Zika virus, dizziness and hearing loss

Timothy C. Hain, MD Return to Index. • Page last modified: March 7, 2021

Main Points:

Zika virus received its name from the Zika forest in Uganda. It has caused several epidemics since its discovery in 1947, but there was no significant attention to this virus until the recent outbreak in Brazil in 2015 (Smith et al, 2016). Zika is transmitted through mosquito bites, as well as through sexual intercourse, and likely also through blood. The majority of infections are likely asymptomatic. Zika diagnosis relies on RT-PCR of bodily fluids, such as serum, urine, or CSF.

GENERAL SIGNS AND SYMPTOMS:

Asymptomatic presentation is common. If symptoms do occur, individuals display a low-grade fever, maculopapular rash, arthralgia, or conjunctivitis 2 to 7 d after infection. (Pyzocha et al, 2017). When contracted prenatally, there can be congenital microcephaly as well as other CNS disturbances.

OTOLOGIC SIGNS AND SYMPTOMS -- Literature review

Speculation about a few cases seen by the author of this page.:

The author has encountered a single young person who spent 3 months in Brazil, came back, and then developed bilateral vestibular loss. The connection here between Zika and the bilateral loss is admittedly tenuous. Still, these viruses may be another source of vestibular nerve damage. As technology for detecting vestibular nerve damage improves (i.e. the VHIT test), we may see more of these situations.

The author has also encountered a single adult who developed Meniere's like symptoms after a Zika infection. Again, the connection is admittedly tenuous.

MECHANISM

Zika virus can directly infect the inner ear cells in animal models, including both the cochlea and the spiral ganglion. Both auditory and vestibular portions of the ear are affected (in chickens). (Thawani et al, 2020). Zika also damages the cochlea of mice with the greatest amount of damage at the apex (Yee et al, 2020).

TESTS

Zika diagnosis relies on RT-PCR of bodily fluids, such as serum, urine, or CSF. Serological testing has also been developed recently inclulding IgM and IGG tests (Cordeiro, 2019)

Hearing testing includes both conventional audiometry and OAE testing.

TREATMENT

There is currently (2020) no treatment proven effective in Zika. There is neither a vaccine nor an antiviral. (Bernatchez et al, 2020)

References