Alexandre Henrique Bezerra Gomes

Socioeconomic conditions as determining factors in the prevalence of systemic and ocular toxoplasmosis in Northeastern Brazil

OBJECTIVE To determine the prevalence of systemic and ocular toxoplasmosis among 1024 students in the city of Natal, Northeastern Brazil, and correlate it with demographic, socioeconomic and epidemiological risk factors. METHODS The study population was randomly selected, asked to fill out a questionnaire, provide a blood sample for IgG and IgM (MEIA) serology and a hemogram, and undergo an eye examination. RESULTS The seroprevalence for IgG was 46% (95% CI = 42.9-49.2%) and that for IgM was 1.4% (95% CI = 0.8-2.4%). The prevalence of ocular lesions was 1.15% (95% CI = 0.6-2.0%). In the univariate analyses, confirmed by multivariate analysis, the socioeconomic conditions were determinants in the prevalence of systemic and ocular toxoplasmosis (mothers schooling = literacy/OR = 2.9 and p < 0.001). CONCLUSIONS The prevalence of systemic toxoplasmosis, although high, was lower than that found in studies performed in the South and Southeast of Brazil, and the incidence of ocular lesions was totally different, being lower by a factor varying from 5 to 17. Although important epidemiological variables, such as owning a cat, drinking unfiltered water or having had contact with lakes or rivers, were found to be correlated with toxoplasmosis in the preliminary analysis, they lost their influence when included in the logistic model. However, further studies must be undertaken to identify the reasons for these findings, including the determination of the strains of Toxoplasma gondii encountered in different regions of the country and the sources of the water utilized by these populations.

Early-stage diffuse unilateral subacute neuroretinitis: improvement of vision after photocoagulation of the worm

AbstractPurpose: To evaluate the visual outcome after direct laser photocoagulation of the worm in patients with early-stage diffuse unilateral subacute neuroretinitis (DUSN).Methods: We report on four patients with DUSN diagnosed in its early stage, in whom the worm was identified and destroyed by laser photocoagulation.Results: In all the four cases, resolution of the inflammatory multifocal lesions was achieved within 1 month of treatment. After that period and during follow-up (mean 11.5 months), visual acuity improved in three eyes and remained unchanged in one eye.Conclusion: The diagnosis of DUSN in its early stage followed by prompt location and destruction of the worm by photocoagulation may improve vision of affected patients.

Clinical Features of 121 Patients With Diffuse Unilateral Subacute Neuroretinitis

PURPOSE To describe the determinant clinical signs to diagnose diffuse unilateral subacute neuroretinitis (DUSN) and the main features related to identification of the live worm. DESIGN Retrospective study performed at the Federal University of Rio Grande do Norte, Rio Grande do Norte, Brazil, between 2003 and 2008. METHODS Patients with early- or late-stage diffuse unilateral subacute neuroretinitis were included. All patients underwent complete ophthalmologic examination and had a minimum of 6 months of follow-up. RESULTS A total of 121 patients were included. Most patients were younger than 20 years (69.42%). Visual acuity was 20/400 or worse in 86 patients (71.7%). Nine patients (7.43%) presented in the early stage and 112 (92.57%) patients presented in the late stage. Subretinal tracks (91.7%), focal alterations of the retinal pigment epithelium (89.3%), small white spots (80.2%), and optic nerve atrophy (76.9%) were the most frequent clinical features. The subretinal worm was identified in 48 patients (39.66%), and laser treatment to destroy it was performed in all cases. The most common location of the nematode was the posterior pole (21 patients). It was observed that the younger the age, the higher the indices of larvae identification (P=.022). Multifocal yellow-white lesions and vitritis were correlated with identification of the worm (P=.001). Mean logarithm of the minimal angle of resolution visual acuity was 1.466 (20/600) and 1.281 (20/400) before and after laser treatment, respectively (P<.005). CONCLUSIONS Identification of clinical signs and diagnosis of diffuse unilateral subacute neuroretinitis in its early stage, followed by prompt location and destruction of the worm by photocoagulation, may improve the vision of affected patients.

Incidência e fatores de risco da retinopatia da prematuridade no Hospital Universitário Onofre Lopes, Natal (RN) - Brasil

PURPOSES: To determine the incidence of retinopathy of prematurity and assess the main risk factors involved in its development. METHODS: Retrospective cohort study carried out from January 2004 to December 2006, at University Hospital Onofre Lopes, Natal (RN) - Brazil. The sample was composed of 663 newborns, with less than or equal to 36 weeks of gestational age and/or birth weight less than or equal to 1,500 g, submitted to the protocol of retinopathy of prematurity in the ophthalmology department of the hospital. The variables were: gender, birth weight, gestational age, duration of oxygen therapy, mechanical ventilation, sepsis and blood transfusion. Data were analyzed through the chi-squared test, Fishers exact test and logistic regression model. RESULTS: Of the 663 cases, retinopathy of prematurity occurred in 414 (62.4%). Of the total sample, 338 (51.0%) were male and 282 (42.5%) female. Mean and standard deviation of weight, gestational age and duration of oxygen therapy were, respectively, 1,334.9 ± 345.6 g, 31.9 ± 2.3 weeks and 10.0 ± 14.0 days. The incidence of retinopathy in premature newborns in the period was 62.4%, 58.0% of cases in 2004, 67.2% in 2005 and 63.0% in 2006. The multiple logistic regression analysis showed that the weight less than 1,000 g (p<0.001; adjOR=17.18, CI= 6.52-45.29) and between 1,000 g and 1,500 g (p=0.002; adjOR -4.20 CI= 1.68-10.48), the time of oxygen lounger than 20 days (p=0.022; adjOR=3.40, CI= 1.19-9.69) and blood transfusion (p=0.022; adjOR -2.06, CI= 1.11-3.83) are independent factors for the disease. CONCLUSIONS: The study showed a high incidence of the disease in the service. A low birth weight, a prolonged oxygen therapy and blood transfusion are factors associated with the development of retinopathy of prematurity. Gestational age is not a reliable parameter for screening of newborns in the service.