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M O Favorov

Publications and source records attributed to M O Favorov.

At least 19 recordsLinked to original sources
PubMed2006

Progress toward tuberculosis control and determinants of treatment outcomes--Kazakhstan, 2000-2002.

INTRODUCTION: In Kazakhstan, during 1995-2002, the annual notification rate per 100,000 population for new cases of tuberculosis (TB) increased from 67.1 to 165.1. Beginning in 1998, public health authorities have used the national case management strategy (DOTS) promulgated by the World Health Organization (WHO) to control TB. Intended goals of DOTS include achieving a cure rate of >85% for persons with newly detected pulmonary TB sputum-smear-positive (PTB+) cases and having PTB+ represent >65% of all PTB cases among adults. Surveillance data collected during 2000-2002 were analyzed to evaluate progress toward achieving these goals and identify factors associated with specific treatment outcomes. METHODS: Surveillance data included the following nonidentifiable information on persons with newly reported cases of PTB: dates of disease onset and treatment initiation; methods of diagnosis; treatment outcomes; HIV status; and selected demographic, socioeconomic, and behavioral characteristics. Cure rates and proportions of PTB+ cases were calculated on the basis of the TB case definition and treatment outcome classification format outlined in DOTS guidelines issued by WHO. Denominator data to calculate rates were obtained from the National Census Office of Kazakhstan. Logistic regression was employed to investigate factors associated with treatment outcomes using Epi Info version 3.2. RESULTS: During 2000-2002, a total of 65,011 new cases of PTB were detected in Kazakhstan. The average annual countrywide notification rate per 100,000 population was 146.0; provincial notification rates varied (range: 65.1-274.0). The countrywide cure rate for newly detected PTB+ was 72.2%; provincial rates varied (range: 65%-81%). Of 59,905 cases of PTB among adults during 2000-2002, a total of 26,804 (44.7%) were PTB+. Unfavorable treatment outcome of new PTB+ cases was associated with alcohol abuse, homelessness, and previous incarceration. CONCLUSION: The cure rate for new PTB+ cases and the proportion of cases of PTB+ among all adults with PTB were below targeted goals. This might, in part, be explained by the 1998 adoption of DOTS. Improving program indicators requires evaluation of detection efforts, laboratory diagnostic capabilities, and adherence to treatment regimens, especially in provinces in which rates are high and among persons at high risk for unfavorable treatment outcomes.

Adolescent↗
PubMed2005

Person-to-person transmission of hepatitis A virus in an urban area of intermediate endemicity: implications for vaccination strategies.

Developing countries with an increasing hepatitis A disease burden may target vaccination to specific groups, such as young children, as an initial control strategy. To better understand transmission of hepatitis A virus in such countries, the authors prospectively studied household and day-care/school contacts of cases in Almaty, Kazakhstan. Overall, by the time of identification of symptomatic index cases, half of transmission had already occurred, having been detected retrospectively. The odds of household contacts' becoming infected were 35.4 times those for day-care/school contacts (95% confidence interval (CI): 17.5, 71.7). Within households, younger age of either index cases or susceptible contacts elevated the odds of secondary infection among susceptible contacts: The presence of a case under 6 years of age raised the odds 4.7 times (95% CI: 1.2, 18.7); and compared with contacts aged 14 years or older, the odds of infection were increased to 7.7 (95% CI: 1.5, 40.3) and 7.0 (95% CI: 1.4, 34.3) among contacts aged 0-6 years and 7-13 years, respectively. Young children are appropriate targets for sustainable hepatitis A vaccination programs in areas undergoing hepatitis A epidemiologic transition. If vaccine is determined to be highly effective postexposure and if it is feasible, vaccinating household contacts could be a useful additional control strategy.

Adolescent↗
PubMed2005

The increasing prominence of household transmission of hepatitis A in an area undergoing a shift in endemicity.

