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Vector competence of Glossina austeni and Glossina brevipalpis for Trypanosoma congolense in KwaZulu-Natal, South Africa
No full textCellular immunity confers transient protection in experimental Buruli ulcer following BCG or mycolactone-negative Mycobacterium ulcerans vaccination
No full textBACKGROUND: Buruli ulcer (BU) is an emerging infectious disease caused by Mycobacterium ulcerans that can result in extensive necrotizing cutaneous lesions due to the cytotoxic exotoxin mycolactone. There is no specific vaccine against BU but reports show some degree of cross-reactive protection conferred by M. bovis BCG immunization. Alternatively, an M. ulcerans-specific immunization could be a better preventive strategy. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we used the mouse model to characterize the histological and cytokine profiles triggered by vaccination with either BCG or mycolactone-negative M. ulcerans, followed by footpad infection with virulent M. ulcerans. We observed that BCG vaccination significantly delayed the onset of M. ulcerans growth and footpad swelling through the induction of an earlier and sustained IFN-gamma T cell response in the draining lymph node (DLN). BCG vaccination also resulted in cell-mediated immunity (CMI) in M. ulcerans-infected footpads, given the predominance of a chronic mononuclear infiltrate positive for iNOS, as well as increased and sustained levels of IFN-gamma and TNF. No significant IL-4, IL-17 or IL-10 responses were detected in the footpad or the DLN, in either infected or vaccinated mice. Despite this protective Th1 response, BCG vaccination did not avoid the later progression of M. ulcerans infection, regardless of challenge dose. Immunization with mycolactone-deficient M. ulcerans also significantly delayed the progression of footpad infection, swelling and ulceration, but ultimately M. ulcerans pathogenic mechanisms prevailed. CONCLUSIONS/SIGNIFICANCE: The delay in the emergence of pathology observed in vaccinated mice emphasizes the relevance of protective Th1 recall responses against M. ulcerans. In future studies it will be important to determine how the transient CMI induced by vaccination is compromised
HIV and STI prevalence among female sex workers in Cote d'Ivoire: why targeted prevention programs should be continued and strengthened
No full textOBJECTIVE: To assess condom use and prevalence of STIs and HIV among female sex workers (FSWs), as part of a comprehensive monitoring and evaluation plan of a nationwide sex worker prevention project in Cote d'Ivoire. DESIGN AND METHODS: Cross sectional surveys were conducted among FSWs attending five project clinics in Abidjan and San Pedro (2007), and in Yamoussoukro and Gagnoa (2009). A standardized questionnaire was administered in a face-to-face interview, which included questions on socio-demographic characteristics, sexual behaviour and condom use. After the interview, the participants were asked to provide samples for STI and HIV testing. RESULTS: A total of 1110 FSWs participated in the surveys. There were large differences in socio-demographic and behavioural characteristics between FSW coming for the first time as compared to FSW coming on a routine visit. The prevalence of N. gonorrhoeae or C.trachomatis was 9.1%, 11.8% among first vs. 6.9% routine attendees (p = 0.004). The overall HIV prevalence was 26.6%, it was lower among first time attendees (17.5% as compared to 33.9% for routine attendees, p<0.001). The HIV prevalence among first attendees was also lower than the proportion of HIV positive tests from routine testing and counselling services in the same clinics. CONCLUSIONS: The results show a relatively high STI and HIV prevalence among FSWs in different cities in Cote d'Ivoire. In the light of these results, prevention efforts should continue to focus on FSWs in the country
Meningoencephalitis complicating relapsing fever in traveler returning from Senegal [letter]
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"I wish I had AIDS": a qualitative study on access to health care services for HIV/AIDS and diabetic patients in Cambodia
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Measuring the perceived pressure and stakeholders' response that may impact the status of the safety of the food chain in Belgium
No full textCorticosteroid modulated immune activation in the TB immune reconstitution inflammatory syndrome
No full textRATIONALE: HIV-tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) is an immunopathological reaction to mycobacterial antigens induced by antiretroviral therapy (ART). Prednisone reduces morbidity in TB-IRIS, but the mechanisms are unclear. OBJECTIVES: To determine the effect of prednisone on the inflammatory response in TB-IRIS (antigen-specific effector T cells, cytokines and chemokines). METHODS: Samples were taken from participants in a randomized placebo-controlled trial of prednisone for TB-IRIS, at 0, 2 and 4 weeks. Participants received prednisone at a dose of 1.5mg/kg/day for 2 weeks followed by 0.75mg/kg/day for 2 weeks, or identical placebo. MEASUREMENTS: Interferon gamma ELISpot. RT-PCR on PBMC after restimulation with heat-killed Mycobacterium tuberculosis and Luminex multiplex cytokine analysis on corresponding tissue culture supernatants. Luminex multiplex cytokine analysis of serum. MAIN RESULTS: 58 participants with TB-IRIS (31 prednisone, 27 placebo) were included. In serum, significant decreases in IL-6, IL-10, IL-12p40, TNFalpha, IFNgamma and IP-10 concentrations during prednisone, but not placebo, treatment were observed. No differences in ELISpot responses comparing prednisone and placebo groups were shown in response to ESAT-6, Acr1, Acr2, 38kDa or heat killed H37Rv M. tuberculosis. PPD ELISpot responses increased over 4 weeks in prednisone group and decreased in placebo group (p=0.007). CONCLUSIONS: The beneficial effects of prednisone in TB-IRIS appear mediated via suppression of predominantly pro-inflammatory cytokine responses of innate immune origin, not via a reduction of the numbers of antigen-specific T cells in peripheral blood
