Prevalence and implications of multiple-strain infections

Area of Science:

• Microbiology
• Infectious Diseases
• Evolutionary Biology

Background:

• Infections often involve multiple strains (genotypes) of a single pathogen, but are typically managed as uniform entities.
• The definition and prevalence of multiple-strain infections are inconsistently addressed in scientific literature.
• Understanding these infections is vital due to their potential impact on host immunity and treatment efficacy.

Purpose of the Study:

• To review the definition, prevalence, and clinical implications of multiple-strain infections.
• To highlight the impact of multiple-strain infections on host-pathogen interactions and disease progression.
• To emphasize the need for considering strain diversity in infection control strategies.

Main Methods:

• Literature review focusing on the definition and prevalence of multiple-strain infections.
• Analysis of existing data on the frequency of multiple-strain infections in human and non-human pathogens.
• Synthesis of theoretical and experimental findings on the effects of multiple-strain infections.

Main Results:

• Multiple-strain infections have been confirmed in 51 human and 21 non-human pathogens, with potential occurrence in most pathogen species.
• Human multiple-strain infections occur at significant frequencies (median 11.3%, mean 21.7%), likely underestimated due to detection limitations.
• These infections can modulate host immune responses, alter disease dynamics through strain competition or cooperation, and facilitate pathogen evolution and gene transfer.

Conclusions:

• Multiple-strain infections significantly influence host-pathogen interactions, disease dynamics, and pathogen evolution.
• Current diagnostic and treatment approaches may be inadequate due to overlooking pathogen strain diversity.
• Incorporating the understanding of multiple-strain infections is essential for advancing infectious disease research and developing novel control strategies.