Etiology of Genital Ulcer Disease and Association With HIV Infection in Malawi.

and ¶Clinical Research Unit, London School of Hygiene & Tropical Medicine, London, UK.
Sexually transmitted diseases (Impact Factor: 2.84). 12/2013; 40(12):923-8. DOI: 10.1097/OLQ.0000000000000051
Source: PubMed


The World Health Organization recommends the use of syndromic management for patients presenting with genital ulcer disease (GUD) in developing countries. However, effective treatment guidelines depend on a current country-specific GUD etiological profile, which may change over time.
From 2004 to 2006, we conducted a cross-sectional analysis of baseline data from patients presenting with GUD at a reference STI clinic in Lilongwe, Malawi. Participants were enrolled in a randomized clinical trial of acyclovir added to syndromic management and followed up for up to 28 days. Serologies for HIV (using parallel rapid tests), herpes simplex virus type 2 (HSV-2; using Focus HerpeSelect IgG2 ELISA [Focus Technologies, Cypress Hill, CA]), and syphilis (rapid plasma reagin confirmed by Treponema pallidum hemagglutination) were determined, with plasma HIV-1 RNA and CD4 count in HIV-positive patients. Genital ulcer disease etiology was determined by real-time multiplex polymerase chain reaction from lesional swabs.
A total of 422 patients with GUD (313 men; 74%) were enrolled. Overall seroprevalence of HIV-1, HSV-2, and syphilis were 61%, 72%, and 5%, respectively. Ulcer etiology was available for 398 patients and showed the following: HSV-2, 67%; Haemophilus ducreyi, 15%; T. pallidum, 6%; lymphogranuloma venereum, 6%; mixed infections, 14%, and no etiology, 20%. Most HSV-2 ulcers were recurrent (75%). Among all patients with HSV-2, HIV prevalence was high (67%) and HIV seroprevalence was higher among patients with recurrent HSV-2 compared with patients with first-episode HSV-2 (78% vs. 39%, P < 0.001).
Herpes simplex virus type 2 ulcers are highly prevalent in this symptomatic population and strongly associated with HIV. Unlike most locations in sub-Saharan Africa, H. ducreyi remains prevalent in this population and requires periodic monitoring and an appropriate treatment regimen.

Download full-text


Available from: Philippe Mayaud, Jan 23, 2015
1 Follower
67 Reads
  • [Show abstract] [Hide abstract]
    ABSTRACT: Chancroid, caused by Haemophilus ducreyi, has declined in importance as a sexually transmitted pathogen in most countries where it was previously endemic. The global prevalence of chancroid is unknown as most countries lack the required laboratory diagnostic capacity and surveillance systems to determine this. H. ducreyi has recently emerged as a cause of chronic skin ulceration in some South Pacific islands. Although no antimicrobial susceptibility data for H. ducreyi have been published for two decades, it is still assumed that the infection will respond successfully to treatment with recommended cephalosporin, macrolide or fluoroquinolone-based regimens. HIV-1-infected patients require careful follow-up due to reports of treatment failure with single dose regimens. Buboes may need additional treatment with either aspiration or excision and drainage.
    Expert Review of Anti-infective Therapy 03/2014; 12(6). DOI:10.1586/14787210.2014.892414 · 3.46 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: (p)ppGpp responds to nutrient limitation through a global change in gene regulation patterns to increase survival. The stringent response has been implicated in the virulence of several pathogenic bacterial species. Haemophilus ducreyi, the causative agent of chancroid, has homologs of both relA and spoT, which primarily synthesize and hydrolyze (p)ppGpp in Escherichia coli. We constructed relA and relA spoT deletion mutants to assess the contribution of (p)ppGpp to H. ducreyi pathogenesis. Both the relA single mutant and the relA spoT double mutant failed to synthesize (p)ppGpp, suggesting that relA is the primary synthetase of (p)ppGpp in H. ducreyi. Compared to the parent strain, the double mutant was partially attenuated for pustule formation in human volunteers. The double mutant had several phenotypes that favored attenuation, including increased sensitivity to oxidative stress. The increased sensitivity to oxidative stress could be complemented in trans. However, the double mutant also exhibited phenotypes that favored virulence. When grown to the mid-log phase, the double mutant was significantly more resistant than its parent to being taken up by human macrophages and exhibited increased transcription of lspB, which is involved in resistance to phagocytosis. Additionally, compared to the parent, the double mutant also exhibited prolonged survival in the stationary phase. In E. coli, overexpression of DksA compensates for the loss of (p)ppGpp; the H. ducreyi double mutant expressed higher transcript levels of dksA than the parent strain. These data suggest that the partial attenuation of the double mutant is likely the net result of multiple conflicting phenotypes.
    Infection and Immunity 06/2014; 82(8). DOI:10.1128/IAI.01994-14 · 3.73 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The (p)ppGpp mediated stringent response is important for the bacterial survival in nutrient limiting conditions. For maximal effect, (p)ppGpp interacts with the co-factor DksA, which stabilizes (p)ppGpp's interaction with RNA polymerase. We previously demonstrated that (p)ppGpp was required for the virulence of Haemophilus ducreyi in humans. Here, we constructed a H. ducreyi dksA mutant and showed it was also partially attenuated for pustule formation in human volunteers. To understand the roles of (p)ppGpp and DksA in gene regulation in H. ducreyi, we defined genes potentially altered by (p)ppGpp and DksA deficiency using RNA-seq. In bacteria collected at stationary phase, lack of (p)ppGpp and DksA altered expression of 28% and 17% of H. ducreyi open reading frames, respectively, including genes involved in transcription, translation, and metabolism. There was significant overlap in genes differentially expressed in the (p)ppGpp mutant relative to the dksA mutant. Loss of (p)ppGpp or DksA resulted in the dysregulation of several known virulence determinants. Deletion of dksA downregulated lspB and rendered the organism less resistant to phagocytosis, and increased its sensitivity to oxidative stress. Both mutants had reduced ability to attach to human foreskin fibroblasts; the defect correlated with reduced expression of the Flp adhesin proteins in the (p)ppGpp mutant but not in the dksA mutant, suggesting that DksA regulates the expression of unknown co-factor(s) required for Flp mediated adherence. We conclude that both (p)ppGpp and DksA serve as major regulators of H. ducreyi gene expression in stationary phase and have both overlapping and unique contributions to pathogenesis. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
    Infection and immunity 06/2015; 83(8). DOI:10.1128/IAI.00692-15 · 3.73 Impact Factor