In the rapidly developing city of Almaty, Kazakhstan, rates of hepatitis A have fallen, but no data on prevalence of antibody to hepatitis A virus (anti-HAV) exist with which to interpret incidence data. In the autumn of 2001, we determined the anti-HAV prevalence among household and school contacts of hepatitis A cases. For contacts aged 0-4 years, 5-9 years, 10-14 years, 15-19 years, or 20-30 years, immune prevalences were 9, 12, 33, 33 and 77% respectively, among immediate-family household contacts and 15, 28, 49, 52 and 77% respectively, among community contacts. Child community contacts were more likely to be immune than their immediate-family household counterparts (odds ratio 2.0, 95% confidence interval 1.3-3.2). Almaty is experiencing an epidemiological shift in hepatitis A incidence. Feasible and effective prevention strategies using hepatitis A vaccine should be explored.

Adolescent↗
PubMed2004

[Detection of antibodies to HIV virus in saliva by express-tests in Uzbekistan].

Saliva tests, when used in screening for antibodies to HIV virus (anti-HIV), makes testing safer, easy-to-fulfill (even outside clinic) and acceptable for a majority of examinees. The main quality parameters of express-test for the detection of anti-HIV in saliva were evaluated for the purpose of using the related approach in the HIV epidemiological supervision. Saliva samples and sera of 81 HIV-infected patients and of 99 presumably non-infected persons were investigated by the "OraQuick" express-test. The data obtained were compared with the results of ELISA-based serum testing. The sensitivity of "OraQuick" made 95% and its specificity was 100%. The test is appropriate for epidemiological investigations and HIV epidemiological supervision but it cannot be recommended for the blood transfusion service.

Adolescent↗
PubMed2001

Hepatitis E virus antibody prevalence among persons who work with swine.

Prevalence of antibody and risk factors to hepatitis E virus (HEV) infection were determined in a cross-sectional study of 2 group-matched populations: swine farmers (n=264) and persons without occupational exposure to swine (n=255) in Moldova, a country without reported cases of hepatitis E. The prevalence of HEV infection was higher among swine farmers than among the comparison group (51.1% vs. 24.7%; prevalence ratio, 2.07; 95% confidence interval [CI], 1.62-2.64). In multivariate analysis, HEV infection was associated with an occupational history of cleaning barns or assisting sows at birth (odds ratio [OR], 2.46; 95% CI, 1.52-4.01), years of occupational exposure (OR, 1.04 per year; 95% CI, 1.01-1.07), and a history of drinking raw milk (OR, 1.61; 95% CI, 1.08-2.40). HEV infection was not associated with civilian travel abroad or having piped water in the household. The increased prevalence of HEV infection among persons with occupational exposure to swine suggests animal-to-human transmission of this infection.

Agricultural Workers' Diseases↗
PubMed2000

Hepatitis E virus infection in chimpanzees: a retrospective analysis.

Different patterns of disease were observed among 11 chimpanzees who were inoculated intravenously with hepatitis E virus (HEV) positive fecal specimens from four different outbreaks (Nepal 1981, Uzbekistan 1981, Pakistan 1985, and Mexico 1986). Five chimpanzees had marginal or no liver enzyme elevations within 70 days of inoculation. Two of the chimpanzees had limited viremia, but did not produce detectable antibody. The four remaining chimpanzees had liver enzyme elevations, viral shedding, viremia, seroconversion to anti-HEV, and detectable HEV antigen in liver biopsy specimens. These results may reflect the range of infection patterns that develop in humans after natural exposure to the HEV.

Animals↗
PubMed2000

Prevalence of antibody to hepatitis E virus among rodents in the United States.

