Mosquito-Borne Diseases in Australia: What You Need To Know

Mosquito-Borne Diseases in Australia: What You Need To Know

Mosquito-borne diseases pose a growing public health risk across Australia, driven by extreme wet weather and warmer conditions that extend breeding seasons. Japanese encephalitis virus, Ross River virus, Barmah Forest virus, Murray Valley encephalitis, Kunjin virus/West Nile virus and dengue fever are the primary threats businesses and workers should understand. Below, we break down each disease, prevention strategies and workplace obligations for keeping employees safe.

The Mosquito Problem in Australia

Along with long days and beach trips during summer comes something less desirable: mosquitoes. This is mainly due to a changing climate, which has led to more extreme wet weather events. Such conditions are ideal for mosquitoes, providing perfect breeding grounds for these insects. Summer in Australia now starts earlier and lasts longer because of climate change, creating more mosquito breeding opportunities than in previous decades.

Mosquito-Borne Diseases in Australia

The most recent and significant threat to emerge is Japanese encephalitis virus (JEV), first detected during summer 2021 after infecting pigs. This virus raises concerns, as it poses a serious threat to public health nationwide.

Japanese Encephalitis Virus (JEV)

Japanese encephalitis virus was once found only in northern Australia. Recently, however, wet weather conditions have made outbreaks more likely across southern states. This virus was not known to exist in South Australia before February 2022.

JEV is closely related to West Nile, Zika, Murray Valley encephalitis, dengue and yellow fever viruses. It is primarily found across Southeast Asia and Western Pacific regions, with an estimated 68,000 cases occurring yearly worldwide.

Prevention and treatment: No specific treatment exists for JEV, and severe cases can often lead to hospital admission. Vaccination is recommended for priority groups and people living in or travelling to risk areas, as advised by the Communicable Diseases Network Australia. For further guidance, refer to the Australian Government Department of Health and Aged Care.

Several other mosquito-borne diseases are present across Australia that businesses and workers should be aware of. These conditions include:

Ross River Virus (RRV)

Ross River virus is South Australia's most common mosquito-borne disease. It primarily affects animals, but can also infect humans, and is commonly found in native species such as wallabies and kangaroos. Experts believe these animals play a role in spreading infection between mosquito populations.

This virus can cause various symptoms, including:

• Fever and chills
• Joint pain
• Muscle pain
• Fatigue
• Rash
• Swollen lymph nodes

The most common symptom of Ross River virus infection is joint pain, affecting any joint in the body. Wrists, knees, ankles, fingers, elbows, shoulders and jaw are most frequently impacted, with pain varying in severity across different joints. Extreme cases can lead to debilitating conditions lasting months or even years.

Prevention and treatment: No known cure exists for this virus, but there are ways to manage symptoms and promote healing. Paracetamol and anti-inflammatory drugs help reduce pain and swelling, while rest, a balanced diet and light exercise support recovery.

Barmah Forest Virus (BFV)

Barmah Forest virus is another common mosquito-borne disease found throughout Australia. Typically, it causes a milder illness than Ross River virus, sharing similar symptoms. Some people, however, develop a more severe form of the disease leading to long-term complications.

Many people infected with BFV will not develop any symptoms. Others may experience:

• Rash
• Joint pain
• Muscle aches
• Fatigue
• Flu-like symptoms
• Swollen lymph glands

Most people recover completely within a few weeks, though some experience symptoms for several months. In sporadic cases, discomfort may persist beyond a year, but a full recovery remains possible even then.

Prevention and treatment: No specific treatment exists for BFV, though medication and rest help manage symptoms. Most affected individuals recover within weeks, while others experience longer-lasting effects.

Murray Valley Encephalitis (MVE)

Murray Valley encephalitis is a zoonotic flavivirus prevalent in northern Australia and Papua New Guinea. Formerly known as Australian encephalitis or Australian X disease, it can cause severe brain inflammation and, in rare instances, death.

MVE remains a rare disease, with only a small number of human cases reported annually across Australia. Common symptoms include:

• Fever
• Headache
• Vomiting
• Stiff neck
• Drowsiness
• Seizures
• Tremors

Prevention and treatment: No vaccine or specific cure exists for MVE, though medicines can treat milder symptoms such as headache and fever. Individuals with severe symptoms may require hospital-based care for close monitoring.

Kunjin Virus/West Nile Virus Infection

Kunjin virus (KUV)/West Nile virus (WNV) infection results from a viral pathogen endemic throughout tropical parts of Australia. Most reported cases occur in northern regions, including parts of the Northern Territory and Queensland.

Symptoms of Kunjin virus/West Nile virus infection range from mild to severe and may include:

• Fever
• Headache
• Malaise
• Muscle pain
• Rash
• Fatigue
• Swollen lymph nodes

Severe cases can progress to encephalitis (brain inflammation) or meningitis (inflammation of membranes surrounding the brain and spinal cord).

Prevention and treatment: Currently, no specific treatment or vaccine exists for Kunjin virus infection. However, pain relief and anti-nausea medications can ease symptoms and support a more comfortable recovery process.

