The epidemic dynamics of hepatitis C virus subtypes 4a and 4d in Saudi Arabia

Abstract

The relatedness between viral variants sampled at different locations through time can provide information pertinent to public health that cannot readily be obtained through standard surveillance methods. Here, we use virus genetic data to identify the transmission dynamics that drive the hepatitis C virus subtypes 4a (HCV4a) and 4d (HCV4d) epidemics in Saudi Arabia. We use a comprehensive dataset of newly generated and publicly available sequence data to infer the HCV4a and HCV4d evolutionary histories in a Bayesian statistical framework. We also introduce a novel analytical method for an objective assessment of the migration intensity between locations. We find that international host mobility patterns dominate over within country spread in shaping the Saudi Arabia HCV4a epidemic, while this may be different for the HCV4d epidemic. This indicates that the subtypes 4a and 4d burden can be most effectively reduced by combining the prioritized screening and treatment of Egyptian immigrants with domestic prevention campaigns. Our results highlight that the joint investigation of evolutionary and epidemiological processes can provide valuable public health information, even in the absence of extensive metadata information.

Hepatitis C virus genotypes in Saudi Arabia: a future prediction and laboratory profile

“…In his recent study on the epidemic dynamics of HCV Al-Qahtani has demonstrated clearly that genotype 4 was transmitted between countries in the region but originated from Egypt. Viral spread between Saudi Arabia and Egypt is predominantly directed towards Saudi Arabia, showing that both HCV genotype 4 epidemics are connected through a source-sink relation, perhaps linked to the large flow of Egyptian migrant workers [ 53 ].…”

In Search of Covariates of HIV-1 Subtype B Spread in the United States—A Cautionary Tale of Large-Scale Bayesian Phylogeography

“…The different trait diffusion models come with different assumptions and their application may also depend on the spatial resolution of the location data. The discrete model makes abstractions of precise geographic data-sometimes made necessary by the absence of fine-scale geographic information-but may still provide a powerful approach to infer epidemiological dynamics, as illustrated in applications like investigating the relevance of migration on public health planning [13][14][15][16][17], identifying the determinants of the spread of dog rabies virus in North Africa [18], or determining the role of swine movements in the dynamics of influenza in the United States [19]. More specifically to HIV, phylogeographic analyses have been used to reconstruct the early continental expansion of HIV-1 group M in Africa [20] and the spread of subtype B across the globe [21] and to North America [22].…”

Cross-country migration linked to people who inject drugs challenges the long-term impact of national HCV elimination programmes

“…As the chronic nature of most HCV infections hampers reliably reconstructing contact networks from patient interviews, virus genetic data can be a valuable alternative source of information for elucidating the geographic history of virus lineages (e.g. 5,6). Using such data, we have recently shown that for the most prevalent subtype among PWID in Spain (40%, 7 ), HCV1a, infections often link to infections abroad -in recent years >50% link to Western European countries, mostly European Union (EU) member states -as opposed to other infections within Spain.…”