A systematic review of neonatal toxoplasmosis exposure and sensorineural hearing loss

Division of Pediatric Otolaryngology, BC Children's Hospital, Department of Surgery, University of British Columbia, Vancouver, BC, Canada.
International journal of pediatric otorhinolaryngology (Impact Factor: 1.19). 03/2009; 73(5):707-11. DOI: 10.1016/j.ijporl.2009.01.012
Source: PubMed


The Joint Committee on Infant Hearing 2007 Position Statement includes in utero toxoplasmosis infection as a risk indicator for delayed-onset or progressive sensorineural hearing loss. It is recommended that children with congenital toxoplasmosis infection undergo audiologic monitoring to identify congenital and delayed-onset sensorineural hearing loss.
To determine the prevalence of sensorineural hearing loss and to develop evidence-based guidelines for audiologic monitoring of children born with congenital toxoplasmosis infection.
Systematic search of Medline, EMBASE and Cochrane databases and manual search of references.
Longitudinal studies reporting an inception cohort identified at birth, with serologic confirmation of toxoplasmosis infection, and long-term serial audiometric evaluation.
Independent extraction of patient and audiometric data.
Descriptive statistics.
The five studies meeting our inclusion criteria report a prevalence of toxoplasmosis-associated hearing loss from 0% to 26%. Improved treatment regimens for toxoplasmosis may account for this range. Three treatment groups were identified and a subgroup analysis of the compiled data was performed. In children receiving limited or no treatment, the prevalence of toxoplasmosis-associated SNHL was found to be 28%. In children prescribed 12 months of antiparasitic treatment but in whom treatment was not confirmed to have started prior to 2.5 months of age and in whom compliance was not ensured, the prevalence of SNHL was 12%. In children treated with 12 months of antiparasitical therapy initiated prior to 2.5 months of age with serologically-confirmed compliance, the prevalence of SNHL was 0%. Only two longitudinal studies were identified and neither reported any cases of delayed-onset or progressive toxoplasmosis-associated SNHL. Children who have received a 12-month course of antiparasitical therapy initiated prior to 2.5 months with serologically-confirmed compliance should have repeat audiometric evaluation at 24-30 months of age. Children with congenital toxoplasmosis that had no treatment, partial treatment, delayed onset of treatment, or compliance issues should undergo annual audiologic monitoring until able to reliably self-report hearing loss.

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    • "Furthermore, other risk factors were present in these children, which may have contributed to their hearing loss. The systematic literature review on toxoplasmosis (Brown et al. 2009) also revealed that there were no reports in the literature of children with neonatal toxoplasmosis who had developed a postnatal hearing loss. "
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    ABSTRACT: : The aim of this study was to investigate whether there was evidence-based support for targeted surveillance programs using a risk-factor registry to detect postnatal hearing loss or whether other programs were available that may be more effective than targeted surveillance. Particularly, it addressed questions that arose along the targeted surveillance pathway, including: () the risk factors used to determine a referral, () referral frequencies, () the relationship between risk factors and a postnatal hearing loss, and () other systems that may be more efficient than the use of risk factors. : A systematic literature review was completed in peer-reviewed and non-peer-reviewed databases. : Publications were obtained using the databases MEDLINE, Cumulative Index of Nursing and Allied Health Literature, and Excerpta Medica on line, and by inspecting the reference lists of relevant articles and expert-committee papers. Quality assessment ratings and data extraction were completed by the research team. : In total, 40 articles met the inclusion criteria and were included in this review. The outcomes drawn from these studies were inconclusive as they were based on small sample sizes and largely from single sites only. With this in mind, from the information obtained: () gestational age, low-birth weight, toxoplasmosis, other infections, rubella, cytomegalovirus (CMV), herpes simplex virus infections, craniofacial anomalies, respirator support, and the administration of aminoglycosides were the more commonly reported risk factors in programs; () referral frequency for monitoring appointments was approximately 3%; and () CMV, extracorporeal membrane oxygenation, congenital diaphragmatic hernia, and persistent pulmonary hypertension of the newborn were associated with postnatal hearing loss, whereas, preauricular skin tags and ear pits, low-birth weight, and toxoplasmosis were not. The review also identified that second-phase universal screening programs, CMV screening, and genetic screening should be explored as potential additions or alternatives to targeted surveillance using risk factors. : Further large-scale, population-based research on available programs for the detection of postnatal hearing loss should be conducted to improve present practice and assist with the development of evidence-based guidelines for hearing monitoring.
    Ear and hearing 09/2012; 33(6):745-56. DOI:10.1097/AUD.0b013e31825b1cd9 · 2.84 Impact Factor
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    • "Toxoplasmosis also has been associated with sensori - neural hearing loss . A literature review looking at the association between this parasitic infection and hearing loss found a scarcity of reliable data ( Brown et al . , 2009 ) . Only five studies met the inclusion criteria for the literature review , and they reported such different results that it is impossible to discern the association between hearing loss and toxoplasmosis ( Brown et al . , 2005 ) . Although the association and cause are not fully understood at this time , a nurse practitioner should be"
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    ABSTRACT: Toxoplasmosis is a rare disease caused by the obligate intracellular protozoan parasite, Toxoplasma gondii. Most persons with toxoplasmosis in the United States are asymptomatic, but if a woman is infected during pregnancy, the parasite can cross the placenta and cause congenital toxoplasmosis in the fetus. The severity of congenital toxoplasmosis depends on when in the pregnancy the mother is exposed, but it can cause ocular and central nervous system disease as well as lead to growth failure and hearing and vision abnormalities. Congenital toxoplasmosis is treated with a combination of pyrimethamine, sulfadiazine, and leucovorin. It is important for pediatric nurse practitioners to be aware of the clinical presentation and treatment of congenital toxoplasmosis.
    Journal of Pediatric Health Care 11/2011; 25(6):355-64. DOI:10.1016/j.pedhc.2010.04.008 · 1.44 Impact Factor
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    ABSTRACT: BACKGROUND: Hearing impairment screening in newborns is a prompt action to identify those who suffer from deafness or hearing loss disorder. This procedure is aimed at early diagnosis of those cases in which quick intervention could prevent subsequent defects and impairments. Evoked otoacoustic emissions (EOAE) test is a screening test which is used to identify patients with hearing problems. This study was conducted to timely diagnose hearing disorder among newborns in order to prevent their verbal disorder through early interventions. METHODS: This was a descriptive cross-sectional study which was carried out on 1232 newborns in Baharestan Hospital, Isfahan, in 2009-2010. Newborns were enrolled during their first month and they were evaluated by EOAE test. RESULTS: The prevalence of hearing loss in this study was 4.8 per 1000 newborns. Those newborns whose responses to the test were more than 60% were accepted in the test. Results of the tests in 50% of newborns who were studied in 2 phases were found negative without risk factors but the rest of subjects had risk factors. CONCLUSIONS: According to prevalence of hearing impairment in this study which could affect infant's verbal skill, hearing screening and efficiency evaluation of hearing screening centers in Iran seems to be necessary.
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