Tuesday November 1, 2016
It's been just over six months months on since the recent Zika virus outbreak was declared a Public Health Emergency of international concern, and there have been a string of regular revelations about the virus, since the last London Doctors Clinic update on the Zika virus.
Zika Virus Symptoms
Someone infected with the Zika virus may present with mild flu-like symptoms, although many people do not experience any symptoms at all. However, in the few symptomatic cases, Zika symptoms include fever, rash, headache, joint & muscle pain.
There is no treatment for the Zika infection, as these virus is usually cleared naturally by the body's immune system, with any symptoms passing within a few days.
The major concern with regards to Zika virus exposure, is the effect of the virus on unborn babies, with lots of evidence to support the link between foetal Zika virus exposure and the incidence of the birth defect Microcephaly.
There is currently little evidence to suggest that the Zika virus is harmful to humans otherwise.
Zika Virus Outbreak
This current outbreak initially started in Brazil, with cases then being reported across the South and Central Americas. Since then, cases had been reported around the world from travellers, who had recently visited such Zika-affected areas.
However, there have since been outbreaks in new countries not initially considered part of the Zika-affected areas, meaning people within these regions have contracted the Zika virus locally, with no recent travel history to Central or South America. For example, there have been reports of Zika transmission in Florida of people with no travel history.
Mosquito Transmission of the Zika Virus
The mosquito responsible for Zika transmission, the aedes aegypti mosquito, is also present across the world, namely across sub-saharan Africa, India, South-East Asia, and even some parts of Northern Australia. Aedes aegypti mosquito eggs also been recently discovered in England, as part of enhanced monitoring of mosquito populations across the UK. However, Public Health England maintain that there is "currently no risk to public health in the UK", with no further evidence of this mosquito's presence in the UK.
The distribution of the aedes aegypti moquito, responsible for Zika transmission
Sexual Transmission of the Zika Virus
The virus was initially known to be transmitted by the aedes mosquito, but was also recently discovered to be transmissible by sexual contact. The viral genetic material was first discovered in semen 62 days after onset of infection, with further reports describing Zika virus being present in semen as long as six months after exposure. Equally, reports of Zika virus being present in vaginal secretions have furthered concerns of the virus' ability to spread by unprotected sexual contact.
The confirmation of transmission by sexual contact is a concern, since it was previously thought that the virus was limited by mosquito presence. Sexual transmission of Zika means people in any country around the world could be at risk, should they have unprotected sexual intercourse with someone who has been in contact with Zika by either sexual or mosquito-transmission.
At London Doctors Clinic we offer comprehensive blood tests and urine screens, for either Zika virus RNA (genetic material), or for Zika virus antibodies. These are offered as part of our post-travel screening service, a segment of our blood test service, for recent travellers to Zika-affected areas.
Zika virus PCR testing must be performed up to 14 days post-exposure to the Zika virus - which is often hard to predict which exact mosquito bite during a period of often a few weeks stay in a Zika-affected area. Ideally, this PCR test will be performed on both urine and a matching blood sample, however it's thought that urine samples are slightly more effective in detecting the virus.
The Zika antibodies test can be performed 3 weeks' after exposure - so after 21 days post-return from the Zika-affected area. This tests for both IgM and IgG antibodies. The IgM antibodies are produced immediately after infection, and will likely only be detectable for a few weeks post-exposure. The IgG antibodies, however, take longer to produce, but will remain detectable in the blood for months to years after infection. Therefore, this antibodies test will be able to detect both recent and previous Zika virus infection.
Unfortunately, we at London Doctors Clinic are as yet unable to perform testing for Zika virus on semen samples, or on vaginal fluid samples, although this is something we are hoping will be possible in future.
Who Can be Tested for the Zika Virus?
We are able to facilitate the Zika testing of any patient concerned about Zika virus, regardless of their symptoms, or lack thereof, as only the minority of patients with Zika actually recall experiencing symtoms. If you're unsure as to whether you should get tested for the Zika virus, try following our inforgraphic made as per the advice of our doctors:
Here is a larger version if you are wondering "Should I get Tested for Zika?"
The Future of Zika
Scientists across the world are currently scrambling to catch up on research on the Zika virus, further to the recent outbreak. For example, a new Zika virus prevention method has been developed and trialled across Brazil and Colombia, whereby millions of genetically modified mosquitos have been released, which are infected the bacteria Wolbachia, which inhibit the mosquito's ability to spread viruse - such as Zika and Dengue - to people.
So if you're at all concerned about the Zika virus, or whether or not you should be tested for it, why not book in for a GP-consultation at any private clinic of our 8 across central London. Each fully qualified and affordable Private GP is experienced in counselling and advising patients on the Zika virus, and would be happy to assist.