The SEN virus, a candidate for inclusion in the alphabet of viral hepatitis, was discovered in 1999 in the blood serum of a patient with HIV infection with increased activity of ALT and ACT and negative results of the serum test for HAV, HGV and TTV markers. It was indicated by the initiates of this patient.
Epidemiology of SEN infection
Studies conducted in various countries and regions of the world have shown a high level of spread of the virus among various population groups. Most often, it was detected in patients who underwent heart surgery, who received blood transfusion and who subsequently developed acute hepatitis A or E (83.3%); patients with chronic hepatitis no A or E (68%). In the group of people who have an increased risk of infection with hepatitis viruses with a parenteral mechanism of transmission of the pathogen, the frequency of detection of SEN-DNA is 2-3 times higher than the frequency of detection of it in primary donors.
What causes SEN infection?
SEN virus is a non-shell particle containing ring single-stranded DNA. According to the physico-chemical and structural characteristics, the SEN-virus is referred to the family Circoviridae (as well as TTV ). It has several genotypes, the genotypes D and N. Are most often identified.
Symptoms of SEN infection
It has been established that HAV, HBV, HCV, HDV and HEV can cause acute and chronic hepatitis, however HGV is considered opportunistic.
Hepatitis can be one of the manifestations of diseases caused by other viruses, microorganisms and helminths. Most often, symptoms of liver damage are detected with spirochaetosis, yersiniosis, herpes-viral infections (infectious mononucleosis, cytomegalovirus infection). In addition, hepatitis is one of the main symptoms of yellow fever and can develop with protozoal infections (malaria, amebiasis, leishmaniasis, toxoplasmosis). Jaundice, as the most vivid sign of hepatitis, can occur with salmonellosis, listeriosis, tuberculosis, helminthiases (opisthorchiasis, fascioliasis, toxocariasis, ascaridosis, schistosomiasis). Very often hepatitis is observed in sepsis of various etiologies. An acute viral hepatitis caused by parvovirus B19 is described.
Diagnosis of SEN infection
It should be remembered that if a negative test results for markers of hepatitis AG viruses, excluding another infectious nature of hepatitis, the doctor can meet with liver damage with primary biliary cirrhosis, primary sclerosing cholangitis. In view of the similarity of the onset of the disease, changes in the biochemical parameters of the blood, patients with autoimmune, drug and alcoholic hepatitis often enter the infectious hospital. Finally, hepatitis can be the first manifestation of Wilson-Konovalov's disease.
Nevertheless, even with the exclusion of all listed diseases, in some cases the etiology of hepatitis remains unclear, although epidemiological data, clinical features of the disease, the nature of liver damage and biochemical changes suggest a viral etiology of the disease. As a rule, such patients are diagnosed as "unspecified viral hepatitis" (ICD-10 code is B19). It can also be referred to as viral hepatitis, neither A nor G. The "applicants" for the role of etiological agents of this hepatitis can be TTV and SEN viruses.
Laboratory diagnosis of SEN infection
The main method for detecting TTV at the present time is PCR. Attempts have been made to create a test system for determining the IgM and IgG content of a TTV virus. It was shown that antibodies of class M appear at the beginning of the disease, circulate simultaneously with TTV DNA, and then disappear, and antibodies of class G appear. However, these methods of laboratory diagnostics are in the stage of scientific development and are not yet used in clinical practice. In addition, there are no commercial test systems for detecting SEN virus markers in body fluids.