. En la industria alimentaria son cada vez mas conscientes de la posibilidad de contaminacion de sus productos con protozoos y estadios de helmintos y platelmintos; estos parasitos se han convertido en riesgos para la salud publica y en una preocupacion para quienes trabajan en la comercializacion de alimentos.Los productos frescos, en particular la lechuga, son consumidos con una preparacion minima y, al ser empleadas crudas en las ensaladas, son un vehiculo

A DNA vaccine that expresses the premembrane/membrane (prM) and envelope (E) genes of dengue virus serotype-1 was tested for immunogenicity and protection against dengue-1 virus challenge in Aotus nancymae monkeys. The vaccine, in 1 mg doses, was administered intradermally (ID) to three monkeys and intramuscularly (IM) to three others, For controls, a 1 mg dose of vector DNA was administered ID to two monkeys and IM to one. All animals were primed and then boosted at one and five months post priming. Sera were collected monthly and analyzed for dengue-1 antibodies by enzyme linked immunosorbent assay (ELISA) and plaque reduction neutralization test (PRNT). Dengue-1 antibodies were detectable in the sera from ID and IM vaccine inoculated animals one month after the first boast and peaked one month after the second boost. The antibody levels from sera of animals that received the vaccine via the ID route were twice those from sera of animals that received the vaccine via the IM route. Six months after the second boost all inoculated and two naive monkeys were challenged with 1.25 x 10(4) plaque forming units (PFU) of dengue-1 virus. Two vaccine immunized animals were protected from viremia while the others showed a reduction in viremia. The mean days of viremia were 1 and 1.3 for the animals that were immunized with the vaccine via the ID or IM route, respectively vs 4 and 2 mean days of viremia in the animals inoculated with control DNA. Naive animals were viremic for an average of 4 days. All of the three control monkeys that received control DNA inoculum by either the ID or IM route had an intermittent viremia pattern with one or more negative days interspersed between the positive days. This pattern was not observed in any of the vaccine recipients or the naive control monkeys. These results demonstrate that DNA immunization is a promising approach for the development of dengue vaccines and that A. nancymae monkeys are suitable for dengue vaccine trials. (C) 2000 Elsevier Science Ltd. All rights reserved.

OBJECTIVES. This study examined the prevalences of antibodies to Treponema pallidum, Chlamydia trachomatis, and herpes simplex virus type 2 in a sample of Peruvian adults. METHODS. Among adults seeking health certification in Lima, Peru, 600 were randomly selected to undergo interviews and serologic testing. RESULTS. Men's reported mean lifetime number of partners (10.6) far exceeded women's (1.1), yet antibody to sexually transmitted infection pathogens among sexually experienced participants was 2.8 times more prevalent among women than among men. Among men, female sex workers accounted for 37% of recent partners, and only sex with female sex workers while using condoms less than half of the time was independently associated with antibody (odds ratio = 3.6, 95% confidence interval = 1.5, 8.8). among women, number of partners was associated with any sexually transmitted infection antibody, while intercourse before 18 years of age was associated with C trachomatis antibody. At every level of perceived risk, sexually transmitted infection antibody was more frequent among women. CONCLUSIONS. Men having unprotected sex with female sex workers had the greatest risk of acquiring infections and (by inference) of transmitting them to women.

The first confirmed outbreak of dengue fever in Peru occurred during 1990 in Iquitos, a city of approximately 300,000 residents in the Amazon region. Because of the apparent establishment of endemic transmission of this mosquito-borne viral disease following the outbreak, epidemiologic studies were initiated in 1992. Blood specimens and data on demographic, environmental, and medical history factors were collected from volunteers in an urban sector of Iquitos, in a rural area on the outskirts of Iquitos, and in three nearby jungle communities. A follow-up blood specimen was obtained approximately one year later from a sample of subjects. Sera were tested for dengue IgG antibody by an enzyme-linked immunosorbent assay, and specificity was verified using a plaque-reduction neutralization test. Dengue antibody prevalence was 66% in the urban population, 26% in the rural population, and 32-67% in the three jungle areas. A significant association was found between age and antibody prevalence, with a steady increase in prevalence from 18% among subjects less than five years of age to greater than 90% for subjects more than 50 years old. Increased antibody prevalence also was associated with urban and jungle residence and with a piped source of household drinking water. Seroconversions were documented in four of five surveyed communities. These results indicate that dengue virus transmission continues in and around Iquitos and suggest that transmission also occurred prior to the 1990 epidemic.

