Zika virus associated with microcephaly

A widespread epidemic of Zika virus (ZIKV) infection was reported in 2015 in South and Central America and the Caribbean. A major concern associated with this infection is the apparent increased incidence of microcephaly in fetuses born to mothers infected with ZIKV. Microcephaly (an abnormally small brain) wasobserved, with almost complete agyria, hydrocephalus, andmultifocal dystrophic calcifications in the cortex and subcortical white matter, with associated cortical displacement and mild focal inflammation [1].

An autopsy of the fetus and placenta was performed 3 days after termination of the pregnancy, with an extensive sampling of all organs, placenta, and umbilical cord. Samples were fixed in 10% buffered formalin and embedded in paraffin. Fresh tissue samples were collected for microbiologic investigations. Brain and spinal cord were fixed in 27% buffered formalin for 3 weeks, after which a neuropathological examination was performed with extensive sampling of the brain and spinal cord. Sections of all tissue samples were stained with hematoxylin and eosin. Immunostaining for glial fibrillary acid protein, neurofilaments, human leukocyte antigen DR (HLA-DR), CD3 (to highlight T cells) [2,3], and CD20 (to highlight B cells) was performed on representative CNS samples. Microbiologic Investigation RNA was extracted from 10 mg of the placenta, lungs, heart, skin, spleen, thymus, liver, kidneys, and cerebral cortex with the use of a TRI zol Plus RNA purification kit Real-time RT-PCR for the detection of ZIKV RNA (NS5) and one-step RT-PCR for the detection of the envelope-protein coding region (360 bp) were performed as described previously.

In Microbiologic Investigation RNA micro Positive results for ZIKV were obtained on RT-PCR assay only in the fetal brain sample, where 6.5*107 viral RNA copies per milligram of tissue were detected Histologic examination of the placenta confirmed focal calcifications in villi and decidua, but no inflammation was found. There were no relevant pathological changes in other fetal organs or in the umbilical cord or fetal membranes. Fetal karyotyping with the use of microarray technology showed a normal 46XY (male) profile [4].

Indirect immunofluorescence revealed granular intracytoplasmic reaction in destroyed neuronal structures, which pointed to a possible location of the virus in neurons the Histologic examination of the placenta confirmed focal calcifications in villi and decidua, but no inflammation was found. There were no relevant pathological changes in other fetal organs or in the umbilical cord or fetal membranes. Fetal karyotyping with the use of microarray technology showed a normal 46XY (male) profile.

There is concerning data linking Zika virus infection with GBS and microcephaly, warranting vigilant prevention and screening measures for travelers to Zika -affected areas, particular pregnant women. Zika virus disease is still largely a condition of poverty that is thriving in an at-risk climate. The Zika virus is receiving increased attention by the media due to its recent spread primarily in Central and South America. This virus has been known to exist since 1947. Approximately 80% of persons that become infected with the Zika virus do not experience illness or symptoms. In persons that express symptoms, the illness is relatively mild with fever, rash, fatigue and/orjoint pain lasting several days. Severe disease requiring hospitalization is uncommon. There is apossibility of microcephaly in children when a woman is exposed to the virus during pregnancy.There is currently no vaccine to prevent the disease, and research of the current outbreak andunderstanding this disease is evolving.

The Zika virus is primarily transmitted to humans through mosquito bites, but it is reported to have been transmitted through sexual contact and blood transfusions as well. The risk to persons in Western Pennsylvania is low at this time. Those who travel to the impacted areas ,such as Central America and South America, and even some counties in Florida, are advised tounderstand the risks of Zika and take into account preventative measures before traveling.Members of the Pitt community should be aware of resources available to help keep travelers safe and up to date about this evolving health threat.

 

REFERENCES

  1. .http://www.nejm.org/doi/full/10.1056/nejmoa1600651#t=article
  2. ."Zika Virus Microcephaly And Guillain-Barre Syndrome Situation Report" Colin Carlson, Eric Dougherty, Wayne Getz. An ecological assessment of the pandemic threat of Zika virus. bioRxiv 040386; doi: 10.1101/040386 "CDC Concludes Zika Causes Microcephaly and Other Birth Defects". CDC. 13 April 2016. Retrieved 14 April 2016.
Year: 2017
City: Shymkent
Category: Medicine