Humans ; Rhabdomyolysis/epidemiology* ; Disease Outbreaks/prevention & control*

Disease Outbreaks ; Humans ; Influenza, Human ; epidemiology ; prevention & control

Child ; Humans ; Mpox (monkeypox)/prevention & control* ; Disease Outbreaks

OBJECTIVEforecast the epidemic trend and to evaluate the effect of outbreak control measures by investigation of a varicella outbreak event with a discrete time delay SEIR model.

METHODSA discrete time delay model was formulated by discretization method based on a continuous SEIR model with the consideration of the time delay effect on latent period and communicable period. The epidemic trend forecast was carried out based on the number of expected cases. The theoretical effect evaluation was assessed by comparing the results from different emergency control measures.

RESULTSWithout any control measures, the theoretical attack rate was 30.16% (504/1671). The course of the epidemic lasted for 4 months and the peak epidemic time was 78 days after the onset of the first case. 'Generation' phenomenon had been observed in the course of the epidemic with the interval of two weeks. The actual number of cases was decreased by 89.48% (451/504) compared with the number of expected cases under no control measure scenario. With the rigorous quarantine measure for all cases on their onset day, when the measure was conducted on 0, 14, 28, 42 days after the onset of the first case, the total numbers of expected cases were 22, 59, 127 and 220 respectively. With the quarantine measure conducted on 14 days after the onset of the first case, when the proportion of quarantine was 30%, 50%, 70%, 90%, the total number of expected cases were 485, 457, 386 and 169, respectively. With the emergent vaccination for all persons, when the measure was conducted on 0, 14, 28, 42 days after the onset of the first case, the total numbers of expected cases were 7, 26, 81 and 202 respectively. With the emergent vaccination conducted on 14 days after the onset of the first case, when the immunization coverage rate was 30%, 50%, 70%, 90%, the total numbers of expected cases were 354, 246, 127 and 40, respectively.

CONCLUSIONThe number of expected cases can be regarded as the reference to evaluate the effect of control measures. The simulation results suggest that it will get more benefits to conduct control measures earlier in varicella outbreak events, and the effect of emergent vaccination is better than that of quarantine measure under the same conditions.

Chickenpox ; epidemiology ; prevention & control ; Communicable Disease Control ; methods ; Disease Outbreaks ; prevention & control ; Humans ; Incidence ; Models, Theoretical

OBJECTIVETo evaluate the development and operation on measles surveillance system.

METHODSTo formulate surveillance program, and then establish surveillance system on measles in Hainan province before the case surveillance was conducted. Descriptive epidemiological method was used to analyze the measles cases reported through the notifiable diseases epidemic situation report system and measles surveillance system during 2004 - 2008 in Hainan province.

RESULTSFrom 2004 to 2008, through surveillance system, 3040 suspected measles cases were reported which was 96.00% higher than that from the notifiable diseases epidemic situation report system. When the measles surveillance system was first established in 2004, the number of cases reported by the surveillance system was less than that from the epidemic report system, however, the sensitivity of the surveillance system had been increasing since 2005. In 2008, the number of suspected cases reported by surveillance system was 19.12 times more than from the epidemic report system. The proportion of confirmed cases in the total suspected cases was decreasing annually, from 90.34% to 4.48%, along with the increase of the sample collection rate, from 22.73% to 99.12%. The proportion of laboratory confirmed cases in the total confirmed cases increased from 7.55% to 86.97%. With suspected cases, the IgM antibody positive rate on measles and rubella were 31.57% and 34.52%, respectively. In Hainan, the epidemic pattern of measles had been sporadic, except for 2006 as there occurred several outbreaks in that year. The of disease incidence had an obvious seasonal peaks, from March to June. Measles mainly attacked children under 15 years of age, accounted for 86.68% of the age group. Children with no immunity or unknown immune history accounted for 85.67%.

CONCLUSIONThe sensitivity of surveillance system had been increasing annually since it was developed and the incidence had been dropping to its lowest level. These achievements had built a solid foundation for the eventual elimination of measles.

China ; epidemiology ; Disease Outbreaks ; prevention & control ; Humans ; Incidence ; Measles ; epidemiology ; prevention & control ; Population Surveillance

Disease Outbreaks ; prevention & control ; Humans ; Influenza A Virus, H5N1 Subtype ; Influenza Vaccines ; Influenza, Human ; prevention & control

Child, Preschool ; Disease Outbreaks ; prevention & control ; Humans ; Mumps ; epidemiology ; prevention & control ; Mumps Vaccine ; Treatment Outcome

Disease Outbreaks ; prevention & control ; Humans ; Influenza, Human ; drug therapy ; epidemiology ; prevention & control

Tuberculosis (TB) is one of the global major public health problems. China has the second highest TB burden worldwide. This article introduces the epidemiology of TB in China and elucidates the progress and challenges in TB prevention and control.
China ; epidemiology ; Disease Outbreaks ; prevention & control ; Humans ; Public Health ; methods ; Tuberculosis ; prevention & control

Chickenpox ; prevention & control ; China ; Disease Outbreaks ; prevention & control ; Humans ; Schools ; Vaccination ; statistics & numerical data