Zika on the mind

Fighting the constant dengue battle,can Sri Lanka take on another Aedes aegypti borne disease?

by Carol Aloysius

With the number of Zika cases now spreading across 24 countries, several thousands being found to be positive for the mosquito borne disease, and the disease being linked with abnormalities in brain development in pregnancy and autoimmune illness, there has been a dramatic change in the perception of researchers and experts probing the virus and its impacts.

Previously regarded as a very mild illness causing just a slight rash and fever, and with no significant long-term complications, Zika has now become a virus of grave concern.

So what causes Zika? How is it transmitted? How is it treated? How can we prevent it? And should we be worried in Sri Lanka? The Sunday Observer asked these questions from several health experts and this is what they had to say.

According to Dr Paba Pallihawadana, Chief of Epidemiology Unit , Zika is an emerging disease caused by the Aedes aegypti, the same mosquito that causes dengue, chikengunya and yellow fever. The Unit has compiled a fact sheet on the virus, which is now available on its website.

Dr Pallihawadana said, the virus was transmitted in humans through the bite of an infected Aedes species mosquito. "This is a day time mosquito, which bites people who live indoors and outdoors and inhabit places close to large human populations.

When a mosquito feeds on a person already infected by the virus, it can become infected and in turn infect non infected persons by biting them and passing on the virus to them," he said.

Diagnose

When questioned how the disease is diagnosed, she said, people living in areas where there is ongoing transmission of Zika, who develop a fever rash, pain around the eye, red eyes, and joint pains, are suspected of having contracted the virus and are diagnosed through a test called PCR (Polymercase Chain Reaction), a virus location from blood samples.

She said there is no specific treatment for the virus, as there is still no vaccine to treat or prevent it. Treatment is based on the symptoms, she said, explaining, "Usually our advice is for patients to get plenty of fluids to keep their bodies hydrated, and rest. Medicines to relieve symptoms such as paracetamol will help give relief to pain and fever. At no time should patients take aspirin, which thins the blood, and other non steroidal and anti inflammatory drugs (NSAIDS) like ibuprofen and naproxen."

She said if the symptoms persist, patients are urged to contact a government registered medical practitioner for advice.

Dr Sarath Amunugama, Deputy Director General Public Health, meanwhile said all precautions were in place to meet any emergency with regard to a Zika outbreak in Sri Lanka. "Although we have not imposed travel restrictions, we are advising travellers from Sri Lanka to infected countries on what to wear - long sleeved clothes and what to carry- insect repellents and to always sleep under a mosquito net. We are also advising pregnant women to stay away from those countries until their babies arrive".

Dr. Amunugama said Sri Lanka had long experience in dealing with communicable diseases such as dengue and much strides had been made in diagnosis, treatment and prevention methods recently. "We have 20 or more sentinel hospitals and all our hospitals and their staff has been informed what to do in the case of any patient with a communicable disease," he said.

Control

When asked how the spread of Zika can be controlled, he said the best way was by reducing the number of breeding sites for this mosquito. "Reducing the source and contact between mosquitoes and people can help to bring the disease under control. Keeping your gardens clean of small containers like yoghurt cups and plastic bags, repairing broken drains, cleaning roof tops and gutters, can go a long way in reducing the mosquito population in your neighbourhood, as the Aedes aegypti mosquito is essentially a domestic insect which can fly only around 15 metres, he said, elaborating that if someone's neighbour has a mosquito that is infected with either the dengue virus or say the virus that causes chickungunya or even Zika, that person can be infected as well when it flies into your garden!

Dr A.M.R. Thowfeek, Director, Dengue Control Unit Director said the Zika threat had not yet reached any Asian country, but agreed that Sri Lanka need to be vigilant. Since the same mosquito causing Zika also caused the outbreaks of chickungunya (he denied it was spreading in the country at present) and dengue, which he admitted was still prevalent in certain identified areas, he noted that mosquito breeding sites needed to be reduced immediately due to the change in weather patterns and the sudden showers of heavy rains followed by bright sunshine.

"This is the ideal ground for mosquito breeding. So make sure there are no pools of rain water in your garden and even the holes in trees are covered to prevent mosquitoes breeding. Fish tanks help. But most of all inculcate the sense of responsibility to keep your house and surroundings clean, in every member of your family - from the youngest to the oldest".

He said the Unit had embarked on surveillance and better diagnostics as well as prevention and prediction of the spread of the aegypti mosquito to previously uninfected regions in the context of climatic change, had resulted in a sharp drop in the number of dengue cases in the past few months.

According to Epidemiology Unit statistics, 4685 suspected cases of dengue had been reported in January this year. Approximately 52 percent were from the Western Province, with Colombo District heading the list with 1533 cases. The Municipal Council area in Colombo reported 512 cases with a total of 1533 including other areas in Colombo.

Dr Thowfeek said the Health Ministry will commence a mosquito control programme involving other stake holders and the Tri Forces and Local Government personnel on February 11,12 and 13.

Vigilance

WHO Country Representative for Sri Lanka, Dr Jacob Kumalesan, who expressed similar views on Zika said it did not require hospitalisation since it was a self limiting disease . However, due to the very strong evidence now available of a link between Zika and neurological disorders leading to shrunken brains in babies born to infected mothers or in infected countries, which had been well documented in Brazil, it was necessary to be vigilant.

At present he said, the disease had spread to 24 countries mostly in Latin America and the Caribbean, where too there had been a parallel increase in abnormalities in brain development in pregnancy and autoimmune illness. He said no vaccine had been developed yet and the causative link too required more research, which would take several years.

He assured that Sri Lanka had all the equipment and testing kits to meet with any emergency and that the Health Ministry had already initiated the necessary steps to raise awareness and initiate control measures from the point of arrival from an infected country.

"The main thing is not to panic unnecessarily. We believe that all those with symptoms such as we have described, will act responsibly and visit their nearest doctor for advice".