Epidemiological and etiological analysis of two infantile cases of serogroup B epidemic cerebrospinal meningitis epidemics in Shandong Province, 2021 / 中华预防医学杂志

Two cases of epidemic situation of serogroup B meningitis in infants in Shandong Province in 2021 were investigated. Samples of cases and their close contacts were collected for isolation, culture and identification of Neisseria meningitides (Nm). The isolates were subjected to multi-locus sequence typing, outer membrane protein porA and fetA genotyping and drug sensitivity test. Two laboratory-confirmed outbreaks of serogroup B meningitis were reported from Yantai city and Linyi city. The indicated cases were infants aged 5 months and 2 months old respectively. They were not vaccinated with meningitis vaccine. Their epidemiological characteristics and clinical manifestations were similar and the prognosis was good. The same sequence type (ST) of serogroup B Nm strains as the indicated cases was detected in the samples of close family contacts, but without subsequent cases. Among them, Yantai strain was were identified as the type ST-8920, belonging to CC4821 clonal complex, and the genotypes of porA and fetA were p1.21-2, 23 and F3-1. Linyi strain was a new type, belonging to CC4821 clonal complex and the genotypes of porA and fetA were p1.20, 23 and F1-91. The above strains were resistant to penicillin, ciprofloxacin, levofloxacin and Chemitrim, and their sensitivity to cephalosporin decreased. Two cases of infant serogroup B epidemic were relatively rare in China, which were different from the epidemiological and pathogenic characteristics of other Nm serogroups in the past.

Preliminary analysis on the prevalence and causes of breakthrough hepatitis B virus infection among children in Shandong province, China / 中华预防医学杂志

<p><b>OBJECTIVE</b>To know the prevalence and probable causes of breakthrough hepatitis B virus (HBV) infection among children born after the introduction of universal infant hepatitis B vaccination in Shandong province, China.</p><p><b>METHODS</b>The subjects of this study were selected from the provincial hepatitis B serosurvey conducted in 2006, who were born between 1992 and 2005 (aged 1-15 years) and were confirmed to have completed three or more doses of hepatitis B vaccine. Finally 3527 subjects were involved in this study and were investigated using a unified question are. Blood samples were collected from them to detect hepatitis B surface antigen (HBsAg), antibody against HBsAg (Anti-HBs) and antibody against hepatitis B core antigen (Anti-HBc). The parents of children positive for HBsAg were followed up. Blood samples were collected from their parents to detect for HBsAg. The rate and correlative factors of breakthrough HBV infection were gotten by single-factor and multiple-factor analysis.</p><p><b>RESULTS</b>For the 3527 subjects, the overall prevalence rates of breakthrough HBV infection were 3.15% (111/3527), which decreased while birth year grew (χ(2)(Trend) = 44.83, P < 0.01) , the rate of subjects born in 1992 was the highest (9.9%, 16/161) , subjects born in 2000 was the least (0.8%, 2/258) , the rate of the self-report positive HBsAg status of mother, father and the other family members (15.22%, 7/46;34.09%, 15/44;17.65%, 6/34) were higher than the negative (2.99%, 104/3481, 2.76%, 96/3483, 3.01%, 105/3493) (χ(2) values were 22.28, 13.97, 23.68, respectively, all P values were < 0.01) , timely first dose of hepatitis B vaccine (5.37%, 41/763) was higher than the subjects that not in time (2.53%, 70/2764) (χ(2) = 15.596, P < 0.01) . The overall prevalence rates of breakthrough chronic HBV infection was 1.08% (38/3527), which decreased while birth year grew (χ(2)(Trend) = 9.96, P < 0.05) , the rate of subjects born in 1992 was the most (3.1%, 5/161) , subjects born in 1997 was the least (0.4%, 1/261) , the rate of the self-report positive HBsAg status of mother, father and the other family members (13.04%, 6/46;29.55%, 13/44;17.65%, 6/34) were higher than the negative (0.92%, 32/3481;0.72%, 25/3483;0.92%, 32/3493) (χ(2) values were 62.62, 338.80, 88.44, respectively, all P values were < 0.05) , timely first dose of hepatitis B vaccine (1.83%, 14/763) was lower than the subjects that not in time (0.87%, 24/2764) (χ(2) = 5.16, P = 0.02) . Multiple factors analysis showed that compared to the negative, the self-report positive HBsAg status of father, mother increased the risk of breakthrough HBV infection,OR (95%CI) values were 3.73 (1.09-12.75) and 26.76 (11.86-60.37) , respectively (all P values were < 0.05) , compared with eastern cities, the risk of western cities were the highest (OR (95%CI) = 6.00 (2.50-14.40) , P < 0.05) the risk of children born in 1992-2001 was higher than those born in 2002 ( (OR (95%CI) = 1.91 (1.10-3.32) , P < 0.05) . Compared to the negative, the self-report positive HBsAg status of father, mother and the other family members increased the risk of breakthrough chronic HBV infection,OR (95%CI) values were 7.51 (1.44-39.17) , 99.99 (34.29-291.62) , 8.94 (1.81-44.10) , respectively (all P values were < 0.05) , compared with eastern cities, the risk of western rural areas were the highest (OR (95%CI) = 12.51 (2.78-56.25) , P < 0.05) , sharing tooth brush with the others increased the risk (OR (95%CI) = 8.67 (1.14-66.14) , P < 0.05) . Among HBsAg-positive children, those with HBsAg positive mother and father accounted for 12/23 and 6/19, respectively.</p><p><b>CONCLUSION</b>The prevalence of breakthrough HBV infection and breakthrough chronic HBV infection among children was low in Shandong province. Mother to infant transmission might be the main reason for the infection while the role of the horizontal transmission within the family shouldn't be ignored.</p>

