Intra-household clustering of hepatitis C virus infection in Karachi, Pakistan

The prevalence of hepatitis C virus infection in β-thalassemia patients in Pakistan: a systematic review and meta-analysis

Background

Hepatitis C virus infection is the most commonly reported bloodborne infection in Pakistan. Frequent blood transfusions in β-thalassemia patients expose them to a high risk of HCV infection. The purpose of this paper is to summarise the current data on the prevalence of HCV infection in β-thalassemia patients in Pakistan by using a systematic review and meta–analysis.

Methods

PubMed, EMBASE, Web of Sciences, the Cochrane Library, Directory of Open Access Journal and local databases were systematically searched for studies published between January 1st, 1995 and May 31st, 2019. Meta-analysis was performed using the DerSimonian and Laird random-effects models with inverse variance weighting. The presence of publication bias was tested by Egger test, and the methodological quality of each included article was evaluated by the STROBE.

Results

We identified a total of 229 potential studies, of which 27 studies were finally considered in the meta-analysis. The pooled prevalence of HCV in β-thalassemia patients in Pakistan was 36.21% (95% CI: 28.98–43.75%) based on 5789 β-thalassemia patients, but there was considerable heterogeneity. Meta-analysis estimated the HCV prevalence among the β-thalassemia patients at 45.98% (95% CI: 38.15–53.90%) in Punjab, 31.81% (95% CI: 20.27–44.59%) in Sindh, and 28.04% (95% CI: 13.58–45.26%) in Khyber Pakhtunkhwa. Meta–regression analysis showed that geographical location was a key source of heterogeneity.

Conclusions

The pooled prevalence of HCV in β-thalassemia patients in Pakistan was more than one in three, and higher than in neighbouring countries. It varies regionally within the country. With the use of standard prevention procedures during blood transfusion, the risk of HCV transmission in β-thalassemia patients could be controlled and the prevalence of HCV in β-thalassemia patients reduced.

Vertically acquired hepatitis C virus infection: Correlates of transmission and disease progression

The worldwide prevalence of hepatitis C virus (HCV) infection in children is 0.05%-0.4% in developed countries and 2%-5% in resource-limited settings, where inadequately tested blood products or un-sterile medical injections still remain important routes of infection. After the screening of blood donors, mother-to-child transmission (MTCT) of HCV has become the leading cause of pediatric infection, at a rate of 5%. Maternal HIV co-infection is a significant risk factor for MTCT and anti-HIV therapy during pregnancy seemingly can reduce the transmission rate of both viruses. Conversely, a high maternal viral load is an important, but not preventable risk factor, because at present no anti-HCV treatment can be administered to pregnant women to block viral replication. Caution is needed in adopting obstetric procedures, such as amniocentesis or internal fetal monitoring, that can favor fetal exposure to HCV contaminated maternal blood, though evidence is lacking on the real risk of single obstetric practices. Mode of delivery and type of feeding do not represent significant risk factors for MTCT. Therefore, there is no reason to offer elective caesarean section or discourage breast-feeding to HCV infected parturients. Information on the natural history of vertical HCV infection is limited. The primary infection is asymptomatic in infants. At least one quarter of infected children shows a spontaneous viral clearance (SVC) that usually occurs within 6 years of life. IL-28B polymorphims and genotype 3 infection have been associated with greater chances of SVC. In general, HCV progression is mild or moderate in children with chronic infection who grow regularly, though cases with marked liver fibrosis or hepatic failure have been described. Non-organ specific autoantibodies and cryoglobulins are frequently found in children with chronic infection, but autoimmune diseases or HCV associated extrahepatic manifestations are rare.

Identification of risk factors for hepatitis B and C in Peshawar, Pakistan

Background

Hepatitis B and C need immediate worldwide attention as the infection rates are too high. More than 240 million people have chronic (long-term) liver infections. Every year, about 600,000 people die globally due to the acute or chronic consequences of hepatitis B and more than 350,000 people die from hepatitis C-related liver diseases.

Methods

Our study was designed as a case-control, descriptive study. It was conducted through formal interviews by using structured questionnaires. A total of 100 cases were included, with four controls for each case.

Results

This study confirms household contact, history of dental work, history of surgery, sexual contact, and history of transfusion (blood and its components) as the main risk factors which are responsible for the increased prevalence of hepatitis.

