TABLE 1.

Primary exposure and proxy variables for parasitic infections and allergic outcomes used in the analysis

Variables	Description of measures	Reference ranges and variable coding
Helminth exposure
Ascaris IgE	Antibody isotype immune responses to A. lumbricoides	(Present) or high IgE ≥0.35 kU/L = 1 (Absent) or low/normal IgE <0.35 kU/L = 2
Ascaris eggs	Eggs detected in stool specimens	Yes = 1 No = 2
Trichuris eggs	Eggs detected in stool specimens	Yes = 1 No = 2
Allergy‐related disorders	Asthma and rhinitis	Yes = 1 No = 2
Total IgE	Serum total IgE	Low <70 kU/L = 2 High ≥70 kU/L = 1
Eosinophils	Pro‐inflammatory white blood cells for parasitic infections or allergic reactions	Low/normal <0.35 × 106 cells/ml = 2 High ≥0.35 × 106 cells/ml = 1
IgE Atopy	Allergen‐antigen‐specific immunoglobulin E measurements	Allergic ≥0.175 kU/L = 1 Non‐allergic <0.175 kU/L = 2
IgE fx3	Food‐antigen‐specific immunoglobulin E measurements	Allergic ≥0.175 kU/L = 1 Non‐allergic <0.175 kU/L = 2
Asthma recall	Participant's description of ever experiencing symptoms indicative of asthma such cough, wheeze, shortness of breath and chest tightness and the isiXhosa name ‘umbefu’ and/or current/past clinician prescription of medication for such, at any stage in life	Yes = 1 No = 2
Rhinitis recall	Participant description of ever experiencing symptoms indicative of rhinitis such as sneezing, itching, nasal congestion, runny nose and postnasal drip; and the isiXhosa name for rhinitis ‘umfinxizo’ and/or current/past clinician prescription of medication for such at any stage in life	Yes = 1 No = 2

Abbreviations: IgE fx3, immunoglobulin E food allergy screen; IgE, immunoglobulin E.