# Infection or infestation? Clarifying terminology for human and zoonotic food- and waterborne parasites

## TL;DR

This paper clarifies the difference between infection and infestation in parasitology to improve scientific communication and public health understanding.

## Contribution

The paper proposes a clear guideline to distinguish infection from infestation based on parasite multiplication within the host.

## Key findings

- Infection involves parasite multiplication within the host, while infestation does not.
- Protozoa always cause infections due to their need to multiply.
- Helminths usually cause infestations, though some species have exceptions.

## Abstract

The terms infection and infestation are often used interchangeably in parasitology, yet the distinction between them is fundamental to accurate scientific communication. An analysis of recent literature, specifically within the journal Food and Waterborne Parasitology, reveals a predominant use of “infection,” even when describing helminths that do not multiply within the human host, a context where “infestation” would be scientifically more precise. This paper clarifies these definitions, highlights biological exceptions, and proposes a streamlined guideline for human or zoonotic food- and waterborne parasites: “If a parasite multiplies within the host, the process should be termed an infection; if no multiplication occurs, it should be considered an infestation.” Adopting this convention would enhance terminological consistency and stimulate necessary discussion among parasitologists, ultimately benefiting research, clinical practice, and public health communication.

•Infection and infestation are distinct terms; correct use improves parasitology clarity.•Infection involves parasite multiplication within the host; infestation does not.•Protozoa always cause infections due to obligatory multiplication.•Helminths usually cause infestations, with notable species-specific exceptions.

Infection and infestation are distinct terms; correct use improves parasitology clarity.

Infection involves parasite multiplication within the host; infestation does not.

Protozoa always cause infections due to obligatory multiplication.

Helminths usually cause infestations, with notable species-specific exceptions.