Silver A Wolf | Search PubMed

PubMed2026

First year of ongoing invasive Haemophilus influenzae type b outbreak among middle-aged people who use drugs and people who experience homelessness in Hamburg, Germany, September 2024 to August 2025.

We report an ongoing outbreak of invasive Haemophilus influenzae type b (Hib) disease among people who use drugs (PWUD) and people experiencing homelessness (PEH) in Hamburg, Germany. Between 1 September 2024 and 31 August 2025, 20 adult Hib cases were reported. The cases were either residents of Hamburg (16/20) or stayed in Hamburg during the exposure period (4/20). Whole genome sequencing identified a link between 18 cases (median age 50 years (range 26-77); six female, 12 male, three died). An epidemiological link (i.e. drug consumption in the open drug scene) could be established for 15 of the 18 cases. Control measures included post-exposure chemoprophylaxis for close contacts (n = 4), vaccination offers (n = 69 doses administered by 31 August 2025) and an information campaign targeting PWUD, PEH and staff members of addiction support centres. We describe the first Hib outbreak among adults in Europe and document drug use and homelessness as suspected risk factors. Based on these findings, national vaccination recommendations issued by the Standing Committee on Vaccination in Germany (STIKO) were updated to include vaccination and post-exposure prophylaxis recommendations in outbreak settings for PWUD and PEH. Control measures are currently being evaluated and expanded.

Humans↗

PubMed2025

Comparative genomics of Mycobacterium avium subsp. hominissuis strains within a group of captive lowland tapirs.

Within a group of three captive lowland tapirs (Tapirus terrestris) suffering from clinically apparent mycobacteriosis, non-tuberculous Mycobacterium avium subsp. hominissuis (MAH) strains were isolated from the animals and the tapir's enclosure. Based on MIRU-VNTR findings, which identified two closely related INMV profiles (124 and 246), a micro-evolutionary event was assumed, and four available MAH strains were submitted to whole genome sequencing (short- and long-read technologies). Surprisingly, the differences based on single nucleotide polymorphisms (SNPs) were exceptionally high between the four strains, i.e., between 841 and 11,166 bases, due to a strong impact of homologous recombination. Thus, an ad hoc core genome multilocus sequence typing (cgMLST) scheme was created and pangenome analysis was conducted for determining the genomic similarity between the strains. The INMV246 isolate obtained from sputum on the enclosure floor and one INMV124 isolate of tapir #2 showed the highest congruence, suggesting that both originated from a shared source. The other two INMV124 isolates were genomically distinct from these strains. Nevertheless, in all four strains two plasmids were detected, which were highly conserved between the strains. The study showed that the genomic variability between MAH strains isolated from the same site within a short period of time can be exceptionally high and the influence of homologous recombination needs to be considered when determining MAH strain relationships, particularly via SNP analyses.

Animals↗