Study on epidemic characteristics and etiology of community acquired pneumonia in Guangzhou from 2009 to 2012 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the epidemic characteristics and pathogenic spectrum of community acquired pneumonia (CAP) in Guangzhou from 2009 to 2012.</p><p><b>METHOD</b>14 major comprehensive hospitals were selected from 11 districts as sentinel hospitals for CAP cases surveillance, including 18 982 223 in total during the 4 years. The characteristics of pathogenic spectrum of CAP were stratified and analyzed by year, age and season.</p><p><b>RESULTS</b>18 982 223 cases were included in the surveillance from year 2009 to 2012, in which 56 618 cases were CAP. The number of CAP cases increased from 8677 in year 2009 to 19 947 in year 2012 in Guangzhou; while the percentage of visits for CAP raised from 0.22% (8677/3 893 800) to 0.41% (19 947/4 839 766). The difference showed statistical significance (χ(2) = 2693.00, P < 0.05). Among the hospitalized CAP cases, 66.05% (10 954/16 585) were aged ≤ 5 years old or > 66 years old. The percentage of cases infected by a single pathogen was 88.11% (14 613/16 585), while co-infected cases accounted for 4.17% (691/16 585). Bacteria accounted for the largest proportion of 65.25% (10 821/16 585) as a single pathogen, followed by mycoplasma 13.54% (2245/16 585), virus 9.01% (1494/16 585) and chlamydia 0.32% (53/16 585). The proportion of virus infection was increasing from 4.74% to 11.64%. The difference showed statistical significance (χ(2) = 135.32, P < 0.05). Bacteria infection was the leading causes for CAP cases in all age groups; however the percentage increased with the increasing of ages. The rate of bacterial infection was increased from 48.35% (2993/6191) among children aged ≤ 5 years old to 81.31% (3873/4763) among adults aged over 65 years (χ(2) = 1632.00, P < 0.05). The rate of atypical pathogens (mycoplasma, chlamydia) for children ( ≤ 15 years old) (25.99%, 1805/6945) was higher than that for adults aged ≥ 16 years old (5.12%, 494/9640) (χ(2) = 2.11, P < 0.05). The effect from season on the pathogenic spectrum was not observed.433 hospitalized CAP cases were dead from 2009 to 2012. Case fatality rate was highest among people aged over 65 years old (4.70%, 224/4763) and lowest among children aged between 6 to 15 years old (0.27%, 2/754).</p><p><b>CONCLUSION</b>The incidence of community acquired pneumonia was rising in Guangzhou from 2009 to 2012. Bacteria was the dominant pathogen. Children and old people were the high-risk population of community acquired pneumonia; while co-infection was still at low level.</p>

Evaluation on the risks of H5, H7 and H9 avian influenza infections in Guangzhou: using data from the 2006-2012 avian influenza surveillance program / 中华流行病学杂志

<p><b>OBJECTIVE</b>To analyze the results of avian influenza surveillance program in Guangzhou from 2006 to 2012 and to evaluate the risk of infections with H5, H7 and H9 subtypes avian influenza viruses.</p><p><b>METHODS</b>Avian influenza surveillance system in Guangzhou consisted five components:serum surveillance on occupational population, environmental specimen surveillance of avian influenza virus, avian flu emergency surveillance, influenza viruses surveillance on ILI patient and surveillance on pneumonia of unknown causes. Hemagglutination inhibition test was conducted to detect the antibodies against H5, H7 and H9 while RT-PCR was used to test the nucleic acid of H5, H7 and H9 viruses.</p><p><b>RESULTS</b>From 2006 to 2012, 4103 serum specimens were collected from occupational populations and the overall positive rate of H5/H7/H9 antibodies was 3.82% . The antibody positive rates for H5, H7 and H9 were 0.22% ,0.00% and 3.70% respectively. 4 serum specimens for H5 and H9 simultaneously showed antibody positive. The positive rate of H9 among occupational populations(4.21%)appeared higher than that from the control population(2.16%). 2028 specimens were collected from poultry sites and 55 samples found positive for H5 nucleic acid (positive rate:2.71%), 14 samples positive for H9 nucleic acid (positive rate:0.69%), 5 specimens, simultaneously positive for H5 and H9 nucleic acids. However, none of the samples showing H7 nucleic acid positive. From 2006 to 2012, all the tested H5/H7/H9 virus were negative from the respiratory/serum specimens among those close contacts of patients or high risk groups through the avian flu emergency surveillance program,ILI patient influenza virus surveillance programs or pneumonia of unknown causes surveillance program.</p><p><b>CONCLUSION</b>Contamination of H5/H9 avian influenza virus did exist in the poultry sites in Guangzhou, especially in the wet Markets. The H5/H9 avian influenza virus caused asymptomatic infection was proved to be existed within the population exposed to the poultry, suggesting that the poultry occupational population in Guangzhou was under the risk of avian influenza virus infection.</p>

An epidemiological investigation on a food-born outbreak of noroviru caused by Sydney 2012 G II.4 strain / 中华流行病学杂志