Conclusion

The important risk factors, responsible for the high prevalence of hepatitis B and C in our society are household contact, history of dental work, history of surgery, sexual contact, and history of transfusion (blood and its components). The odds ratio of probability for these risk factors are: 4.2 for household contact history, 4.1 for history of dental work, 3.9 for sexual contact, 2.7 for history of surgery, and 2.1 for history of transfusion. Associations of other predictor variables (diabetes status, education level, profession, contact sports, intravenous drug abuse, residence, immunosuppression, and skin tattoos) were not statistically significant.

Pathogenesis of hepatitis C during pregnancy and childhood

The worldwide prevalence of HCV infection is between 1% and 8% in pregnant women and between 0.05% and 5% in children. Yet the pathogenesis of hepatitis C during pregnancy and in the neonatal period remains poorly understood. Mother-to-child transmission (MTCT), a leading cause of pediatric HCV infection, takes place at a rate of <10%. Factors that increase the risk of MTCT include high maternal HCV viral load and coinfection with HIV-1 but, intriguingly, not breastfeeding and mode of delivery. Pharmacological prevention of MTCT is not possible at the present time because both pegylated interferon alfa and ribavirin are contraindicated for use in pregnancy and during the neonatal period. However, this may change with the recent introduction of direct acting antiviral agents. This review summarizes what is currently known about HCV infection during pregnancy and childhood. Particular emphasis is placed on how pregnancy-associated immune modulation may influence the progression of HCV disease and impact MTCT, and on the differential evolution of perinatally acquired HCV infection in children. Taken together, these developments provide insights into the pathogenesis of hepatitis C and may inform strategies to prevent the transmission of HCV from mother to child.

Stochastic modelling of intra-household transmission of hepatitis C virus: evidence for substantial non-sexual infection

OBJECTIVE

To simulate the probability of HCV transmission from an HCV seropositive index patient to susceptible household contacts through non-sexual exposures.

METHODS

A modified Reed-Frost stochastic simulation model was used to assess the probability of HCV transmission from an HCV seropositive index patient to susceptible household contacts through non-sexual exposures. This mathematical model does not require the specification of infection onset times for individual, nor is it necessary to identify the chains of household infections. Therefore, this model can be used with serologic data on detected asymptomatic infections. The HCV serological data on 341 non-sexual household contacts of 86 HCV seropositive index patients were used in this simulation study. The frequency distribution of HCV infection of susceptibles for each household size of 4-8 initial susceptibles was calculated. A maximum likelihood procedure was used to estimate the non-sexual household transmission parameter for HCV infection for the range of household sizes studied and was used in 1000 stochastic iterations. The goodness-of-fit test was carried out to compare the observed proportions of households where HCV transmission occurred to one or more initial susceptible with mean expected simulated proportions of such households with varying sizes ranging from 4 to 8 initial susceptibles.

RESULTS

The maximum likelihood estimates (90% probability interval (PI)) of binomial probability of HCV transmission within households with varying number of initial susceptible non-sexual household contacts ranged from 0.248 (90%PI: 0.031, 0.560) to 0.164 (90%PI: 0.011, 0.440) for household size of 4 and 8 respectively. The χ(2) goodness-of-fit test of observed and mean expected simulated proportions of households wherein at least one of the susceptibles was infected revealed good fit for households of all sizes examined (P ≥ 0.96). In a household, the probability of HCV transmission from the index HCV seropositive patient to susceptible via non-sexual contacts tended to decrease linearly as the household size increased from four to seven.

CONCLUSION

Intra-household HCV transmission through non-sexual contacts may have substantial impact on HCV transmission and needs to be considered in an HCV control program.

Effectiveness of blood donor questionnaire directed at risk factor for transfusion transmitted infections in Pakistani population

Background:

Deferring blood donors who admit to high-risk behavior on questioning are likely to eliminate those in window period for transfusion transmitted infections (TTI). However, many questions have been implemented in some countries as part of donor history questionnaire, based on precautionary principle and not on evidence, and can result in increased donor losses. This study aims to identify effective risk-directed questions having high predictive value, in local context which can form part of blood donor deferral policies. For this, a case control study in a hospital blood bank having donation services was carried out prospectively over a period of three years.

