Despite best efforts from health authorities across the world, it's possible the COVID-19 coronavirus outbreak could continue to get worse in the weeks to come. Although the growth rate of confirmed cases in mainland China has slowed, other countries, such as Italy, South Korea, and Iran, have seen an explosion of incidents.

While the financial markets around the world have responded negatively to this news, smart investors can find a few good investment opportunities in the midst of the situation. In particular, companies that provide health services could have tremendous upside potential as the COVID-19 epidemic continues to unfold.

Here are three companies you should consider adding to your portfolio before the COVID-19 outbreak spreads further.

A stethoscope against the background of a rising stock chart

Image source: Getty Images.

1. CVS Health

CVS Health (NYSE:CVS) has been a bit of an underperformer over the past couple of weeks, shedding about 12% of its market value during the second half of February. While the ongoing COVID-19 epidemic could have played a role, it's just as likely (if not more so) that investors are worried about Democratic presidential candidate Bernie Sanders, who won the Nevada Democratic caucus back on Feb. 22. With Sen. Sanders advocating for a single-payer national health insurance system, health insurance companies face a significant threat to their business should he end up winning the presidential election.

Despite this, management remains quite optimistic for 2020. In CVS's recent fourth-quarter results, the company raised its guidance, projecting annual revenue of $262.0 billion to $265.5 billion, up 2% to 3.5%. The healthcare giant also handily beat analyst estimates for the fourth quarter, bringing in $66.9 billion in revenue as opposed to the $64.0 billion expected by Wall Street.

While the long-term position for CVS looks good, there's a strong case to be made that the company can benefit from the short-term COVID-19 situation as well. Recently, CVS and Walgreens warned Americans that there could be major shortages of hand sanitizer and other cleanliness products as the COVID-19 outbreak gets worse. Short-term sales of products at CVS's retail pharmacies could quickly shoot up over the next few weeks, while visits to its 1,100 or so medical clinics could rise as COVID-19 fears grow.

2. Teladoc

Teladoc Health (NYSE:TDOC) has been one of the big winners in February, with shares ending the month up about 23%. The company has emerged as one of the premier telehealth service providers, allowing doctors and other healthcare professionals to provide medical appointments via videoconferencing technology, whether from a smartphone, computer, tablet, or otherwise. Right now, about 40% of all Fortune 500 companies have a partnership with Teladoc to provide telehealth benefits to their employees.

Revenue has been growing substantially, with 2019 sales coming in at $553.3 million, a 32% increase from the $417.9 million reported for 2018. It's not surprising that investors are excited about the company, and the COVID-19 outbreak has only further fueled the rise of its stock.

A doctor having a teleconference with a patient.

Image source: Getty Images.

Officials from both the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC) said that communities, hospitals, and clinics should increase the use of telehealth service providers as COVID-19 spreads. With medical facilities in countries where outbreaks have worsened -- such as Italy and South Korea -- becoming increasingly crowded, Teladoc could see a surge of appointments from new users in the upcoming weeks and months.

Wall Street analysts have already responded with significant upgrades to Teladoc's stock. Analysts from Cowen and Piper Sandler have increased their price targets for the company by 50% and 63% respectively.

3. 1Life Healthcare

1Life Healthcare (NASDAQ:ONEM), also referred to as One Medical, went public back on Jan. 31 with a lot of fanfare. Shares of the newly minted healthcare stock jumped almost 60% on its first day of trading, but since then, they've given back some of their value.

One Medical charges a $200 annual fee to members, who then have access to over 70 clinics across the country, as well as 24/7 access to the company's digital health services, which include telehealth appointments. As the demand for telehealth services increases, One Medical, like Teladoc, could see a significant boost in new users.

Like most early-stage healthcare technology companies, 1Life Healthcare is reporting a significant loss as it grows. But it's backed by a number of major investors, including Carlyle Group and Alphabet's Google Ventures; the latter is one of 1Life Healthcare's biggest clients, accounting for 10% of its revenue.

Following the confirmation of the first COVID-19-related death on American soil, which occurred in Washington state, U.S. health authorities are becoming increasingly worried about further outbreaks on the West Coast. Concern is increasing because the first patient who died contracted the virus neither from traveling, nor from contact with someone who had traveled recently.

1Life Healthcare has a heavy West Coast presence, headquartered in San Francisco with in-person clinics in Seattle, San Diego, and soon Portland. Should a surge of COVID-19 outbreaks occur in the U.S., 1Life Healthcare is in an excellent position to see a significant surge in customers.