Retrospective Study of Infections with Corynebacterium diphtheriae Species Complex, French Guiana, 2016-2021.

Human infections with Corynebacterium diphtheriae species complex (CdSC) bacteria were rare in French Guiana until 2016, when the number of cases diagnosed increased. We conducted an epidemiologic, multicenter, retrospective study of all human CdSC infections diagnosed in French Guiana during January 1, 2016-December 31, 2021. A total of 64 infectious episodes were observed in 60 patients; 61 infections were caused by C. diphtheriae and 3 by C. ulcerans. Estimated incidence increased from 0.7 cases/100,000 population in 2016 to 7.7 cases/100,000 population in 2021. The mean patient age was 30.4 (+23.7) years, and male-to-female ratio was 1.7:1 (38/22). Of the 61 C. diphtheriae isolates, 5 tested positive for the diphtheria toxin gene, and all results were negative by Elek test; 95% (61/64) of cases were cutaneous, including the C. ulcerans cases. The increase in reported human infections underscores the need to raise awareness among frontline healthcare practitioners to improve prevention.

Imported Toxigenic Corynebacterium Diphtheriae in Refugees with Polymicrobial Skin Infections, Germany, 2022.

During August-December 2022, toxigenic Corynebacterium diphtheriae was isolated from 25 refugees with skin infections and 2 refugees with asymptomatic throat colonization at a refugee reception center in Germany. None had systemic toxin-mediated illness. Of erosive/ulcerative skin infections, 96% were polymicrobial. Erosive/ulcerative wounds in refugees should undergo testing to rule out cutaneous diphtheria.

Outbreak of Corynebacterium diphtheriae among asylum seekers in Belgium in 2022: operational challenges and lessons learnt.

Since 2022, European countries have been facing an outbreak of mainly cutaneous diphtheria caused by toxigenic Corynebacterium diphtheriae among asylum seekers. In Belgium, between 1 March and 31 December 2022, 25 cases of toxigenic C. diphtheriae infection were confirmed among asylum seekers, mostly among young males from Afghanistan. Multi-locus sequence typing showed that most isolates belonged to sequence types 574 or 377, similar to the majority of cases in other European countries. The investigation and management of the outbreak, with many asylum seekers without shelter, required adjustments to case finding, contact tracing and treatment procedures. A test-and-treat centre was organised by non-governmental organisations, the duration of the antimicrobial treatment was shortened to increase compliance, and isolation and contact tracing of cases was not possible. A vaccination centre was opened, and mobile vaccination campaigns were organised to vaccinate a maximum of asylum seekers. No more cases were detected between end December 2022 and May 2023. Unfortunately, though, three cases of respiratory diphtheria, including one death, were reported at the end of June 2023. To prevent future outbreaks, specific attention and sufficient resources should be allocated to this vulnerable population, in Belgium and at international level.

Cutaneous ulcers revealing diphtheria: A re-emerging disease imported from Indian Ocean countries?

INTRODUCTION: Diphtheria due to Corynebacteriumdiphtheriae (C. diphtheriae) has become rare in developed countries. In France only 10 cases of toxigenic diphtheria have been reported since 1989, in all cases causing pharyngitis and all emanating from endemic countries with exception of one contact case. We report herein 13 cases with cutaneous diphtheria, in 5 of which diphtheria toxin was produced, and all imported into France between 2015 and 2018. OBSERVATIONS: Thirteen patients aged 4 to 77 years presented painful and rapidly progressive round ulcerations of the legs, that were superficial and in some cases purulent, with an erythematous-purple border covered with greyish membrane. Bacteriological sampling of ulcers revealed the presence of C. diphtheriae. Only 6 patients had been properly immunized over the preceding 5 years. DISCUSSION: These cases underline the resurgence of cutaneous diphtheria and the circulation of toxigenic strains in France following importation from Indian Ocean countries. This may constitute an important reservoir for ongoing transmission of the disease. Re-emergence of this pathogen stems from the current migratory flow and decreased adult booster coverage. CONCLUSION: Cutaneous diphtheria should be considered in cases of rapidly developing painful skin ulcers with greyish membrane, especially among patients returning from endemic areas, regardless of their vaccination status. The clinician should order specific screening for C. diphtheriae from the bacteriologist, since with routine swabbing Corynebacteriaceae may be reported simply as normal skin flora. Vaccination protects against toxigenic manifestations but not against actual bacterial infection. Early recognition and treatment of cutaneous diphtheria and up-to-date vaccination are mandatory to avoid further transmission and spread of both cutaneous and pharyngeal diphtheria.

Toxigenic Corynebacterium diphtheriae-Associated Genital Ulceration.

