The Infection Of Haemophilus Influenzae And Natural Immunity Antibody Level Researches On Healthy Children In Partial Jiangsu Province

Haemophilus influenzae is one of the most common causes of invasive bacterial infection in young children worldwide now, approximately 30% acute respiratory diseases were caused by Hi, especially serotype b. In the past 60 years, various researches on Hib have being processed in many countries widely. After the introduction of conjugate Hib vaccines in 80's last century, decreases in incidence of Hib disease in several countries have been well documented. Up to 2004, 94 countries have added Hib conjugated vaccines into national childhood immunization programs. Unfortunately, China is still out of program, like many other developing countries ,a major barrier to the rational introduction of Hib vaccine has been the limited availability of credible disease burden data among children. To reach this target, a population-based epidemiological surveillance on healthy children wasconducted in the area of Binhai, Danyang, Chuzhou of Jiangsu Province.PartⅠNatural immunity antibody level to Haemophilus influenzae type b polysaccharide in Jiangsu Province The public antibody levels directly influence the occur of diseases,while people of different countries, regions, races and ages have different levels of antibody, the cognition of the levels therefore is directive to the rational use of vaccines. ELISA was used to detect the Hib-PRP natural immunity antibody level in serum of healthy children. And the main results are briefly stated as follows:1. Total level of Hib-PRP antibodyThe total positive ratio of the three regions is 60.81% (869/1429) (it is treated as positive when serum Hib-PRP antibody level≥0.15μg/mL),and average GMT is 0.60μg/mL.2. Antibody levels of different regions among childrenThe positive ratios of Binhai, Danyang and Chuzhou are respectively 46.64%, 66.14% and 72.44%.There is no remarkable difference between Chuzou and Danyang(X~2=2.50, P=0.066),while the differences between Chuzou and Binhai, Danyang and Binhai have statisticant meanings(X~2=50.01, P＜0.001; X~2=30.70, P＜0.001).3. Antibody levels among children of different agesThere is a consanguineous tie between antibody level and age, the antibody concentrations can as high as 0.72μg/mL, 1.39μg/mL, 1.13μg/mL respectively in umbilical cord blood, and then reduce with the increase of ages to a bottom at 4～6-month old, bounce back remarkably, especially in danyang and cuzhou, to a level of greater than 1μg/mL after 5-year old.PartⅡThe investigation of oropharyngeal carriage of Haemophilus influenzae among healthy children in partial Jiangsu provinceHaemophilus influenzae is one kind of common bacteria at human nasopharyngeal and oropharyngeal, the natural carriage among healthy people is an important factor in infect diseases caused by Hi. The carriage at oropharyngeal of healthy children is about 20%-40%, so this investigation can provide references for preventing this disease and clinic treatment. The investigation of oropharyngeal carriage among children in partial Jiangsu province was detected via the combination of bacterial cultivation and PCR in spring. The results are as follows:1. Children were divided into several groups follow this rule: every two months while are little than 1-year, and one year as the scale when those are older than 1-year. The Hi carriage ratio of these groups are respectively 55.65%,53.76%,66.02%,54.88%,62.12%,59.15%,63.24%,61.54%,63.33% and 50.56%. It is clear; the third group (3～4-month old) has the highest ratio.2. The positive ratios reduce with ages at first to a bottom, and then bounce back. The positive ration of antibody greater than 50% after 1-year old. 3. No difference of Hi carriage ratio was found between male and female.PartⅢThe surveillance of Hib bacterial meningitis in NanjingHib conjugated vaccine has added into national childhood immunization programs in developed countries. Like many other developing countries, China is still out of this list. The lack of acknowledge about these diseases causing by Hib, especially the incidence and the burden of this bacteria, is the greatest barrier. There is just one investigation on the incidence of Hib meningitis in China has been done by Pro. Yang in HeFei Province, 1990-1992.From 2006 December to 2008 December, Chinese Centers for Disease Prevention and Control carries out a research on bacterial meningitis in Nanjing city, Jiangsu Province. From 2006 December to 2007 April, there are 10 bacterial meningitis in Nanjing, just one is Hib meningitis, about 10%.