HIV type 1 group M subtype G in Cameroon: five genome sequences

Area of Science:

• Virology
• Genetics
• Epidemiology

Background:

• Human Immunodeficiency Virus type 1 (HIV-1) subtype G is a significant global health concern.
• Understanding the genetic diversity and geographic distribution of HIV-1 subtypes is crucial for effective prevention and treatment strategies.
• Previous studies indicated a limited presence of pure subtype G in Cameroon, despite its contribution to recombinant strains.

Purpose of the Study:

• To characterize near full-length viral genome sequences of five putative subtype G strains from Cameroonian blood donors.
• To determine the phylogenetic relationship and genetic makeup of these newly identified HIV-1 strains.
• To assess the prevalence and role of subtype G in the HIV-1 epidemic in Cameroon.

Main Methods:

• Obtaining near full-length viral genome sequences from five HIV-1 positive Cameroonian blood donors.
• Utilizing partial genome sequences from gag, pol, and env regions for initial identification.
• Performing phylogenetic analysis to ascertain subtype classification and identify recombination events.

Main Results:

• All five identified strains were confirmed as pure subtype G, with no evidence of intersubtype recombination.
• Phylogenetic analysis revealed that the Cameroon subtype G sequences were intermixed with global isolates, not forming a distinct geographic subcluster.
• While pure subtype G accounts for only 4.5% of HIV-1 infections in Cameroon, subtype G genome segments are present in 67% of all infections.

Conclusions:

• The identification of pure subtype G strains in Cameroon expands the known genetic diversity of HIV-1.
• These findings suggest that subtype G plays a substantial role in the formation of intersubtype recombinant strains in Cameroon.
• The addition of these sequences to the HIV database will aid in a more comprehensive understanding of HIV-1 subtype origins, classification, and the evolution of circulating recombinant forms (CRFs).