"Begging the Question"-Does Toxocara Infection/Exposure Associate with Multiple Sclerosis-Risk?

Area of Science:

• Neuroimmunology
• Infectious Diseases
• Parasitology

Background:

• The etiology of multiple sclerosis (MS) remains largely unknown.
• Infectious agents, including nematodes, are being investigated as potential contributors to MS.
• Toxocara species are common parasitic roundworms with zoonotic potential.

Purpose of the Study:

• To systematically review and meta-analyze observational studies.
• To evaluate the association between Toxocara infection/exposure and multiple sclerosis (MS).
• To determine the pooled odds ratio (OR) for MS in individuals with anti-Toxocara antibodies.

Main Methods:

• Systematic literature search of public databases.
• Inclusion of observational studies investigating Toxocara and MS.
• Random-effects meta-analysis to calculate pooled odds ratio (OR) and 95% confidence intervals (CIs).

Main Results:

• Six studies involving 473 MS patients and 647 controls were included.
• Seroprevalence of anti-Toxocara IgG antibodies was 13.1% in MS patients versus 4.8% in controls.
• A significant association was found: pooled OR = 3.01 (95% CI: 1.46-6.21).

Conclusions:

• A potential association exists between Toxocara infection/exposure and multiple sclerosis (MS).
• The findings suggest Toxocara may be a risk factor or contributor to MS.
• Further well-designed, controlled studies are needed to confirm this association due to identified publication bias.