Kōrero: Epidemics

Whārangi 6. New epidemics and new vaccines, 1970s to 21st century

Ngā whakaahua me ngā rauemi katoa o tēnei kōrero

Control of diseases

Since the 1970s immunisation programmes have successfully controlled some diseases, such as hib disease (haemophilus influenzae type B, which can cause meningitis and epiglottitis), which has been virtually eradicated. A campylobacteriosis (a gastro-intestinal disease mainly caused by eating chicken that has not been properly cooked) epidemic peaked in 2006 and then abated, probably due to new regulatory standards in the poultry industry.

Ongoing problems

Though epidemics have become less frequent, studies have found that hospital admission and discharge rates for infectious diseases have increased since at least the 1980s. This counters the prevailing wisdom that these diseases have become less of a burden. Because of air travel, New Zealand is no longer an isolated country and has become affected by more diseases as they spread through the world; notably HIV/AIDS, SARS (seasonal acute respiratory syndrome) and influenza. The 2009 influenza A (H1N1 – generally known as swine flu) pandemic caused more than 3,000 cases and 20 deaths in New Zealand. Despite improved uptake of annual influenza vaccination, seasonal influenza epidemics continue to have an impact, especially on older people. On average, about 40 deaths are linked to influenza each year. The 2020 COVID-19 coronavirus pandemic was characterised by influenza-like symptoms and also affected older people disproportionately.

Brain fever

Meningococcal disease is a bacterial disease. It causes meningitis (an inflammation of the protective membranes covering the brain and spinal cord) and septicaemia (blood poisoning). Severe infections can cause shock, coma and death within a few hours if not treated quickly with antibiotics. Meningococcal disease can have serious long-term effects for survivors, including deafness and epilepsy.

Meningococcal disease

An outbreak of meningococcal group A in Auckland in 1985–86 was controlled by mass immunisation. Meningococcal disease reached epidemic proportions in the 1990s and early 2000s.

A new group B epidemic started in 1991 – 78 cases were recorded then, compared to an average of 51 per year (1.5 cases per 100,000 people) prior to this – and quickly became a major outbreak.

The highest infection rates were among Māori and Pacific Island children under five years of age. The upper North Island was the most affected, particularly Northland, Auckland and Rotorua. The epidemic peaked in 2001 with 650 cases (17.4 cases per 100,000 people), and 252 deaths were attributed to meningococcal disease between 1991 and 2007.

Dangerous work

In 2005 scientist Jeanette Adu-Bobie fell ill with meningococcal septicaemia caused by meningococcal B after working in an Environmental Science and Research (ESR) laboratory in Porirua. She had both legs, her left arm and the fingers on her right hand amputated to save her life. Initially, ESR said they could find no link between her workplace and her illness. However, later reports concluded that it was highly likely that this is where Dr Adu-Bobie caught the disease. She received compensation of $117,000.

A new vaccine developed specifically for the New Zealand strain of meningococcal group B was introduced in 2004. More than 1.1 million children and young adults were immunised. This was one of New Zealand’s largest mass-immunisation campaigns and involved schools, primary health care providers and district health boards. It cost over $200 million. Reported cases declined from 342 in 2004 to 105 (1.7 per 100,000) in 2007, by which time the epidemic was regarded as controlled.

HPV immunisation

In the 21st century the Ministry of Health developed new vaccination programmes to protect future generations from highly prevalent viruses that were associated with particular health risks. In 2008 it introduced a programme that made vaccination against the HPV (Human Papillomavirus) available to young women born in 1990 and 1991. This was directed at protecting girls from the sexually transmitted HPV virus before they became sexually active. HPV has been linked to carcinoma of the cervix and invasive cancer. In 2017 this vaccine became free to everyone aged 9–26. Those under 15 receive two doses of the vaccine, six months apart. HPV virus has also been linked to increased risk of cancers of the mouth and tongue.

Me pēnei te tohu i te whārangi:

Geoff Rice, 'Epidemics - New epidemics and new vaccines, 1970s to 21st century', Te Ara - the Encyclopedia of New Zealand, http://www.TeAra.govt.nz/mi/epidemics/page-6 (accessed 30 November 2020)

He kōrero nā Geoff Rice, i tāngia i te 5 May 2011, reviewed & revised 15 May 2018