Warehouse club retailer Costco’s net income rose 1.1% to $266m (£163.3m) for the first quarter ending November 22.

Net sales increased 5.5% to $16.92bn (£10.39bn). Excluding fuel and the effects of currency fluctuations, comparable store sales were up 2% in the US and 8% internationally.

The retailer has also been hit by an increase in healthcare costs for its employees, as staff turnover has dropped from 20% to 12%.