Why am I hearing about Cyclospora Infection (Cyclosporiasis) in the news?
There is currently an outbreak of Cyclospora in USA. Cyclospora is an intestinal parasite that is known to cause gastroenteritis. The US Centre for Disease Control and Prevention(CDC) has confirmed over 6,700 cases (at the time of writing) of the Cyclospora parasite that causes diarrhoea, nausea and other gastrointestinal symptoms and it was investigating over 11,500 possible cases.
If you’ve recently returned from overseas with persistent diarrhoea, stomach cramps or unexplained fatigue, you may have heard reports of Cyclospora infections affecting travellers. Although Cyclospora remains relatively uncommon in Australia, international travel and imported fresh produce mean Australians can occasionally become infected.
At Crown St Medical Centre in Surry Hills, our experienced GPs regularly assess patients with gastroenteritis, travel-related illnesses and prolonged diarrhoea. Early diagnosis is important because Cyclospora is frequently missed if doctors are not specifically looking for it.
Whether you live in Surry Hills, Darlinghurst, Paddington, Redfern, Waterloo, Green Square or Woollahra, our team can investigate persistent gastrointestinal symptoms, organise appropriate laboratory testing, provide effective treatment and help prevent complications.
What is Cyclospora?
Cyclospora is an intestinal parasite known scientifically as Cyclospora cayetanensis. It causes an illness called cyclosporiasis (also known as cyclosporiasis), an infection of the small intestine leading to prolonged watery diarrhoea and gastrointestinal symptoms.
Unlike many bacterial causes of food poisoning, Cyclospora infections often last for weeks or even months if untreated.
The parasite is transmitted through ingestion of contaminated food or water. Importantly, a person who has recently become infected cannot immediately infect another person because the parasite requires time in the environment to become infectious.
This means household spread is uncommon compared with viral gastroenteritis such as norovirus.
Why Has Cyclospora Been in the News in the USA?
The United States experiences seasonal outbreaks almost every year, particularly during the warmer months.
The US Centers for Disease Control and Prevention (CDC) has investigated multiple outbreaks linked to imported fresh produce including:
- Fresh basil
- Coriander (cilantro)
- Salad leaves
- Mixed lettuce
- Raspberries
- Snow peas
- Sugar snap peas
- Fresh herbs
Many outbreaks involve produce imported from countries where Cyclospora is endemic.
Because contaminated produce is often distributed widely before illness is recognised, hundreds of people may become infected during a single outbreak.
American public health authorities continue to monitor outbreaks closely each summer because cases have increased substantially over the past decade.
Is Cyclospora a Threat in Australia?
Fortunately, Australia has relatively few locally acquired Cyclospora infections.
Most Australian cases occur in:
- International travellers
- Recent migrants
- Individuals returning from endemic countries
- Occasionally from imported food products
The risk for someone living in Surry Hills who has not travelled internationally remains very low.
However, increasing international food imports and overseas travel mean Australian doctors remain alert for Cyclospora in patients presenting with persistent diarrhoea.
Your GP may consider Cyclospora if:
- You recently travelled overseas
- Symptoms have persisted longer than one week
- Routine stool cultures are negative
- There is no obvious alternative diagnosis
Where is Cyclospora Found?
Cyclospora is more common in tropical and subtropical regions including parts of:
- Central America
- South America
- Mexico
- Caribbean
- Southeast Asia
- Nepal
- India
- Pakistan
- Papua New Guinea
- Middle East
- Some African countries
Travellers consuming uncooked fruit, salads or untreated water are at increased risk.
How Does Cyclospora Spread?
People become infected after swallowing mature Cyclospora oocysts.
Transmission usually occurs through:
Contaminated Fresh Produce
The most common source worldwide.
Examples include:
- Herbs
- Leafy greens
- Berries
- Fresh vegetables
Contaminated Water
Unsafe drinking water may contain the parasite.
Food Handling
Fresh foods washed with contaminated water may transmit infection.
Importantly, Cyclospora is not usually spread directly from person to person, unlike many viral diarrhoeal illnesses.
Symptoms of Cyclospora Infection
Symptoms usually develop approximately one week after exposure.
The hallmark symptom is persistent watery diarrhoea.
Other symptoms include:
- Frequent loose stools
- Abdominal cramping
- Bloating
- Excessive gas
- Nausea
- Reduced appetite
- Weight loss
- Fatigue
- Low-grade fever
- Muscle aches
- Headache
Many patients describe symptoms that improve temporarily before returning again over several weeks.
Without treatment, illness may continue for several weeks or even months.
Why Can Cyclospora Be Difficult to Diagnose?
Cyclospora can easily be mistaken for:
- Irritable bowel syndrome
- Viral gastroenteritis
- Food poisoning
- Giardia infection
- Inflammatory bowel disease
- Microscopic colitis
Routine stool cultures performed for bacterial gastroenteritis will not detect Cyclospora.
Specific laboratory testing is required.
This is why informing your GP about recent overseas travel is extremely important.
Who is Most at Risk?
Although anyone can become infected, certain groups are more vulnerable.
International Travellers
Travelling to endemic countries remains the largest risk factor.
People Eating Raw Produce
Fresh salads, herbs and berries may pose a higher risk than cooked foods.
Immunocompromised Patients
People living with:
- HIV
- Cancer
- Organ transplants
- Immunosuppressive medications
may develop more severe or prolonged illness.
Older Adults
Dehydration can develop more quickly.
Young Children
Children are more susceptible to dehydration from prolonged diarrhoea.
Pregnant Women
Although Cyclospora has not been shown to directly harm pregnancy, dehydration and nutritional deficiencies can affect maternal health.
When Should You See a GP?
