From the end of 1994 to the beginning of 1995, 49 patients with hemorrhagic symptoms were hospitalized in the Makokou General Hospital in northeastern Gabon. Yellow fever (YF) virus was first ...diagnosed in serum by use of polymerase chain reaction followed by blotting, and a vaccination campaign was immediately instituted. The epidemic, known as the fall 1994 epidemic, ended 6 weeks later. However, some aspects of this epidemic were atypical of YF infection, so a retrospective check for other etiologic agents was undertaken. Ebola (EBO) virus was found to be present concomitantly with YF virus in the epidemic. Two other epidemics (spring and fall 1996) occurred in the same province. GP and L genes of EBO virus isolates from all three epidemics were partially sequenced, which showed a difference of <0.1% in the base pairs. Sequencing also showed that all isolates were very similar to subtype Zaire EBO virus isolates from the Democratic Republic of the Congo.
Generic screening test for HIV infection PLANTIER, Jean-Christophe; LEMEE, Véronique; NABIAS, René ...
AIDS (London),
06/2006, Volume:
20, Issue:
9
Journal Article
Peer reviewed
Open access
More than 30 million individuals infected by HIV world-wide live in poor countries. Major efforts are being made to improve access to antiretroviral drugs in these countries, but the diagnosis and ...monitoring of HIV-infected patients remains problematical. Alternative methods and specific programmes have recently been developed for treatment and resistance monitoring, but there are no screening or confirmatory tools specifically designed for developing countries.
A treatment-reinfection study design was used to investigate the relationships between host immunologic and/or genetic factors and resistance to reinfection with Plasmodium falciparum. Sixty-one ...children in Gabon were enrolled in a cross-sectional study to measure the prevalence of each human plasmodial species. All were given amodiaquine for radical cure of parasites, and 40 were subsequently followed-up for 30 weeks. Successive blood smears were examined to measure the delay of reappearance in blood of asexual stages of P. falciparum parasites. Presence of infection during the cross-sectional survey was associated with male sex, non-deficient glucose-6-phosphate dehydrogenase activity, plasma interleukin-10 level, and anti-LSA-Rep antibody concentration. Resistance to reinfection was related to the presence of anti-LSA-J antibodies, and the absence of anti-LSA-Rep antibodies. Moreover, P. malariae-infected subjects were usually co-infected with P. falciparum, and were also more rapidly reinfected with P. falciparum after treatment, compared with those without P. malariae infection.
Summary Natural killer (NK) cell activity is impaired in Chlamydia trachomatis‐infected patients. The mechanisms behind the altered NK functions are not clear, but data concerning NK and ...antibody‐dependent cellular cytotoxicity (ADCC) activity have been reported. To investigate whether this impairment is related to a defect at the target cell binding and/or the postbinding level, we evaluated highly purified NK cells obtained from 125 C. trachomatis‐infected patients and compared them with 101 normal controls for their ability to kill K‐562 and U‐937 cell lines using a 51Cr release assay; release tumour necrosis factor‐alpha (TNF‐α) and interferon‐gamma (IFN‐γ); and kill anti‐IgM preincubated P‐815 cell line (ADCC activity). We found a decrease in the lytic capability of NK cells from C. trachomatis‐infected patients against target cell lines; decreased ability to kill bound target cells; and low levels of released TNF‐α and INF‐γ after incubation with U‐937 cells. Taken together, these findings suggest that the impaired NK cell reaction during chlamydial infection is related to defects both at the target and postbinding levels. However, the precise mechanisms remain to be determined. The inability to restore normal NK activity after long‐term culture in the presence of high levels of recombinant IL‐2 support the hypothesis of an anergic process during chlamydial infection.
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