In October 2016, an adolescent boy sought care for acute genital ulceration in Cologne, Germany. We presumed a sexually transmitted infection, but initial diagnostic procedures yielded negative results. He was hospitalized because swab samples from the lesion grew toxigenic Corynebacterium diphtheriae, leading to the diagnosis of possibly sexually transmitted cutaneous diphtheria.

An unusual case of post-trauma polymicrobial cutaneous diphtheria.

We report a rare case of post-traumatic cutaneous diphtheria in a patient referred from a hospital in rural India. The diagnosis of cutaneous diphtheria was confirmed by the isolation of Corynebacterium diphtheriae cultured from the ulcer of the leg, along with Staphylococcus aureus, Streptococcus pyogenes, and Arcanobacterium haemolyticum. The patient was kept on isolation and treated with erythromycin for 14 days without antitoxin. He was discharged when his subsequent cultures turned out to be negative. Chemoprophylaxis was also given to his family members. Such a case highlights the revisiting of vaccination strategies and the role of cutaneous carriers in transmission of this deadly disease.

Molecular Characterization of Corynebacterium diphtheriae Outbreak Isolates, South Africa, March-June 2015.

In 2015, a cluster of respiratory diphtheria cases was reported from KwaZulu-Natal Province in South Africa. By using whole-genome analysis, we characterized 21 Corynebacterium diphtheriae isolates collected from 20 patients and contacts during the outbreak (1 patient was infected with 2 variants of C. diphtheriae). In addition, we included 1 cutaneous isolate, 2 endocarditis isolates, and 2 archived clinical isolates (ca. 1980) for comparison. Two novel lineages were identified, namely, toxigenic sequence type (ST) ST-378 (n = 17) and nontoxigenic ST-395 (n = 3). One archived isolate and the cutaneous isolate were ST-395, suggesting ongoing circulation of this lineage for >30 years. The absence of preexisting molecular sequence data limits drawing conclusions pertaining to the origin of these strains; however, these findings provide baseline genotypic data for future cases and outbreaks. Neither ST has been reported in any other country; this ST appears to be endemic only in South Africa.

Diphtheria in Europe.

A rising number of diphtheria cases were recorded in Europe in 2022, including in Belgium, within the newly arriving young migrant population. In October 2022, Médecins Sans Frontières (MSF) opened a temporary roadside container-clinic offering free medical consultations. Over 3 months of activity, the temporary clinic detected 147 suspected cases of cutaneous diphtheria with 8 laboratory-confirmed cases growing toxigenic Corynebacterium diphtheriae. This was followed by a mobile vaccination campaign, during which 433 individuals living rough in squats and informal shelters were vaccinated. This intervention has shown how even in Europe's capital, access to preventive and curative medical services remains difficult for those who need it the most. Appropriate access to health services, including routine vaccination, are crucial to improve the health status among migrants.

Un nombre croissant de cas de diphtérie a été enregistré en Europe en 2022, y compris en Belgique, au sein de la population de jeunes migrants nouvellement arrivés. En octobre 2022, Médecins Sans Frontières (MSF) a ouvert un conteneur-clinique temporaire en bord de route offrant des consultations médicales gratuites. En 3 mois d'activité, la clinique temporaire a détecté 147 cas suspects de diphtérie cutanée et 8 cas confirmés en laboratoire de Corynebacterium diphtheriae toxigène. Cette opération a été suivie d'une campagne de vaccination mobile, au cours de laquelle 433 personnes vivant dans la rue, dans des squats et des abris informels, ont été vaccinées. Cette intervention a montré que même dans la capitale de l'Europe, l'accès aux services médicaux préventifs et curatifs reste difficile pour ceux qui en ont le plus besoin. Un accès adéquat aux services de santé, y compris une vaccination de routine, est primordial pour améliorer l'état de santé des migrants.

A Rare Case of Locally Contracted Cutaneous Corynebacterium diphtheriae.

A 32-year-old man with a history of intravenous heroin use and housing instability presented with three years of worsening left forearm and wrist "infection," which had progressed over the past few months with worsening purulence, pain, and deformity. In the emergency department, he was afebrile with stable vitals. Superficial cultures drawn demonstrated polymicrobial growth, including heavy growth of Corynebacterium diphtheriae. He was treated with vancomycin and then IV penicillin to complete 10 days of therapy. Given the uncharacteristic appearance of the lesion, a biopsy was recommended, but the patient left against medical advice. Later, the diphtheria isolate was identified as C. diphtheriae var. mitis by the Centers for Disease Control and Prevention (CDC). This describes an atypical case of cutaneous diphtheria, a disease that is infrequently seen in the United States due to the high prevalence of routine vaccination.

Cutaneous infection by non-diphtheria-toxin producing and penicillin-resistant Corynebacterium diphtheriae strain in a patient with diabetes mellitus.