The prevalence of antibodies to hepatitis C virus (anti‐HCV) was determined in 105 patients with biopsy‐proven chronic liver disease and 128 comparison patients without any evidence of liver pathology living in Lima, Peru. Using a second‐generation EIA screening and supplemental immunoblot assay, anti‐HCV was detected in four of 13 patients with chronic hepatitis, in 11% of 85 patients with cirrhosis, and in none of seven patients with hepatocellular carcinoma. Only two (1.6%) comparison patients without liver disease had anti‐HCV. Hepatitis B surface antigen (HBsAg) was found in 23% of patients with chronic hepatitis, 12% of patients with cirrhosis, and three of seven patients with hepatocellular carcinoma. There was no evidence of chronic viral hepatitis or alcohol abuse (reported by one‐third of subjects) in 48% of chronic liver disease patients. These preliminary data suggest that among this South American population neither hepatitis B nor hepatitis C infection is the predominate cause of chronic liver disease and that other infectious or environmental factors may be important. © 1994 Wiley‐Liss, Inc.

Four hundred female sex workers attending a sexually transmitted disease clinic in Lima, Peru, were interviewed for demographic information and medical, contraceptive, and sexual practice histories. Cervical cultures were done for Neisseria gonorrhoeae and Chlamydia trachomatis, and serum was tested for antibodies to human immunodeficiency virus, human T cell lymphotropic virus type I (HTLV-I), Treponema pallidum, C. trachomatis, herpes simplex virus type 2 (HSV-2), and Haemophilus ducreyi. The prevalence of HTLV-I increased with duration of prostitution from 3.6% (< 3 years) to 9.3% (3-6 years) to 15.9% (> 6 years; P < .01). After adjustment for duration of prostitution, reduced risk of HTLV-I was significantly correlated with condom use for more than half of all sexual exposures for > 3 years (odds ratio [OR], 0.34; 95% confidence interval [CI], 0.13-0.89). Further adjusting for condom use, HTLV-I seropositivity was associated with C. trachomatis (OR, 3.7; 95% CI, 1.4-13.2) and with antibody to HSV-2 (OR, 3.7; 95% CI, 0.5-29.6). Thus, duration of prostitution, lack of consistent condom use, and past infection with C. trachomatis were significantly associated with HTLV-I seropositivity.

A Peruvian female prostitute population was evaluated over a 3-year period to determine the incidence and risk factors of retroviral and viral hepatitis transmission. At three survey periods, a questionnaire was administered and serum samples were obtained. A total of 966 subjects were studied, with 34% followed for 38 months, 22% followed for 18 months, and 44% evaluated just once. On initial evaluation, 3 (0.3%) had HIV-1 antibody, 170 (17.6%) had HTLV-I antibody, 578 (59.8%) had anti-HBc, and 7 (0.7%) had antibody to hepatitis C virus. The mean annual incidence of HTLV-I and hepatitis B infection was 1.6% and 4.7%, respectively. Univariate and logistic regression analysis of prevalence data indicated an association between sexual activity and HTLV-I and hepatitis B infection, but no independent risk factors were identified in cohort analysis. Parenteral risk factors were not associated with transmission, except for a small percentage of subjects who may have acquired hepatitis B infection from blood transfusions. These findings suggest that there is a high incidence of HTLV-I and hepatitis B infection from heterosexual contact in this female prostitute population.

Twenty (18%) of 111 Peruvian men with sexually acquired human immunodeficiency virus infection were found also to be infected with human T-lymphotrophic virus type I or II in a retrospective study. At the time of data evaluation, 75 patients had reached Centers for Disease Control stage IV (clinical acquired immunodeficiency syndrome) and had not received antiviral medication; mortality in this group was 63.3% (38/60) among patients infected with human immunodeficiency virus alone and 80% (12/15) in the dually infected group. Of the 50 patients who had died, survival time from onset of stage IV to death was shorter in the dually infected group (5.02 +/- 3.27 months) than in those with human immunodeficiency virus infection alone (10.07 +/- 4.42 months). In Peru, sexually acquired human immunodeficiency virus infection in men is often accompanied by human T-lymphotrophic virus type I/II infection, and dual retrovirus infection is associated with a shorter survival after onset of clinical acquired immunodeficiency syndrome.

