الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
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Abstract
Poliomyelitis is an acute viral infection. It is one of the communicable diseases affecting the central nervous system, and independently resulting in paralysis. Poliovirus infection may be restricted to the intestine, or may spread systemically with or without reaching the CNS . Paralytic poliomyelitis occurs both sporadically and epidemically . However major epidemiological changes have affected poliomyelitis since the introduction of poliovaccines in the mid 1950s . Two types of vaccines are available, one is fonTIalin inactivated (Salk vaccine, TPV) which is given parenterally and the other is live attenuated (Sabin vaccine, OPV) which is given orally. OPV is the vaccine of choice. It is still recommended as the primary vaccine for most countries including Egypt, as it confers both humoral and intestinal immunity like the natural infection. Available technologies hold the promise of being able to eradicate poliomyelitis, and the WHO is providing global leadership to achieve this goal by the year 2000 : One of the major elements of ,poliomyelitis eradication strategy is achieving and sustaining high levels of immunization coverage. Thus, it will become increasingly important to evaluate the efficacy of OPV and the immunization schedules currently in use to determine whether they will be sufficient to achieve and sustain intemlption in transmission of wild polioviruses among the population. The aim of this study was to detect the presence of specific serum antibodies to the three types of poliovinlses , to compare the presence of secretory antibodies against poliovinlses with that of the serum, and to compare the effectiveness of ELISA and neutralization techniques in the detection of antibodies against poliovimses . Two hundred children were enrolled in the study, their ages ranged between one to twelve years. These children were attending public hospitals, private hospitals, as well as doctor clinics for non relevant medical problems. All relevant data were collected ITom each child (as age at first dose, booster doses, compliance with the schedule, health status of the child during and following vaccination) . Two-hundred senlm samples, and one-hundred saliva samples were collected ITom children and were tested by ELISA technique for detection of senllll IgG and salivary IgA antibodies against poliovirus types I , II , and III and evaluation of their titers. At the same time, 30 senllll and 30 saliva samples were chosen randomly and tested by neutralization technique for the presence and levels of neutralizing antibodies against poliovirus types I , II , and III. Detection and titration of serum /gG and salivary /gA antibodies by EL/SA Each sample was tested in four-ten fold serial dilutions. Antibodies preseut in senlm or salivary dilutions reacted with poliovirus serotype coated on the microtiter plates. Unbound reactants were then washed out. S,ubsequently , peroxidaseconjugated antibodies to human IgG or IgA were added, fol1owing incubation and washing substrate was added and the peroxidase conjugate bound to IgG or IgA antibodies reacted with the substrate producing a colour. The enzymatic reaction was stopped by the addition of sulphuric acid and the resulting colour was measured. The titers of antibodies were expressed as the interpolated reciprocal dilution which gives an absorption of 0.2 above the background. Detection and titration of seru~ /gG or salivary IgA antibodies by neutralization test The method used was known as constant senl1n-varying virus technique. A constant senlm or saliva dilution was tested against varying dilutions of the vinls ’. Samples that contained specific antibodies against the tested poliovinls serotype, had neutralized the infectivity of the virus. The neutralizing capacity of the serum or saliva sample was expressed in terms of its ability to reduce the titer of the virus in a susceptible host system, as compared with the control in which the vinls was inoculated alone into this host system. From the results of this study, it was found that the seroprevalence rates of poliovinls antibodies among tested children were 97 , 94 , and 85 against poliovinls types I , 11 , and III respecti vely . The senlm and saliva samples of the tested children were evaluated as regards the mean titers of IgG or IgA antibodies in relation to age, sex, time elapsed since last vaccine dose, compliance with the schedule of vaccination, number of booster doses, and OCCUITence of fever following vaccination.