Diphtheria is a potentially fatal infection, mostly caused by diphtheria toxin (DT)-producing Corynebacterium diphtheriae strains. During the last decades, the isolation of DT-producing C. diphtheriae strains has been decreasing worldwide. However, non-DT-producing C. diphtheriae strains emerged as causative agents of cutaneous and invasive infections. Although endemic in countries with warm climates, cutaneous diphtheria is rarely reported in Brazil. Presently, an unusual case of skin lesion in a Brazilian elderly diabetic patient infected by a penicillin-resistant non-DT-producing C. diphtheriae strain was reported. Laboratory diagnosis included mass spectrometry and multiplex PCR analyses. Since cutaneous diphtheria lesions are possible sources of secondary diphtheria cases and systemic diseases and considering that penicillin is the first line of antimicrobial agent for the treatment of these infections, the detection of penicillin-resistant strains of diphtheria bacilli should be a matter of concern. Thus, cases similar to the presently reported should be appropriately investigated and treated, particularly in patients with risk factor (s) for the development of C. diphtheriae invasive infections, such as diabetes. Moreover, health professionals must be aware of the presence of C. diphtheriae in cutaneous lesions of lower limbs, a common type of morbidity in diabetic patients, especially in tropical and subtropical countries.

Diphtheria Immunity in Australia: Should we be Concerned?

OBJECTIVES: We report the results of the 2007 national serological survey of immunity to diphtheria in Australia to assess the impact of recent schedule changes on diphtheria immunity, and the adequacy of current policy in the context of increased international travel of people and pathogens. METHODS: Residual sera (n =1656) collected opportunistically from Australian laboratories in 2007 were tested for diphtheria antibody levels using an enzyme immunoassay, with the protective threshold defined as ≥0.1 IU/mL. About 40% of adults aged ≥30 years are susceptible to diphtheria; following the removal of the 18-month booster and its replacement with a dose in adolescence offered through school-based dTpa vaccination program, 59% of children aged 3 years were susceptible to diphtheria, whilst adolescents demonstrated improved immunity. RESULTS: There is no apparent boosting of diphtheria immunity from meningococcal group C conjugate (MCC) or seven-valent pneumococcal conjugate (7vPCV) vaccines in relevant age groups. CONCLUSION: Australians who travel to diphtheria-endemic areas should be up-to-date with their vaccinations. Close monitoring of population immunity levels against diphtheria remains important to ensure that immunity does not decline to a level where wide-spread transmission would be possible.

A hyperalgesic ulcer on return from Senegal.

Diphtheria is an infectious disease transmitted by air or by contact. There are three main species of corynebacterium: diphtheriae, ulcerans, and pseudotuberculosis. They may or may not secrete a toxin responsible for serious cardiac or neurological complications. The frequent clinical presentations are diphtheria angina and cutaneous diphtheria. When it is suspected, it is urgent to send cutaneous or pharyngeal samples to the National Reference Center. If toxin is present, serotherapy should be instituted and the case should be reported. Antibiotic therapy with amoxicillin or azithromycin is the standard treatment. Vaccine prevention begun in the middle of the 20th century has helped to slow epidemics.

Diagnosis in France of a Non-Toxigenic tox Gene-Bearing Strain of Corynebacterium diphtheriae in a Young Male Back From Senegal.

Cutaneous diphtheria is uncommon in Europe. In this study, we report a case of imported cutaneous infection due to a non-toxigenic but tox gene-bearing (NTTB) strain of Corynebacterium diphtheriae. The NTTB strains are recognized as emerging pathogens across Europe, and physicians and bacteriologists should be aware of the circulation of these strains.

Cutaneous Corynebacterium Infection Presenting with Disseminated Skin Nodules and Ulceration.

In the context of the European migrant crisis, more and more cases of cutaneous diphtheria are seen. A typical presentation includes painful cutaneous ulcerations with grayish-whitish pseudomembranes. Here we present 2 male Eritrean patients suffering from cutaneous nontoxigenic Corynebacterium diphtheriae (patient 1) and Corynebacterium striatum (patient 2) infection.

Cutaneous Corynebacterium diphtheriae: A traveller's disease?

A Canadian soldier incurred a nonhealing traumatic skin ulcer while on duty in Somalia. The diagnosis of localized cutaneous diphtheria was confirmed by isolation of a toxigenic strain of Corynebacterium diphtheriae from the ulcer. The patient was placed in isolation and treated with erythromycin and penicillin for 10 days without antitoxin. He was released when two consecutive daily cultures were negative. Public health officials evaluated his wife, two children and close contacts for carriage, but no carriers or secondary cases were identified. Cutaneous diphtheria as a diagnostic and management patient problem and potential public health problem are discussed.