The analysis of "a" dominant mutation of hepatitis B virus in community-based population of Shandong Province, China / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To determine the rate and type of "a" dominant mutation of hepatitis B virus (HBV) in community-based population of Shandong province and the possible effect of hepatitis B vaccination upon "a" dominant mutation.</p><p><b>METHODS</b>The anticipants aged 1-59 years were selected by multi-stage random sampling from the general population of Shandong province. Hepatitis B vaccination status was obtained by inquisition (for those over 15 years old) or immunization record (for those under 14 years old). The blood samples were collected and detected for HBsAg by ELISA. HBV DNA was extracted from the sera with positive HBsAg and S gene was amplified by nested-PCR. The PCR produce was sequenced and compared with the standard sequence.</p><p><b>RESULTS</b>Overall, 7601 anticipants were investigated. HBV DNA was successfully amplified and sequenced in 102 of 239 samples with positive HBsAg. 14.70% sera samples mutated in HBV "a" determinant region and 13 mutation types were detected. There were no statistically differences in the mutation rate by age groups (born before or after national universal infant hepatitis B vaccination) and hepatitis B vaccination status.</p><p><b>CONCLUSION</b>The "a" determinant mutation seemed to be uncommon in community-based population of Shandong province and the mutation sites were relatively scattered. Hepatitis B vaccination has no effect on "a" dominant mutation of hepatitis B virus.</p>

