[Diphtheria and infections caused by Corynebacterium diphtheriae in 1997]

The resurgence of diphtheria in Zinder, Niger

BACKGROUND

Diphtheria is a re-emerging bacterial disease in developing countries with low vaccination coverage.

OBJECTIVES

This is a descriptive cross-sectional study of diphtheria cases reported to the DRSP/Zinder from March 14, 2022 through June 26, 2023.

METHODS

It includes cases reported through epidemiological surveillance and data on patients hospitalized in the infectious and tropical diseases department of the Zinder National Hospital (SMIT).

RESULTS

A total of 32 patients were included in this study. The median age was 12 years [4-22 years]. Key symptoms included dysphagia and odynophagia (100 %), false membranes (84.4 %), fever (46.9 %), thrombocytopenia (39.3 %), cervical lymphadenopathy (37 %), respiratory distress (15.6 %), epistaxis (12.5 %), gingival bleeding (9.4 %), agitation (6.2 %) and paresis (3.1 %). Renal function was altered in 74 % of cases. Diagnostic confirmation was procured through culture on oropharyngeal swabs. Corynebacterium diphtheriae was isolated in 26.31 % (5/19) of cases. Patients were treated with macrolides and diphtheria antitoxin. The case fatality rate was 31.2 %. Poor prognostic factors included gingival bleeding (p = 0.0262), respiratory distress (p = 0.0374), and thrombocytopenia below 50,000 platelets/mm3 (p = 0.0020).

CONCLUSION

Diphtheria is a deadly re-emerging disease. The fight against this condition necessitates improved vaccination coverage.

Strain-dependent arthritogenic potential of the zoonotic pathogen Corynebacterium ulcerans

During the last decade the majority of diphtheria cases in Europe had Corynebacterium ulcerans as the etiologic agent with dogs and cats as the reservoir hosts. However, little has been documented about the virulence factors of this zoonotic pathogen. To set up an in vivo experimental C. ulcerans infection model, conventional Swiss Webster mice were intravenously infected with different doses (from 1 × 10(7) to 5 × 10(9) bacteria per mouse) of C. ulcerans strains, namely 809 (from human lower respiratory tract), BR-AD22 (from asymptomatic dog nares) and CDC-KC279. Mortality rates were demonstrated by LD(50) values ranging from 1.9 × 10(8) to 1.3 × 10(9). Viable bacteria were recovered from blood, kidneys, liver, spleen and joints. For CDC-KC279 and 809 strains (2 × 10(8)mL(-1)) approximately 85% and 72% of animals with articular lesions were observed, respectively; BR-AD22-infected mice showed no signs of arthritis. CDC-KC279 and 809 strains exhibited higher arthritogenic potential when compared to the homologous toxigenic (ATCC27012) and non-toxigenic (ATCC27010) strains of Corynebacterium diphtheriae. A high number of affected joints and arthritis index in addition to the histopathological features, including subcutaneous edema, inflammatory infiltrate, damage to bone tissue and synoviocyte hypertrophy, indicated a strain-dependent ability of C. ulcerans strains to cause severe polyarthritis. A correlation between the arthritis index and systemic levels of IL-6 and TNF-α was observed for C. ulcerans strains, with the exception of the non-arthritogenic BR-AD22 strain. In conclusion, C. ulcerans revealed a strain-dependent arthritogenic potential independent of DNAse, PLD and diphtheria toxin production.

[Acute group A beta-hemolytic streptococcus membranous laryngotracheobronchitis in an adult]

OBJECTIVE

To describe the first case of a group A beta-hemolytic streptococcus laryngotracheobronchitis as well as the other possible etiologies in a case of acute dyspnea.

METHODS

We report the case of a 46-year-old woman with a doubtful vaccination status who presented clinical features of croup (laryngotracheobronchitis). She developed respiratory distress and required endotracheal intubation.

RESULTS

The endoscopy demonstrated a great deal of crust and pseudomembrane detachment. Bacterial culture grew group A beta-hemolytic streptococcus. Progression was good with antibiotics and corticosteroid treatment.

CONCLUSION

Bacterial acute pseudomembranous croup (laryngotracheobronchitis) is rare. We must search for the most frequent diagnoses such as diphtheria and epiglottitis. This is the first case to be reported in the literature.