Zika virus may ‘linger in semen for up to 2 months after symptoms fade’, raising fears of sexual transmission
- Man found to have traces of Zika in his semen 2 months after infection
- 68-year-old infected in Cook Islands returned to the UK in 2014
- Tests revealed he had the virus in his blood, and subsequent samples revealed it was still present in his semen at 27 and 62 days post infection
- Raises fears the virus could be transmitted via sexual contact, experts say
- Officials in Texas confirmed a case of sexual transmission last week
- But, it remains rare, with only one other case ever recorded, experts note
- For more of the latest on the Zika virus visit www.dailymail.co.uk/zikavirus
The Zika virus may lurk in a man’s semen long after any symptoms of the disease disappear, experts today warned. It raises fears the disease, which is spreading through the Americas, could be spread via sexual contact.
Last week, health officials in Texas confirmed the first known case of sexual transmission of Zika during this outbreak, which started early last year. Sexual transmission of the virus is very rare. Prior to the Texas cases there is just one other report of the disease being spread via sexual contact.
In 2008, a researcher from Colorado caught the virus overseas, and apparently his wife then became infected when he returned. The discovery of the virus in the semen of a British man two months after he was first infected with Zika, now adds to the evidence.
The 68-year-old man became infected in 2014, while he was in French Polynesia, researchers at Public Health England noted. They said he began to complain of a fever, lethargy, and developed a rash – all indicative of the virus – after returning from the Cook Islands. He was tested for the virus while he still had a fever, and low levels of Zika were detected in blood samples.
Subsequent tests of semen showed positive results at 27 days, and 62 days after the start of the man’s symptoms. The findings were reported in Emerging Infectious Diseases, published by the US Centers for Disease Control and Prevention.
The scientists note that though they detected Zika in the man’s semen samples, they did not grow active virus from that sample in the laboratory.
It suggests that while present in the man’s semen, it was unlikely to have proven a route of transmission.
But, the researchers note: ‘Although we did not culture infectious virus from semen, our data may indicate prolonged presence of virus in semen, which in turn could indicate a prolonged potential for sexual transmission of this flavivirus.
‘Moreover, these findings could inform decisions regarding what control methods are implemented and which specimen types are best suited for diagnostic detection.’
Last month Public Health England advised male travelers returning from Zika-affected countries to use condoms during sex, if their partner was pregnant or was planning on becoming pregnant. Experts advise men use condoms for up to six months if they were diagnosed as having Zika virus.
Men returning from affected countries with no symptoms, and no formal diagnosis, are advised to use condoms for 28 days, PHE officials said.
Responding to the case in Texas, last week, Dr Derek Gatherer, lecturer in biomedical and life sciences at Lancaster University, said: ‘The main implication is that unprotected sex should be avoided both when visiting affected areas, and also after recovery from any feverish illness contracted during visits to such an area until absence of virus in seminal fluid can be confirmed.’
Furthermore Professor Luis Cuevas, of the Liverpool School of Tropical Medicine said though the risk of sexual transmission is rare, the advise is for people diagnosed with Zika virus to use condoms for six months after infection.
Those people who fear they may have been exposed, though not confirmed, should use condoms for one month after returning from an infested area, he added.
‘There is no systematic information on the duration of excretion of the virus in sexual secretions and studies are needed to document whether it remains infectious beyond a few weeks,’ Professor Cuevas said.
‘It is thus advisable adults exposed to Zika follow the recommendation of using condoms until more information becomes available.’
More often, sufferers become infected after being bitten by a mosquito carrying the virus.
In the vast majority of cases the virus triggers mild symptoms, including fever, rash, joint pain and conjunctivitis.
However, the World Health Organisation yesterday declared the current outbreak of Zika virus, predominantly in South America, a global public health emergency.
WHO director-general Dr Margaret Chan said she was moved to do so, after growing evidence the virus can trigger potentially life-threatening birth defects in newborn babies.
In assessing the level of threat, Dr Chan said 18 experts and advisers looked in particular at the strong association, in time and place, between Zika infection and a rise in cases of microcephaly – where a baby is born with a small or incomplete brain.
Dr Chan said: ‘The experts agreed that a causal relationship between Zika infection during pregnancy and microcephaly is strongly suspected, though not yet scientifically proven.’