Epidemiologic and surveillance studies on avian influenza in live-bird markets in New York and New Jersey, 2001.

In 2001, all 109 retail live-bird markets (LBMs) in New York and New Jersey were surveyed for the presence of avian influenza virus (AIV) by a real time reverse transcriptase/polymer chain reaction assay (RRT/PCR) and results compared to virus isolation (VI) in embryonating chicken eggs. The RRT/PCR had a 91.9% sensitivity and 97.9% specificity in detecting presence of AIV at the market level. However, the sensitivity at the sample level is 65.87%. The RRT/PCR is a reliable method to identify AIV at the market level. In addition, a cross-sectional epidemiologic study of the LBMs showed that, during the past 12 months, markets that were open 7 days per week and those that also sold rabbits had the highest risk for being positive for AIV. Markets that were closed one or more days per week and those that performed daily cleaning and disinfecting had the lowest risk for being AIV positive.

Development of real-time RT-PCR for the detection of avian influenza virus.

A real-time reverse transcriptase/polymerase chain reaction (RRT-PCR) assay was developed using hydrolysis probes for the detection of avian influenza virus (AIV) and the H5 and H7 subtypes. The AIV specific primers and probes were directed to regions of the AIV matrix gene that are conserved among most type A influenza viruses. The H5 and H7 primers and probes are directed to H5 and H7 hemagglutinin gene regions that are conserved among North American avian influenza viruses. The sensitivity and specificity of this RRT-PCR assay was compared to virus isolation (VI) in chicken embryos with 1550 clinical swab samples from 109 live-bird markets (LBMs) in New York and New Jersey. RRT-PCR detected influenza in samples from 61 of 65 (93.8%) of the LBMs that were the sources of VI positive samples. Of the 58 markets that were positive for H7 influenza by hemagglutination inhibition assay, RRT-PCR detected H7 influenza in 56 markets (96.5%). Too few H5 positive samples were obtained to validate the H5 RRT-PCR assay in this study. Although RRT-PCR was less sensitive than VI on an individual sample basis, this study demonstrated that the AIV and H7 RRT-PCR assays are good tools for the rapid screening of flocks and LBMs.

Development of multiplex real-time RT-PCR as a diagnostic tool for avian influenza.

A multiplex real-time reverse transcriptase-polymerase chain reaction (RRT-PCR) assay for the simultaneous detection of the H5 and H7 avian influenza hemagglutinin (HA) subtypes was developed with hydrolysis type probes labeled with the FAM (H5 probe) and ROX (H7 probe) reporter dyes. The sensitivity of the H5-H7 subtyping assay was determined, using in vitro transcribed RNA templates, to have a reproducible detection limit for H7 of approximately 10(4) HA gene copies and approximately 10(4)-10(5) HA gene copies of H5. A direct comparison of H5-H7 multiplex RRT-PCR with hemagglutination inhibition (HI) was performed with 83 AI RRT-PCR and virus isolation positive tracheal and cloacal swab samples obtained from various avian species and environmental swabs from live-bird markets in New York and New Jersey. Both multiplex RRT-PCR and HI agreed on the subtype determination of 79 (95.2%) of the 83 samples, of which 77 were positive for H7 and two were determined to be non-H5/non-H7 subtypes. No samples were determined to be the H5 subtype by either assay.

The effect of various disinfectants on detection of avian influenza virus by real time RT-PCR.

An avian influenza (AI) real time reverse transcriptase-polymerase chain reaction (RRT-PCR) test was previously shown to be a rapid and sensitive method to identify AI virus-infected birds in live-bird markets (LBMs). The test can also be used to identify avian influenza virus (AIV) from environmental samples. Consequently, the use of RRT-PCR was being considered as a component of the influenza eradication program in the LBMs to assure that each market was properly cleaned and disinfected before allowing the markets to be restocked. However, the RRT-PCR test cannot differentiate between live and inactivated virus, particularly in environmental samples where the RRT-PCR test potentially could amplify virus that had been inactivated by commonly used disinfectants, resulting in a false positive test result. To determine whether this is a valid concern, a study was conducted in three New Jersey LBMs that were previously shown to be positive for the H7N2 AIV. Environmental samples were collected from all three markets following thorough cleaning and disinfection with a phenolic disinfectant. Influenza virus RNA was detected in at least one environmental sample from two of the three markets when tested by RRT-PCR; however, all samples were negative by virus isolation using the standard egg inoculation procedure. As a result of these findings, laboratory experiments were designed to evaluate several commonly used disinfectants for their ability to inactivate influenza as well as disrupt the RNA so that it could not be detected by the RRT-PCR test. Five disinfectants were tested: phenolic disinfectants (Tek-trol and one-stroke environ), a quaternary ammonia compound (Lysol no-rinse sanitizer), a peroxygen compound (Virkon-S), and sodium hypochlorite (household bleach). All five disinfectants were effective at inactivating AIV at the recommended concentrations, but AIV RNA in samples inactivated with phenolic and quaternary ammonia compounds could still be detected by RRT-PCR. The peroxygen and chlorine compounds were effective at some concentrations for both inactivating virus and preventing amplification by RRT-PCR. Therefore, the RRT-PCR test can potentially be used to assure proper cleaning and disinfection when certain disinfectants are used.

