You might have heard of something called “cryptosporidiosis” recently, closely followed by warnings to stay away from your local swimming pool if you’ve had diarrhoea.

More than 700 cases of this gastrointestinal disease were reported in Queensland in January, which is 13 times more than in January last year. Just under 500 cases have been recorded in New South Wales this year to-date, while other states have similarly reported an increase in the number of cryptosporidiosis infections in recent months.

Cryptosporidiosis has been listed as a national notifiable disease in Australia since 2001.
But what exactly is it, and should we be worried?

What causes cryptosporidiosis, and who is affected?

Cryptosporidiosis is the disease caused by the parasite Cryptosporidium, of which there are two types that can make us sick. Cryptosporidum hominis only affects humans and is the major cause of recent outbreaks in Australia, while Cryptosporidium parvum can also affect animals.

The infection is spread by spores called oocysts in the stools of humans and animals. When ingested, these oocysts migrate and mature in the small bowel. They damage the small bowel lining and can lead to diarrhoea, nausea, vomiting, fever and abdominal discomfort.

Most people develop symptoms anywhere from one to 12 days after becoming infected. Usually these symptoms resolve within two weeks, but the illness may last longer and can be severe in those with a weakened immune system.

Children and the elderly tend to be the most commonly affected. Cryptosporidiosis is more prevalent in young children, particularly those under five, but the disease can affect people of any age.

So how do we catch it?

Most major outbreaks of cryptosporidiosis have been due to people drinking contaminated water. The largest recorded outbreak occurred in Milwaukee in 1993 where 403,000 people were believed to have been infected.

Cryptosporidium oocysts are very small in size and in Milwaukee they passed through the filtration system of one of the water treatment plants undetected, infecting the city’s water supply. As few as ten oocysts can cause infection, making it possible for contaminated drinking water to affect a very large number of people.

Four days after infection a person with cryptosporidiosis can shed up to ten billion oocysts into their stool a day, with the shedding persisting for about two weeks. This is why one infected person in a swimming pool can infect the entire pool in a single visit.

Cryptosporidium oocysts excreted in the faeces of infected humans and animals can also reach natural bodies of water such as beaches, rivers and lakes directly through sewer pipes or indirectly such as in manure transported with surface runoff after heavy rain.

One study which modelled Cryptosporidium concentrations in rivers around the world estimated there are anywhere from 100 to one million oocysts in a litre of river water.

In Australia, cryptosporidiosis outbreaks tend to occur during the late spring and early summer periods when there’s an increase in recreational water activities such as swimming in natural water holes, water catchments and public pools. We don’t know exactly why cases have seen such a surge this summer compared to other years, but we know Cryptosporidium is very infectious.

Oocysts have been found in foods such as fresh vegetables and seafood but these are not common sources of infection in Australia.

What about chlorine?

Contrary to popular belief, chlorine doesn’t kill off all infectious microbes in a swimming pool. Cryptosporidium oocysts are hardy, thick-walled and resistant to chlorine and acid. They are not destroyed by chlorine at the normal concentrations found in swimming pools.

We also know oocysts can be significantly protected from the effects of chlorine in swimming pools by faecal material, so the presence of even small amounts of faecal matter contaminated with Cryptosporidium in a swimming pool would necessitate closure and a thorough decontamination.

Young children and in particular children in nappies are known to increase the potential for disease transmission in recreational water. Proper nappy changing, frequent bathroom breaks and showering before swimming to remove faecal residue are helpful ways to reduce the risk.

Some sensible precautions

Other measures you can take to reduce yours and others’ risk of cryptosporidiosis include:

• avoid swimming in natural waters such as rivers and creeks during and for at least three days after heavy rain
• avoid swimming in beaches for at least one day after heavy rain
• avoid drinking untreated water such as water from rivers or springs. If you need to drink untreated water, boiling it first will kill the Cryptosporidium
• avoid swallowing water when swimming if you can
• if you’ve had diarrhoea, avoid swimming for at least two weeks after it has resolved
• avoid sharing towels or linen for at least two weeks after diarrhoea has resolved
• avoid sharing, touching or preparing food that other people may eat for at least 48 hours after diarrhoea has resolved
• wash your hands with soap and water after going to the bathroom or before preparing food (Cryptosporidium is not killed by alcohol gels and sanitisers).

Not all cases of diarrhoea are due to cryptosporidiosis. There are many other causes of infectious gastroenteritis and because the vast majority of the time recovery is uneventful you don’t need to see a doctor unless very unwell. If you do suspect you may have cryptosporidiosis you can ask your doctor to refer you for a stool test.

