BISMARCK, N.D. (AP) — North Dakota health officials say the number of confirmed variant cases of the coronavirus has doubled this month and are warning about the possibility of another wave of infections. The state lab has identified 79 total cases of four variants, said Kirby Kruger, director of the Health Department’s Disease Control Division. The includes 50 of the one first identified in the United Kingdom, 28 of the two California variants and one of the South African variant. Total active cases of COVID-19 have nearly doubled in North Dakota and Kruger cites variants as a key factor