Annette Zimmermann, VP analyst, told iTWire in response to a query that this prediction was made on the assumption that factories would stop production from 28 January to 14 February.
"At this point we can only assume that things will be under control on 14 February and production can proceed as normal then," she added.
If this was the case, then overseas sales would not be affected, Zimmermann said.
Apple, which has more than 40 stores in China and depends the country for about a fifth of its total sales, has closed mainland stores and corporate offices until 9 February.
Beijing has asked many factories to stay shut until 10 February. But Reuters reported that a number of companies had kept manufacturing going. Among them was Huawei which resumed work on Monday, this being restricted to the southern province of Guangdong.
The agency also reported that Foxconn, a major production site for Apple and other vendors, could see a big hit to production if the factory closure went for another week.
It said until now Foxconn had faced only a small impact and had been using factories from Vietnam, India and Mexico to fill the shortfall.
But despite the numbers of infections rising, some companies in Wuhan, the epicentre of the outbreak, have continued production, with one among being Yangtze Memory Technologies.
iTWire also contacted tech research firms Canalys and Counterpoint Research for their take on the impact of the virus. If they do reply, their responses will be added here.