Short communication: prevalence of antibodies against Coxiella burnetii (Q fever) in children in The Gambia, West Africa.

Objective: To estimate the prevalence of antibodies against Coxiella burnetii (Q fever) among children in eight villages in The Gambia, West Africa.

Methods: Sera of 796 children aged 1-15 years were tested for presence of antibodies against phase II of C. burnetii by ELISA.

Potent autologous and heterologous neutralizing antibody responses occur in HIV-2 infection across a broad range of infection outcomes.

Few studies have explored the role of neutralizing antibody (NAb) responses in controlling HIV-2 viremia and disease progression. Using a TZM-bl neutralization assay, we assessed heterologous and autologous NAb responses from a community cohort of HIV-2-infected individuals with a broad range of disease outcomes in rural Guinea-Bissau. All subjects (n = 40) displayed exceptionally high heterologous NAb titers (50% inhibitory plasma dilution or 50% inhibitory concentration [IC(50)], 1:7,000 to 1:1,000,000) against 5 novel primary HIV-2 envelopes and HIV-2 7312A, whereas ROD A and 3 primary envelopes were relatively resistant to neutralization.

Maternal proviral load and vertical transmission of human T cell lymphotropic virus type 1 in Guinea-Bissau.

The relative importance of routes of transmission of human T cell lymphotropic virus type 1 (HTLV-1) in Guinea-Bissau is largely unknown; vertical transmission is thought to be important, but there are very few existing data. We aimed to examine factors associated with transmission in mothers and children in Guinea-Bissau, where HTLV-1 is endemic (prevalence of 5% in the adult population). A cross-sectional survey was performed among mothers and their children (aged <15 years) in a rural community in Guinea-Bissau.

Neurologic manifestations of human immunodeficiency virus-2: dementia, myelopathy, and neuropathy in West Africa.

While well documented in human immunodeficiency virus (HIV)-1, neurologic sequelae have not been systematically evaluated in HIV-2. After excluding for confounding comorbidities, 67 individuals from a rural cohort in Guinea-Bissau (22 HIV-2 participants, 45 seronegative controls) were evaluated. HIV + individuals were divided into CD4 < 350 and CD4 ≥ 350 for analysis.

Seroprevalence of hepatitis B and C virus in HIV-1 and HIV-2 infected Gambians.

Background: The prevalence of HIV/hepatitis co-infection in sub-Saharan Africa is not well documented, while both HIV and HBV are endemic in this area.

Objective: The aim of this study is to determine the seroprevalence of HBV and HCV virus in HIV-infected subjects in the Gambia.

Methods: Plasma samples from HIV infected patients (190 individuals with clinically defined AIDS and 382 individuals without AIDS) were tested retrospectively for the presence of HBV sero-markers and for serum HBV DNA, screened for HCV infection by testing for anti-HCV antibody and HCV RNA.

HTLV-1 in rural Guinea-Bissau: prevalence, incidence and a continued association with HIV between 1990 and 2007.

Background: HTLV-1 is endemic in Guinea-Bissau, and the highest prevalence in the adult population (5.2%) was observed in a rural area, Caió, in 1990. HIV-1 and HIV-2 are both prevalent in this area as well.

Undetectable plasma viral load predicts normal survival in HIV-2-infected people in a West African village.

Background: There have been no previous studies of the long-term survival and temporal changes in plasma viral load among HIV-2 infected subjects.

Methods: 133 HIV-2 infected and 158 HIV-uninfected subjects from a rural area in North-west Guinea-Bissau, West Africa were enrolled into a prospective cohort study in 1991 and followed-up to mid-2009. Data were collected on four occasions during that period on HIV antibodies, CD4% and HIV-2 plasma viral load.

Two distinct epidemics: the rise of HIV-1 and decline of HIV-2 infection between 1990 and 2007 in rural Guinea-Bissau.