Book an appointment promptly if you experience:
- Diarrhoea lasting longer than 7 days
- Bloody diarrhoea
- Fever
- Severe abdominal pain
- Significant weight loss
- Signs of dehydration
- Persistent diarrhoea after overseas travel
- Ongoing fatigue after gastroenteritis
Investigations Available in Australia
Australian pathology laboratories DO NOT routinely investigate Cyclospora when clinically suspected.
Your GP may recommend:
Stool PCR Testing
Many modern multiplex gastrointestinal PCR panels detects parasites but does not routinely screen for Cyclospora. Your GP may refer to your local Public Health Unit for advice on testing and treatment.
Stool Microscopy
Special staining techniques can identify Cyclospora oocysts.
These require the laboratory to specifically examine for parasites.
Stool Ova, Cysts and Parasites Examination
Often requested when:
- Travel history
- Persistent diarrhoea
- Suspected parasitic infection
are present.
Blood Tests
Although blood tests cannot diagnose Cyclospora directly, they may assess:
- Electrolytes
- Kidney function
- Inflammatory markers
- Nutritional status
- Liver function
Treatment of Cyclospora
Cyclospora is highly treatable.
First-Line Treatment
The recommended treatment is:
Trimethoprim-sulfamethoxazole (TMP-SMX)
This antibiotic combination is highly effective.
Symptoms often improve within several days.
Hydration
Maintaining fluid intake is essential.
Patients may require:
- Oral rehydration solution
- Increased fluids
- Electrolyte replacement
Nutrition
During recovery, patients should eat:
- Simple carbohydrates
- Bananas
- Rice
- Toast
- Lean protein
Avoid excessive dairy and alcohol until symptoms resolve.
Alternative Treatments
Patients allergic to sulfonamide antibiotics require specialist advice because alternative treatments are generally less effective, and management may involve infectious diseases consultation.
Possible Complications
Untreated Cyclospora may result in:
- Chronic diarrhoea
- Weight loss
- Dehydration
- Malnutrition
- Fatigue
- Reduced quality of life
Complications are more likely in immunocompromised individuals.
Can Cyclospora Be Prevented?
Prevention focuses on food and water safety.
Travellers should:
- Drink bottled or treated water where appropriate
- Wash hands frequently
- Peel fruit where possible
- Avoid raw herbs if hygiene is uncertain
- Wash fresh produce thoroughly
- Choose well-cooked foods
Is Cyclospora Contagious?
Direct spread between family members is uncommon.
The parasite must mature in the environment before becoming infectious.
Good hand hygiene remains important to prevent many gastrointestinal infections.
Cyclospora Compared with Other Causes of Diarrhoea
| Condition | Typical Duration | Antibiotics? |
| Viral gastroenteritis | 1–3 days | No |
| Salmonella | Several days | Sometimes |
| Campylobacter | 5–7 days | Sometimes |
| Giardia | Weeks | Yes |
| Cyclospora | Weeks to months untreated | Yes |
When Should You Seek Emergency Care?
Seek urgent medical attention if you develop:
- Severe dehydration
- Confusion
- Persistent vomiting
- Bloody diarrhoea
- Severe abdominal pain
- High fever
- Inability to keep fluids down
Why Choose Crown St Medical Centre?
At Crown St Medical Centre, our experienced GPs provide comprehensive assessment of:
- Persistent diarrhoea
- Gastrointestinal infections
- Travel medicine
- Foodborne illness
- Dehydration
- Tropical diseases
- General practice care
Patients from Surry Hills, Darlinghurst, Paddington, Redfern, Waterloo, Green Square and Woollahra can access evidence-based assessment, pathology referrals and appropriate treatment.
If you have recently travelled overseas or are experiencing ongoing gastrointestinal symptoms, early assessment can help reach a diagnosis sooner and reduce the duration of illness.
Book an Appointment Online with Crown St Medical Centre if you are concerned about persistent diarrhoea, travel-related illness or dehydration.
Frequently Asked Questions
- What causes Cyclospora infection?
Cyclospora is caused by the parasite Cyclospora cayetanensis, usually acquired from contaminated food or water.
- Can I catch Cyclospora from another person?
Direct person-to-person spread is uncommon because the parasite must mature in the environment before it becomes infectious.
- Is Cyclospora common in Australia?
No. Most Australian cases are associated with overseas travel or, less commonly, imported food products.
- How long does Cyclospora last?
Without treatment, symptoms may persist for weeks or even months. Appropriate antibiotic treatment usually shortens the illness.
- How is Cyclospora diagnosed?
Diagnosis is made using specialised stool tests, such as PCR panels or ova, cysts and parasite examinations. Routine bacterial stool cultures alone do not detect Cyclospora.
- What is the treatment for Cyclospora?
The first-line treatment is trimethoprim-sulfamethoxazole (TMP-SMX), along with maintaining hydration and supportive care.
- Who is most at risk of severe illness?
Travellers to endemic regions, people with weakened immune systems, older adults, young children and those with prolonged dehydration are at greater risk.
- When should I see a GP?
Seek medical advice if diarrhoea lasts more than a week, you have recently travelled overseas, or you develop dehydration, significant weight loss, fever or persistent abdominal pain.
- Can Cyclospora be prevented?
Practising good hand hygiene, drinking safe water while travelling and washing or peeling fresh produce can reduce the risk of infection.
- Can Crown St Medical Centre help?
Yes. Our GPs can assess persistent gastrointestinal symptoms, arrange appropriate investigations, provide treatment where indicated and coordinate specialist referral if needed.
Last medically reviewed: 4 August 2026
Reviewed by: Doctors at Crown St Medical Centre – Surry Hills Doctors & GPs
Location: Crown Street, Surry Hills NSW