The recent identification of antibody to hepatitis E virus (HEV) in pigs, sheep, and cattle and characterization of an HEV isolated from domestic pigs suggest animal reservoirs for this virus. To investigate whether rodents might be a natural reservoir of HEV, the prevalence of anti-HEV was determined among a variety of species throughout the United States. Serum samples were obtained from 806 rodents of 26 species in 15 genera. Anti-HEV prevalence was assessed by 2 EIAs (mosaic protein- and 55-kDa protein-based), which gave concordant results. The highest prevalence of antibody was found in the genus Rattus (59.7%; 166/278). Overall, rodents from urban habitats had a significantly higher prevalence of anti-HEV than did animals captured from rural areas. A high prevalence of anti-HEV was found in animals captured on mainland versus barrier islands. The results from this study provide convincing evidence of widespread HEV or HEV-like infection in rodents of the United States.

Animals↗
PubMed2000

Universal immunization: the diphtheria control strategy of choice in the Republic of Tajikistan, 1993-1997.

During the 1993-1997 diphtheria epidemic in Tajikistan, the incidence rate was the highest observed throughout the Newly Independent States of the former Soviet Union (76.2 cases/100,000 population in 1995). Factors that contributed to this situation included an increase in the number of persons who were not fully immunized, a breakdown of health care services and disease surveillance, civil war, an increase in migration, shortages of qualified medical personnel, and shortages of products, resources, and services. The Ministry of Health and numerous international organizations have worked to address the needs of the republic, and in the fourth quarter of 1995, the number of reported cases began to decrease. It is believed that this decrease was largely the result of routine immunization, implementation of national immunization days, and use of a World Health Organization-recommended system for working with patients and contacts, and it underscores the importance of universal diphtheria immunization with special booster doses in such an epidemic setting.

Adolescent↗
PubMed1997

Prevalence of and risk factors for antibody to hepatitis E virus seroreactivity among blood donors in Northern California.

To evaluate antibody to hepatitis E virus (anti-HEV) seroreactivity, 5000 US blood donors were tested for anti-HEV by two EIAs: a mosaic protein assay (MPr-EIA) and a recombinant protein assay (RPr-EIA). Overall, 59 (1.2%) were seroreactive by MPr-EIA and 70 (1.4%) were seroreactive by RPr-EIA. The overall concordance between tests was 98.5% (4925/5000); the concordance among reactive sera by either test was only 27% (27/102). In a case-control study, seroreactive persons were more likely than seronegative persons to have traveled to countries in which HEV is endemic (odds ratio [OR] for MPr-EIA = 4.3, P < .001; OR for RPr-EIA = 2.5, P = .005), but 31% of MPr-EIA anti-HEV-reactive persons and 38% of RPr-EIA anti-HEV-reactive persons had no history of international travel. These findings suggest that travelers to regions in which HEV is endemic can acquire subclinical HEV infection. The significance of anti-HEV seroreactivity among persons without an international travel history needs to be determined.

Adult↗
PubMed1997

Detection of hepatitis G virus (HGV) RNA: clinical characteristics of acute HGV infection.

The role of hepatitis G virus (HGV) infection in acute non-A-E hepatitis was investigated in adults with viral hepatitis. HGV RNA was present in 1 of 28 patients with non-A-E hepatitis but 9 of 22 with hepatitis C (P < .003). HGV RNA-positive patients (HGV-infected and HGV-hepatitis C virus [HCV]-coinfected) developed light-to-moderate jaundice. Clinical and biochemical features of HGV-positive and HCV-positive patients and patients with non-A, non-G hepatitis were similar. Three patients with HGV-HCV coinfection, tested within 18 months after disease onset, have remained HGV RNA-positive but have become HCV RNA-negative. Only 1 non-A-E hepatitis patient was confirmed as being infected with HGV alone, suggesting that HGV is not the main etiologic agent of non-A-E hepatitis. Although HGV RNA was significantly associated with hepatitis C, patients with mixed HCV-HGV infections did not demonstrate a more severe course of disease than did patients with HCV infection.

Acute Disease↗
PubMed1996

IgM and IgG antibodies to hepatitis E virus (HEV) detected by an enzyme immunoassay based on an HEV-specific artificial recombinant mosaic protein.

