, P = 0.01) and much more likely to feel at risk of getting HIV (OR 9.3, P = 10(-4)). Individuals who considered religion to be very important were not more likely to report intending to or actually having become faithful to protect themselves from AIDS. CONCLUSION: These findings stress the need to intensify the involvement of religious authorities in HIV/STD prevention at the local level.

Identification of all HIV type 1 group M subtypes in Senegal, a country with low and stable seroprevalence.

A total of 343 HIV-1-positive samples obtained between June 1996 and March 1999 was genetically characterized in the envelope region by HMA and/or sequencing. The env subtype distribution was as follows: 290 (84.6%) A, 22 (6.5%) B, 16 (4.7%) C, 8 (2.5%) D, 1 (0.03%) E, 1 (0.03%) F1, 4 (1.2%) G, and 1 (0.03%) H. For 77 samples the p24 region from the gag gene was also sequenced, and for 9 (11.6%) the subtypes between env and gag were different. Phylogenetic tree analysis showed the predominance of AG-IBNG-like viruses among gag and env subtype A sequences. HMA is relatively simple and requires less sophisticated technical facilities compared with sequencing, and in Senegal 323 (94.2%) of the 343 samples could be identified by this technique. However, in the actual configuration of the assay, discrimination between the recombinant AG-IBNG-like recombinant viruses, which are predominant in Senegal, and the nonrecombinant subtype A viruses is not possible.

Preventive attitudes towards the threat of AIDS: process and determinants in rural Senegal.

This report is intended to identify the determinants of preventive attitudes and thereby enable the further elaboration of effective prevention programs in a country where the HIV epidemic has remained controlled. Across-sectional survey using a standardized questionnaire was conducted among a sample of 866 adults of the general population of the rural area of Niakhar, Senegal. The analysis identified psychosocial determinants related to preventive attitudes and the influence of sociodemographic characteristics and of sources of AIDS information on these determinants. Psychosocial determinants of preventive attitudes differed according to gender: Among men, personal risk perception was associated with preventive attitudes. Among women, level of AIDS-related knowledge, communication about AIDS, and optimism about the future were associated with preventive attitudes. Sociodemographic factors and sources of information were similar for men and women: Preventive attitudes were adopted primarily by young, educated subjects who had been exposed to urban life. Religion appeared to be a major obstacle to preventive attitudes. Preventive messages broadcast on radio or television may be determinative. Our results call for a strengthened collaboration with religious leaders and a focus on risk perception to rationalize preventive actions. We also encourage the targeting of vulnerable populations, such as women in rural areas, by developing preventive messages to be delivered through national media (radio, television) and by staff from health centers, which most women visit, at least for prenatal care.

Low and stable HIV infection rates in Senegal: natural course of the epidemic or evidence for success of prevention?

OBJECTIVES: To document the level of HIV infection in Senegal and also to review evidence of the impact of efforts in prevention, developed by the National AIDS Control Programme and the Civil Society, on the level of the HIV epidemic. METHODS: Research, compilation and critical review of all relevant data on HIV and sexually transmission diseases (STDs) epidemiology, sexual behaviour, and the efforts in prevention developed in Senegal. RESULTS: From 1989 to 1996, the levels of HIV infection estimated in four sentinel urban regions remained stable at around 1.2% in the population of pregnant women, and at 3% in male STD patients. It had increased to 19% in female sex workers. A strong political and community commitment led to an early response to the HIV/AIDS epidemic that has been extended since 1986. Blood transfusion safety was established at the start of the HIV epidemic. The level of knowledge of preventive practices relating to HIV/AIDS among the general population exceeded 90% in the early 1990s. From 1991 to 1996, a 30% to 66% decrease of the STD prevalence rates was observed in pregnant women and sex workers in Dakar. In 1997, 33% of men aged 15-49 years in Dakar reported having had sex with non-regular partners. Among them 67% reported condom use. CONCLUSIONS: It is not possible to know what the course of the HIV epidemic in Senegal would have taken in the absence of efforts at prevention. Certainly, several factors that pre-dated the occurrence of AIDS in Senegal laid the groundwork for a positive response. However, data from a number of sources do reveal the successfulness of efforts in prevention. From available data, Senegal can rightfully claim to have contained the spread of HIV by intervening early and comprehensively to increase knowledge and awareness of HIV/AIDS and to promote safe sexual behaviour.

Risk factors for negative sputum acid-fast bacilli smears in pulmonary tuberculosis: results from Dakar, Senegal, a city with low HIV seroprevalence.

SETTING: Two teaching hospitals in Dakar, Senegal, a West African country with a low prevalence of human immunodeficiency virus (HIV) infection. OBJECTIVE: To determine whether patients with HIV-associated pulmonary tuberculosis have fewer acid-fast bacilli (AFB) in their sputum as assessed by routine microscopy, and to correlate the findings with systematically obtained clinical, radiographic and laboratory variables. DESIGN: Prospective study from November 1995 to October 1996 of 450 consecutive patients diagnosed with pulmonary tuberculosis. RESULTS: Tuberculosis was diagnosed in 380 patients (84.4%) by positive bacteriology, in 61 (13.6%) by a favorable response to anti-tuberculosis chemotherapy, and in nine (2.0%) by the presence of a miliary radiographic pattern. Forty (8.9%) patients were HIV-seropositive. AFB-negative smears were found in 14/40 (35.0%) of the HIV-seropositive patients with pulmonary tuberculosis compared with 71/410 (17.3%) of the seronegative patients (risk ratio [RR] = 2.02, 95% confidence interval [CI] 1.26-3.24, P = 0.01). Multivariate analysis revealed that AFB smear negativity was associated with absence of cavitation (P = 0.002), lack of cough (P = 0.005), the presence of HIV seropositivity (P = 0.02), a CD4+ cell count above 200/mm3 (P = 0.02), and age over 40 years (P = 0.03). CONCLUSIONS: Compared with HIV-seronegative patients with pulmonary tuberculosis, seropositive patients in Dakar, Senegal, are more likely to have negative sputum-AFB smears. This phenomenon has now been observed in seven of eight sub-Saharan African countries with varying HIV seroprevalence from which reports are available.

Human immunodeficiency virus type 1 subtypes differ in disease progression.

At least 10 different genetic human immunodeficiency virus type 1 (HIV-1) subtypes (A-J) are responsible for the AIDS pandemic. Much of the understanding of HIV-1 disease progression derives from studies in the developed world where HIV infection is almost exclusively subtype B. This has led many to question whether the properties and consequences of HIV-1 infection can be generalized across subtypes that afflict the majority of infected persons in the developing world. From 1985 to 1997, a prospective study of registered female sex workers in Senegal tracked the introduction and spread of HIV-1 subtypes A, C, D, and G. In clinical follow-up, the AIDS-free survival curves differed by HIV-1 subtype. Women infected with a non-A subtype were 8 times more likely to develop AIDS than were those infected with subtype A (hazard ratio=8.23; P=. 009), the predominant subtype in the study. These data suggest that HIV-1 subtypes may differ in rates of progression to AIDS.