Clinical Feature And Epidemiology Among The Patients With Measles In Northern China Region

BackgroundDuring the period from December.2013 to the first half of 2014, a large number of measles cases emerged in Beijing and Shenyang cities. Then, are there any clinical characteristics and epidemic among these patients with measles? How about the immunological and virological characteristics for these measles patients? Whether the sudden rise in the measles incidence rate was due to viral gene mutation? Therefore, our purpose is to address the above-mentioned issues.Materials and methodsWe collected the clinical data of the 112 measles in-patients who were hospitalized in our hospital during January-May,2014. Simultaneously, we also recruited age-and sex-matched healthy controls with 30 adult measles cases; we collected the heparin anti-coagulation data of the measles inpatients during acute phase and recovery phase as well as the heparin anti-coagulation data of controls, performed immunological assay in flow cytometry and carried out statistical analysis on the results. We collected the blood serum and throat swabs of the measles patients who were receiving treatment in our hospital (n=112) and Shenyang No.6 People’s Hospital (n=150), performed test on measles virus IgM antibody, isolated virus to make gene sequencing, and analyzed the molecular characteristics of measles virus N gene and H gene.Results1. Epidemiology and clinical feature of the measles patients:Among 112 measles inpatients, 46 (41.07%)cases had contacted with measles patients prior to disease onset; 78 (69.64%) cases have never been inoculated with measles vaccine; there are 85 (75.89%)adult cases.The median eruption time after fever is 3 days (2-4), the median number of fever days is 7 days (6-9); the clinical manifestations mainly included fever(100%), skin rash(100%), cough (90.18%), running nose (85.71%), conjunctivitis(100%) and oral Koplik spot (78.57%). There were 37 (33.04%)cases of measles complicated pneumonia, including 10(76.92%) cases<8 months,19 (22.35%)cases aged over 18, with the difference statistically significant(P< 0.01); there were 56 (50%)cases of liver damage, including 2 (3.57%)cases< 8 months and 51 (91.07%)cases aged over 18, with difference statistically significant(P< 0.01). COX regression model revealed that, whether the measles patients are complicated with pneumonia is an independent risk factor which affects the total course of disease (P< 0.01).2. Immunology and virology feature of mealses patients:During the acute phase and the recovery phase of 30 adult measles patient, the proportions of CD4+IL17+, CD4+IFN-y+and CD8+FNγ+Τ lymphocytes reduced as compared with that of the control group(P< 0.05); For the measles patients during acute phase, the proportion of CD8-IL22+cells obviously increased, and both the differences in comparison with the recovery phase and the control group have statistical significance(P< 0.05). For the measles patients, the proportion of regulatory T lymphocyte obviously increased. Among the 262 measles patients, there were 234 (89.32%) cases with positive virus IgM antibody,82 (31.30%)strains of positive measles virus were isolated with throat swabs, which were of H1a genotype; H protein gene sequencing showed that there were S240N, Y481N and P397L substitute mutations.Conclusions1:Higher pneumonia incidence rate (48.65%) was observed among measles patients who is under 18-year-old, while liver damage was more prominent among the adult patients with measles(60.00%). Pneumonia is an independent risk factor which may affect the total disease course of measles patient2:The total lymphocyte count of adult measles patients reduced, CD4+T lymphocyte count of measles patients during acute phase shown decrease trend while CD8+ T lymphocyte count shown increase trend. For the measles patients, CD3+IFNγ+ and CD4+IL17+ T lymphocyte count remarkably reduced; CD8+DL22+ T lymphocyte count remarkably increased during acute phase while gradually decreasedduring recovery phase. For me measles patients, the proportions of Treg cells obviously increased during both acute phase and recovery phase.3:The virus which causes measles outbreak in Northern China in 2014 was mainly of H1a genotype, which is the major genotype of epidemic measles at present in China The results of H protein gene suggested that, live attenuated measles virus vaccine which is applied at present is still able to effectively protect the susceptible population.