The epidemiology of hepatitis B in female prostitutes was studied in a cross-sectional survey of 467 prostitutes and 510 control prenatal clinic patients from Lima and Iquitos, Peru. Prostitutes reported a mean of 8.8 +/- 6.7 years of active prostitution and a mean of 205 +/- 137 sexual contacts in the month prior to the study. Hepatitis B surface antigen (HBsAg) was found in comparable percentages of prostitutes (1.7%) and controls (0.8%; P = .305). In contrast, seropositivity for both antigen and antibody markers (HBsAg, anti-HBs, or anti-hepatitis B core) was found in a significantly higher percentage of prostitutes than controls (67.0% vs. 10.0%; P less than .0001). By multivariate analysis, both prostitution (odds ratio [OR] 14.6) and the number of years of exposure as a prostitute (OR 3.2 for 10 years of exposure at age 35 years) were significantly associated with seropositivity for hepatitis B markers when adjusted for age. In this study, the prevalence of HBsAg was not substantially increased in highly active female prostitutes compared with the general population, even though hepatitis B transmission was greatly increased. These data suggest that in adult women with a high level of hepatitis B infection, hepatitis B antigenemia may not persist as frequently as previously indicated in studies of other populations.

Journal Article Basic Study and Laboratory Standardization Get access Abram S. Benenson, Abram S. Benenson From the Department of Community Medicine, University of Kentucky Medical Center, Lexington, Kentucky; the Department of Pediatrics, University of California at San Diego and Los Angeles, California; the Department of Pediatrics, University of Colorado, Denver, Colorado; the Department of Pediatrics, St. Louis University, St. Louis, Missouri; Vesicular Disease Laboratory, Center for Disease Control, Atlanta, Georgia; and the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland Search for other works by this author on: Oxford Academic PubMed Google Scholar James D. Cherry, James D. Cherry From the Department of Community Medicine, University of Kentucky Medical Center, Lexington, Kentucky; the Department of Pediatrics, University of California at San Diego and Los Angeles, California; the Department of Pediatrics, University of Colorado, Denver, Colorado; the Department of Pediatrics, St. Louis University, St. Louis, Missouri; Vesicular Disease Laboratory, Center for Disease Control, Atlanta, Georgia; and the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland Search for other works by this author on: Oxford Academic PubMed Google Scholar Kenneth McIntosh, Kenneth McIntosh From the Department of Community Medicine, University of Kentucky Medical Center, Lexington, Kentucky; the Department of Pediatrics, University of California at San Diego and Los Angeles, California; the Department of Pediatrics, University of Colorado, Denver, Colorado; the Department of Pediatrics, St. Louis University, St. Louis, Missouri; Vesicular Disease Laboratory, Center for Disease Control, Atlanta, Georgia; and the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland Search for other works by this author on: Oxford Academic PubMed Google Scholar James D. Connor, James D. Connor From the Department of Community Medicine, University of Kentucky Medical Center, Lexington, Kentucky; the Department of Pediatrics, University of California at San Diego and Los Angeles, California; the Department of Pediatrics, University of Colorado, Denver, Colorado; the Department of Pediatrics, St. Louis University, St. Louis, Missouri; Vesicular Disease Laboratory, Center for Disease Control, Atlanta, Georgia; and the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland Search for other works by this author on: Oxford Academic PubMed Google Scholar David W. Alling, David W. Alling From the Department of Community Medicine, University of Kentucky Medical Center, Lexington, Kentucky; the Department of Pediatrics, University of California at San Diego and Los Angeles, California; the Department of Pediatrics, University of Colorado, Denver, Colorado; the Department of Pediatrics, St. Louis University, St. Louis, Missouri; Vesicular Disease Laboratory, Center for Disease Control, Atlanta, Georgia; and the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland Search for other works by this author on: Oxford Academic PubMed Google Scholar James Nakano, James Nakano From the Department of Community Medicine, University of Kentucky Medical Center, Lexington, Kentucky; the Department of Pediatrics, University of California at San Diego and Los Angeles, California; the Department of Pediatrics, University of Colorado, Denver, Colorado; the Department of Pediatrics, St. Louis University, St. Louis, Missouri; Vesicular Disease Laboratory, Center for Disease Control, Atlanta, Georgia; and the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland Search for other works by this author on: Oxford Academic PubMed Google Scholar Ursula T. Rolfe, Ursula T. Rolfe From the Department of Community Medicine, University of Kentucky Medical Center, Lexington, Kentucky; the Department of Pediatrics, University of California at San Diego and Los Angeles, California; the Department of Pediatrics, University of