By Alan Baldwin

MONZA, Italy (Reuters) - Outbreaks of the mosquito-borne Zika virus in Singapore and Malaysia have barely registered with Formula One drivers due to race there this month but there is some concern behind the scenes.

Five of the last eight rounds of the championship are in regions where Zika has been reported -- Singapore and Malaysia before Texas and Mexico in October and Brazil in November.

Authorities in Singapore said they had detected 151 people with Zika as of midday Thursday. The first locally-transmitted infection was reported on Saturday.

The floodlit Singapore Grand Prix, one of the most popular races on the calendar and held at night in the steamy city state, is scheduled for Sept. 18 with team staff, sponsors and media there for days before.

While teams have had plenty of time to prepare for Brazil, and Texas has had no reported cases of Zika transmitted by mosquitoes, sources indicated Singapore could pose more of a logistical headache if key staff opt out at short notice on medical advice.

Those willing to discuss their plans at the Italian Grand Prix said they had not experienced any late pullouts so far, however.

"We are supplying anti-mosquito products and long-sleeved outfits and we have sent yesterday a brief to everybody about how to take care and all the why, what and how about it," McLaren Racing Director Eric Boullier told Reuters.

"Everybody is going," he added.

Manor racing director Dave Ryan said his team were taking the 'normal precautions'.

"We've briefed all the guys, we're offering them the option of wearing long-sleeved garments and obviously supplying them with the right protection...and just making them as informed as they possibly can be," he told Reuters.

"And it's fine. We're comfortable with it."

The Zika virus, which has spread through the Americas and the Caribbean since late last year, has been linked to microcephaly - a severe birth defect in which babies are born with abnormally small heads and underdeveloped brains.

Several countries, including the United States, have warned pregnant women or those trying to have children not to travel to Singapore, where the race promoter has said planning for the event is going ahead "as per normal".

Williams' Finnish driver Valtteri Bottas, who was in Brazil last month for the Rio de Janeiro Olympics where swimmer girlfriend Emilia Pikkarainen was competing, was one of those drivers unaware of the Singapore outbreak.

"I haven't heard about it...I'll need to keep the overalls on, then," he said. "I'm still going. That's for sure."

Nico Rosberg, the German who is battling Mercedes team mate Lewis Hamilton for the title and who became a father for the first time last year, expressed more concern.

"As a family man now I will be very interested and I will look into it," he told Reuters when asked about Singapore. "I started discussions on it already yesterday, actually."

(Reporting by Alan Baldwin, editing by Toby Davis)