To investigate the characteristics and risk factors of an outbreak of acute hemorrhagic conjunctivitis (AHC) in a boarding middle school in Guangdong Province, in order to provide a scientific evidence for effective prevention and control of campus AHC outbreaks.
From September 1st to 28th 2023, case identification was conducted among 559 students and 60 faculty members using standardized definition. Descriptive analysis was conducted on the three distrubution patterns of the outbreak. Questionnaires were designed, and a case-control study was adopted to analyze the possible risk factors of the disease transmission. The propensity score matching (PSM) method was used to control the difference of baseline data.
A total of 269 cases of AHC were identified, with an attack rate of 43.46%. The pathogen was confirmed as Coxsackie virus A24 variant (CA24v). Among these, 264 cases were students (attack rate of 47.23%) and 5 were staff (attack rate of 8.33%). A total of 153 pairs of PSM were successfully matched. After PSM matching, there were no statistically significant differences in gender, grade and class between the case group and the control group (χ2=0.12, 5.41, 11.24, P>0.05). The results of multivariate Logistic regression analysis showed that middle school students whose towels contacted with others (OR=1.81), and direct contact with other AHC cases recently (OR=4.89) were more likely to have AHC; while wearing glasses (OR=0.43) and frequent use of hand sanitizer (OR=0.37) were less likely to have AHC (P < 0.05).
The outbreak of AHC is caused by CA24v, demonstrating rapid spread and extensive impact within the school setting.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |