Guinea-Bissau Zika cases not from Americas strain: WHO

September 2, 2016

Zika cases found in Guineau-Bissau do not stem from the virus strain linked to a surge in birth defects in Latin America, the World Health Organization said.

When Guinea-Bissau announced in early July that it had recorded several cases of Zika, it was believed to be the second country in West Africa hit by the so-called Asian strain of the virus after Cape Verde.

That strain has been spreading like wildfire in Latin America since 2015, and has more recently taken hold in Asia, with researchers warning Friday that 2.6 billion people worldwide were in danger of infection.

But in a report published late Thursday, WHO said that "in Guinea-Bissau, the gene sequencing results of the four confirmed Zika cases sent in July have preliminarily confirmed that the cases are of the African lineage."

This, it said, means that the cases were "not (from) the predominant global outbreak Asian lineage."

The African strain of the Zika virus, which takes its name from Uganda's tropical Zika forest where it was first discovered in 1947, has been widespread on the continent since then.

But until recently, Zika caused little concern, as it usually led only to mild, flu-like symptoms, with many Africans appearing to have built up immunity against the virus.

It remains a mystery whether immunity to the African Zika strain can offer protection against the Asian strain.

Benign in most people, Zika has been linked to a form of severe birth defect called microcephaly which causes newborns' heads to be abnormally small.

It can also cause rare adult-onset neurological problems such as Guillain-Barre Syndrome (GBS), which can result in paralysis and even death.

'Further surveillance needed'

In its report, WHO said "investigation of five reported cases of microcephaly" was going on in Guinea-Bissau.

While the African strain of the virus found in the country had "not been associated with microcephaly and other neurologic complications, further surveillance is needed," the UN health agency said.

Since the spread of Zika did not spark concern before the current outbreak began last year, WHO pointed out that little work had been done previously to track the virus and there had been only "very few confirmed cases of the African lineage."

Peter Salama, the WHO's chief on outbreaks and health emergencies, told reporters Friday that the microcephaly cases in Guinea-Bissau had been detected even earlier than the Zika cases, stressing that it remained unclear if they had any connection with the virus.

"At the moment, we don't know the answer," he said.

In an outbreak that started mid-2015, more than 1.5 million people have been infected with Zika in Brazil, and more than 1,600 babies born with abnormally small heads and brains.

Seventy countries and territories have reported local mosquito-borne Zika transmission, with Brazil by far the hardest hit.

WHO declared the outbreak an international public health emergency last February, and the UN agency said Friday that that assessment still stands.

Explore further: Paraguay reports first two cases of Zika birth defect

Related Stories

Paraguay reports first two cases of Zika birth defect

July 27, 2016
Paraguay reported its first two cases Wednesday of babies born with microcephaly linked to the Zika virus, which is blamed for a surge in the birth defect across Latin America.

Guinea-Bissau records first three cases of Zika

July 3, 2016
Guinea-Bissau has recorded three cases of Zika, becoming the second country in West Africa where the dangerous viral disease has been detected, the government said on Saturday.

African Zika cases under control on Cape Verde: health chief

May 24, 2016
The only African cases of the Zika virus strain linked to surging cases of neurological disorders and birth defects are under control on Cape Verde, the Atlantic island's health chief has said.

Zika strain from Americas outbreak spreads in Africa for first time: WHO (Update)

May 20, 2016
The Zika virus strain linked to surging cases of neurological disorders and birth defects in Latin America has now been found in Africa, health officials said Friday, as the first fatality on French territory was reported ...

Guatemala confirms first Zika-linked microcephaly, paralysis

August 17, 2016
The main hospital in Guatemala's capital on Wednesday confirmed the country's first case of a Zika-linked birth defect in a newborn and two cases of a related nerve disorder.

Zika threat lingers in Latin America

August 4, 2016
As the Olympics open this week in Rio de Janeiro, Latin America is still reeling from Zika, the mosquito-borne virus blamed for causing brain damage in babies.

Recommended for you

Groundbreaking investigative effort identifies gonorrhea vaccine candidates

September 19, 2017
Researchers at Oregon State University have identified a pair of proteins that show promise as the basis for a gonorrhea vaccine.

Snail fever progression linked to nitric oxide production

September 14, 2017
Bilharzia, caused by a parasitic worm found in freshwater called Schistosoma, infects around 200 million people globally and its advance can lead to death, especially in children in developing countries.

Systems analysis points to links between Toxoplasma infection and common brain diseases

September 13, 2017
More than 2 billion people - nearly one out of every three humans on earth, including about 60 million people in the United States - have a lifelong infection with the brain-dwelling parasite Toxoplasma gondii.

Study clears important hurdle toward developing an HIV vaccine

September 13, 2017
An international team of researchers has demonstrated a way of overcoming one of the major stumbling blocks that has prevented the development of a vaccine against HIV: the ability to generate immune cells that stay in circulation ...

As 'flesh-eating' Leishmania come closer, a vaccine against them does, too

September 13, 2017
Parasites that ulcerate the skin, can disfigure the face, and may fatally mutilate its victim's internal organs are creeping closer to the southern edges of the United States.

Promising clinical trial results could give doctors a new tool against drug-resistant strains of malaria parasite

September 13, 2017
Tulane University researchers have developed a new drug that is effective against non-severe cases of malaria, according to results from an FDA-supervised clinical trial published in the latest issue of The Lancet Infectious ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.