Colorado, Denver, Colorado; the Department of Pediatrics, St. Louis University, St. Louis, Missouri; Vesicular Disease Laboratory, Center for Disease Control, Atlanta, Georgia; and the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland Search for other works by this author on: Oxford Academic PubMed Google Scholar John E. Schanberger, John E. Schanberger From the Department of Community Medicine, University of Kentucky Medical Center, Lexington, Kentucky; the Department of Pediatrics, University of California at San Diego and Los Angeles, California; the Department of Pediatrics, University of Colorado, Denver, Colorado; the Department of Pediatrics, St. Louis University, St. Louis, Missouri; Vesicular Disease Laboratory, Center for Disease Control, Atlanta, Georgia; and the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland Search for other works by this author on: Oxford Academic PubMed Google Scholar Warren A. Todd, Warren A. Todd From the Department of Community Medicine, University of Kentucky Medical Center, Lexington, Kentucky; the Department of Pediatrics, University of California at San Diego and Los Angeles, California; the Department of Pediatrics, University of Colorado, Denver, Colorado; the Department of Pediatrics, St. Louis University, St. Louis, Missouri; Vesicular Disease Laboratory, Center for Disease Control, Atlanta, Georgia; and the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland Search for other works by this author on: Oxford Academic PubMed Google Scholar Fernando DeCastro, Fernando DeCastro From the Department of Community Medicine, University of Kentucky Medical Center, Lexington, Kentucky; the Department of Pediatrics, University of California at San Diego and Los Angeles, California; the Department of Pediatrics, University of Colorado, Denver, Colorado; the Department of Pediatrics, St. Louis University, St. Louis, Missouri; Vesicular Disease Laboratory, Center for Disease Control, Atlanta, Georgia; and the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland Search for other works by this author on: Oxford Academic PubMed Google Scholar ... Show more Frances L. Horvath, Frances L. Horvath From the Department of Community Medicine, University of Kentucky Medical Center, Lexington, Kentucky; the Department of Pediatrics, University of California at San Diego and Los Angeles, California; the Department of Pediatrics, University of Colorado, Denver, Colorado; the Department of Pediatrics, St. Louis University, St. Louis, Missouri; Vesicular Disease Laboratory, Center for Disease Control, Atlanta, Georgia; and the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland Search for other works by this author on: Oxford Academic PubMed Google Scholar Aurora Bairan, Aurora Bairan From the Department of Community Medicine, University of Kentucky Medical Center, Lexington, Kentucky; the Department of Pediatrics, University of California at San Diego and Los Angeles, California; the Department of Pediatrics, University of Colorado, Denver, Colorado; the Department of Pediatrics, St. Louis University, St. Louis, Missouri; Vesicular Disease Laboratory, Center for Disease Control, Atlanta, Georgia; and the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland Search for other works by this author on: Oxford Academic PubMed Google Scholar Irving A. Phillips, Irving A. Phillips From the Department of Community Medicine, University of Kentucky Medical Center, Lexington, Kentucky; the Department of Pediatrics, University of California at San Diego and Los Angeles, California; the Department of Pediatrics, University of Colorado, Denver, Colorado; the Department of Pediatrics, St. Louis University, St. Louis, Missouri; Vesicular Disease Laboratory, Center for Disease Control, Atlanta, Georgia; and the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland Search for other works by this author on: Oxford Academic PubMed Google Scholar George J. Galasso, George J. Galasso From the Department of Community Medicine, University of Kentucky Medical Center, Lexington, Kentucky; the Department of Pediatrics, University of California at San Diego and Los Angeles, California; the Department of Pediatrics, University of Colorado, Denver, Colorado; the Department of Pediatrics, St. Louis University, St. Louis, Missouri; Vesicular Disease Laboratory, Center for Disease Control, Atlanta, Georgia; and the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland Search for other works by this author on: Oxford Academic PubMed Google Scholar Martha J. Mattheis Martha J. Mattheis From the Department of Community Medicine, University of Kentucky Medical Center, Lexington, Kentucky; the Department of Pediatrics, University of California at San Diego and Los Angeles, California; the Department of Pediatrics, University of Colorado, Denver, Colorado; the Department of Pediatrics, St. Louis University, St. Louis, Missouri; Vesicular Disease Laboratory, Center for Disease Control, Atlanta, Georgia; and the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland Search for other works by this author on: Oxford Academic PubMed Google Scholar The Journal of Infectious Diseases, Volume 135, Issue 1, January 1977, Pages 135–144, https://doi.org/10.1093/infdis/135.1.135 Published: 01 January 1977