<p><b>OBJECTIVE</b>To identify the source of infection, route of transmission and risk factors related to a cluster of acute gastroenteritis cases in a university of Guangzhou.</p><p><b>METHODS</b>Cases were identified according to the definition. Descriptive epidemiological approaches and case-control study designs were employed in the analysis. All the samples were tested for norovirus by RT-PCR. Positive samples were subjected to both nucleotide sequence and homology analysis.</p><p><b>RESULTS</b>A total of 141 cases related to norovirus gastroenteritis were identified in January 8 to 21, 2013, with the attack rate as 8.5 per thousand (141/16,600). The peak in morbidity was seen on January 8 to 9. No clustering was found in different classes or dormitories. Results from the case-control study revealed that early cases were infected in Restaurant A (OR = 3.46, 95% CI: 1.07-11.16) and the cold shredded chicken set meal (OR = 17.82, 95% CI: 4.46-78.17) served at lunch (OR = 4.34, 95% CI: 1.18 -17.37) on January 7 was under suspicion. A total of 266 samples, including rectal swabs from the patients and kitchen wokers, leftover food and environmental swabs, were collected. Twenty-one samples (collected from 17 persons) were positive for norovirus by RT-PCR. About 29.6% (8/27) of the kitchen workers in the Restaurant A were tested positive for the virus. The pathogen was identified as the new norovirus genotype II.4 variant, termed Sydney 2012. The virus strains isolated from the patients among student and staff and the kitchen workers were 100% identical in their nucleotide sequence.</p><p><b>CONCLUSION</b>This was the first reported acute gastroenteritis outbreak caused by the new norovirus genotype II.4 variant, Sydney 2012, which showed that the food was contaminated by the asymptomatic kitchen workers who carried the virus.</p>

Risk evaluation on H7N9 avian influenza in Guangzhou, China / 中华流行病学杂志

<p><b>OBJECTIVE</b>We conducted both quick surveillance and evaluation programs within one week after the novel H7N9 influenza cases had been released by the Ministry of Health (MOH), to get the basic information on H7N9 virus in Guangzhou.</p><p><b>METHODS</b>We sampled live birds from food markets and the natural habitat of birds to detect H7N9, H5 and H9 viruses. We interviewed workers from both markets and natural habitats. We also reviewed records on pneumonia patients with unknown causes from the surveillance system, to find clues related to the identification of severe pneumonia.</p><p><b>RESULTS</b>We sampled 300 specimens from 49 stalls in 13 food markets and a natural habitat but none showed H7N9 positive result. A chopping block was detected positive of carrying H5 avian influenza virus, while another 4 specimens including a chicken cage, a duck cage, a chopping block and a pigeon cage were detected positive of carrying H9 avian influenza virus. In the past month, no sick, dead birds or ILI cases among the workers were discovered. 21.2% (7/33) of the stalls did not follow the set regulations for prevention. 10.3% (4/39) of the stalls had the cages cleaned, 4 days after the inspection. 3.7% (2/54) of the workers wore masks and 40.7% (22/54) of them wore gloves during the slaughtering process. 102 bird feces specimens were tested negative on H7N9 virus. No pneumonia cases with unknown reason were identified. From April 3(rd) to 17(th), we found 26 severe pneumonia cases but with negative results on influenza A (H7N9).</p><p><b>CONCLUSION</b>According to the data and information from 1) lab tests, 2) pneumonia cases with unknown reasons under the surveillance system, 3) the identification of severe pneumonia cases, and 4) preventive measures and actions taken by the workers, we inferred that no H7N9 virus or related cases were found prior to April in Guangzhou. However, the risk of H7N9 epidemic does exist because of the following reasons:1) improper market management process, 2) negligent behavior of the workers and 3) potential trend of the national situation, suggesting strategies related to poultry markets management, health education and preventive measures against the avian influenza need to be strengthened.</p>

Association of physical activity with bone mass in premenarche Chinese girls / 中华预防医学杂志

<p><b>OBJECTIVE</b>To assess the association of physical activity with bone mass in premenarche girls.</p><p><b>METHODS</b>Bone mineral density (BMD) and bone mineral content (BMC) at the whole body, femoral neck, Ward triangle and L1-L4 spine were measured using dual-energy X-ray absorptiometry (DXA) in 194 premenarche girls (10 +/- 1, year). Physical activity and dietary calcium intakes were assessed by using frequency questionnaire and diary.</p><p><b>RESULTS</b>It was found that BMD and BMC were significantly and positively associated with weight-bearing physical activities (WBPA) (P < 0.01), total physical activities (TPA) (P < 0.01) rather than non-weight-bearing physical activity (P > 0.05) at all the studied bone sites (P < 0.01). Both BMC and BMD were tending to a better increase of WBPA. When WBPA increases from 227 to 415 (kcal/d), mean BMC and BMD were increased in 17.5%-29.0% and 8.8%-17.1%, respectively.</p><p><b>CONCLUSION</b>It should be helpful for premenarche girls to improve bone mass by increasing physical activities, especially weight-bearing physical activities.</p>