To develop an enzyme immunoassay (EIA) for IgM antibody to hepatitis E virus (HEV) (IgM anti-HEV) and IgG antibody to HEV (IgG anti-HEV), a synthetic gene encoding several liner immunodominant antigenic epitopes from HEV structural proteins was assembled as a chimeric recombinant mosaic protein (Mpr) with glutathione S-transferase and used as an immunodiagnostic target. In addition, a neutralization confirmation test was developed using individual synthetic peptides. Among 614 patients with acute hepatitis from 10 geographically distinct outbreaks, IgG anti-HEV was found in 546 (88.9%), with a range of 77-100% depending on the outbreak. Of 130 patients tested for IgM anti-HEV, 126 (96.9%) were positive. Among patients tested within 4 months of onset of jaundice, 37/37 (100%) were IgG anti-HEV positive. For patients from whom sera were collected 1-16 days after onset of jaundice, the geometric mean IgG titer (GMT) was 1:47,000; the GMT increased to 1:70,710 30-40 days after onset of jaundice and decreased to 1:1,778 3-4 months after the onset of jaundice. For patients tested 6-8 months after onset of jaundice, 11/12 (92%) were IgG anti-HEV positive, and the GMT was 1:2,908. IgM anti-HEV was detected in 43/43 (100%) sera collected 1-40 days after onset of jaundice, and the GMT for IgM anti-HEV was 1:10,000 at that time. For sera collected 3-4 and 6-12 months after onset of jaundice, 7/14 (50%) and 5/12 (40%) respectively, were IgM anti-HEV positive. In conclusion, an artificial mosaic protein composed of linear antigenic epitopes from open reading frame 2 (ORF2) and ORF3 of HEV has been successfully applied to the development of a sensitive and specific EIA for the detection of IgG and IgM anti-HEV activity. These assays were used for the verification of HEV infection in outbreak settings and for the diagnosis of HEV infection in sporadic cases.

Acute Disease↗
PubMed1996

Artificial mosaic proteins as new immunodiagnostic reagents: the hepatitis E virus experience.

BACKGROUND: Naturally occurring viral proteins derived from cell culture and recombinant proteins expressed in procaryotic systems have been used extensively as target proteins in the development of immunoassay methods for the detection of antibodies. However, immunoassays utilizing these proteins often yield false-positive reactions suggesting that it may be possible to identify and remove regions responsible for these non-specific reactions. OBJECTIVE: In this paper we describe a new strategy for the construction of immunoreactive recombinant proteins designed to improve immunoassay specificity. STUDY DESIGN: A synthetic gene encoding an artificial polypeptide composed of antigenic epitopes of the hepatitis E virus (HEV) proteins was constructed from short oligonucleotides by the polymerase chain reaction (PCR). The polypeptide comprises a mosaic of three antigenically dominant regions from the protein encoded by open reading frame 2 (ORF2), one antigenically active region from the protein encoded by ORF3 of the Burmese HEV strain, and one antigenically active region from the protein encoded by ORF3 of the Mexican strain. The mosaic protein was expressed in Escherichia coli as a chimera with glutathione-S-transferase or beta-galactosidase. RESULTS: Guinea pig sera containing antibodies to the corresponding HEV synthetic peptides were used to demonstrate by immunoblot analysis and by enzyme immunoassay (EIA) the presence and accessibility of all HEV-specific antigenic epitopes designed into the mosaic protein. Both hybrid proteins were shown by immunoblot analysis using a panel of human anti-HEV-positive and -negative sera to be HEV-specific. A sensitive and specific EIA was developed to detect IgG anti-HEV activity in human sera. A neutralization test using individual synthetic peptides corresponding to the epitopes designed into the mosaic protein was also developed to confirm IgG anti-HEV activity by absorbing the specimen before retesting by EIA. CONCLUSION: An artificial mosaic protein composed of short linear HEV-specific antigenic epitopes was constructed from synthetic oligonucleotides by PCR and used to develop a sensitive and specific EIA for the detection of anti-HEV activity in human sera.

Journal Article↗