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Stabile HD, McCandless K, Donlan RA, Gaston JR, Humphreys TL. Transmission of viable Haemophilus ducreyi by Musca domestica. PLoS Negl Trop Dis 2024; 18:e0012194. [PMID: 38814945 PMCID: PMC11139276 DOI: 10.1371/journal.pntd.0012194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 05/06/2024] [Indexed: 06/01/2024] Open
Abstract
Haemophilus ducreyi was historically known as the causative agent of chancroid, a sexually-transmitted disease causing painful genital ulcers endemic in many low/middle-income nations. In recent years the species has been implicated as the causative agent of nongenital cutaneous ulcers affecting children of the South Pacific Islands and West African countries. Much is still unknown about the mechanism of H. ducreyi transmission in these areas, and recent studies have identified local insect species, namely flies, as potential transmission vectors. H. ducreyi DNA has been detected on the surface and in homogenates of fly species sampled from Lihir Island, Papua New Guinea. The current study develops a model system using Musca domestica, the common house fly, as a model organism to demonstrate proof of concept that flies are a potential vector for the transmission of viable H. ducreyi. Utilizing a green fluorescent protein (GFP)-tagged strain of H. ducreyi and three separate exposure methods, we detected the transmission of viable H. ducreyi by 86.11% ± 22.53% of flies sampled. Additionally, the duration of H. ducreyi viability was found to be directly related to the bacterial concentration, and transmission of H. ducreyi was largely undetectable within one hour of initial exposure. Push testing, Gram staining, and PCR were used to confirm the identity and presence of GFP colonies as H. ducreyi. This study confirms that flies are capable of mechanically transmitting viable H. ducreyi, illuminating the importance of investigating insects as vectors of cutaneous ulcerative diseases.
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Affiliation(s)
- Haley D. Stabile
- Department of Biology, Allegheny College, Meadville, Pennsylvania, United States of America
- Lake Erie College of Osteopathic Medicine, Erie, Pennsylvania, United States of America
| | - Kayla McCandless
- Department of Biology, Allegheny College, Meadville, Pennsylvania, United States of America
- Krystal Biotech, Inc., Pittsburgh, Pennsylvania, United States of America
| | - Rachel A. Donlan
- Department of Biology, Allegheny College, Meadville, Pennsylvania, United States of America
- University of Pittsburgh Medical Center, Department of Microbiology and Molecular Genetics, Pittsburgh, Pennsylvania, United States of America
| | - Jordan R. Gaston
- Department of Biology, Allegheny College, Meadville, Pennsylvania, United States of America
- University of Pittsburgh Medical Center, St. Margaret Hospital, Pittsburgh, Pennsylvania, United States of America
| | - Tricia L. Humphreys
- Department of Biology, Allegheny College, Meadville, Pennsylvania, United States of America
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Ndzomo P, Tchatchouang S, Njih Tabah E, Njamnshi T, Tsanga MVN, Bondi JA, Handley R, González Beiras C, Tchatchueng J, Müller C, Lüert S, Knauf S, Boyomo O, Harding-Esch E, Mitja O, Crucitti T, Marks M, Eyangoh S. Prevalence and risk factors associated with Haemophilus ducreyi cutaneous ulcers in Cameroon. PLoS Negl Trop Dis 2023; 17:e0011553. [PMID: 38150487 PMCID: PMC10791135 DOI: 10.1371/journal.pntd.0011553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 01/09/2024] [Accepted: 12/15/2023] [Indexed: 12/29/2023] Open
Abstract
Epidemics of yaws-like cutaneous ulcers are regularly documented in children in the tropics. They occur mainly in poor and remote communities without access to health facilities. The integration of molecular tools into yaws control efforts has made it possible to describe Haemophilus ducreyi (HD) as a major cause of cutaneous ulcers. The objective of this study was to determine the prevalence of HD as cause of cutaneous ulcers, investigate its presence in asymptomatic individuals and identify associated risk factors. A cross-sectional study was conducted in yaws endemic districts of Cameroon. Participants included people presenting yaws-like ulcers and asymptomatic individuals. Swab samples were collected from each participant and tested for HD and Treponema pallidum (TP) using an