Molecular typing of Neisseria meningitidis serogroup C strains with pulsed field gel electrophoresis in China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the characteristics of epidemiology and molecular typing on Neisseria meningitidis serogroup C strains associated with outbreaks of Anhui province and sporadic cases in China, using pulsed field gel electrophoresis (PFGE).</p><p><b>METHODS</b>212 Neisseria meningitidis serogroup C strains were isolated from invasive meningococcal cases, close contacts and healthy carriers, including 48 strains from Anhui province with 38 strains associated with serogroup C outbreaks. PFGE were performed by genomic DNA digestion with Nhe I restriction enzyme. The results of PFGE were analyzed by BioNumerics software (Version 4.0, Applied Maths BVBA, Belgium).</p><p><b>RESULTS</b>A total number of 212 Neisseria meningitidis serogroup C isolates were typed by 43 patterns, named AH1 to AH43. In China, AH1 pattern was the major PFGE pattern with 69.3% (n = 147) of all strains, distributed in 11 provinces. Three types of PFGE patterns (AH1 to AH3) were found in 48 strains from Anhui province, in which, 93.8% (n = 45) belonged to AH1. 97.4% (n = 37) of 38 strains associated with serogroup C outbreaks in Anhui province showed AH1 pattern. A total of 53 serogroup C strains were isolated from invasive meningococcal cases with 67.9% (36/53) of AH pattern. 71.9% (87/121) of serogroup C strains isolated from contacts of invasive meningococcal cases was AH1 pattern and 63.2% (24/38) of the strains from healthy carriers showed AH1 pattern.</p><p><b>CONCLUSION</b>By PFGE typing and analysis, AH1 pattern of Neisseria meningitidis serogroup C strains was proved to be the main clone which causing the outbreaks in Anhui province and might be responsible for the sporadic serogroup C meningococcal disease epidemics else where in the country.</p>

Analysis on the changing of age patterns among rubella patients after rubella vaccine immunization for children in Shandong Province, China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To analyze the changing of age patterns among rubella patients after implementing rubella vaccine immunization to children in Shandong province since 1995.</p><p><b>METHODS</b>Epidemiologic data on rubella through surveillance system for suspected measles from 1999 to 2004 and data on rubella vaccination were used and analyzed.</p><p><b>RESULTS</b>The annual average incidence rate of rubella from 1999 to 2004 had been 0.59 per 100 thousands population while 81.17% of cases were concentrated during the outbreaks. 77.77% of the cases were school children between 7-15 years old and 7.93% of the cases were under 7 years old. The age-median of cases were 10.37, 11.66, 11.41, 12.81, 14.28 and 13.96 years old from 1999 to 2004, respectively. The estimated coverage of rubella vaccine for pre-school children was about 60% but only 20% were for school children.</p><p><b>CONCLUSION</b>The peak age of cases moved from youth towards adolescence which indicated that women with child-bearing age might have been under risk of developing the congenital rubella syndrome (CRS). It is necessary to carry out screening test of rubella antibody and vaccination to women with child-bearing age and the immunization strategy should be established to guide the control of rubella and CRS.</p>

Epidemiological analysis of cases with rash and fever illness after measles vaccine inoculation during 1999 to 2002 in Shandong province, China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the incidence of cases with rash and fever illness (RFIs) after measles vaccine (MV) inoculation.</p><p><b>METHODS</b>During 1999 to 2002, 150 RFIs cases reported by the special measles surveillance system in Shandong province, China, were investigated and analyzed epidemiologically.</p><p><b>RESULTS</b>7 674 690 ml MV were distributed during 1999 to 2002 and the annual average incidence of RFIs cases after MV inoculation was 0.20/10 000 ml (0.2 ml per dose). There was significant difference of incidences each year (chi(2) = 10.13, P < 0.05). All RFIs cases were sporadically distributed without epidemiological links. Clinical symptoms showed that 88.67% of the 150 RFIs cases having > 38.5 degrees C fever and 75.33% of all cases appeared typical rash after 4 to 11 days (the medium was 8 days) after MV inoculation. The order of rash onset among RFIs cases was consistent with that of regular measles cases caused by wild virus. 68.67% of the RFIs cases had first MV inoculation and 94.71% were 8 to 12 month-olds. IgM sera antibody test from RFIs cases were rubella negative and 45.65% positive for measles.</p><p><b>CONCLUSION</b>RFIs due to allergic reaction or measles vaccine virus infection might occur after MV inoculation. There seemed to be a correlation between RFIs incidence and the doses of MV. Measles virus genotype analysis needs to be carried out to confirm if the onset of some RFIs cases is aetiologically associated to MV vaccine virus infection.</p>