Table 2

Distribution of presenting symptoms and causes of illness in two most affected systems (respiratory and gastrointestinal)

Affected system	Respiratory	Gastrointestinal	Total
Sex
Male	23	37	60
Female	30	56	86
Total	53	93	146
Main symptom
Fever	15	16	31
Pain	46	42	88
Diarrhoea, vomiting	0	83	83
Dyspnoea, cough	13	0	13
Other	0	2	2
Total	74	143	217
Cause of illness
Infection	50	24	74
Exercise-induced	0	1	1
Environmental	2	67	69
Other	1	1	2
Total	53	93	146