Review for 10.1186/s12876-023-02880-7 (2023)

Title: Clinical factors associated with acute abdominal symptoms induced by gastric anisakiasis:
A multicenter retrospective cohort study
Version: 1 Date: 13 Jun 2023
Reviewer's report:
I very much enjoyed reading the MS that brings interesting and valuable data, although
conditioned by factors that authors frankly acknowledged at the end.
Some additional results should be presented, although they are not directly important for the
analyses, but I am sure that it will trigger more referencing of the paper.
My comment are following, listed not by importance, but by the sequence they appear in the MS.
Gastric anisakidosis, not anisakiasis: the former includes genera within Anisakidae family, and
the latter only genus Anisakis
Please add the definition of mucosal atrophy, and related causes. It is defined better in the
methodology, but it should be briefly defined at the beginning.
Please define consecutive patients (those there were coming with reinfection, or relapse of
symptoms?) and multiple Anisakis cases.
Please add a figure marking the centres and associate the number of symptomatic and
asymptomatic per centre.
How atrophy, oedema and other histopathological changes were evidenced; biopsy or
endoscopy, or combination? This should be explicitly said. State also the techniques used for
other blood tests analyses.
It is not clear what is the difference between close and open-type atrophy.
Interesting anamnestic data would be time laps of symptoms, e.g., time when they started till
time they stopped for any reasons (treatment, spontaneously…). Is this available just to give
some frequency distribution?
The collected data are very interesting, and authors should make more effort to present it.
Please produce a frequency distribution graph for the number of patients and larvae. In addition,
were all larvae L3? Also, break down the number of cases and frequency distribution of larvae
in patients by year, and compare the incidence among the years and among the centres. Is there
the same incidence over years, and are there centres that show higher incidence?
Please define multiple A. cases.
Of identified larvae, where they all migrating through the stomach wall, or were isolated from
the stomach lumen? It is not clearly written in the results.
Please rephrase, it is not clear which part relates to which: The presence of atrophy in the
Anisakis larvae’s penetrating area and surrounding edema, erythema, or erosion was positive in
43 (20.3%) and 164 (77.4%) lesions, respectively.
If there WBC total was higher in symptomatic, why eosinophils have been higher in the
asymptomatic? Can authors explain this (except the small sample size for asymptomatic)?
It is recognised the division of anisakiasis in gastro/intestinal, ectopic, gastro(allergic) and
asymptomatic-IgE-positive clinical types, while authors mention only GI and allergic. Please
correct this.
Exclude the part in discussion about allergy, as it is not relevant for this study.
“gastrointestinal anisakiasis and anisakis allergy were not clearly separated in a previous report”
– it is not clear to which report authors refer.
Asymptomatic anis. has been studied by Moneo et al. Please refer to his work in Spain to
reference some of your statements.
Higher threshold of pain is demonstrated in females, as they undergo and survive delivery pain.
Try to reformulate the statement please.
Table 2, 3, 5: highlight the stat. sign. and state at what level it was calculated.