The Zika Epidemic Has Just Begun

Now with 189 confirmed locally-transmitted cases. Certainly, there are many more still unknown and yet to come.

In fact, its spread had already been happening for a while under our noses. The Zika test takes three hours to show if a patient is positive or negative for the virus. The first suspicion was on Aug 22, when a GP in Aljunied raised the alarm over a series of suspicious cases to MOH. MOH believed it was a mild viral illness, and asked that further cases be brought to the Communicable Disease Centre (CDC). Then on Aug 25, a 47-year-old woman, Patient A, was referred to the CDC and was confirmed to be infected (ST’s report said she went to CDC on Aug 26, Today says Aug 25). All past cases in the area were dug up and tested and it turned out that people were being infected as far back as July 31. MOH announced Patient A on Aug 27. The other 55 cases were announced on Aug 28 and Aug 29.



The answer to questions posed to MOH about why two days passed between Patient A presenting herself to the CDC and the first announcement was vague.

Since Zika was “almost inevitable”, and since an imported case had already been reported in May, shouldn’t the ministry already have been expecting to see locally-transmitted cases? Why were blood tests not carried out as soon as the GP in Aljunied reported a suspicious trend of viral infections? Why were blood tests not carried out for all individuals presenting such symptoms – did the ministry have to wait for a trend to develop?

MOH said that since the affected persons did not travel to infected countries, they were considered low-risk. This is why they did not test them immediately. The ministry chose to wait and see. Yet it is known that only one in five Zika-infected persons actually presents symptoms. With confirmed infections in places like Thailand and Vietnam, should Singapore not already have begun to treat Zika symptoms more seriously? Why was an individual’s lack of travel to Zika-affected areas a factor that puts them at low risk?

MOH said that there was no cover up for the rash of Zika infections, a question raised in light of the Hepatitis C outbreak last year. In that case, 16 ministry and hospital staff were disciplined for, among other faults, withholding the announcement of the outbreak.

But it is hard to test for a disease that doesn’t present itself in a very unique way. Sometimes the fever is not present. It is hard, but should MOH have set a higher bar?

Dr Leong Hoe Nam, the infectious diseases specialist at Mount Elizabeth Novena Hospital who diagnosed Singapore’s first Zika case in May, thinks that MOH should have done better.

“Every single mild case of fever, they should have investigated,” said Dr Leong, “It was a chance to break the cycle. Kudos to the GP who picked up the trend. We must remember that Zika is very mild, compared to dengue. Patients may not be sick enough to go to hospital but to the GP instead. So the GP now is the gatekeeper.”

Ms Tin Pei Ling, who is the MP for the ward that Patient A lives in, said, “It would have been most ideal to take a more conservative approach at that point in time, if there had been early suspicion, to check if there were any positive cases. But I suppose MOH would have taken the balanced approach between alarming everyone and doing proper checks.”

Would we have been alarmed? The number of cases, 41, is high compared to other countries in the region. It is low, however, when compared with the more deadly dengue, for which there have been nearly 11,000 cases, of which majority were probably locally-transmitted, since the start of this year.

Perhaps it is time we started acting as if Zika could well have traveled beyond the Aljunied cluster. That’s how it got spread so far in the first place, isn’t it?

UK, US, Australia, Japan and Taiwan issue travel advisories for Singapore as Zika cases rise.

AUSTRALIA TRAVEL ADVISORY:
There is ongoing transmission of Zika virus in Singapore. All travellers should protect themselves from mosquito bites. Adopt additional measures advised by the Department of Health, including deferring non-essential travel if pregnant, avoiding pregnancy for two months following your return and other advice for both males and females (see Health). The level of advice has not changed. We continue to advise Australians to exercise normal safety precautions in Singapore.

Pregnant woman in S'pore tests positive for Zika

UPDATED: AUGUST 31, 2016

SINGAPORE — A pregnant woman living in the Aljunied Crescent/Sims Drive area has tested positive for Zika virus infection, the Ministry of Health (MOH) announced on Wednesday (Aug 31) night. This is the first such case in Singapore.

“Her doctor is following up close with her to monitor her health and the development of her baby,” said the MOH. The woman, who tested positive on Wednesday, will be referred to a maternal-foetal medicine specialist for counselling and advice, said the ministry.

The news comes a day after the MOH announced free testing at public healthcare institutions for pregnant women with Zika symptoms or who have partners with the virus, as well as those recommended by their doctors.

The MOH had also issued an advisory on pregnancy and Zika on Tuesday. Noting that Zika could have more serious consequences for pregnant women — their children could be born with microcephaly — the MOH said that pregnant women diagnosed with Zika would be referred to a maternal-foetal medicine specialist for counselling and advice.


MORE ON THE DANGER OF ZIKA:

Much of the focus around the mosquito-borne Zika virus has been on pregnant women and brain abnormalities in fetuses, but now scientists think some adult brain cells could be vulnerable too. Infections may even be as destructive as Alzheimer’s disease.
By engineering mice to mimic the human Zika infection, and using fluorescent biomarkers to tag infection sites, scientists at the Rockefeller University and La Jolla Institute for Allergy and Immunology found that adult neural progenitor cells could be hijacked by the virus, leading to brain shrinkage and mental impairment.

“Our results are pretty dramatic – in the parts of the brain that lit up, it was like a Christmas tree,” said Professor Joseph Gleeson, head of Laboratory of Pediatric Brain Disease at The Rockefeller University, in a released statement about the new study. “It was very clear that the virus wasn't affecting the whole brain evenly, like people are seeing in the fetus.”

Gleeson said in healthy individuals, neural progenitor cells become fully formed neurons and are resistant to Zika, but for some people with weakened immune systems, they may be vulnerable to the virus.

The mature brain, Gleeson said, is learning, and memory that is impacted by Zika could bring about a cognitive decline that is normally associated with Alzheimer's disease or depression.

“In the adult, it's only these two populations that are very specific to the stem cells that are affected by virus. These cells are special, and somehow very susceptible to the infection,” Gleeson said. “Based on our findings, getting infected with Zika as an adult may not be as innocuous as people think.”

“Zika can clearly enter the brain of adults and can wreck havoc,” said Sujan Shresta, a professor at the La Jolla Institute of Allergy and Immunology. “But it’s a complex disease. It’s catastrophic for early brain development, yet the majority of adults who are infected with Zika rarely show detectable symptoms. Its effect on the adult brain may be more subtle, and now we know what to look for.”

But scientists said it raises the disturbing possibility of long term mental impairment in Zika-infected adults.

“The virus seems to be travelling quite a bit as people move around the world,” said Gleeson. “Given this study, I think the public health enterprise should consider monitoring for Zika infections in all groups, not just pregnant women.”

The epicenter of the current Zika epidemic is Brazil, where the Olympic Games were in full swing in Rio de Janeiro just a couple of weeks ago.

In February, the World Health Organization declared the outbreak a “public health emergency of international concern,” as evidence grew of Zika's association with birth defects.

The virus is chiefly spread by the Aedes aegypti mosquito, which is common throughout the tropical and subtropical Americas.

The new findings were published in Cell Stem Cell on August 18.

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