Descriptive and surveillance studies of suppliers to New York and New Jersey retail live-bird markets.

Low pathogenicity avian influenza virus (AIV) H7N2 has been isolated since 1994 from retail live-bird markets (LBMs) in the northeastern United States. This study examines the suppliers to the LBMs in New York and New Jersey. In 2001, 185 supplier premises in nine states were surveyed for the presence of AIV by virus isolation (VI) in embryonating chicken eggs. No H7 or H5 virus was isolated. In addition, 104 producer premises in two states were serologically negative for H7 and H5 AIV. Information on management practices was obtained via questionnaire for 191 premises in 12 states. The survey results suggest that current biosecurity practices at supplier premises could be improved, especially regarding movement of birds. The study supports the hypothesis that H7N2 AIV is primarily maintained within the LBMs and, if reintroduction from suppliers is occurring, it is likely reintroduced at a very low level or from suppliers not included in this study.

[Health status and fitness of the young men for military service]. / Sostoianie zdorov'ia i prigodnost' iunoshei k sluzhbe v armii.

Submitted in the article are medical causes of unfitness of those men called up for military service in peace-time. These include psychic dysfunctions (22%), traumata (18.5%), disorders of the nervous system and sensory organs (14.5%), of the osteomuscular system and connective tissue (13.3%), digestive diseases (8.6%). Mental disorders, those of the nervous system and sensory organs, the endocrine system and digestive organs rank first among causes of striking the serviceman off the register, coming up to 40.9%, 31.2%, and 6.8% respectively. Age has been established at which disease manifestations causing unfitness for military service come to reveal themselves: in 58.4 percent of registrants the above manifestations were first diagnosed in childhood, in 5.4 percent--at 16 to 17 years of age, in 36.2 percent--at call-up age.

Prevalence and risk association for Trichinella infection in domestic pigs in the northeastern United States.

To determine Trichinella infection in a selected group of farm raised pigs, 4078 pigs from 156 farms in New England and New Jersey, employing various management styles, were selected based on feed type (grain, regulated waste, non-regulated waste). The number of pigs bled from each farm were based on detecting infection assuming a 0.05 prevalence rate. Serum was tested by enzyme-linked immunoassay for antibodies to Trichinella spiralis. Seropositive pigs were tested by digestion at slaughter (when possible) for the presence of Trichinella larvae. Questionnaires completed at the time of serum collection were used to develop descriptive statistics on farms tested and to determine measures of association for risk factors for the presence of Trichinella-seropositive pigs. A total of 15 seropositive pigs on 10 farms were identified, representing a prevalence rate of 0.37% and a herd prevalence rate of 6.4%. A total of nine seropositive pigs and one suspect pig from six farms were tested by digestion; four pigs (representing three farms) harbored Trichinella larvae at densities of 0.003-0.021 larvae per gram (LPG) of tissue; no larvae were found in six pigs. Risk factors which were significantly associated with seropositivity included access of pigs to live wildlife and wildlife carcasses on the farm; waste feeding had no statistically significant association with seropositivity for Trichinella infection in pigs. The presence of Trichinella infection in pigs in New England and New Jersey has declined during the past 12 years when compared with previous prevalence studies.

[Ways of improving medical services for schoolchildren]. / Puti sovershenstvovaniia meditsinskogo obespecheniia shkol'nikov.

The protection and promotion of schoolchildren's health might be ensured by means of differential approach to the use of different forms of organization of medical provision and its further improvement with due regard for regional conditions. The development of All-union programme "Schoolchildren" is needed which would provide for a scientific base for improving organizational and health-promoting activities at general education schools and boarding schools.