ABSTRACT
Objective To identify the risk factors for reported sudden rise of measles incidence in November,2011,in some areas of Hubei province.Methods We analyzed all measles patients reported in the measles surveillance system from November 2011 to February 2012 in two prefectures with highest attack rates and their vaccination history by reviewing vaccination records.We interviewed patients' parents by telephone to obtain the history of visiting health care within 7 to 21 days before onset.We also used case-crossover study to estimate the relative risk (RR) of hospital acquired infection and to compare the exposure to health care between 7-21 days before onset to 37-51 days before onset among measles patients.Results Totally 140 patients were reported in the two prefectures.Reported measles incidence rates among the population aged ＜8 m (69/100 000) and 8 m to 17 m (72/100 000) were higher than other age groups (rang from 0 to 5.8 per 100 000).Among the population aged 8 m to 17 m,estimated vaccination coverage was lower than 75％,and it was lower than 90％ among those aged 18 m to 3 yrs.During 7-21 days before onset,58％(29/50) of the patients had an exposure to health care settings,compared to 14％ (7/50) of patients during 37 to 51 days before onset (MH RR=5.4,95％ confidence interval=2.1-14.0).Conclusion Under the condition of measles vaccination coverage lower than 95％,iatrogenic infection was a risk factor for measles in Hubei.
ABSTRACT
Objective To identify the epidemic characteristics and risk factors of an emerging infectious disease-severe fever with thrombocytopenia syndrome (SFTS) in Hubei province.Methods Active surveillance program on SFTS was set up in monitoring sites-hospitals,at the township level or above,in Suizhou,Huanggang and Wuhan from January to December,2010.Specific surveillance program on SFTS was launched across the province in hospitals above the county level.Cases that matched the definition of surveillance case were identified and reported to Centers for Disease Control and Prevention (CDCs).Cases were interviewed and their blood samples collected and detected using PCR and virus isolation.We also conducted serum antibody surveys among healthy population and livestock and surveillance on vector ticks in those high-epidemic areas.Results 188 cases that matched the definition of surveillance case and 21 deaths were reported in 11 cities,32 countries and 100 towns in 2010,with an incidence rate of 0.33/106.The fatality rate was 11.2％.Data showed that the patients were from hilly areas at the altitude elevated between 28-940 meters.The epidemic period was between April and December with the peak from May to September.The youngest case was an 11-year old,while the eldest was 81 with median age as 56-year old.95.3 ％ of the patients were farmers.All Patients did not have the history of traveling,two weeks before the onset of SFTS.93.6％ of the patients engaged in different kind of work which was associated with agriculture.52.8％ of the patients had been exposed to ticks.22.0％ of the patients had been bitten by ticks.Skin injury was found in 64.2％ of the patients.Samples from 129 cases (68.6％) were collected and detected,with 67.4％ of them (87 cases) showed positive by Real time-PCR for SFTS virus.An elevation in antibody titer by a factor of four or evidence of sero-conversion was observed in 11 patients; SFTS virus was isolated from 2 patients.The total antibody positive rates were 3.8％,55.0％ (6/11 ),36.7％ (2/3) and 80.0％ (4/5) respectively in healthy population,dogs,sheep and cows.Ticks from grass,cattle and sheep were detected positive by Real time-PCR.Conclusion Most cases of SFTS in Hubei were infected by SFTS virus,and cases of livestock were infected by SFTS virus.Ticks might serve as an important vector.Skin injury,exposure to tick bites seemed to be the risk factors.