A fifth case of monkeypox has been detected in New Zealand, the Ministry of Health has confirmed.

The person had recently returned from overseas and is now isolating in the Auckland region.

Manatū Hauora confirmed the case on Saturday evening, and said there was no evidence of community transmission and public health staff had determined the risk for the country is low.

The Ministry said it has been providing advice over the last few week to public health units and sexual health clinics to help with identifying potential cases.

The government has secured more than 500 courses of monkeypox medicine but no date has been set for them to become available.

The World Health Organisation declared a global health emergency for monkeypox in July, and has confirmed more than 50,000 cases globally, with a small number of deaths.

What is monkeypox and how do you catch it?

Monkeypox was previously a rare little-known infection, but this year cases began occuring more widely globally. In the UK there have been around 3000 confirmed cases since May, and the US Centres for Disease Control reports almost 20,000 cases.

Infections are usually mild and the risk to the general population is low, but stocks of a vaccine to guard against the virus are limited.

Monkeypox is caused by the monkeypox virus, a member of the same family of viruses as smallpox, although it is much less severe and experts say chances of infection are low.

It occurs mostly in remote parts of central and west African countries, near tropical rainforests. In those regions, there have been more than 1200 cases of monkeypox since the start of the year.

Two main strains of the virus - west African and central African - are known to exist, and it's the milder one from west Africa which is now circulating in other regions of the world.

The unusually high numbers of people infected with monkeypox outside of Africa with no travel links to the region, means community is occuring in some places, including the UK and USA.

What are the symptoms?

Initial symptoms include fever, headaches, swellings, back pain, aching muscles.

Once the fever breaks a rash can develop, often beginning on the face, then spreading to other parts of the body, most commonly the palms of the hands and soles of the feet.

The rash, which can be extremely itchy or painful, changes and goes through different stages before finally forming a scab, which later falls off. The lesions can cause scarring.

The infection usually clears up on its own and lasts between 14 and 21 days.

Most cases of the virus are mild, sometimes resembling chickenpox, and clear up on their own within a few weeks.

Monkeypox can sometimes be more severe. At least twelve people have died worldwide with it in the most recent outbreak.

How do you catch it?

Monkeypox can be spread when someone is in close contact with an infected person. The virus can enter the body through broken skin, the respiratory tract or through the eyes, nose or mouth.

It has not previously been described as a sexually transmitted infection, but it can be passed on by close contact.

UK medical authorities are advising anyone with the virus to abstain from sex while they have symptoms.

While there is currently no available evidence that monkeypox can be spread in sexual fluids, people confirmed to have the virus are advised to use condoms for eight weeks after infection as a precaution.

It can also be spread by contact with infected animals such as monkeys, rats and squirrels, or by virus-contaminated objects, such as bedding and clothing.

Are gay men at greater risk?

Although some of the cases have been seen in gay and bisexual men, anyone who comes into close contact with someone who has monkeypox could potentially get the virus.

The UK Health Security Agency (UKHSA) has said "a notable proportion" of the recent cases in the UK and Europe have been found in gay and bisexual men "so we are particularly encouraging them to be alert to the symptoms and seek help if concerned".

How common are outbreaks?

The virus was first identified in a captive monkey and since 1970 there have been sporadic outbreaks reported across 10 African countries.

In 2003 there was an outbreak in the US, the first time it had been seen outside Africa. Patients caught the disease from close contact with prairie dogs that had been infected by small mammals imported into the country. A total of 81 cases were reported, but none resulted in deaths.

In 2017, Nigeria experienced the largest known outbreak. There were 172 suspected cases and 7 percent of victims were men between 21 and 40 years old.

What is the treatment?

Outbreaks can be controlled by infection prevention.

Vaccination against smallpox has been proven to be 85 percent effective in preventing monkeypox.

Antiviral drugs may also help and the NZ has secured about 500 doses of one, called tecovirimat, for this.

-RNZ with BBC (sources WHO and UKHSA)