Brucellosis in Marine Mammals: Meta-Analysis of Prevalence, Infection Patterns, Host Specificity and Zoonotic Potential

Abstract

Background: Marine brucellosis, primarily caused by Brucella species, presents significant ecological and public health challenges, impacting marine biodiversity and posing zoonotic risks. Despite ongoing research, data on the disease's prevalence, host specificity and transmission within marine ecosystems remains limited, underscoring the need for comprehensive analysis.

Objective: This review assesses Brucella infection patterns in marine mammals, focusing on prevalence, species susceptibility and implications for conservation and health strategies.

Methods: We conducted a systematic review and meta-analysis using PubMed, Web of Science and Scopus, covering studies from 2001 to 2024. Random-effects models were employed to analyse prevalence rates, transmission pathways and regional variations, accounting for high inter-study heterogeneity.

Results: The analysis revealed substantial variation in Brucella detection rates, ranging from 0.25% to 100%, with an average pooled prevalence of approximately 30%. Species-specific susceptibility was identified, with cetaceans showing the highest infection rates (52%), followed by other marine mammals (30%) and pinnipeds (18%). High prevalence rates were observed in species such as striped dolphins and beluga whales, particularly in the Mediterranean and Arctic regions. Geographic patterns indicated Asia as the region with the highest prevalence (36%), followed by Oceania and Antarctica, suggesting environmental and population density factors may influence infection rates. Smaller studies displayed a tendency toward higher reported detection rates, indicating potential publication bias.

Conclusion: This meta-analysis underscores the widespread prevalence of Brucella in marine mammals and the pressing need for advanced diagnostics, strengthened surveillance and targeted interventions, particularly in high-risk regions and species. An interdisciplinary, collaborative approach including the development of molecular diagnostic tools and international research partnerships will be essential to support conservation efforts and mitigate zoonotic risks associated with marine brucellosis.

Keywords: Brucella prevalence; marine brucellosis; marine mammal health; molecular diagnostics; zoonotic disease.

FIGURE 1

PRISMA 2020 flow diagram illustrating the study selection process for the systematic review and meta‐analysis of Brucella spp. in marine mammals. A total of 875 records were identified through database searching. After removal of 147 duplicates and screening of 728 records, 48 studies were included in the final meta‐analysis.

FIGURE 2

Forest plot of brucellosis detection rates by study, showing proportion and confidence intervals across various studies.

FIGURE 3

Trends in Brucella prevalence in marine mammals over time.

FIGURE 4

Average detection rate in cetaceans versus pinnepeds.

FIGURE 5

Detection rate (%) of brucellosis in marine mammals across different continents.

FIGURE 6

Funnel plot of brucellosis detection proportions in marine mammals, illustrating publication bias based on standard error and proportion distribution.