Dynamics of community-acquired meningitis syndrome outbreaks in southern France

Madjid Morsli; Florian Salipante; Quentin Kerharo; Agathe Boudet; Robin Stephan; Catherine Dunyach-Remy; Christine Zandotti; Jean-Philippe Lavigne; Michel Drancourt

doi:10.3389/fmicb.2022.1102130

Dynamics of community-acquired meningitis syndrome outbreaks in southern France

Front Microbiol. 2023 Jan 26:13:1102130. doi: 10.3389/fmicb.2022.1102130. eCollection 2022.

Authors

Madjid Morsli^{1

2}, Florian Salipante³, Quentin Kerharo⁴, Agathe Boudet⁵, Robin Stephan⁵, Catherine Dunyach-Remy⁵, Christine Zandotti^{1

4}, Jean-Philippe Lavigne⁵, Michel Drancourt^{1

2

4}

Affiliations

¹ IHU Méditerranée Infection, Marseille, France.
² Aix-Marseille-Université, IRD, MEPHI, IHU Méditerranée Infection, Marseille, France.
³ Laboratoire de biostatistique, Épidémiologie Clinique, Santé Publique, Innovation et Méthodologie, CHU de Nîmes, Université de Montpellier, Nîmes, France.
⁴ Laboratoire de Microbiologie, Assistance Publique-Hôpitaux de Marseille, IHU Méditerranée Infection, Marseille, France.
⁵ VBIC, INSERM U1047, Université de Montpellier, Service de Microbiologie et Hygiène Hospitalière, CHU Nîmes, Nîmes, France.

Abstract

In southern France, cases of community-acquired meningitis syndrome (CAM) are typically clustered as outbreaks with determinants which remain unknown. This 61-month retrospective investigation in Nîmes and Marseille university hospital laboratories, yielded 2,209/20,779 (10.63%) documented CAM cases caused by 62 different micro-organisms, represented by seasonal viral etiologies (78.8%), including Enterovirus, Herpes Simplex Virus (HSV), and Varicella-Zoster Virus (VZV; 1,620/2,209 = 73.4%). Multi correspondence analysis revealed an association of infection with age and sex, with the risk of infection being relatively higher in young men, as confirmed by Fisher's exact test (p < 10^-3). Bacterial meningitis accounted for 20% of cases, mostly caused by Streptococcus pneumoniae (27.4% of cases), Neisseria meningitidis (12.5%), and Haemophilus influenzae (9.5%) with bacteria/virus coinfection (0.9%), and only six cases of documented fungal meningitis. In total, 62.6% of cases, of which 88.7% were undocumented, arose from 10 outbreaks. 33.2% of undocumented cases were aged >60 years compared to 19.2% of documented cases (p < 0.001), and viral infection was more common in the summer (87.5%) compared to other seasons (72.3%; p < 0.001). Outbreaks most often started in Nîmes and moved eastward toward Marseille at a speed of ~9 km/day, and these dynamics significantly correlated with atmospheric temperature, especially during summer outbreaks. In particular, the incidence of Enterovirus-driven outbreaks correlated with temperature, revealing correlation coefficients of 0.64 in Nîmes and 0.72 in Marseille, and its occurrence in Marseille lagged that in Nîmes by 1-2 weeks. Tracing the dynamics of CAM outbreak during this retrospective investigation in southern France yielded a speed of displacement that correlated with the variation in temperature between both cities, and these results provide clues for the next occurrence of undocumented outbreaks.

Keywords: cerebrospinal fluid; community-acquired meningitis; dynamics; etiology; nondocumented meningitis; outbreak; season.