Encephalitis associated with Zika virus infection and reactivation of the varicella-zoster virus in a Brazilian child

Abstract We report a case of encephalitis associated with Zika virus infection and reactivation of varicella-zoster virus in the central nervous system of a Brazilian child. This case raises the possibility that reactivation of the latent varicella-zoster virus may be a mechanism of neurological impairment induced by acquired Zika virus infection.

MENINGOENCEPHALITIS DUE TO VARICELLA ZOSTER VIRUS IN AIDS PATIENTS. REPORT OF ELEVEN CASES AND REVIEW OF THE LITERATURE / Meningoencefalite pelo vírus varicela-zoster em pacientes com AIDS. Relato de onze casos e revisão da literatura

Neurological complications of varicella-zoster virus (VZV) are infrequent and include various clinical pictures. The reactivation of VZV in patients with AIDS is generally associated with an acute and severe meningoencephalitis. We report the epidemiological, clinical and virological data from 11 consecutive patients with diagnosis of HIV/AIDS and central nervous system (CNS) involvement due to VZV. All patients were male and seropositive for HIV. The primary risk factor for HIV infection was unprotected sexual contact. The median of CD4 T cell count was 142 cells/µL. All of them presented signs and symptoms of meningoencephalitis. Six patients (54.5%) presented pleocytosis; they all showed high CSF protein concentrations with a median of 2.1 g/dL. Polymerase chain reaction of cerebrospinal fluid specimen was positive for VZV in all of them and they were treated with intravenous acyclovir at doses of 30/mg/kg/day for 21 days. Overall survival was 63% (7 of 11 patients). The four dead patients had low cellular counts in CSF, below the median of this parameter. VZV should be included among the opportunistic pathogens that can involve CNS with a diffuse and severe meningoencephalitis in patients with advanced HIV/AIDS disease.

As complicações neurológicas do vírus varicela-zoster (VVZ) são pouco frequentes e incluem vários quadros clínicos. A reativação do VVZ em pacientes com AIDS é geralmente associada com meningoencefalite aguda e grave. Nós relatamos os dados epidemiológicos, clínicos e virológicos de onze pacientes consecutivos com diagnóstico de HIV/AIDS e comprometimento do sistema nervoso central (SNC) devido ao VVZ. Todos os pacientes eram do sexo masculino e soropositivos para HIV. O principal fator de risco para a infecção pelo HIV foi o contato sexual sem proteção. A mediana da contagem de células CD4 T foi de 142 cel/µL. Todos apresentavam sinais e sintomas devido à meningoencefalite. Seis pacientes (54,5%) apresentaram pleiocitose; todos apresentaram hiperproteinorraquia com mediana de 2,1 g/dL. A reação em cadeia da polimerase de amostra do líquido cefalorraquidiano foi positiva para VVZ em todos eles. Todos os pacientes foram tratados com aciclovir por via intravenosa em doses de 30 mg/kg/dia durante 21 dias. A sobrevida global foi de 63% (sete de 11 pacientes). Os quatro pacientes mortos tiveram uma escassa resposta celular no LCR abaixo da mediana para este parâmetro. O VVZ deve ser incluído entre os patógenos oportunistas que podem comprometer o SNC com meningoencefalite difusa e grave em pacientes com doença avançada por HIV/SIDA.

Investigation of an epidemic of Reye's syndrome in northern region of India.

OBJECTIVE: To determine the extent, epidemiological and clinical features of an epidemic of non-inflammatory encephalopathy in northern region of India. DESIGN: Surveillance of referred cases having unconsciousness after a short bout of fever during October and November 1997. Case control study in 7 most affected villages. METHODS: Active case finding was done to assess the extent and severity of the epidemic by interviewing health professionals and by reviewing mortality records in 10 districts of Haryana, Punjab and Chandigarh. A house to house survey was conducted in seven most affected villages. A case was defined as any child of less than 15 years of age, who had prodromal fever followed by vomiting and unconsciousness with subsequent recovery or death. Two age and sex matched controls who had fever without unconsciousness were taken for each case, one from nearby house and another staying furthest from the affected house. These groups were compared for various epidemiologic factors, clinical features and treatment pattern. Residual medicines used by affected patients were tested for presence of salicylate. Local village practitioners were interviewed for their knowledge and attitude towards use of aspirin in a febrile child. RESULTS: Information regarding 129 affected children (M: F=1 : 1) could be obtained. Age ranged between 1 to 12 years (mean 5.8 years). Most were from rural or semi-suburban areas. Attack rate was 5.4/1000 and case fatality rate was 72%. Multiple sibs were affected in 9.3%. History of fever was reported by 83%, vomiting preceding unconsciousness by 83% and abnormal behavior by 65%. Abnormal posturing was reported in 55%. Seventeen (61%) of 28 samples had IgM antibodies in serum/CSF against measles. Twelve (36%) of 33 serum samples tested positive for Varicella zoster virus. None gave history of aspirin intake and 10 samples of residual drugs did not contain salicylate. However, 6 out of 19 blood samples taken from affected patients contained salicylate. Environmental factors were in favor of Japanese encephalitis (JE) but brain biopsy and serology disproved it. Based on earlier report of JE from this area, the cases in present epidemic were being reported as JE before this study was undertaken. Intensive fogging with malathion was being undertaken as antimosquito measure, specially around the affected houses. Local village practitioners (n = 37) were unaware of contraindications of aspirin in a febrile child. CONCLUSION: Measles and varicella zoster emerged as the probable etiologies for the viral prodrome precipitating these cases of Reye's syndrome. Aspirin might have a contributory role. Malathion is another putative cofactor.