Resistencia del virus de inmunodeficiencia humano (VIH) a zidovudina (AZT): análisis genotípico en cepas aisladas de pacientes chilenos / Resistance of human immunodeficiency virus (VIH) to zidovudine: genotypic analysis in strains isolated from chilean patients

Background: Resistance of HIV to AZT is the result of mutations in the pol gene that codifies the enzyme reverse transcriptase. Aim: To asses the resistance to antiretroviral drugs in Chhilean patients infected with HIV. Material and methods: The presence of mutations was searched in 22 patients infected with HIV. The emergence or persistence of these mutations was studiend in sequential samples of 19 patients. The presence of the mutation that confers resistance to didanosine (ddi) was studied in those subjects exposed to the drug. Polymerase chain reaction techniques were used to analyze mutations in codons 41, 70 and 215 of the pol gene (resistance to AZT) and the mutation in codon 71 (resistance to DDI). Results: On admission, none of the patients without previous exposure to AZT had drug resistance mutations. Seven of 12 patients (58.3 percent) that had received AZT had mutations in codon 215. In two, they were associated to a mutation in codon 41 and in two, to a mutation in codon 70. After a mean follow up of 14 months, 13 of 15 patients (86 percent) that received AZT had viral strains genotypically resistant to the drug. In nine of these, the resistance was associated with disease progression. None of the 10 patients that received DDI had the mutation in codon 74 that confers resistance to the drug. However, in one of these patients, that never receided AZT, virus with a mutation in codon 215 was detected. Conclusions: A high percentage of patients that have received monotheraphy with AZT have genotypic resistance to the drug. This resistance is associated with clinical and immunological derangement in 70 percent of these subjects

Neuroborreliosis en Chile: caso pediátrico de probable adquisición por mascotas importadas / Neuroborreliosis in Chile: pediatric case probably due to imported pets

Lyme disease, caused by spirochete Borrelia burgdorferi, has several clinical manifestations and is transmitted to man by tick bites. In Chile and Latin America, several cases have been reported, but none with inmunoblot confirmation or isolation of the infecting organism. We report a 9 year old boy consulting with bilateral facila palsy, polyradiculoneuritis with tetraparesis and meningeal irritation. Cerebrospinal fluis analysis showed increased protein concentration without pleocytosis and negative viral or bacterial cultures. IgM antibodies against Borrelia burgdorferi, were positive by ELISA and were confirmed by immunoblot at the Reference Laboratory of the University of Connecticut. The child had a recent contact with hamsters brought from Germany. The substantiation of Lyme disease existence in Chile should prompt the search and isolation of the causal agent

Brote epidémico de meningitis por echovirus 30 en la Region Metropolitana: 1993 / Epidemic outbreak of meningitis due to echovirus 30

En el transcurso de 1993, un número inusualmente alto de solicitudes de diagnóstico de enterovirus por casos de meningitis aséptica, provenientes de la Región Metropolitana, se recibieron en el Laboratorio de Enterovirus del ISP. En ese período fueron analizadas 154 muestras de deposiciones y 145 líquidos cefalorraquídeos correspondientes a 237 pacientes, resultando un 26,6 por ciento de aislamientos de enterovirus. Echovirus 30 constituyó el 79,4 por ciento de estos aislamientos y fue por sí solo responsable del aumento de positividad registrada. En años anteriores este virus había sido detectado en nuestro país, sin embargo no se aisló a lo largo del año precedente. Los casos analizados tendieron a presentarse en escolares y a edades mayores que las usuales para este tipo de infecciones. El brote de meningitis aséptica descrito pareció iniciarse con anterioridad al de meningitis meningocóccica ocurrido ese mismo año, desconociéndose cualquier posible asociación entre ellos