Dengue Fever

Dengue fever occurs across tropical and subtropical regions worldwide. Though not endemic to Australia, one of its host mosquitoes, Aedes aegypti, is found here. Early dengue cases in Australia were recorded in Townsville during the late 19th century, later appearing across other parts of Queensland and northern New South Wales in the early 20th century.

Dengue fever can cause severe illness and, occasionally, death. Symptoms include:

• High fever
• Severe headaches
• Pain behind the eyes
• Nausea and vomiting
• Muscle and joint pain
• Rash

Prevention and treatment: No antiviral treatment or vaccine is currently available to prevent dengue fever. Personal care combined with environmental management remains the recommended approach for reducing exposure risk.

Notification Requirement for Mosquito-Borne Diseases

Japanese encephalitis, Ross River virus, Barmah Forest virus, Kunjin virus/West Nile virus, Murray Valley encephalitis and dengue fever are all notifiable diseases in Australia. This means suspected cases must be reported to your local public health unit, allowing officials to investigate and provide advice on treatment and prevention. Learn more about broader reporting obligations in our guide on notifiable incidents in Australia.

By law, certain infections must be notified to relevant authorities, with penalties applying for failing to report. Notification allows public health officials to act quickly, preventing further spread while providing information and advice to those who may have been exposed.

Workplace Safety Against Mosquito Bites

JEV outbreaks were reported among pigs across South-Eastern Queensland, New South Wales, Northern Territory, Victoria and South Australia during the first and second quarters of 2022. In response, Safe Work Australia developed new guidance for reducing exposure risk for persons conducting a business or undertaking (PCBU).

As a PCBU, you must take all reasonable measures to eliminate mosquito-borne disease risks. Where elimination isn't possible, minimise exposure as much as practicable through control measures such as:

• Assessing risks of exposure to mosquito-borne illness within your workplace
• Ensuring employees get vaccinated, particularly those within priority groups
• Implementing mosquito control measures, such as removing standing water where mosquitoes lay eggs, and using insect repellent
• Providing workers with training on avoiding mosquito exposure
• Monitoring worker health closely and providing prompt medical treatment if illness develops
• Supplying workers with appropriate personal protective equipment
• Reviewing current workplace policies and procedures related to health and safety, including pest control measures

For related guidance on managing infectious disease risks, see our article on coronavirus workplace health and safety.

Mosquito-Borne Disease Risk Management for Workplaces

Mosquito-borne diseases can significantly impact businesses, causing employees to miss work and customers to avoid affected companies. Businesses therefore need robust health and safety programs to reduce disease transmission risks. Start by utilising safety documentation, such as resources from SafetyDocs, to develop safe systems of work that protect your business. For seasonal context, read our related post on summer and the increase of mosquito-borne diseases.

Safety Management Plan (SMP)

A safety management plan outlines how a business minimises and manages health and safety risks. It identifies who holds responsibility for specific actions and when those actions must occur, while providing a step-by-step guide for identifying, assessing and controlling risks.

Having an SMP in place for mosquito-borne disease safety ensures everyone understands their roles and responsibilities concerning this ongoing issue.

Safe Operating Procedures (SOP)

Safe operating procedures give employees clear instructions for completing tasks safely. Workers with close contact with mosquitoes should follow these procedures diligently to protect themselves from being bitten.

Consider documents such as the Outdoor Work Safe Operating Procedure and Working with Livestock Safe Operating Procedure to support your program.

Waste Management Plans

Wastewater not disposed of properly can create breeding grounds for mosquitoes. Proper waste management plans help businesses ensure their waste doesn't contribute to local mosquito problems.

Emergency Response Procedure

An emergency response procedure should be in place if an employee gets bitten and becomes ill. Say a worker develops seizures — staff should know first aid basics, how to respond, and whom to contact for assistance, such as an ambulance service.

Pest Control Management

Pest control management plans help businesses manage mosquitoes and other pests effectively. A qualified professional should design these programs, ensuring they remain effective and meet your business's specific needs.

Create Your Safety Program With SafetyDocs

A comprehensive health and safety program is essential for protecting workers, customers and your business overall. Utilising safety documents offers an easy pathway toward developing these programs efficiently.

Keep employees safe from mosquito-borne diseases by implementing the right policies and procedures. SafetyDocs by SafetyCulture can help you get started with our templates.

SafetyDocs offers a wide range of content-rich solutions that are:

2022 Compliant

We take compliance seriously, with all documents checked against the latest legislative changes. Our documents are written by an expert team with years of experience managing safety hazards and monitoring compliance. Plus, they all include a free legislation reference list.

Industry-Leading

We are Australia's leading provider of safety documents, offering a wide range of content for different industries. So no matter your business, we have the right solution to keep your workplace safe.

Customisable

You can customise all documents to meet your business's specific needs. For example, add your company logo, colours, and adjust content to ensure relevance to your particular workplace.

Start managing risks from mosquito-borne diseases by using the following templates:

• Mosquito-Borne Disease Safety Plan
• Mosquito-Borne Disease Safe Operating Procedure
• Bites and Stings Prevention and Treatment Safe Work Method Statement — see our guide on when you need a SWMS for more information
• Environmental Site Assessment Checklist

Get started with SafetyDocs today and create a comprehensive health and safety program tailored to your workplace.