The Investigation On Scrub Typhus Group、Typhi Group And Spotted Fever Group Of Xinyang,HeNan Province

Background and ObjectsRickettsial diseases is a class diseases which is serious threat to human health,it is Natural foci of zoonotic diseases too.Most rickettsial disease is epizootic, only when people occasionally intervene insect vector and host natural link between the infection would suffer from the disease.Rickettsia can proliferate in the host endothelial cells and causes vascular inflammation in human organs.The early clinical manifestations of rickettsial diseases are bites ulcers,swollen lymph nodes,fever, headache,with or without rash.Late may be due to heart,liver,kedney and other organ failure and death. Studies show that there are at least10kinds of rickettsial diseases exist in our courntry currently including Scrub Typhus Group(STG)、Typhi Group (TG)and Spotted Fever Group(SFG) et cetera.Rickettsial diseases has been effectively controlled in developed countries currently.Our country has been no interruption for rickettsial disease research too,and has made great progress in rickettsial disease surveillance and control from liberation to now.Although there has not been a large scale of rickettsial disease outbreaks in recent years,but the dissemination of rickettsial disease prevalent always interruption. Since most rickettsial disease are natural foci of disease, it is hard to wipe it out.To draw the lessons of the calamities caused by rickettsial disease in World war I and World war II,we should always insist on the research,monitoring and control of rickettsial disease.This study use the technology of immunology and molecular biology to find the proof on exiting of rickettsia in Henan Xinyang area and understand the present state of rickettsial infection prevalence in Hanan Xinyang area by studying the infection of scrub typhus, spotted fever and typhus in this region.MethodsChoose the typical area in Xinyang,collect the ticks、mouses、chiggers and blood serum of fever patients unknown origin in these area.Using the technology of enzyme linked immunosorbent assay(ELISA) to detect the IgG antibody of STG、 TG and SFG in the serum and using the polymerase chain reaction(PCR) to detect the rickettsia in the ticks、mouses and chiggers respectively.Results1.We collect727blood serum of fever patients unknown origin in these area altogether, ticks516(there are367Haemaphysalis longicornis and149Tick Rmicroplus),174mouse(most are Apodemus agrarius) and about1000chiggers.2.Detect the IgG in the blood serum of unknown orighin:there are111TG IgG antibodies positive,positive rate is15.27%;there are69SFG IgG antibodies positive,positive rate is9.49%;there are11STG IgG antibodies positive,positive rate is1.51%.3.Detect the pathogens in the mouse spleens、chiggers and ticks:there are SFG pathogens is detected in ticks,but no any pathgen is detected in both mouse spleens and chiggers.The pathogen detected in ticks is confirmed to be Rickettsia Heilongjiang by sequencing.Conclusions1.There exist TG、STG and SFG in Xinyang region,and TG is dominant. 2.Ticks hlongicornis are major media of rickettsial diseases in Xinyang.