established qPCR method. Additionally, demographic, habitat, proximity, and hygiene characteristics were collected using a structured questionnaire. A total of 443 individuals participated in the study, including 271 ulcer cases and 172 asymptomatic contacts. The prevalence of HD in ulcers was 30.3% (Confidence Interval (CI) 95% [24.8-35.7]) and the prevalence of asymptomatic HD carriage was 8.6% (CI95% [4.5-12.9]). TP was also detected in our sample among ulcer cases but in lower proportion (5.2% CI95% [2.5-7.8]) compared to HD. The adjusted logistic regression model showed that women were as much at risk of having HD cutaneous ulcer as men regardless of age. Physical proximity to a confirmed ulcer case was the major factor identified favouring HD transmission. HD ulcers were more likely to be present on Bantu individuals compared to Baka as well as HD colonization. These findings highlight HD as the most common cause of cutaneous ulcers in yaws-endemic communities in Cameroon. The exact implications of detecting HD on intact skin are not yet clear. Further studies are needed to understand the significance of this carriage in the spread dynamics of the disease.
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Affiliation(s)
- Philippe Ndzomo
- Centre Pasteur du Cameroun, Yaounde, Cameroon
- Department of Microbiology, Faculty of Science, University of Yaounde 1, Yaounde, Cameroon
| | | | - Earnest Njih Tabah
- National Yaws, Leishmaniasis, Leprosy and Buruli ulcer Control Programme, Ministry of Public Health, Yaounde, Cameroon
- Department of Public Health, Faculty of Medicine and Pharmaceutical Sciences, University of Dschang, Dschang, West Cameroon
| | - Theophilus Njamnshi
- National Yaws, Leishmaniasis, Leprosy and Buruli ulcer Control Programme, Ministry of Public Health, Yaounde, Cameroon
- Department of Medical Laboratory Sciences, Faculty of Health Sciences, University of Buea, Buea, Cameroon
| | | | | | - Rebecca Handley
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Camila González Beiras
- Department of Infectious Diseases, Hospital Universitari Germans Trias i Pujol, Badalona, Spain
| | | | - Claudia Müller
- Institute of International Animal Health/One Health, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald—Insel Riems, Germany
| | - Simone Lüert
- Institute of International Animal Health/One Health, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald—Insel Riems, Germany
| | - Sascha Knauf
- Institute of International Animal Health/One Health, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald—Insel Riems, Germany
| | - Onana Boyomo
- Department of Microbiology, Faculty of Science, University of Yaounde 1, Yaounde, Cameroon
| | - Emma Harding-Esch
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Oriol Mitja
- Department of Infectious Diseases, Hospital Universitari Germans Trias i Pujol, Badalona, Spain
| | - Tania Crucitti
- Experimental Bacteriology Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar
| | - Michael Marks
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Hospital for Tropical Diseases, University College London Hospital, London, United Kingdom
- Division of Infection and Immunity, University College London, London, United Kingdom
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Mahé A. [What's new in clinical dermatology?]. Ann Dermatol Venereol 2019; 145 Suppl 7:VIIS1-VIIS10. [PMID: 30583751 DOI: 10.1016/s0151-9638(18)31283-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In this article, we performed a review of all new data of clinical relevance for the dermatologists that were published in the medical literature between September, 2017 and September, 2018. Besides advances that will be useful in day-to-day dermatological practice, we intended to give a more general perspective to this review by taking into account certain international health issues that might in final concern each of us in a globalized world. Focus were more particularly done on the following topics: infectious diseases (including sexually transmitted infections), neglected tropical diseases, adverse effects of drugs, bullous diseases, allergology, wound healing, dermatology on black skin, and public health dermatology.
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Affiliation(s)
- A Mahé
- Service de dermatologie, hôpital Louis-Pasteur, 68024 Colmar cedex, France.
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