Tracking the entry routes of hepatitis C virus as a surrogate of HIV in an HIV-low prevalence country, the Philippines.
From 2002 to 2007, 1,590 individuals were enrolled in an active surveillance program conducted in Metro Cebu, Philippines, where the anti-HCV-positive rate was significantly and constantly high among injecting drug users (83%, 793/960; 71-88%), especially among those living in downtown (89%, 683/770; 87-100%), despite the extremely low percentage of anti-HIV-positives (0.34%, 3/874). Sampling areas were then enlarged nationwide and the number of samples increased to 2,645 at the end of 2007. A total of 444 samples were positive for HCV RNA. Phylogenetic analysis based on NS5B and E1-E2 regions revealed that the most dominant HCV subtype was 1a, and followed by 2b, 2a, and 1b, and that the HCV strains had the largest variety in Metro Manila and its vicinity (P < 0.01). Interestingly, subtype 1b was detected solely in Metro Manila, and four HCV strains collected in this area showed higher homology to specific foreign strains retrieved from the Genbank/EMBL/DDBJ database with bootstrap values of 68-95% comparing with other strains analyzed in this nationwide study. These data suggest that HCV strains may be introduced occasionally into the Philippines possibly through Metro Manila as a main entry point. Considering the fact that an HIV epidemic started primarily via contaminated needle sharing in Asia, the constantly high rate of HCV infections and the newly introduced foreign HCV strains in the absence of HIV epidemic warrant further investigation on HCV entry and spread for early detection of an HIV epidemic in the Philippines.
Kageyama
Seiji
S
Department of Viral Infection and International Health, Kanazawa University, Kanazawa, Japan. skageyama@med.tottori-u.ac.jp
Agdamag
Dorothy May D
DM
Alesna
Evelyn T
ET
Abellanosa-Tac-An
Ilya P
IP
Corpuz
Aura C
AC
Telan
Elizabeth Freda O
EF
Que
Ernesto R
ER
Leaño
Prisca Susan A
PS
Jereza
Lourdes D
LD
Emphasis
Yvonne Ethyl E
YE
Prasetyo
Afiono A
AA
Tanimoto
Tomoaki
T
Ichimura
Hiroshi
H
D016000:Cluster Analysis; D005260:Female; D005838:Genotype; D015658:HIV Infections / Q000453:epidemiology / Q000635:transmission / Q000821:virology; D016174:Hepacivirus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D006526:Hepatitis C / Q000453:epidemiology* / Q000635:transmission / Q000821:virology*; D006801:Humans; D008297:Male; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D010679:Philippines / Q000453:epidemiology; D010802:Phylogeny; D011110:Polymorphism, Genetic; D015995:Prevalence; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D015819:Substance Abuse, Intravenous / Q000150:complications; D014759:Viral Envelope Proteins / Q000235:genetics; D017361:Viral Nonstructural Proteins / Q000235:genetics; D012324:RNA-Dependent RNA Polymerase
D014759:Viral Envelope Proteins; D017361:Viral Nonstructural Proteins; C087035:E1 protein, Hepatitis C virus; C091015:glycoprotein E2, Hepatitis C virus; C087036:NS-5 protein, hepatitis C virus; D012324:RNA-Dependent RNA Polymerase