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Hepatitis ICAAC Report 1: identifying unknown routes for HCV transmission
Reported by Jules Levin
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There were several sessions devoted to HCV/HIV coinfection at this year's ICAAC. This is a good sign saying that at least ICAAC and I think the HIV scientific community is beginning to recognize the importance of addressing HCV in HIV, and is beginning to incorporate research and education about HCV into the various HIV scientific conferences and meetings. There were two symposiums and Meet-The -Experts panel lectures at this ICAAC meeting. As well, there was a significant poster session and oral slide session devoted to HCV. The quality of the abstracts and sessions were mixed, and doctors at the symposium and docs I met at the conference displayed to me an inadequate and sometimes misinformed knowledge about treating HCV in HIV. Progress in HCV/HIV is very slow and the Federal government is slow in recognizing and funding areas of need in HCV and HCV/HIV coinfection, including prevention, an adequate care infrastructure, and education for the HIV Community (doctors, patients, service providers). Following this report will be a series of additional ICAAC Hepatitis Reports. All ICAAC and other conference reports are posted to and archived at the NATAP website (www.natap.org).
G Raguin and a French research group (abstract V-681) reported on what was widely considered an interesting study: "A National Multicenter Case-Control Study of Risk Factors for Community-Acquired Hepatitis C". Certain risk factors for acquiring HCV have been identified. Transfusions used to be a major risk until the blood supply was cleaned by developing testing for blood supply and now this risk is considered very low. Currently, IVDU and sharing related drug using paraphenalia such as needles are considered the major risk for acquiring HCV. However, 20-40% of HCV-infected do not have recognized risk factor, leading to speculations that other as-yet-undiscovered modes of transmission may exist. This French study is a case-control study to investigate the routes of transmission in patients with no recognized risk factor.
Several potential routes or sources of HCV transmission have been suggested: previous hospitalization or surgery, hemodialysis and plasmapheresis, organ transplantation, GI endoscopy, parenteral treatment (IV) for schistosomiasis, tatooing, piercing, nasal cocaine use, activities during incarceration. This study sets out to test these ideas.
HCV-seropositive pts were recruited in 57 French hospitals. Controls (comparison group) were recruited from the general population through a random telephone survey and matched for age, sex, residence and number of chronic diseases. All answered an epidemiological interviewer-administered questionnaire on potential risk factors for HCV. HCV+ patients were excluded if they had a history of transfusion or IV drug use. Patients with sexual and occupational exposure, HIV infection, hemodialysis and transplantation were also excluded. Controls were matched with the case patients for age, sex, residence. 500 HCV-infected patients (age 53.4; males 55%) and 750 controls were studied between 1997 and 2000. 72% of HCV-infected patients had chronic hepatitis, 9% had cirrhosis, and 9% had asymptomatic HCV with normal liver enzymes. 65% had genotype, 25% genotype 2 or 3. 50% of cases and control patients had 1 or more chronic diseases.
RESULTS
The authors reported that this large case-control study identified 15 independent risk factors for HCV infection in patients with no standard risk factors. The authors said they confirm these suspected risk factors such as: hospital stays, GI endoscopy, abortion, IV=IM injections, acupuncture, and intrnasal cocaine. They reported identifying these new risk factors: violent sports, manicure/chiropy, and depilation. The authors reported that altogether these risk factors could explain 74% of unidentified routes of infection. For hospitalization, GI endoscopy and IV/IM injections have positive correlation with the number of exposures and risk for acquiring HCV. The Odds Ratio for GI endoscopy in this study was 2.1 if person had less than 2 exposures and 4-fold risk if person had greater than 2 exposures. A sensitivity analysis, performed on 2 subsets of subjects gave similar results. The authors conclude that this study shows that hospital stays, GI endoscopy, some dermatological procedures and cocaine use are risk factors for community-acquired HCV in France, and we also provide evidence for less-recognized risk factors.
Here are the odds ratios for increased risk by these exposures. All are statisticaly significant.
Hospitalizations
Surgery (non obstetrical) 1.7 fold increased risk
Medical (any reason) 2.1
Endoscopy
Digestive 1.9 (risk not increased by biopsy & anasthesia)
Obstetrical
Voluntary abortion 1.8
Dermatological Procedure
Varicose vein sclerosing 1.7
Diathermy 3.0
Cutaneous ulcers, wounds 10.0
Ambulatory Care
Acupuncture 1.6
Tetanus Ig injection 1.7
IM injection 1.4
IV injection 1.7
Lifestyle
Chiropodist/manicurist 1.8
Depilation at beauty salon 2.0
Violent sport (boxing, rugby) 2.4
Intranasal cocaine 4.6
For some of these risk factors the number of study subjects among cases and controls were small and the confidence ratio wide but these risk factors were all statistically significant.
The following were not associated with acquiring HCV infection.
Obstetrical surgery, delivery
Non digestive endoscopy, puncture, biopsy, catheterisation
Miscarriage, in vitro fertilization, IUD
Electromyography
Hemorroid care
Ambulance use
Other ambulatory procedures: mesotherapy, infiltrations, desensitization
Dental procedures
Other lifestyle: tatooing, piercing, contact lenses, shaving
Incarceration, military service
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