Zika virus, dizziness and hearing loss
Timothy C. Hain, MD • Return to Index. • Page last modified:
March 7, 2021
- Zika virus (ZIKV) is a mosquito-borne arbovirus from the Flavivirus family. The main concern with Zika has to do with prenatal infections and congenital microcephaly.
- Recently (beginning in 2016), there have been multiple reports of hearing loss associated with Zika. This is not common, and it is relatively rare in adults.
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
- Leal et al (2016) reported that A retrospective assessment of a series of 70 infants aged 0-10 months with microcephaly and laboratory evidence of Zika virus infection. Five (7%) infants had sensorineural hearing loss, all of whom had severe microcephaly.The prevalence of sensorineural hearing loss was 5.8% (four of 69), which is similar to that seen in association with other congenital viral infections.
- Vinhaes et al (2017) reported that "In 2015, during the outbreak of Zika virus (ZIKV) in Brazil, we identified 3 cases of acute hearing loss after exanthematous illness. "
- Leite studied 45 children (about 10 months old) and found "most of the children evaluated had completed cochlear function and middle ear results refer in compatible with their age range."
- Barbosa et al (2019) reported that there is not yet enough data to be sure about hearing loss in Zika cases. Subsequently Barbosa stated that "Prenatal exposure to Zika virus does not always determine hearing impairment. This risk seems to be more associated to the severity of the central nervous system damage. "
- Fandino-Cardenas et al (2019) did not find hearing loss in 43 children.
- Ficenec et al (2019) reported that "Fourteen articles discussing Zika virus and subsequent complications were included. Across these studies, 56 (21.2%) of 264 Zika-infected individuals were found to have HL."
- Cristina da Silva Rosa (2020) reported that there were "hearing changes (between 5.8% and 68.42%). "
- Fara et al (2020) reported studying children that "Including the first and second evaluation, the frequency of audiological alterations was 5.1%. Of the four children diagnosed with hearing loss, two were carriers of ZIKV, one had suspected ZIKV infection, and one was asymptomatic with confirmed exposure to the virus. "
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.
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).
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.
There is currently (2020) no treatment proven effective in Zika. There is neither a vaccine nor an antiviral. (Bernatchez et al, 2020)
- Barbosa, M. H. M., et al. (2019). "Auditory findings associated with Zika virus infection: an integrative review." Braz J Otorhinolaryngol 85(5): 642-663.
- Barbosa, M. H. M., et al. (2020). "Normal Hearing Function in Children Prenatally Exposed to Zika Virus." Int Arch Otorhinolaryngol 24(3): e299-e307.
- Bernatchez, J. A., et al. (2020). "Drugs for the Treatment of Zika Virus Infection." J Med Chem 63(2): 470-489.
- Cordeiro, M. T. (2019). "Laboratory diagnosis of Zika virus." Top Magn Reson Imaging 28(1): 15-17.
- Cristina da Silva Rosa, B., et al. (2020). "Speech-language disorders in children with congenital Zika virus syndrome: A systematic review." Int J Pediatr Otorhinolaryngol 138: 110309.
- Fandino-Cardenas, M., et al. (2019). "Zika Virus Infection during Pregnancy and Sensorineural Hearing Loss among Children at 3 and 24 Months Post-Partum." J Trop Pediatr 65(4): 328-335.
- Faria, A. O. P., et al. (2020). "Audiological Findings in Children Suspected to Have Been Exposed to the Zika Virus in the Intrauterine Period." Otol Neurotol 41(7): e848-e853.
- Ficenec, S. C., et al. (2019). "A Review of Hearing Loss Associated with Zika, Ebola, and Lassa Fever." Am J Trop Med Hyg 101(3): 484-490.
- Leal, M. C., et al. (2016). "Hearing Loss in Infants with Microcephaly and Evidence of Congenital Zika Virus Infection - Brazil, November 2015-May 2016." MMWR Morb Mortal Wkly Rep 65(34): 917-919.
- Leite, R. F. P., et al. (2018). "Hearing Screening in children with Congenital Zika Virus Syndrome in Fortaleza, Ceara, Brazil, 2016." Epidemiol Serv Saude 27(4): e2017553.
- Pyzocha, N. J., et al. (2017). "Zany Over Zika Virus: An Overview of Diagnosis and Treatment Modalities." Curr Sports Med Rep 16(2): 109-113.
- Smith and others. Zika virus disease for neurologists. Neurology Clinical Practice, Dec 2016, 515-521
- Thawani, A., et al. (2020). "Zika virus can directly infect and damage the auditory and vestibular components of the embryonic chicken inner ear." Dev Dyn 249(7): 867-883.
- Vinhaes, E. S., et al. (2017). "Transient Hearing Loss in Adults Associated With Zika Virus Infection." Clin Infect Dis 64(5): 675-677.
- Yee, K. T., et al. (2020). "Zika virus infection causes widespread damage to the inner ear." Hear Res 395: 108000.