Epidemiologic and genotypic distribution of hepatitis C in Iraqi pregnant women

number: 
298
إنجليزية
Degree: 
Imprint: 
Medicine
Author: 
Waqar Abdul Qahar Al-Kubaisy
Supervisor: 
Dr.Amjad D. Niazi
Dr.Ali R. Omer
year: 
1998
Abstract:

Hepatitis C virus (HCV) infection is a major new public health challenge. Hepatitis C occurs world wide, and in all ages, and among all racial / ethnic groups studied. The high rate of persistent infection with this virus creates a large reservoir of persons who are infectious to others, resulting in multiple opportunities for transmission of the disease. Because there are many factors that predispose pregnant women to harbor HCV, and because the prevalence of HCV antibody may very dramatically from one geographic location to another, a comprehensive molecular- epidemiological multicentre cross-sectional study, of Iraqi pregnant women, not selected for risk factor, was designed. The main aims of this study were (1) to estimate the prevalence of hepatitis C virus antibody (anti-HCV) among the studied group (2) to investigate the association between HCV acquisition risk factor(s) with ftnti-HCV seropositivity, viremia and HCV isolate genotype(s). (3) to identify the Unconfounding risk factor(s) that act independently for HCV acquisition by using multivariate analysis. The anti CV seroprevalence study was performed on 3491 Iraqi pregnant women (14-50 years old) during their third trimester, randomly selected from attendance to health care institutes, covering 19 of 121 health care institutes of Baghdad. Utilizing the third generation of enzyme immunoassay (EIA-3), 160 (4.58 %) were anti-HCV seropositive, and successively followed by immunoblot essay (LiaTek-III) yielded 112 - positive, reactive anti-HCV, giving a minimal anti-HCV prevalence rate of (3.21%). In addition, the number of indeterminate and negative LiaTek-III were 20 and 28 respectively. Furthermore, 59 of 94 mother's sera (irrespective to LiaTek-III reaction)were HCV-RNA positive by reverse transcription- polymerase chain reaction (RTPCR). nterestingly, of those 59 positive HCV-RNA, 7 were previously diagnosed as indeterminate Lia Tek-III. Using well advanced method of DNA enzyme immunoassay (DEJA) based on 6 different genotype specific primers, directed against the 5' untransulated (51 URT) as well as the core region. Interestingly, all except 2 (who were previously diagnosed as indeterminate LiaTek-III)of theS9HCV-RNA positive sera were genotyped / subtyped, demonstrated in a single (1, la, Ib, 3a or 4) or in a mixed (dual (1 & 4), (Ib & 4), (3a&4) pattern of infection. Strikingly, the predominant circulating genotype among Iraqi pregnant women were HCV-4 29/57 (50.87%), followed by HCV-lb (35.08%), HCV-la (22.8 %)HCV-1 (14.03%) and HCV-3a (5.26%). Notably, the study failed to demonstrate a significant association between HCV genotype and mode of HCV acquisition, except with HCV-lb which was found significantly associated with pregnant women having a history of anti-D immunoglobulin treatment P= 0.04, as well as older women with mean age of 33.9 + 5.446,P<0.05. The potential of 18 different factors, including demographic end behavioral characteristics (age, residency, marital status, education occupation of mother and tattooing) obstetric and gynecological history (gravidity, parity, of the mother, previous history of normal vaginal delivery "NVD", history of abortion, curettage and delivery by Cesarean section (CS)), medical & surgical history (Blood transfusion, anti-1) immunoglobulin and history of jaundice were statistically analyzed, based on bivariate, as well as multivariate analysis. This Study revealed (5.32%) of Iraqi pregnant women had no identified risk factor. Moreover, all except three variables (history of jaundice, residency and tattooing) were significantly found associated with anti-HCV seropositivity, and act as a risk of HCV infection, measured by odd's ratio, with the following values, mother being illiterate OR=1.669 95% C. I. 1.035-2.692) health care worker (OR=6.818, 95 % C.I. =2.908-15.985). Age being > 30 years OR=1.717, 95% C.I, -1.173-2.514), second marriage (OR=2.877 95% C.I. -1.061-7.781) multigravida (OR= 2.142 95 % C.I =1.27-3.613), grand multiparous (OR=1.881 95% C.I= 1.172-3.08) history of abortion (OR=2.316 95% C.I. = 1.601 -3.351), Curettage (OR=3.355 95% C.I. =2.342-4.805) C.S. OR=2.003 95 % C.I..1271-3.155) astound history of blood transfusion (OR=7.543 95% C.I. 4.640-12.2 l)Anti-D-immunoglobulin injection (OR=3.32 95% C.I=1.473-6.82) intraspousal transmission (OR=19.343 95% C.I. =6.715-54.291)), steadily increases risk of HCV infection was detected, that was corroborated more, by the direct positive significant correlation between HCV acquisition (OR) and increasing number of abortion r=0.985, P=0.0021, parity r=0.772 p=0.041 and anti-D immunoglobulin injection r=0.943, P=0.015. Notably this study documented an astounding finding that Iragi pregnant women from a second event of pregnancy (OR=1.962, 95% C.I. =1.304-2.953), with 2 5 parity (OR= 1.703 95% C.I. = 1.047-2.770), receiving 2 3 and -D immunoglobulin injection OR= 8.317 95% C.I. = 1.204-42.892) or with at least from a single episode of abortion OR= 2.001 95% C.I. = 1.283-3.119) be at a significant risk of exposure, for HCV acquisition . Surprisingly, nosocomial HCV transmission was demonstrated from this study, since medical services at governmental as well at private hospital were significantly associated with increases seroprevalence of HCV antibodies. Thus pregnant women underwent curettage managed at governmental hospital (OR=3.26 95% C.I. 2.098-5.065) as well as private clinic (OR= 7554 95% C.I 1.528-4.268) were exposed to risk of HCV infection. However, health services offered at the governmental hospital were found to be associated with HCV acquisition, through N.VD. (OR=1.779 95% C.I. =1.032-3.068) and cesarean dellvery) (OR=2.141 95% C.I. =1.35-3.393). Based on multivariate regression analysis, only, age of 30 years and over (adjusted OR=1.061 95 % C.I. 1.0324-1.0902) as well as blood transfusion (adjusted OR= 1.938 95% C.I. 1.646-2.281) were demonstrated independently, as an unconfounding risk factors for contraction of HCV infection, among the studied group. Moreover a direct correlation between the increased OR of HCV |Infection and the increased number of transfused blood units was confirmed by multiple logistic regression analysis (r=0.98 P=0.00056). The risk of exposure HCV increases from OR= 3.145 95% C.I. 1.369-6.242 to 7.543 95% C.I. 4.640.12.21 for those pregnant women who received one up to 2 6 blood unit.respectively. Therefore this study demonstrate that Iraqi pregnant women be at risk of post transfusional HCV infection following the first transfused blood unit. Notably based on multivariate analysis, this study documented that blood transfusion as well as the age of the mother > 30 years being as predictor for the possibility HCV seropositivity, applying the following equation. Lit OR HCV—5.255+ 0.0592 x age + 0.6616 x blood unit transfused Thus [based on logistic regression analysis there were two variables that were unconfoundebly predicting factor for possibility of HCV positivity. The follow-up of 26 offspring enrolled in this study from 25 anti-HCV positive mother, failed to demonstrate mother - to - infant HCV transmission, based on serological antibody, as well as molecular analysis . explanation of all the risk factors and other molecular parameters investigated in this study have been fully and thoroughly discussed and interpreted. In conclusion, the study demonstrated, that HCV infection is a public health problem in Iraqi with blood transfusion as the major rout of transmission. ; Thus blood donor screening with a restrict policy be recommended, utilizing the latest generation of serological screening EIA and its confirmatory Immunoblotting assays, corroborated with molecular analysis RT-PCR. Moreover, since nosocomial HCV transmission has been clearly demonstrated in the current study, thus promotion of the health services be recommended, to overcome all of the drawback, resulted from the embargo,which has been emposed on Iraq since 1991. The molecular part of this study, revealed that there were 5 different HCV gentype / subtypes, circulating among Iraqi pregnant women, in a single or double infection, with HCV-4 was found as the most prominent genotype . No significant association had been demonstrated between HCV genotype/ subtype and mode of HCV transmission with the exception of HCV-lb which was significantly associated with previous history of anti-D immunoglobulin injection