Transmissable diseases in New Zealand

Find out about the most common and significant transmissible diseases in New Zealand, and the challenges they pose to the workplace.

The spread of communicable diseases is a significant public and occupational health issue, both in Aotearoa New Zealand (New Zealand) and overseas.

New Zealand has had a long history of communicable and deadly disease outbreaks, including influenza, hepatitis, measles, and, more recently, COVID-19 (Rice, 2018; Turnbull, 2022) in which the control and prevention of such diseases has been a constant challenge.

Communicable diseases, also known as infectious diseases or transmissible diseases, are illnesses that result from the infection, presence, and growth of pathogenic (capable of causing disease) biologic agents in an individual human or other animal host (see the World Health Organisation, 2023).

There is evidence that Māori and Pacific people have a higher rate of contracting communicable diseases than other cohorts (MoH, 2020).

There are legal requirements around the surveillance and control of communicable diseases and these are set out under the Health Act (1956). Where surveillance and control is required, public health professionals will guide the population.

As seen with the outbreak of COVID-19, such diseases can place a significant burden on both the employee and employer (Kocakülâh, 2017) and therefore reducing the spread of communicable diseases is essential for ensuring the future health and well-being of both workers, the employers and the general public.

If an outbreak occurs in a workplace this has impacts on absenteeism and reduced productivity. While physical health is affected, there are also psychosocial consequences in relation to loss of work time and psychological distress for those who lose work.

Some examples of transmissible diseases

Hepatitis

Hepatitis is a viral infection that causes inflammation and damage to the liver (Health Navigator New Zealand, 2023).

In New Zealand, Hepatitis A, B, C, and D can be found with varying frequencies. However, Hepatitis C remains the most common (The Hepatitis Foundation of New Zealand, n.d.).

Hepatitis is spread through contaminated blood, bodily fluids, or food and water, making workers in certain industries more susceptible than others.

Workers in healthcare and emergency services, especially, are more at risk due to the nature of their work and the tasks they are expected to undertake (Coppola et al., 2016).

As part of the Communicable Disease Control Manual, the Ministry of Health (Manatū Hauora) (2012) states that employers must assess infected healthcare workers and adjust their duties accordingly. They also reinforce that those who are infected should make healthcare workers aware of their infection before being treated.

Measles

Measles is a highly contagious viral infection that can spread from person to person through respiratory droplets and can cause serious health complications for individuals who are infected.

Measles outbreaks have occurred sporadically in New Zealand, with the most recent being in 2019 (Turner, 2019).

Like other communicable diseases including tuberculosis, measles can survive on surfaces after an infected individual has left the area, which further contributes to the transmission of the infection. An individual remains infectious even when they are not displaying symptoms (WHO, 2023).

In New Zealand, the measles-mumps-rubella (MMR) vaccine is available to children aged 12 months and over to help control outbreaks and serious illnesses caused by measles (Health Navigator, 2023). Efforts from Manatū Hauora to promote vaccination, through the use of public health campaigns and educational initiatives, have helped to increase awareness and improve health outcomes, especially for the Māori population (Wehipeihana et al., 2022).

Tuberculosis

Tuberculosis is serious communicable disease in New Zealand, with incidence rates in recent years have been higher than those in Australia, the United States, and Canada (Verrall, et al., 2020).

There are approximately 300 cases of tuberculosis (TB) diagnosed each year in New Zealand. Almost 4 out of 5 TB cases in New Zealand (2011-2015) were contracted outside of New Zealand (particularly South and Central Asia). In the same period, approximately half of all New Zealand-born cases of TB were of Māori ethnicity (Ministry of Health, 2023c).

TB is spread through droplets transmission through cough, sneezing or splitting. TB can stay inactive in someone’s body for many years before it develops. TB can also spread via aerosol transmission through possums to the rest of livestock on farmland.

Historically, Manatū Hauora has guidance for all aspect of TB care because of the potentially catastrophic consequences of outbreaks.

Influenza

Influenza, commonly known as the ‘flu, is a highly contagious respiratory illness that can spread quickly through workplaces.

Influenza tends to have a greater impact through winter, hospitalising thousands annually (see Ministry of Health (Manatū Hauora), 2023a).

While influenza numbers have dropped exponentially over the last couple of years due to increased health measures and border closures (Turner & Huang, 2020), numbers are expected to rise again with more people arriving in New Zealand. This poses a threat to the health of many individuals as the communal immunity to the illness will be much lower (MoHealth, 2023b).

Symptoms of influenza include coughing, fever, and body aches, and can lead to serious complications, especially in vulnerable populations, such as the elderly or those who are immunocompromised (Keilich, 2019).

Given the highly contagious nature of influenza and the adverse impact it can have on certain groups of people, government health agencies and most workplaces encourage all staff to be vaccinated annually.

COVID-19

Like seasonal flu, COVID-19 and its variants can be transmitted from person to person. The virus is not only spread by aerosol droplets but can also stay on surrounding surfaces for a long time, thereby increasing chances of rapid transmission to a lot of people

COVID-19 has had a significant impact on workplaces worldwide—including New Zealand, where strict strict and proactive measures to manage the spread of the virus were put in place.

While these restrictions have since loosened, WorkSafe and Manatū Hauora still encourage people to take steps to reduce the spread of COVID-19 within the workplace. For example, mask use in small office spaces or busy retail and hospitality areas when adequate social distancing cannot be practised. They also encourage the use of face masks and social distancing when around vulnerable populations, including aged-care facilities and hospitals.

The unprecedented nature of COVID-19 meant that many employers and workers found the restrictions challenging, and they struggled to adjust to ‘hybrid’ and ‘working from home’ roles (Gorjifard & Crawford, 2021). Further, workers in New Zealand who were employed in essential roles experienced poorer well-being outcomes and higher anxiety levels during lockdowns (Bell et al., 2021).

While challenges presented by COVID-19 remain, New Zealand continues to adapt to the ever-changing environment through policies and procedures at the national, sector and workplace levels.