Objectives: To assess changes in HIV incidence and prevalence in Caió, a rural area of Guinea-Bissau, between 1990 and 2007.

Design: Three cross-sectional community surveys.

Methods: In 1990, 1997, and 2007, surveys were conducted among adults.

Declining trend of serological syphilis among genitourinary medicine patients in the Gambia, West Africa.

Background: Syphilis is a common disease in Africa and may be an important contributor to the HIV epidemic. Trends in syphilis prevalence are important in their own right and because syphilis is a cofactor for HIV infection. In this study we analyzed trends in serological syphilis prevalence at a sexually transmitted infections (STI) clinic in The Gambia.

Presence of a multidrug-resistance mutation in an HIV-2 variant infecting a treatment-naive individual in Caio, Guinea Bissau.

We report the possible transmission of drug-resistant human immunodeficiency virus type 2. A 66-year-old woman from rural Guinea Bissau who had no obvious antiretroviral exposure was found to harbor a variant with the multidrug-resistance mutation Q151M. Finding this mutation among a drug-naive population presents an important public health issue that needs to be addressed for treatment to be effective.

Virological response to highly active antiretroviral therapy in patients infected with human immunodeficiency virus type 2 (HIV-2) and in patients dually infected with HIV-1 and HIV-2 in the Gambia and emergence of drug-resistant variants.

Drug design, antiretroviral therapy (ART), and drug resistance studies have focused almost exclusively on human immunodeficiency virus type 1 (HIV-1), resulting in limited information for patients infected with HIV-2 and for those dually infected with HIV-1 and HIV-2. In this study, 20 patients, 12 infected with HIV-2 and 8 dually infected with HIV-1 and HIV-2, all treated with zidovudine (ZDV), lamivudine (3TC), and lopinavir-ritonavir (LPV/r), were followed up longitudinally for about 3 years. For 19/20 patients, viral loads were reduced to undetectable levels; the patient whose viral load remained detectable reported adverse effects associated with LPV/r that had caused him to stop taking all the drugs.

Robust Gag-specific T cell responses characterize viremia control in HIV-2 infection.

HIV-2 infection in the majority of infected subjects follows an attenuated disease course that distinguishes it from infection with HIV-1. Antigen-specific T cells are pivotal in the management of chronic viral infections but are not sufficient to control viral replication in HIV-1-positive subjects, and their function in HIV-2 infection is not fully established. In a community-based cohort of HIV-2 long-term nonprogressors in rural Guinea-Bissau, we performed what we believe is the first comprehensive analysis of HIV-2-specific immune responses.

Is HIV-2- induced AIDS different from HIV-1-associated AIDS? Data from a West African clinic.

Background: Although AIDS is less frequent following HIV-2 than HIV-1 infection, it is unclear whether the clinical picture and clinical course of AIDS are similar in the two infections.

Objectives: To compare the pattern of AIDS-defining events, CD4 cell count at the time of AIDS diagnosis, survival from time of AIDS, and CD4 cell count near time of death in HIV-1 and HIV-2-infected patients.

Methods: Adult patients with AIDS who attended the clinics of the MRC in The Gambia were enrolled.

Evaluation of the dried blood spot filter paper technology and five testing strategies of HIV-1 and HIV-2 infections in West Africa.

Simple robust approaches are needed to monitor the prevalence and incidence of HIV in Africa. The aim of this study was to evaluate the use of dried blood spot (DBS) as an alternative to serum or plasma for sentinel surveillance. Paired DBS and blood samples were obtained from 200 patients attending a genito-urinary medicine clinic in West Africa.

Sixteen years of HIV surveillance in a West African research clinic reveals divergent epidemic trends of HIV-1 and HIV-2.

Background: The HIV-1 epidemic in West Africa is characterized by a slower rise than that in Eastern and Southern Africa. The HIV-2 epidemic in West Africa may be declining, but few long-term data exist.

