[Epidemiological and molecular biological analysis of causes of rise of hepatitis A incidence in Republic of Tuva in 2008].
OBJECTIVE
Analysis of hepatitis A (HA) incidence in Tyva Republic in 2008 exploiting traditional epidemiological and molecular methods.


METHODS
Epidemiological analysis of HA cases and contact persons in Erzinsky and Kyzyl regions of Tyva Republic was performed. Class M and G antibodies to HAV were determined in serum samples (n = 28), and HAV RNA--in stool samples (n = 16). Phylogenetic analysis of HAV RNA sequence was performed for VP1/2A region of the HAV genome with length 394 nucleotides.


RESULTS
Cases of HA were registered during 3.5 months. Water supply sources did not have deviations from established standards. According to results of interviews, common food factor, which was able to cause the rise of HA incidence, was not determined. Signs of fecal contamination were revealed on environmental objects in preschool institutions and schools that demonstrate the low level of hygienic behaviour. It was shown that all cases of HA are related with different variants of the virus belonged to genotype IA that points to the absence of common source of infection.


CONCLUSIONS
Results of epidemiological and genetic analysis of HAV demonstrate that observed rise in HA incidence in Tyva Republic are connected with phase of seasonal rise of HA incidence, which is characteristic for its perennial dynamics with active realization of contact route of virus transmission.
Popova
O E
OE
Kiuregian
K K
KK
Il'chenko
L Iu
LIu
Isaeva
O V
OV
Kozhanova
T V
TV
Dmitriev
P N
PN
Salchak
L K
LK
Glushko
E A
EA
Saryglar
A A
AA
Oorzhak
N D
ND
Oorzhak
A D
AD
Mikhaĭlov
M I
MI
D003546:Cysteine Endopeptidases / Q000235:genetics; D005243:Feces / Q000737:chemistry; D014644:Genetic Variation; D006506:Hepatitis A / Q000453:epidemiology*; D035922:Hepatitis A Antibodies / Q000097:blood; D030041:Hepatitis A virus / Q000235:genetics* / Q000276:immunology*; D006801:Humans; D006920:Hygiene; D015994:Incidence; D010802:Phylogeny; D012367:RNA, Viral / Q000032:analysis; D012426:Russia / Q000453:epidemiology; D012621:Seasons; D016036:Seroepidemiologic Studies; D014764:Viral Proteins / Q000235:genetics; D015678:Viral Structural Proteins / Q000235:genetics
D035922:Hepatitis A Antibodies; D012367:RNA, Viral; C096539:VP1 protein, hepatitis A virus; D014764:Viral Proteins; D015678:Viral Structural Proteins; D003546:Cysteine Endopeptidases; C057400:picornain 2A, Picornavirus