Association between pertactin-producing Bordetella pertussis and fulminant pertussis in infants: a multicenter study in France, 2008-2019.

OBJECTIVES: Virulence factors of the causative agent, Bordetella pertussis, may be involved in fulminant pertussis, the most severe form of whooping cough (pertussis) in infants. We aimed to assess the association between fulminant pertussis and the status of pertactin (PRN) production of B. pertussis clinical isolates. METHODS: Symptomatic infants aged <6 months and with a positive B. pertussis culture from 2008-2019 were included. B. pertussis isolates and clinical data were collected from French hospital laboratories through the national pertussis surveillance network. Fulminant pertussis was defined as a case with a leukocyte count > 40 x 109/L and at least one of the following criteria: respiratory failure, pulmonary hypertension, shock, or multiple organ failure. PRN production was assessed by western blotting. Baseline characteristics of infants and microbiological findings were compared between patients with and without fulminant pertussis. To identify patient and microbiological features associated with fulminant pertussis, a multivariable modified Poisson regression model was developed with confounders selected using a directed acyclic graph. RESULTS: We included 361 infants with pertussis (median age 63 days [interquartile range, 39-86]), of which 32 (9%) progressed to fulminant pertussis. None of the mothers was vaccinated during pregnancy. Of the 361 implicated B. pertussis isolates, 294 (81%) produced PRN. Patients with fulminant pertussis were more often neonates (adjusted relative risk [aRR] 3.62, 95% confidence interval [CI] 1.76-7.44), infants with a history of prematurity (aRR 7.08, 95%CI 3.06-16.36), unvaccinated infants (aRR 4.42, 95%CI 1.02-19.24), and infants infected by PRN-producing isolates (aRR 3.76, 95%CI 1.02-13.83). CONCLUSIONS: PRN-producing B. pertussis was independently associated with an increased risk of fulminant pertussis. In a context where PRN-containing aP vaccines favor the emergence of PRN-deficient isolates, our study suggests a positive role for such vaccines in driving the evolution of B. pertussis populations towards reduced virulence.

A rare case of Prosthetic Joint Infection associated with Coxiella burnetii.

We report here the case of a Prosthetic Joint Infection (PJI) associated with Coxiella burnetii in a 62-year-old man with a revised total hip arthroplasty. The diagnosis was performed first by 16S rDNA sequencing on hip fluid aspirate, and confirmed by specific qPCR. Q fever has been reported in few cases of Prosthetic Joint Infections, often associated with chronic evolution and iterative surgeries. This case report alerts about such an unexpected diagnosis in a patient with no known risk factors.

Visual loss related to macular subretinal fluid and cystoid macular edema in HIV-related optic neuropathy.

Optic nerve involvement may occur in various infectious diseases, but is rarely reported after infection by the human immunodeficiency virus (HIV). We report the atypical case of a 38-year-old patient in whom the presenting features of HIV infection were due to a bilateral optic neuropathy associated with macular subretinal fluid and cystoid macular edema, which responded well to antiretroviral therapy.

Mycobacterium malmoense: an underestimated nontuberculous mycobacterium.

We present a case report of Mycobacterium malmoense in a 53-year-old white man. The incidence of M. malmoense infections is a rare event compared with other nontuberculous mycobacteria, but it has increased since 1980, especially in northern Europe. Many patients have disposing underlying diseases. In most cases, it is a pulmonary infection. The most frequent used antibiotics are rifampicin (or rifabutin), ethambutol, and clarithromycin.