We followed the presence of
Zika virus (
ZIKV) in four healthy
adults (two
men and two
women), for periods ranging from 78 to 298 days post symptom onset. The
patients were evaluated regarding the presence of the
virus in different
body fluids (
blood,
saliva,
urine and
semen), development of
immune responses (including
antibodies,
cytokines and
chemokines), and
virus genetic variation within samples collected from
semen and
urine during the
infection course. The
analysis was focused primarily on the two
male patients who shed the
virus for up to 158 days after the initial symptoms.
ZIKV particles were detected in the
spermatozoa cytoplasm and
flagella, in immature
sperm cells and could also be isolated from
semen in
cell culture, confirming that the
virus is able to preserve integrity and infectivity during replication in the
male reproductive system (MRS). Despite the damage caused by
ZIKV infection within the MRS, our data showed that
ZIKV infection did not result in
infertility at least in one of the
male patients. This
patient was able to conceive a
child after the
infection. We also detected alterations in the
male genital cytokine milieu, which could
play an important
role in the replication and
transmission of the
virus which could considerably increase the
risk of
ZIKV sexual spread. In addition, full
genome ZIKV sequences were obtained from several samples (mainly
semen), which allowed us to monitor the evolution of the
virus within a
patient during the
infection course. We observed genetic changes over
time in
consensus sequences and lower frequency intra-host single
nucleotide variants (iSNV), that suggested independent compartmentalization of
ZIKV populations in the reproductive and urinary systems. Altogether, the present observations confirm the
risks associated with the long-term replication and shedding of
ZIKV in the MRS and help to elucidate patterns of intra-host
genetic evolution during long term replication of the
virus.