Inicio del brote de Influenza A (H1N1) pandémica en Chile: caracterización genética de los primeros casos detectados / Genetic characterization of the virus causing H1N1 influenza pandemic in Chile: Analysis of the first detected cases

Background: Following the announcement of the Influenza A(H1N1) pandemic by the World Health Organization in April 2009, a surveillance program was carried out in Chile to detect the introduction of the virus in the country and to monitor its propagation and impact. Aim: To describe the onset of the outbreak and the genetic characterization of the pandemic H1N1 influenza virus in the first detected cases in Chile. Material and Methods: Analysis of18 clinical samples coming from suspicious patients, received in a National Reference Laboratory. RNA reverse transcription and real time influenza gene DNA amplification was carried out in a 7500 Fast and Step One Real Time PCR Systems of Applied Biosystems and MxPro-Mx3000P thermocycler from Stratagene. Super Script III Platinum One-Step Quantitative RT-PCR was used. Results: The virus was first detected in three persons returning from the Dominican Republic via Panamá and a child from the east zone of Santiago. Genetic characterization of the virus showed that the child was infected by a different variant of the pandemic virus than the three persons returning from the Caribbean. Conclusions: The onset of the Influenza outbreak in Chile apparently carne from two different epidemiological groups. The spread of the virus detected in the voyagers was limited immediately However the virus of the fourth case was found in different regions of Chile.

Situación actual de la hepatitis B en Chile / Present situation of hepatitis B in Chile

Background: Hepatitis B virus infection generates carriers and 8 percent will evolve to a chronic phase. Aim: To perform a compilation of studies on hepatitis B in Chile and other sources of information to estímate the impact of this disease in our country. Material and methods: Published and unpublished evidence about the infection, in the general population and risk groups in our country, was compiled and reviewed critically. Informal interviews to experts, revisión of the mandatory notification book of the Ministry of Health and collection of data from laboratories that study hepatitis B virus, were also carried out. Results: The seroprevalence of chronic carriers in blood donors is nearly O.3 percent. Among risk groups such as health care personnel, the figure is O.7 percent, among homosexuals 29 percent, among HIV positive patients 30 percent, among sexual workers 2 percent and among children with chronic hemodialysis, 9 percent. Prevalence rate according to notified cases in 2004 was 1.8 x 100,000 habitants. Detection of viral hepatitis B surface antigen in ¡aboratories occurs in 0.2 percent of donors and 1.396 of non donors. Conclusions: The seroprevalence of hepatitis B virus, the lack of notification, and the introduction of hepatitis B vaccine to our Regular Program of Immunizations, are arguments to develop in Chile a hepatitis B and C surveillance system.

Títulos de anticuerpos anti-VTLV-I en individuos infectados seropositivos / Anti HTLV-I antibody titers in seropositive infected individuals

The aim of this study was to determine anti HTLV-I antibody titers in seropositive symptomatic and asymptomatic infected subjects. One hundred seven infected subjects (47 with spastic paraparesis and 60 asymptomatic) were studied. HTLV-I antibodies were determined using indirect immunofluorescence in cells infected with the retrovirus. The mean titer was 1/234 in asymptomatic subjects and 1/2138 in symptomatic patients (p<0,001). These results suggest an association between HTLV-I antibody titers and clinical stage of infected subjects