With outbreaks of several strands on the rise, it may be time to brush up on the causes of, vaccinations, and cures for hepatitis.

Weighing in at over 3 pounds, your liver is one of the largest organs you have. It’s also one of the busiest.

For instance, it’s your liver that converts the nutrients in foods you eat into substances your body can use. It helps produce the proteins that help your blood clot. And thanks to your liver, your body can produce up to 1,000 ml — over 4 cups — of bile each day. This yellow-green digestive liquid breaks down and helps your body absorb fats.

Long story short, a liver that works well is vital to your health, and one of the biggest threats to it is an inflammatory condition known as hepatitis.

If that rings a bell, it’s because hepatitis A has been in the news a lot recently. From California to Tennessee, outbreaks are on therisein the United States and around the globe. (One Australian woman recently died from it aftereating recalled pomegranate seeds.)

With that in mind, it’s probably (past) time to educate yourself aboutallthe strains of hepatitis, the best ways to prevent infection, and the treatments for each that are available today.

Unwashed produce. Raw shellfish from contaminated water. A sick food handler who didn’t wash their hands before preparing your meal. These are just a few ways you can contract hepatitis A (HAV). The virus isspread through foodor water that contains microscopic amounts of stool from someone who’s infected . (It can also be spread through some types of sex.)

“Most people never think about hepatitis A, but outbreaks [in the news] show how vulnerable we are, even for people who have no risk factors, unless you consider going to a 4thof July picnic risky,” said Dr. Nancy Reau, a hepatitis expert at Rush University Medical Center in Chicago and a member of the American Liver Foundation’s National Medical Advisory Committee. “HAV is foodborne so it can affect anyone.”

You’ll know it if you get sick. HAV symptoms include stomach upset, diarrhea, fever, and jaundice (yellowed skin and eyes) that can last several months.

What you need to know:“You can’t get HAV from a toilet seat,” said Dr. Rudolph Bedford, a gastroenterologist at Providence Saint John’s Health Center in Santa Monica, California, who’s had several patients ask.

Still, it’s important to avoid coming into contact with water that’s contaminated with fecal matter.

“总是洗手soap and water after you go to the bathroom, or changing a diaper,” Bedford said.

The good news:While HAV often passes on its own within a few months, and most people make a full recovery , it can be prevented with a simple vaccine shot. The vaccine’s recommended for all children one year or older,if you’re travelingto a country where HAV is common (such as Africa, Asia, and South or Central America) or you have a condition thatputs you at high riskof infection.

“Personally, I think it should be part of a general health exam,” said Dr. Douglas Dieterich, professor of liver disease at Icahn School of Medicine at Mount Sinai in New York and a member of the American Liver Foundation’s National Medical Advisory Committee. “No vaccine is 100 percent [effective], but it’s as close as you can get.”

You can’t get this strain of hepatitis by eating a bad salad. HBV is only transmitted through blood or other body fluids. An infected mother will give it to her baby, for instance. Sharing needles puts you at risk , too.

If left untreated, HBV can lead to cirrhosis and liver cancer, each of which can be potentially fatal . But what can make HBV tricky to catch is that many people don’t have symptoms . Not to mention,only 25 percentof adults are vaccinated against the disease.

What you need to know:HBV isn’t new — not by a long shot. Last spring,researchersfrom the University of Cambridge in England found an extinct strain of the virus in remains of Bronze Age skeletons across Europe and Asia.

“In 600 years, [HBV] has adapted extremely well to man. Obviously, it’s very smart,” said Dieterich.

Up to2.2 millionAmericans today are infected with HBV, according the U.S. Department of Health and Human Services, and that number is on the rise.

The good news:A vaccine for HBV has been available since the 80s and when administered correctly, is 95 percent effective . But “because it requires 3 shots over 6 months, only 50 percent of people get the last shot,” said Dieterich. “Over six months, they forget about it.”

Last year, anew HBV vaccinewas approved by the U.S. Food and Drug Administration. HEPLISAV-B is the only 2-dose HBV shot for adults, both of which can be completed within a month.

