Two new case reports added more detail to the Zika virus clinical picture, with one from Brazil describing congenital eye problems in a baby born without microcephaly and the other a report from France documenting sexual transmission 44 days after the male partner's infection—a much longer delay than earlier reports.
Authors of both reports published their findings in letters to The Lancet.
The report on ocular problems in newborn without microcephaly seems to underscore a recent statement from the World Health Organization (WHO) that maternal Zika infections cause a wider array of birth defects than previously thought, some likely still unknown, signifying a new congenital syndrome.
Meanwhile, the case of sexual transmission involved more than double the longest reported delay after infection thus far—19 days.
Zika suspicions and eye screening
The baby in the ocular findings report was born at 38 weeks with no apparent microcephaly but with lower- and upper-limb spasticity and computed tomography brain findings that included cerebral calcifications in the basal ganglia, ventriculomegaly, and lissencephaly, according to the report from the Recife-based team. The mother reported having no Zika-related symptoms during pregnancy.
Ophthalmologic exam when the baby was 57 days old revealed a chorioretinal scar, seen in other congenital Zika virus infections.
Immunoglobulin M (IgM) testing on the baby's cerebrospinal fluid was positive for Zika virus, and lab tests on the mother and infant ruled out other possible causes of infection
The authors said the case highlights that microcephaly shouldn't be the only criteria for congenital Zika virus infection, and they urged public health authorities to provide fundus screening to babies with suspected congenital Zika infections, because eye problems might go undetected if microcephaly is the only criterion that triggers further screening.
Transmission more than a month after man was sick
The sexual transmission report involves a couple from France in their early 60s who traveled to Martinique. The man's Zika symptoms began 3 days before they returned to their home country. The woman didn't have any symptoms during the trip, but 40 days after arriving back in France, she developed a rash and joint pain.
Blood and urine tests were done on the woman 9 days after her illness onset, with the urine sample positive on the reverse-transcriptase polymerase chain reaction (RT-PCR) test. Serologic tests were positive for Zika IgM and IgG, confirming an acute Zika virus infection.
Serologic testing on the man, done 53 days after his symptom onset, were positive for Zika IgM and IgG, and specificity was confirmed by neutralizing antibody testing. A urine sample collected the same day and a semen sample obtained 67 days after symptom onset were negative for Zika virus.
The researchers said the couple didn't live in or stay in an area after their trip where Aedes mosquitoes are present and neither had received any blood components. However, they had unprotected sex several times after they got back.
The authors said the timing of the woman's infection, factoring in an incubation period of 3 to 12 days, supports delayed sexual transmission, which took place from 32 to 41 days after her partner got sick. The period for returning travelers to practice safe sex, especially for reproductive-age women, should be extended past 1 month in all guidance, the authors said.
The WHO's sexual transmission guidance, which was updated yesterday, recommends safe sex or abstinence for at least 8 weeks for men and women returning from areas of Zika transmission. The recommendation is 6 months if the male partner was symptomatic. The US Centers for Disease Control and Prevention (CDC) also recommends condom use or abstinence for at least 8 weeks for asymptomatic men, and 6 months for men who had Zika symptoms.
Jun 7 Lancet letter on ocular findings in absence of microcephaly
Jun 7 Lancet letter on delayed sexual Zika virus tranmission