Methods: In a research clinic in The Gambia, HIV-1 and HIV-2 prevalence trends among all new patients being tested for HIV were examined over a 16 year period (1988 till 2003).

CD8+ T cell responses to human immunodeficiency viruses type 2 (HIV-2) and type 1 (HIV-1) gag proteins are distinguishable by magnitude and breadth but not cellular phenotype.

The mechanisms underlying the relatively slow progression of human immunodeficiency virus type 2 (HIV-2) compared with HIV-1 infection are undefined and could be a result of more effective immune responses. We used HIV-2 and HIV-1 IFN-gamma enzyme-linked immunospot assays to evaluate CD8(+) T cell responses in antiretroviral-naive HIV-2- ('HIV-2(+)') and HIV-1-infected ('HIV-1(+)') individuals. Gag-specific responses were detected in the majority of HIV-2(+) and HIV-1(+) subjects.

Baseline plasma viral load and CD4 cell percentage predict survival in HIV-1- and HIV-2-infected women in a community-based cohort in The Gambia.

Objectives: To estimate and compare the all-cause mortality rates among HIV-1-infected, HIV-2-infected, and uninfected women and to assess the predictive value of baseline plasma viral load (PVL) and CD4 cell percentage (CD4%) for mortality.

Design: Cohort study.

Methods: At presentation to antenatal clinics in The Gambia in 1993-1995, pregnant women were screened for antibodies to HIV-1 and HIV-2.

Body mass index at time of HIV diagnosis: a strong and independent predictor of survival.

Background: Identification of basic prognostic indicators of HIV infection is essential before widespread antiretroviral therapy can be implemented in low-technology settings. This study assessed how well body mass index (BMI:kg/m2) predicts survival.

Methods: BMI within 3 months of HIV diagnosis was obtained from 1657 patients aged > or = 15 years, recruited in a seroprevalent clinical cohort in The Gambia since 1992 and followed up at least once.

Incidence of tuberculosis and survival after its diagnosis in patients infected with HIV-1 and HIV-2.

Background: In sub-Saharan Africa, tuberculosis (TB) is the most frequently diagnosed opportunistic infection and cause of death among HIV-infected patients. HIV-2 has been associated with less immune suppression, slower disease progression and longer survival.

Objective: To examine whether the incidence of TB and survival after TB are associated with CD4 cell count rather than HIV type.

No differences in cellular immune responses between asymptomatic HIV type 1- and type 2-infected Gambian patients.

Fewer people infected with human immunodeficiency virus (HIV) type 2 progress to acquired immunodeficiency syndrome, compared with those infected with HIV-1. To understand the immune mechanisms leading to slow progression in HIV-2 infection, cell-mediated immune responses were compared between the 2 infections in asymptomatic subjects with a CD4 cell count > or =20%. Interferon- gamma release from T lymphocytes and the cytotoxicity of CD8+ T lymphocytes were measured by ELISPOT and 51Cr release assays.

Survival of HIV-1 and HIV-2 perinatally infected children in The Gambia.

Background: The risk of mother-to-child transmission (MTCT) of HIV-2 is much lower than that of HIV-1, but the long-term prognosis of perinatally infected HIV-2 children is unknown. We re-visited children who were part of a large MTCT study in The Gambia (conducted during 1993-1997), in order to compare the long-term survival of children perinatally infected with HIV-2 with that of seronegative and of HIV-1 infected children.

Methods: Five to eight years' follow-up of a cohort of children born to HIV-negative, HIV-1 positive, and HIV-2 positive mothers.

Regional differences in HIV trends in The Gambia: results from sentinel surveillance among pregnant women.

Objective: To monitor HIV-1 and HIV-2 trends in The Gambia, West Africa.

Methods: In 1993-1995 a nationwide survey among 29 670 pregnant women attending eight antenatal clinics estimated the seroprevalence of HIV-1 at 0.6%, and of HIV-2 at 1.