Still, you may have to ask for it. “Most primary care providers will think of the hepatitis vaccine if you say you’re traveling to a high-risk country, but they may forget that immunity should be considered in all patients,” Reau said.

If you were born in a foreign country, have had multiple sex partners, used drugs, or had transfusions, talk to your doctor.

And if you’re diagnosed with HBV, there’s still reason to be optimistic. “In the next five years,” said Dieterich, “we’ll probably have a cure.”

Contrary to online rumors you may have read, hepatitis C can’t be spread through hugging or kissing an infected person. It’s not present in breastmilk, and you won’t get sick by sharing lip balm with someone else. HCV is a bloodborne virus , which means you get it by coming into contact with the blood of someone who already has it.

It’s possible (although not common) that you could get HCV by using someone’s razor. A tattoo shop that doesn’t properly sterilize their needles could expose you too, as could sharing needles through drug use.

HCV is sometimes also transmitted sexually. HIV-infected men who have sex with other men are at highest risk .

Like HBV, HCV can be tough for doctors to spot. 80% of people who have it show zero symptoms, sometimes for decades. “The virus has a way of reducing the immune system response to its presence,” said Dieterich.

What you need to know:If you think you’re at risk of HCV — for example, you have tattoos and piercings, have HIV, inject or snort drugs, or have received a blood transfusion — ask your doctor to screen you with a simple blood test. Getting diagnosed early is key to preventing more serious liver problems down the road.

You can also get tested outside your medical network, for instance, at a health fair. If you donate blood, always provide your contact information. That way, if something turns up during your blood screening, you’ll be notified.

The good (and bad) news:Treatments for chronic HCV have come a long way over the last few years. “There was a time when it was cause for a liver transplant. Quite frankly, we’re now able to cure it with one pill for 12 weeks. That’s how far we’ve come,” said Bedford.

90 percent of people can be successfully treated, and with minimal side effects . Yet, HCV drugs aren’t getting to all the people who need them.

When researchers at the Perelman School of Medicine at the University of Pennsylvania combed through over 9,000 prescriptions sent to a national specialty pharmacy for 15 months, they found that 52.4 percent of private insurers denied claims for life-saving HCV drugs. Medicaid denied 34.5 percent of patients and Medicare said no to nearly15 percent.

“These denials are due in part to the high cost of the HCV antivirals and insurers’ concerns [about] these drugs inflating their budgets,” said Dr. Vincent Lo Re III, MSCE, an associate professor of disease and epidemiology at U Penn and senior author of the study.

“Fewer than 10 percent of chronic HCV patients receive treatment,” said Re. “From a public health standpoint, these denials make elimination of HCV, which is feasible, quite difficult to achieve.”

Although HDV, also known as “hepatitis delta,” is considered the most severe form of hepatitis, it’s what’s known as an “incomplete” virus. It requires hepatitis B to copy itself. That means you can only get HDV if you have HBV .

Of the estimated 240 million people in the world who have hepatitis B, as many as20 millionof them may also have HDV.

What you need to know:An HBV vaccine can protect you against this particular strain of hepatitis. And, in fact, “the only treatment for HDV is treating for HBV,” Dieterich said.

The good news:Over a dozen drugs are currentlyin developmentto treat HDV. For instance, Lonafarnib, a drug originally meant to treat different kinds of cancer, may be able to stop HDV from replicating itself. Testing will begin inclinical trialsthis year.

Hepatitis E (HEV)

Like hepatitis A, HEV is transmitted through infected food and water . It’s rare in the United States but common in other countries where water and sanitation are in short supply .

What you need to know:Like HAV, HEV is fecal-oral transmitted. “Super sanitation — hand washing, making sure you eat cooked food — can go a long way towards preventing it,” said Dieterich.

Because some types of HEV have been linked to pork, boar, and deer meat, take care to eat fully cooked food when you travel to other countries. Avoid drinking water that hasn’t been purified .

The good news:Like HAV, HEV typically goes away on its own without specific treatment. One day, a shot to prevent it may even be available through your doctor’s office. A HEV vaccine is already licensed in China .