[Efficacy of absorbance ratio of ELISA antibodies [corrected] for hepatitis C virus of 3th generation in the prediction of viremia evaluated by PCR]. / Eficacia del cociente de absorbancia de un análisis inmunoenzimático de tercera generación para anticuerpos al virus de hepatitis C en la predicción de viremia por reacción en cadena de polimerasa.

BACKGROUND: In order to decrease the burden of suffering and the costs derived from confirmatory molecular assays, a better strategy is badly needed to decrease the rate of false positive results of the enzyme-linked immunoassay (ELISA) for detection of hepatitis C virus (HCV) antibodies (Anti). OBJECTIVE: To establish the best cutoff of the S/CO rate in subjects with a positive result of a microparticule, third generation ELISA assay for Anti-HCV, for predicting viremia as detected by polymerase chain reaction (PCR) assay. METHODS: Using the result of the PCR assay as "gold standard", a ROC curve was build with the results of the S/CO rate values in subjects with a positive result for ELISA HCV assay. RESULTS: Fifty two subjects (30 male, 22 female, 40 +/- 12.5 years old) were included. Thirty four (65.3%) had a positive RNA HCV PCR assay. The area under the curve was 0.99 (95% CI: 0.98-1.0). The optimal cutoff for the S/CO rate was established in 29: sensitivity: 97%; specificity: 100%: PPV: 100%; NPV: 94%. CONCLUSIONS: Setting the cutoff of the S/CO in 29 results in a high predictive value for viremia as detected by PCR in subjects with a positive ELISA HVC assay. This knowledge may result in a better decision taking for the clinical follow up of those subjects with a positive result in the ELISA screening assay for HCV infection.

[Epidemiologic and situational panorama of hepatitis C in Mexico]. / Panorama epidemiológico y situacional de la hepatitis C en México.

OBJECTIVE: To determine the epidemiological situation of Chronic Hepatitis C (CHC) in our country. BACKGROUND DATA: Chronic Hepatitis C affects 170 million people worldwide, and about 0.7% of Mexican population. There is no enough epidemiological information about CHC in our country, and it is very probable that some cases are not even detected. METHODS: An investigation poll was performed. Age, gender, birthday, weight, race, residence and birth place, routes of transmission, ALT levels, histological, serological and molecular diagnosis, evidence of complications and previous treatments were recorded. A data recollection sheet was dispatched to different country provinces; they had 6 months to answer it, in order to recollect all information. RESULTS: 831 patients were analized (58.6% female and 41.4% male) with the following distribution in our country provinces: Aguascalientes 15, Chihuahua 12, Distrito Federal 495, Durango 10, Jalisco 89, Guanajuato 78, Yucatán 8, Querétaro 11, Sonora 40, Tabasco 15, Baja California 5, Veracruz 13, Tamaulipas 2 and 38 patients of Nuevo León. The highest incidence of CHC was found at fifth and sixth decade of life (28.5% y 26.7% respectively. The weight distribution was 36.2% < 65kg, 34.6% 65-75 kg and 29.2% > 75 kg. 86.5% had chronic hepatitis and 13.2% cirrhosis. The risk factors for HCV infection analysis showed that the main route of transmission was via contaminated blood (64.2%); when we excluded the patients that were exposed before 1995, the incidence was lowered to 4.5%. The higher incidence was showed between 1970 and 1990 (68%). The intravenous drug users were predominantly male and on those patients in the provinces near the north border line of our country. The predominant genotype was gen- 1 no matter the province (72.2%), in the intravenous drug users genotype 3 was found in 25%. The viral load was similar in all the provinces. 75% of the patients had have treatment and 22.5% had have two cycles, 50% of cirrhotic patients had have treatment whereas only 28% of the patients with late complications had have it. The most common treatment was pegylated alpha-2a interferon plus ribavirine. CONCLUSIONS: 1. The main route of transmission was blood transfusion. There is a marked decrease in the incidence of post-transfusional hepatitis since the introduction of anti-VHC antibody screening of blood donors (4.5%). 2. The time between the infection and diagnosis was 23 years for chronic hepatitis and 26 years for cirrhosis. 3. Intravenous drugs use was an important route of transmission in the north of our country. 4. The predominant genotype was gen-1. 5. Almost all the patients with chronic hepatitis received treatment, the most common used was pegylated interferon alpha-2a and ribavirin. 6.50% of the patients with CHC have late complications.