In Clinical Q & A (GP, 19 May), a question asked: 'A colleague working in Saudi Arabia has found an isolated elevation in ALT in up to 40 per cent of population screened.'
May I suggest that brucellosis be considered as a possible cause for ALT elevation before the lab recalibrates its ALT test?
It has a high prevalence in Saudi Arabia due to the ingestion of unpasteurised camel, goat and sheep milk in nomadic communities. Brucella can take six weeks to culture and poses infectious risks to laboratory staff.
Serology is not without false negatives. Thus the infection is often difficult to pick up unless one is specifically looking for it.
Dr Sarah Thio, West Newton, Somerset.