Infection characteristics of patients in acute gastroenteritis outbreaks caused by noroviruses / 中华实验和临床病毒学杂志

Objective@#To analyze the infection characteristics of patients in acute gastroenteritis outbreaks caused by noroviruses.@*Methods@#Between April 2014 and March 2016, the clinical data and samples were collected from the patients in acute gastroenteritis outbreaks caused by noroviruses in Beijing. Noroviruses were detected and genotyped using real time RT-PCR, and the infection characteristics of norovirus gastroenteritis were analyzed using the descriptive epidemiological method.@*Results@#A total of 1743 clinical diagnosed cases of norovirus gastroenteritis were collected, and children under 12 years old accounted for 77.68% (1354/1743). The detection rate of noroviruses was 73.98% (509/688). The detection rates of noroviruses in fecal, swab and vomitus samples were gradually decreased (χ2=67.798, P<0.001). Among these clinical diagnosed cases, vomiting was the most common symptom (93.98%), followed by abdominal pain (40.34%), diarrhea (30.35%) and fever (27.94%). The most common symptom of patients under 6 years old was vomiting(98.14%), whereas diarrhea was most common among over 18 years old patients (68.12%). With the increase of age of the patients, the incidence of vomiting was gradually decreased (χ2=100.913, P<0.001), whereas the incidence of diarrhea was gradually increased (χ2=261.164, P<0.001). There was no statistical difference in vomiting, diarrhea and abdominal pain symptoms between patients infected with genogroup Ⅰ and Ⅱ noroviruses, and patients infected with genogroup Ⅱ (34.49%, 149/432) had the higher incidence rate of fever than that of genogroup Ⅰ (18.18%, 14/77) (χ2=7.985, P<0.01).@*Conclusions@#Noroviruses mainly infected children under 12 years old in acute gastroentertis outbreaks. The most common symptom of patients with acute gastroenteritis caused by noroviruses was vomiting, and the incidences of vomiting and diarrhea were significantly correlated with age of the patients. Patients infected with genogroup Ⅱ had the higher incidence rate of fever than genogroup Ⅰ infection.

Epidemiological and clinical features of norovirus infection among diarrhea patients from the enteric clinics in Beijing, 2013-2014 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To investigate the epidemiological and clinical characteristics of norovirus infection on diarrhea patients from the enteric clinics in Beijing.</p><p><b>METHODS</b>From April 2013 to March 2014, 1 892 fecal specimens and related epidemiological information were collected among diarrhea patients visiting the enteric clinics in Beijing. Norovirus was detected by real time RT-PCR, and data was analyzed under the descriptive epidemiological method.</p><p><b>RESULTS</b>A total of 269 positive cases were found among 1 892 diarrhea patients, with a positive rate as 14.2%. Norovirus caused diarrhea mainly occurred in seasons with lower temperature. Higher positive rates of norovirus were found in northwest mountainous area. Norovirus diarrhea was more commonly seen in children between 6 month and 5 years old, with differences between the two groups statistically significant (P = 0.006). Compared with other occupation, a higher infection rate was identified in children, with differences between the two groups statistically significant (P = 0.025). Nausea and vomiting appeared more common in diarrhea patients with norovirus infection, with differences between the two groups statistically significant (P < 0.05).</p><p><b>CONCLUSION</b>Norovirus was an important pathogen which causing diarrhea in patients visiting the enteric clinics in Beijing. The virus was seen more in patients aged between 6 months and 5 years old. Nausea and vomiting were the common symptoms seen in patients with norovirus diarrhea.</p>

Study on the genotype and epidemic characteristics of diarrheagenic Escherichia coli isolated from diarrheal patients in Beijing / 中华流行病学杂志

Objective To understand the distribution of virulence gene and the epidemiological characteristics of diarrheagenic Escherichia(E.) coli (DEC) from diarrheal patients in Beijing. Methods Stool specimens from diarrheal patients were cultured which were collected from the hospitals under sentinel surveillance program,during 2012-2013. DNA was examined by real-time PCR. Results 253 out of 6 370 specimens were positive for DEC detection with the rate as 4.0%. A total number of 262 DEC strains were isolated. Two different pathotypes of DEC strains with mixed infection,were isolated from 9 specimens. Different pathotypes would show the following profiles:42.8% for enteropathogenic E. coli (EPEC) including 42.0% atypical and 0.8% typical;38.9% for enterotoxigenic E. coli(ETEC)including 24.8%st positive,9.9%lt positive and 4.2%st and lt both positive;15.3% for enteroaggregative E. coli(EAEC);2.7% for enteroinvasive E. coli(EIEC);one strain STEC with serotype O26 ∶ K60. ETEC had obvious characteristics on age. All kinds of DEC were isolated throughout the year with seasonal fluctuation. Conclusion DEC isolates from diarrheal patients in Beijing were dominated by EPEC and ETEC,with atypical ones accounted for the majority of EPEC. One specimen was found under mixed infection. Pathotypes DEC were found to have different age and seasonal distributions.

