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.

Most people with knee osteoarthritis can control their pain and improve their mobility without surgery, according to updated treatment guidelines from the Australian Commission on Safety and Quality in Health Care.

So what is knee osteoarthritis and what are the best ways to manage it?

More than 2 million Australians have osteoarthritis

Osteoarthritis is the most common joint disease, affecting 2.1 million Australians. It costs the economy A$4.3 billion each year.

Osteoarthritis commonly affects the knees, but can also affect the hips, spine, hands and feet. It impacts the whole joint including bone, cartilage, ligaments and muscles.

Most people with osteoarthritis have persistent pain and find it difficult to perform simple daily tasks, such as walking and climbing stairs.

Is it caused by ‘wear and tear’?

Knee osteoarthritis is most likely to affect older people, those who are overweight or obese, and those with previous knee injuries. But contrary to popular belief, knee osteoarthritis is not caused by “wear and tear”.

Research shows the degree of structural wear and tear visible in the knee joint on an X-ray does not correlate with the level of pain or disability a person experiences. Some people have a low degree of structural wear and tear and very bad symptoms, while others have a high degree of structural wear and tear and minimal symptoms. So X-rays are not required to diagnose knee osteoarthritis or guide treatment decisions.

Telling people they have wear and tear can make them worried about their condition and afraid of damaging their joint. It can also encourage them to try invasive and potentially unnecessary treatments such as surgery. We have shown this in people with osteoarthritis, and other common pain conditions such as back and shoulder pain.

This has led to a global call for a change in the way we think and communicate about osteoarthritis.

What’s the best way to manage osteoarthritis?

Non-surgical treatments work well for most people with osteoarthritis, regardless of their age or the severity of their symptoms. These include education and self-management, exercise and physical activity, weight management and nutrition, and certain pain medicines.

Education is important to dispel misconceptions about knee osteoarthritis. This includes information about what osteoarthritis is, how it is diagnosed, its prognosis, and the most effective ways to self-manage symptoms.

Health professionals who use positive and reassuring language can improve people’s knowledge and beliefs about osteoarthritis and its management.

Many people believe that exercise and physical activity will cause further damage to their joint. But it’s safe and can reduce pain and disability. Exercise has fewer side effects than commonly used pain medicines such as paracetamol and anti-inflammatories and can prevent or delay the need for joint replacement surgery in the future.

Many types of exercise are effective for knee osteoarthritis, such as strength training, aerobic exercises like walking or cycling, Yoga and Tai chi. So you can do whatever type of exercise best suits you.

Increasing general physical activity is also important, such as taking more steps throughout the day and reducing sedentary time.

Weight management is important for those who are overweight or obese. Weight loss can reduce knee pain and disability, particularly when combined with exercise. Losing as little as 5–10% of your body weight can be beneficial.

Pain medicines should not replace treatments such as exercise and weight management but can be used alongside these treatments to help manage pain. Recommended medicines include paracetamol and non-steroidal anti-inflammatory drugs.

Opioids are not recommended. The risk of harm outweighs any potential benefits.

What about surgery?

People with knee osteoarthritis commonly undergo two types of surgery: knee arthroscopy and knee replacement.

Knee arthroscopy is a type of keyhole surgery used to remove or repair damaged pieces of bone or cartilage that are thought to cause pain.

However, high-quality research has shown arthroscopy is not effective. Arthroscopy should therefore not be used in the management of knee osteoarthritis.

Joint replacement involves replacing the joint surfaces with artificial parts. In 2021–22, 53,500 Australians had a knee replacement for their osteoarthritis.

Joint replacement is often seen as being inevitable and “necessary”. But most people can effectively manage their symptoms through exercise, physical activity and weight management.

The new guidelines (known as “care standard”) recommend joint replacement surgery only be considered for those with severe symptoms who have already tried non-surgical treatments.

I have knee osteoarthritis. What should I do?

The care standard links to free evidence-based resources to support people with osteoarthritis. These include:

• education, such as a decision aid and four-week online course
• self-directed online exercise and yoga programs
• weight management support
• pain management strategies, such as MyJointPain and painTRAINER.

If you have osteoarthritis, you can use the care standard to inform discussions with your health-care provider, and to make informed decisions about your care.

Belinda Lawford, Postdoctoral research fellow in physiotherapy, The University of Melbourne; Giovanni E. Ferreira, NHMRC Emerging Leader Research Fellow, Institute of Musculoskeletal Health, University of Sydney; Joshua Zadro, NHMRC Emerging Leader Research Fellow, Sydney Musculoskeletal Health, University of Sydney, and Rana Hinman, Professor in Physiotherapy, The University of Melbourne

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