Molecular evolution, virology and spatial distribution of HCV genotypes in Pakistan: A meta-analysis

Abstract

Background: Hepatitis C, caused by the Hepatitis C Virus (HCV), is the second most common form of viral hepatitis. The geographical distribution of HCV genotypes can be quite complex, making it challenging to ascertain the most prevalent genotype in a specific area.

Methods: To address this, a review was conducted to determine the prevalence of HCV genotypes across various provinces and as a whole in Pakistan. The scientific literature regarding the prevalence, distribution, genotyping, and epidemiology of HCV was gathered from published articles spanning the years 1996-2020.

Results: Genotype 1 accounted for 5.1% of the patients, with its predominant subtype being 1a at 4.38%. The frequencies of its other subtypes, 1b and 1c, were observed to be 1.0% and 0.31% respectively. Genotype 2 had a frequency of 2.66%, with the most widely distributed subtype being 2a at 2.11% of the patients. Its other subtypes, 2b and 2c, had frequencies of 0.17% and 0.36% respectively. The most prevalent genotype among all isolates was 3 (65.35%), with the most frequent subtype being 3a (55.15%), followed by 3b (7.18%). The prevalence of genotypes 4, 5, and 6 were scarce in Pakistan, with frequencies of 0.97%, 0.08%, and 0.32% respectively. The prevalence of untypeable and mixed genotypes was 21.34% and 3.53% respectively. Estimating genotypes proves to be a productive method in assisting with the duration and selection of antiviral treatment. Different HCV genotypes can exhibit variations in their response to specific antiviral treatments. Different genotypes may have distinct natural histories, including variations in disease progression and severity. Some genotypes may lead to more rapid liver damage, while others progress more slowly.

Conclusions: This information can guide screening and testing strategies, helping to identify individuals at higher risk of developing severe complications. Studying the distribution of HCV genotypes in a population can provide valuable insights into the transmission dynamics of the virus.

Keywords: Genotypes; HCV; Molecular evolution; Pakistan; Spatial distribution.

Fig. 1

Province-wise prevalence of HCV in Pakistan. KP: Khyber Pakhtunkhwa province. Statistical analysis was conducted to determine the prevalence of HCV-infected individuals across all provinces of Pakistan. Punjab province exhibited the highest prevalence at 34.13%, followed by Sindh province at 9.99%. The prevalence in Khyber Pakhtunkhwa province was recorded at 7.78%, while Balochistan showed a prevalence of 2.22%.

Fig. 2

Spatial distribution map of HCV prevalence in Pakistan. The prevalence of HCV genotypes in Pakistan was assessed using the Inverse Distance Weighted (IDW) method in ArcMap 10.5.

Fig. 3

Frequency distribution of HCV genotypes (subtypes) in Pakistan. Microsoft Excel was employed for the analysis of genotype prevalence in Pakistan. Among all the isolates, genotype 3 was the most prevalent, accounting for 65.35%. Within genotype 3, the most frequently observed subtype was 3a, making up 55.15% of the cases, followed by subtype 3b at 7.18%.

Fig. 4

Spatial distribution map of HCV genotypes/subtypes in Pakistan. The prevalence of HCV genotypes in Pakistan was assessed using the Inverse Distance Weighted (IDW) method in ArcMap 10.5. Each map represents the prevalence of HCV genotypes/subtypes.

Fig. 5

Spatial distribution map of untypeable and mixed genotype of HCV in Pakistan.

Fig. 6

Province-wise distribution of HCV genotypes in Pakistan. All the genotypes mentioned, from 1 to 6, are represented by U (untypeable), and M denotes a mixed genotype. After genotype 3 the high prevalence of untypeable genotype (21.34%) was observed which followed genotype 1(5.71%) in Pakistan.