Zika Virus, Fertility and You

The Zika Virus, Fertility and You

Paul Turek MD, FACS, FRSMDirector, The Turek Clinics

Beverly Hills and San Francisco

Zika Infection History and Vectors

• Flavivirus similar to yellow fever, dengue, West Nile.

• Aedes sp. mosquitoes(Ae. aegypti and Ae.

albopictus) • Sexual intercourse• Maternal-fetal• Blood transfusion

(suspected)• All ages at risk of infection

CDC.gov

• First human case: Nigeria 1952• First epidemic: Yap, Micronesia, 2007• First large epidemic, French Polynesia, 2013• Latest epidemic: Brazil, 2015

Zika Infection-Symptoms

• Many have symptoms, but many don’t.

• Typically, fever rash, joint pain or red eyes.

• Also, muscle pain, headache.

• Lasts days to a week• Not lethal• Immune to future

infections

CDC.gov

Zika Infection-Risks

• Fetal microcephaly (less brain tissue and brain damage)

• Fetal eye, ear defects• Impaired growth and

joint issues (clubfoot)• Guillain-Barre Syndrome

CDC.gov

• Among n=442 fetuses in US Zika registry, 6% born with birth defects

• Among n=117 babies of Zika infected women in Rio, 42% were “grossly abnormal” at birth.

Zika Infection-Microcephaly Risk in Brazil

• Bahia, Brazil.• First trimester

infections.• Pink/solid are actual

cases.• White is 50% of actual

rate.• Gray is usual

incidence: <12/10,000 births

Johansson MA et al. NEJM. 2016; 375:1-4.

Zika Infection-Epidemiology of Worldwide Cases

CDC.gov

Lab confirmed cases as of 12/14/16. Excludes cases of travel only Zika infections

Zika Infection-Epidemiology US Cases

CDC.gov

Lab confirmed cases as of 12/28/16. Total cases: 4809; 95.5% are travel related.

Zika Infection-Mouse Male Infertility

Govero J et al. Nature. 2016, Oct 31, Epubl

• Mice infected with 2 strains of Zika virus: Fr. Polynesian and Senegalese.

• Dengue virus (a mosquito born flavovirus) infection served as controls.

• Evaluated viral presence in reproductive tissue, hormones and sperm production in all mice



• Both strains of Zika virus found in testes of mice, unlike Dengue virus.

• Virus observed in mature sperm as well as in Sertoli cells, spermatogonia and primary spermatocytes.

Results



• Zika infected testes looked normal at 1 week.• By week two, atrophy was observed• By week three, testis tissue was destroyed• Although mice cleared the virus, testis atrophy

was not reversible.

Results cont’d



• There were corresponding decreases in testosterone and inhibin B levels in Zika infected male mice.

• Sperm counts were also reduced.• Zika mice showed ¼ of normal fertility in mating

studies.

Results cont’d

Zika Infection-Vaccines

CDC.gov

• Flavovirus vaccines currently exist.• Zika virus vaccine constructs give

protective immune responses in mice and nonhuman primates.

• Two DNA Zika virus vaccine constructs are in clinical trials in the US.

Thomas SJ et al. NEJM. 2016; 375: 1212-16

Health & Medicine

Zika Virus, Fertility and You