Vincent Ho, Associate Professor and clinical academic gastroenterologist, Western Sydney University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Sea moss is the latest “superfood” wellness influencers are swearing by. They claim sea moss products – usually in gel form – have multiple health benefits. These include supporting brain and immune function, or protecting against viruses and other microbes.

But do these health claims stack up? Let’s take a look.

What is sea moss?

Sea moss is produced using a kind of seaweed – particularly red algae – that grow in various locations all around the world. Three main species are used in sea moss products:

• Chondrus crispus (known as Irish moss or carrageenan moss)
• Eucheuma cottonii (sea moss or seabird’s nest)
• Gracilaria (Irish moss or ogonori).

Some products also contain the brown algae Fucus vesiculosus (commonly known as bladderwrack, black tang, rockweed, sea grapes, bladder fucus, sea oak, cut weed, dyers fucus, red fucus or rock wrack).

Most sea moss products are sold as a gel that can be added to recipes, used in smoothies, frozen into ice cubes or eaten on its own. The products also come in capsule form or can be purchased “raw” and used to make your own gels at home.

What’s the evidence?

Sea moss products claim a host of potential health benefits, from supporting immunity, to promoting skin health and enhancing mood and focus, among many others.

But is there any evidence supporting these claims?

Recent studies have reviewed the biological properties of the main sea moss species (Chondrus crispus, Eucheuma cottonii, Gracilaria and Fucus vesiculosus).

They suggest these species may have anti-inflammatory, antioxidant, anticancer, antidiabetic and probiotic properties.

However, the vast majority of research relating to Chondrus crispus, Gracilaria and Fucus vesiculosus – and all of the research on Eucheuma cottonii – comes from studies done in test tubes or using cell and animal models. We should not assume the health effects seen would be the same in humans.

In cell and animal studies, researchers usually administer algae in a laboratory and use specific extracts rich in bioactive compounds rather than commercially available sea moss products.

They also use very different – often relatively larger – amounts compared to what someone would typically consume when they eat sea moss products.

This means the existing studies can’t tell us about the human body’s processes when eating and digesting sea moss.

Sea moss may have similar effects in humans. But so far there is very little evidence people who consume sea moss will experience any of the claimed health benefits.

Nutritional value

Eating sea moss does not replace the need for a balanced diet, including a variety of fruits and vegetables.

Chondrus crispus, Eucheuma cottonii and Gracilaria, like many seaweeds, are rich sources of nutrients such as fatty acids, amino acids, vitamin C and minerals. These nutrients are also likely to be present in sea moss, although some may be lost during the preparation of the product (for example, soaking may reduce vitamin C content), and those that remain could be present in relatively low quantities.

There are claims that sea moss may be harmful for people with thyroid problems. This relates to the relationship between thyroid function and iodine. The algae used to make sea moss are notable sources of iodine and excess iodine intake can contribute to thyroid problems, particularly for people with pre-existing conditions. That is why these products often carry disclaimers related to iodine sensitivity or thyroid health.

Is it worth it?

So you may be wondering if it’s worth trying sea moss. Here are a few things to consider before you decide whether to start scooping sea moss into your smoothies.

A 375mL jar costs around $A25–$30 and lasts about seven to ten days, if you follow the recommended serving suggestion of two tablespoons per day. This makes it a relatively expensive source of nutrients.

Sea moss is often hyped for containing 92 different minerals. While there may be 92 minerals present, the amount of minerals in the algae will vary depending on growing location and conditions.

The efficiency with which minerals from algae can be absorbed and used by the body also varies for different minerals. For example, sodium is absorbed well, while only about 50% of iodine is absorbed.

But sea moss has also been shown to contain lead, mercury and other heavy metals – as well as radioactive elements (such as radon) that can be harmful to humans. Seaweeds are known for their ability to accumulate minerals from their environment, regardless of whether these are beneficial or harmful for human nutrition. Remember, more doesn’t always mean better.

What else am I eating?

While you won’t get a full nutritional breakdown on the jar, it is always wise to check what other ingredients you may be eating. Sea moss products can contain a range of other ingredients, such as lime, monk fruit powder, spirulina and ginger, among many others.

These ingredients differ between brands and products, so be aware of your needs and always check.

Despite their health claims, most sea moss products also carry disclaimers indicating that the products are not intended to diagnose, treat, cure or prevent any disease.

If you have concerns about your health, always speak to a health professional for accurate and personalised medical advice.

Margaret Murray, Senior Lecturer, Nutrition, Swinburne University of Technology

This article is republished from The Conversation under a Creative Commons license. Read the original article.