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 But Amado isn't Brazilian. She lives on the volcanic archipelago of
Cape Verde, 570 km (350 miles) west of Senegal, and is one of 100
pregnant women in the capital of Praia who have contracted Zika
there.
Their fears, and those of West African authorities seeking to
prepare the region's defenses, are shared by global health experts
who say it could have unknown consequences in countries ill-equipped
for another public health emergency following the Ebola epidemic.
Zika, a mosquito-borne virus, was first identified by two Scots,
virologist George Dick and entomologist Alexander Haddow, in a
forest near Entebbe in Uganda in 1947.
The disease itself is mild and 80 percent of those infected do not
feel ill, but it has shot to the top of the global health agenda
after an outbreak in Brazil was suspected of causing a spike in
birth defects.
And now, nearly 70 years after its discovery in mainland Africa, it
is threatening to return to its roots - this time apparently in a
changed form causing large-scale outbreaks.
"Cape Verde has historical links with Brazil and it seems very
likely it has got there from Brazil," said Nick Beeching of
Liverpool School of Tropical Medicine, a Zika expert for the
European Society of Clinical Microbiology and Infectious Diseases.
According to new data from Cape Verde's health ministry, more than
7,000 cases of Zika have been recorded in the country since the
beginning of the epidemic in October 2015, with heavier than normal
rains last summer boosting mosquito numbers.
Beeching believes it is highly probable Zika will soon be back on
the African mainland, thanks to regular flight connections from the
Atlantic islands, potentially triggering a new chain of
transmission.
Regional health officials told Reuters they were most worried about
Zika being exported to Senegal or Guinea Bissau, which shares the
same Portuguese heritage as Cape Verde.
A regional meeting on Zika took place in Dakar on Feb. 9, with
African and Western partners discussing preparations for possible
imported cases, according to officials.
Abdoulaye Bousso, the coordinator of the health emergency operations
center in Senegal, said his country had an active surveillance
program with several "sentinel sites" being established as early
warning points for an outbreak.
"We do not have cases in the country currently but the risk is
there," he said.
MANY MOSQUITOES
Africa is fertile ground for Zika. Researchers have found more than
20 different mosquito species carrying the virus there, although
whether they all transmit the disease effectively to humans is
unclear.
Ultimately, how much damage Zika may cause on this vast continent
will depend on the level of immunity among African populations - and
that hinges, crucially, on the extent to which Zika's genetic
make-up has mutated on its round-the-world trip.
A warning from World Health Organization experts in a paper
published online on Feb. 9 that the virus "appears to have changed
in character" is heightening concerns.
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The exact nature of the shift has yet to be unraveled but Mary Kay
Kindhauser and colleagues said Zika had altered as it moved through
Asia - from an infection causing limited cases of mild illness to
one leading to large outbreaks and, from 2013 onwards, linked to
babies born with neurological disorders and abnormally small heads.
Jimmy Whitworth, a British-based researcher now at the London School
of Hygiene and Tropical Medicine who studied Zika in Uganda back
when it was still a "virological curiosity", said the ground was
shifting and the risks increasing.
"There are a few genetic differences between the African and Asian
lineages, and it looks like the Asian lineages may be better able to
transmit and flourish in a human population," he told Reuters.
What this means on the ground is uncertain. In theory, there may be
some cross-protection between different Zika strains, which could
protect Africans from the latest version.
But Beeching noted that dengue fever, a closely related
mosquito-borne virus, had four recognized strains and there was only
limited and temporary cross-protection between them. "We just don't
know how Zika will spread if it gets to Africa," he said.
Another big question is why there is no apparent link in Africa
between Zika and birth defects, since the continent has been home to
sporadic cases of Zika for decades, if not centuries or millennia.
It may be that any past cases of small heads in newborns, known as
microcephaly, or of the neurological condition Guillain-Barre
syndrome may have been missed in Africa given its limited healthcare
infrastructure.
But Whitworth hopes to go back and take a retrospective look, since
countries including Malawi, Kenya and Uganda have good population
records, head measurement data and serum banks that should make
checks possible.
Back in Cape Verde's Central Hospital in Praia, clinical director
Maria do Ceu says there is so far no evidence from scans of any
microcephaly among the country's infected mothers-to-be, who are due
to deliver their first babies this month.
Amado is optimistic. "The doctor encouraged me to do morphological
ultrasound and told me that I am okay," she said. "It happened
suddenly. I started having blotchy skin and then I went to the
maternity ward. I was followed up and thank God everything is fine."
(Writing and additional reporting by Kate Kelland in London, with
Emma Farge in Dakar; Editing by Pravin Char)
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