Bergen Brunswig, an Orange-based, diversified distributor of health-service and consumer-electronics products, reported that net earnings rose to $7.8 million for the first quarter ended Nov. 30. That compares to a profit of $2.9 million posted a year earlier. Net sales and other revenues from continuing operations increased 5%, to $828 million from $785 million for the first quarter last year. Sales and earnings results of the prior year have been restated to reflect the previously reported discontinuance of the company's medical supply business. Commtron Corp., Bergen Brunswig's consumer electronics subsidiary, experienced a rebound from the fourth quarter of fiscal 1987, although sales and earnings results were significantly below those of the same quarter last year, the company said.