Study on the genotype and epidemic characteristics of diarrheagenic Escherichia coli isolated from diarrheal patients in Beijing / 中华流行病学杂志

Objective To understand the distribution of virulence gene and the epidemiological characteristics of diarrheagenic Escherichia(E.) coli (DEC) from diarrheal patients in Beijing. Methods Stool specimens from diarrheal patients were cultured which were collected from the hospitals under sentinel surveillance program,during 2012-2013. DNA was examined by real-time PCR. Results 253 out of 6 370 specimens were positive for DEC detection with the rate as 4.0%. A total number of 262 DEC strains were isolated. Two different pathotypes of DEC strains with mixed infection,were isolated from 9 specimens. Different pathotypes would show the following profiles:42.8% for enteropathogenic E. coli (EPEC) including 42.0% atypical and 0.8% typical;38.9% for enterotoxigenic E. coli(ETEC)including 24.8%st positive,9.9%lt positive and 4.2%st and lt both positive;15.3% for enteroaggregative E. coli(EAEC);2.7% for enteroinvasive E. coli(EIEC);one strain STEC with serotype O26 ∶ K60. ETEC had obvious characteristics on age. All kinds of DEC were isolated throughout the year with seasonal fluctuation. Conclusion DEC isolates from diarrheal patients in Beijing were dominated by EPEC and ETEC,with atypical ones accounted for the majority of EPEC. One specimen was found under mixed infection. Pathotypes DEC were found to have different age and seasonal distributions.

Study on the genotype and epidemic characteristics of diarrheagenic Escherichia coli isolated from diarrheal patients in Beijing / 中华流行病学杂志

<p><b>OBJECTIVE</b>To understand the distribution of virulence gene and the epidemiological characteristics of diarrheagenic Escherichia(E.) coli (DEC) from diarrheal patients in Beijing.</p><p><b>METHODS</b>Stool specimens from diarrheal patients were cultured which were collected from the hospitals under sentinel surveillance program, during 2012-2013. DNA was examined by real-time PCR.</p><p><b>RESULTS</b>253 out of 6 370 specimens were positive for DEC detection with the rate as 4.0%. A total number of 262 DEC strains were isolated. Two different pathotypes of DEC strains with mixed infection, were isolated from 9 specimens. Different pathotypes would show the following profiles: 42.8% for enteropathogenic E. coli (EPEC) including 42.0% atypical and 0.8% typical; 38.9% for enterotoxigenic E. coli (ETEC) including 24.8% st positive, 9.9% lt positive and 4.2% st and lt both positive;15.3% for enteroaggregative E. coli(EAEC);2.7% for enteroinvasive E. coli (EIEC); one strain STEC with serotype O26:K60. ETEC had obvious characteristics on age. All kinds of DEC were isolated throughout the year with seasonal fluctuation.</p><p><b>CONCLUSION</b>DEC isolates from diarrheal patients in Beijing were dominated by EPEC and ETEC, with atypical ones accounted for the majority of EPEC. One specimen was found under mixed infection. Pathotypes DEC were found to have different age and seasonal distributions.</p>

Analysis of clinical features in patients with influenza A/H1N1 / 中华全科医师杂志

A total of 3499 cases of influenza A (H1N1) were included in this study for analysis.Epidemiological and clinical data of these cases were input into EpiData software and analyzed by SPSS software. Throat swabs were collected from the cases and detected for nucleic acid of influenza A ( H1N1 )virus using real-time polymerase chain reaction (RT-PCR) with fluorescence quantitative method, and time of viral excretion and clinical features of the cases were analyzed. Results showed that 0. 37% of the cases were in-apparent and asymptomatic and the most common symptom of the cases was fever (86. 77% ).Throat swabs converted to negative on the sixth day of onset in average, and no factors related to the time of conversion was found with logistic regression analysis.