Zika Virus Infections: More Data Show Zika Viremia In Mothers, Fetal Infection Link [VIDEO]

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Dec 08, 2016 09:35 AM EST

The study conducted an investigation into the influence of both oxytocin and vasopressin, which is said to be a hormone linked to social bonding, on the brain function in human fathers. (Photo : Getty Images/ Mario Tama)

Spanish researchers reported more evidence of Zika replication in the fetus or placenta, reporting persistent viremia lasting for more than 100 days after manifestation of symptom in a mother of a baby born with microcephaly.

In other developments, Florida reported five more local cases ofZika Virus, all involving people who were sick earlier this fall. The researchers from England that reviewed studies on the effectiveness of 'mosquito control methods' found weak evidence for some of the common strategies.

The patient in the Spanish report is a woman who contracted the Zika virus in December 2015 when she visited Colombia, her home country. The group reported the findings in a letter to the New England Journal of Medicine.

According to CIDRAPnews, her Zika symptoms began at 9 weeks pregnant and blood tests for the virus came back positive for 89 consecutive days until she was 29 weeks. The reverse-transcriptase polymerase chain reaction (RT-PCR) test came back positive for 107 days after symptoms manifested. Tests from urine, vaginal, and endocervical samples came back negative.

Fetal brain ultrasound at 12 and 15 weeks did not show any abnormalities but repeat imaging tests at 20, 24, and 29 weeks revealed bilateral mild ventriculopathy and a shortened corpus callosum with parenchymal calcification and severe atrophy. The Zika viral load present in the mother's amniotic fluid was reported to be higher than that of the blood.

The baby was delivered early at 37 weeks because of fetal growth restriction. At birth all samples from the mother, including those from the placenta, tested negative for Zika. The baby's samples including cerebrospinal fluid were all negative for acute Zika infection. Ultrasound and magnetic resonance imaging confirmed the microcephaly diagnosis.

The group also noted that an earlier report found Zika RNA in a pregnant woman's blood 8 weeks after symptoms manifested and the new findings support the hypothesis that persistent viremia might reflect virus replication in the fetus or placenta.

Researchers added that higher viral load in amniotic fluid, stable blood levels and negative urine findings also support virus replication in reservoirs such as the fetus or placenta. They concluded that persistent Zika RNA present in mother's blood may be a sign of fetal infection.

US Zika developments, Florida Department of Health reported five more local Zika cases. according to an update yesterday, this is the first since Nov 30.

All the five cases involve Miami-Dade County residents who had symptoms in September and October. Therefore, the newly reported cases do not affect the lifting of three active Zika transmission zones. Researchers recently wrapped up probes of the five cases to rule out travel.

Florida now has 249 local Zika cases, plus 15 in which it is not known where the individuals were exposed to the virus. The state has recorded 972 travel-related cases and is monitoring 180 pregnant women who have lab evidence of Zika infection.

Texas health officials said in a Zika update yesterday that the number of local cases is still one, and involving a woman from Cameron County whose illness was reported on Nov 28. The Texas Department of State Health Services (TDSHS) has recorded 270 travel-related Zika cases. The number includes 21 pregnant women, 2 babies infected before birth, and 2 people who had sexual contact with travelers, according Flutrackers.

In US Zika developments, the New York City Department of Health and Mental Hygiene has recorded at least four babies born with Zika-related problems since July, prompting an alert to physicians making a total of five reported cases.

Health officials around the world have urged doctors to remain vigilant for Zika-affected pregnancies, and also to warn pregnant women and women of reproductive-age to take precautions when traveling to areas where the Zika virus is spreading.

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