Materials and Methods:

Two hundred and twenty donors, who were repeatedly reactive for HBsAg, anti-HCV, anti-HIV with EIA, and syphilis with TPHA, were the cases. Eight hundred and eighty four controls were the donors who tested negative for all TTI test. All donors answered seven hepatitis risk directed questions and their responses and reactivity status for TTI were used for statistical analysis with SPSS ver. 15.

Results:

Positive predictive value for history of jaundice at any age for HBsAg was 20%, while PPV for history of surgery in previous six months for both HBsAg and anti-HCVHCV was also around 20%, based on pretest probability of 7%. The post-test probability for these questions was around 30%. Odds ratios with 95% CI did not reveal any significant association of hepatitis with any of seven questions. Donor losses after deferring on basis of two questions were 5.3% per year, while deferral rate after all seven questions was 20%.

Conclusions:

Donors should be permanently deferred if there is history of jaundice at any age, while deferral period after surgery should be one year. Other risk-directed questions should not be used to defer donors. Donor deferral policies should be evidence based and questions with proven efficacy should be made part of donor history questionnaire to minimize donor losses.

Prevalence and risk factors for hepatitis C virus infection in Kech District, Balochistan, Pakistan: most infections remain unexplained. A cross-sectional study

We studied a cross-sectional sample of the population of Kech, a small rural town in Pakistan to determine the prevalence and risk factors for hepatitis C infection. The prevalence of hepatitis C was 110 out of 2000 persons (5·5%, 95% confidence interval 4·5-6·5). Higher rates were identified in males. Independent risk factors identified were age ≥75 years, being a healthcare worker, and injecting drug use. There was a high prevalence of many potential routes of transmission of bloodborne viruses and most people reported at least one potential risk factor.

Intrafamilial viral transmission is not the main cause of the high prevalence of hepatic C virus infection in a village, Putian county, China

BACKGROUND

The prevalence of anti-HCV in the population of a village, which is located in China's Putian County, was 28.9%.

OBJECTIVE

To investigate whether intrafamilial transmission is the main cause of the high prevalence of HCV infection in the village.

STUDY DESIGN

This study surveyed the prevalence of anti-HCV antibody and HCV RNA and analyzed the risk factors for infection. Twenty-seven families consisting of 2 or more cases who were HCV RNA-positive were selected. Genotyping of HCV isolates was performed using a restriction fragment length polymorphism (RFLP) analysis of 5'-NCR. The identity of the nucleotide sequence, the Kimura distance, and the phylogenetic trees between HCV 1b isolates from the same family were compared with that from different families using BioEdit and MEGA4.0 software.

RESULTS

Of 303 anti-HCV-positive subjects, 113 subjects were HCV RNA-positive. The frequency of some risk factors was significantly different between HCV RNA-positive and anti-HCV-negative subjects. Twenty-two pairs had subjects who were both infected with genotype 1b strains. The sequence identities between the 2 isolates from the family pairs ranged from 78.9% to 98.5% for HVR1 and from 92.4% to 97.6% for NS5B, which were not higher than the pairs from different families. The Kimura distances for family pairs ranged from 0.014 to 0.357 for HVR1 and from 0.024 to 0.081 for NS5B. They were not shorter than that from non-family pairs. Only 2 family pairs clustered in the same branch in the dendrogram obtained with NS5B sequences.

CONCLUSIONS

Intrafamilial HCV transmission is not the main cause of the high prevalence of HCV infection in the village.

Investigating the concurrent presence of HCV in serum, oral fluid and urine samples from chronic HCV patients in Faisalabad, Pakistan

Hepatitis C virus (HCV) is normally present in the blood of infected patients; however, it can also be present in some other body fluids. Therefore, in this study, a concurrent presence of HCV-RNA was investigated in oral fluid and urine of 80 Pakistani chronic HCV patients. HCV-RNA was detected in 31 (38.8%) oral fluid and 10 (12.5%) urine samples using RT-PCR in all 80 of the patients whose sera tested positive for HCV-RNA. From this study, it is concluded that, in addition to the blood, HCV RNA can also be found in oral secretions as well as urine of chronic HCV patients.

Hepatitis B and hepatitis C in Pakistan: prevalence and risk factors

BACKGROUND

Pakistan carries one of the world's highest burdens of chronic hepatitis and mortality due to liver failure and hepatocellular carcinomas. However, national level estimates of the prevalence of and risk factors for hepatitis B and hepatitis C are currently not available.

