Singapore 'extremely vulnerable' to Zika virus: Experts

938LIVE reports: Two infectious disease experts say any Zika virus outbreak in Singapore could potentially overshadow the number of dengue cases seen this year.

Monica Kotwani, 938LIVE Channel NewsAsia 20 Jan 16;

SINGAPORE: The Republic is "extremely vulnerable" to the Zika virus, which is spreading throughout Central and South America, said two infectious disease experts.

Speaking to 938LIVE, they said any outbreak in Singapore could potentially overshadow the large number of dengue cases seen this year.

They further recommended that doctors should start documenting the travel history of patients with fever, and test them for the Zika virus should they test negative for dengue. Authorities have been stepping up the fight against a rising number of dengue cases.

Should it be introduced in Singapore, tackling the Zika virus could prove to be challenging, the experts said. The Zika virus is spread by the Aedes mosquito, which is also responsible for transmitting dengue.

According to authorities, the Aedes mosquitoes are breeding in growing numbers in Singapore, due to record high temperatures.

To date, no cases of Zika virus have been reported in Singapore, according to a journal published by the Ministry of Health (MOH) in 2014. Zika is not a legally notifiable disease under the Infectious Diseases Act - this means that patients with the virus are not required to report their condition to the authorities within a prescribed time.

ZIKA’S RAPID SPREAD

In South America, the rapid spread of the virus after eight years of laying low has taken many by surprise, and could be a warning closer to home. In Brazil, about 1.5 million people are thought to have contracted the virus, almost as many as those who have contracted dengue.

The virus has symptoms similar to dengue and chikungunya, such as fever with or without a rash, joint pains and headaches. Unlike dengue, the virus has not been associated with deaths in adults.

However, experts 938LIVE spoke with said they are still concerned. It may be associated with the Guillain-Barre syndrome, a rare neurological condition, and it could also affect pregnant women.

Professor Annelies Wilder-Smith, an Emerging Infectious Diseases expert at Nanyang Technological University's Lee Kong Chian School of Medicine, said the outbreak in Brazil has shown that there is probably a link between the virus and pregnancy-related infections.

She added: “Infection during pregnancy has affected the unborn. Unfortunately, it causes malformations including microcephaly, which is a very small head circumference.

“Several children have already died. This is the main concern and why we are so scared of the Zika virus."

There are already fears Zika could spread to the United States. The US Centers for Disease Control and Prevention (CDC) has recommended that pregnant women consider postponing their travel to areas where the transmission of Zika is ongoing.

Currently, there is no vaccine to prevent the infection of Zika, said MOH in the journal. Patients would usually be given medication to manage symptoms such as fever and joint pain.

Travellers visiting places where human cases of Zika have been reported would be advised to protect themselves from mosquito bites, such as by using insect repellent and wearing long-sleeved garments, said MOH.

Zika virus can cause fever, rash, joint pain and conjunctivitis, with symptoms usually lasting under a week, but in pregnant women, the virus can spread to the fetus and cause brain shrinkage or death. (AFP/Nelson Almeida)

LOCAL REACH OF VIRUS

With globalisation, Prof Wilder-Smith said it is a matter of time before the first imported case of Zika virus is found in Singapore.

It could be spread in Singapore if a person infected overseas arrives in Singapore, and is bitten by an Aedes mosquito. That mosquito could go on to infect other people.

An outbreak could overshadow the current spread of dengue cases, and Prof Wilder-Smith said this is because the population here is “totally non-immune … to the Zika virus”.

However, there is also a chance it could already be here. Professor Duane Gubler, who is with the Duke-NUS Medical School's Emerging Infectious Diseases Programme, said the virus could have been previously misdiagnosed as dengue.

He said: "Zika virus is a close relative of dengue. They both belong to the same genus and same family. They both cause a similar illness and therefore they're misdiagnosed.

“Zika has been known in the region. It's very likely Zika has been circulating silently in places like Indonesia, Malaysia and most likely Singapore. I don't know, it's all speculation. But it's not unlikely that that was occuring.”

Prof Wilder-Smith also said awareness has to be stepped up. "We need to increase awareness among clinicians to also look for Zika in travellers who return with a febrile illness from countries that are currently having Zika virus circulation,” she said.

“Furthermore, all of us need to keep abreast of developments because it's evolving."

Prof Gubler, who also chairs the National Environment Agency’s Dengue Expert Advisory Panel, agrees that physicians must stay vigilant while considering Zika in their diagnoses.

He said authorities need to intensify mosquito control, but that researchers should also look at developing a vaccine for the virus, which could become an important public health problem if indeed microcephaly is linked to it.

- 938LIVE/xk