METHODS

We reviewed the medical and public health literature over a 13-year period (January 1994-September 2007) to estimate the prevalence of active hepatitis B and chronic hepatitis C in Pakistan, analyzing data separately for the general and high-risk populations and for each of the four provinces. We included 84 publications with 139 studies (42 studies had two or more sub-studies).

RESULTS

Methodological differences in studies made it inappropriate to conduct a formal meta-analysis to determine accurate national prevalence estimates, but we estimated the likely range of prevalence in different population sub-groups. A weighted average of hepatitis B antigen prevalence in pediatric populations was 2.4% (range 1.7-5.5%) and for hepatitis C antibody was 2.1% (range 0.4-5.4%). A weighted average of hepatitis B antigen prevalence among healthy adults (blood donors and non-donors) was 2.4% (range 1.4-11.0%) and for hepatitis C antibody was 3.0% (range 0.3-31.9%). Rates in the high-risk subgroups were far higher.

CONCLUSIONS

Data suggest a moderate to high prevalence of hepatitis B and hepatitis C in different areas of Pakistan. The published literature on the modes of transmission of hepatitis B and hepatitis C in Pakistan implicate contaminated needle use in medical care and drug abuse and unsafe blood and blood product transfusion as the major causal factors.

Characterization of HCV strains in an oncohematological pediatric department reveals little horizontal transmission but multiple introductions by un-screened blood products in the past

Because several children were found infected with hepatitis C virus (HCV) at a pediatric oncohematological department in Vilnius, 474 children were tested for anti-HCV. Fifty-eight percent of 96 children treated with blood and plasma products manufactured before the introduction of anti-HCV screening of blood in Lithuania in 1994 were positive for anti-HCV versus 3.4% of those treated after 1994. The possible route of transmission for 45 of these was investigated by phylogenetic analyses within the NS5B region. Children treated before 1995 were infected with a multiplicity of strains of different subtypes, predominantly 1b found in 21 cases, 3a in 5 cases, 2 in 3 cases, 1a in 1 case, and not subtypeable genotype 1 strains in 2 cases. Children who had received blood products after 1994 were infected with only two subtypes, 1b in six and 3a in seven. Genetic analysis showed multiple introductions of HCV before 1995 and that horizontal spread between patients had occurred only to a minor extent at the department. However, two transmission chains involved children treated before 1995. Another chain involved five children treated after 1994. Since the most important risk factor for acquiring hepatitis C was blood products manufactured before the introduction of donor screening for anti-HCV, the spread between children would not have been revealed without molecular tools. These and the background strains provide the first reported sequence data on Lithuanian HCV strains. In general, these were shown to form autochthonous clades, except the 3a strains that were related to strains from the former USSR.

Hepatitis C: current approaches in pediatrics

Chronic hepatitis C virus is one of the leading causes of liver diseases in adults and it is the most common cause of liver transplantation in the USA. Hepatitis C infection in children is less frequent; there is less information about its clinical course. Compared with adults, there are differences in its mode of acquisition, natural history, complications and even available treatments. The aim of this paper is to give an overview of chronic hepatitis C in children.

The management of HCV infected pregnant women and their children European paediatric HCV network

BACKGROUND/AIMS

As evidence accumulates relating to mother-to-child (vertical) transmission of hepatitis C virus (HCV), it is timely to draw up guidelines for the clinical management of HCV infected pregnant women and their children.

METHODS

A review of evidence from the European Paediatric HCV Network (EPHN) prospective study of HCV infected women and their children and other published studies. Meeting of EPHN clinical experts to reach a consensus on recommendations for management. Each recommendation was graded according to the level of evidence.

RESULTS/CONCLUSIONS

Although several risk factors for mother-to-child transmission have been identified, none are modifiable and there are currently no interventions available to prevent vertical transmission of HCV. Data on timing of loss of maternal antibodies and reliability of diagnostic tests inform the optimum follow-up schedule for confirmation or exclusion of infection in children born to HCV infected women. Based on the current evidence, routine antenatal screening for HCV should not be introduced and neither elective caesarean section nor avoidance of breastfeeding should be recommended to HCV infected women to prevent mother-to-child transmission of HCV. HCV/HIV co-infected women should follow existing HIV guidelines.