High Prevalence of HIV, HCV, HBV and Co-Infection and Associated Risk Factors among Injecting Drug Users in Yunnan Province, China

Objective

To estimate the prevalence of HIV, HCV, HBV and co-infection with 2 or 3 viruses and evaluate risk factors among injecting drug users (IDUs) in Yunnan province, China.

Methods

2080 IDUs were recruited from 5 regions of Yunnan Province, China to detect the infection status of HIV, hepatitis B virus (HBV) and hepatitis C virus (HCV). Statistical analysis was performed to evaluate risk factors related to HIV, HCV and HBV infections.

Results

The infection rates among all participants were 25.5% for HIV, 77.7% for HCV, 19.2% for HBV, 15% for HIV/HCV, 0.3% for HIV/HBV, 7.8% for HCV/HBV and 7.1% for HIV/HCV/HBV. The prevalence of virus infection varied widely by region in Yunnan of China. Statistical analyses indicated that high prevalence of HIV and HCV among IDUs was positively associated with the duration of drug injection and sharing needles/syringes; besides, HCV infection was associated with the frequency of drug injection.

Conclusions

HIV, HCV, HBV infections and co-infections were still very prevalent among IDUs in Yunnan province because of drug use behaviors.     

Differential effects of migration and deportation on HIV infection among male and female injection drug users in Tijuana, Mexico

HIV prevalence is rising, especially among high risk females in Tijuana, Baja California, a Mexico-US border city situated on major migration and drug trafficking routes. We compared factors associated with HIV infection among male and female injection drug users (IDUs) in Tijuana in an effort to inform HIV prevention and treatment programs. IDUs aged > or = 18 years were recruited using respondent-driven sampling and underwent testing for HIV, syphilis and structured interviews. Logistic regression identified correlates of HIV infection, stratified by gender. Among 1056 IDUs, most were Mexican-born but 67% were born outside Tijuana. Reasons for moving to Tijuana included deportation from the US (56% for males, 29% for females), and looking for work/better life (34% for females, 15% for males). HIV prevalence was higher in females versus males (10.2% vs. 3.5%, p = 0.001). Among females (N = 158), factors independently associated with higher HIV prevalence included younger age, lifetime syphilis infection and living in Tijuana for longer durations. Among males (N = 898), factors independently associated with higher HIV prevalence were syphilis titers consistent with active infection, being arrested for having 'track-marks', having larger numbers of recent injection partners and living in Tijuana for shorter durations. An interaction between gender and number of years lived in Tijuana regressed on HIV infection was significant (p = 0.03). Upon further analysis, deportation from the U.S. explained the association between shorter duration lived in Tijuana and HIV infection among males; odds of HIV infection were four-fold higher among male injectors deported from the US, compared to other males, adjusting for all other significant correlates (p = 0.002). Geographic mobility has a profound influence on Tijuana's evolving HIV epidemic, and its impact is significantly modified by gender. Future studies are needed to elucidate the context of mobility and HIV acquisition in this region, and whether US immigration policies adversely affect HIV risk.     

Hepatitis C Virus Infection among Injection Drug Users with and without Human Immunodeficiency Virus Co-Infection

The aim of this study is to explore the prevalence of hepatitis C virus (HCV) infection among injection drug users (IDUs) with and without human immunodeficiency virus (HIV) infection in southern Taiwan. For 562 IDUs (265 anti-HIV negative, 297 anti-HIV positive), we analyzed liver function, anti-HIV antibody, anti-HCV antibody, HCV viral loads, and hepatitis B surface antigen (HBsAg). HIV RNA viral loads and CD4 cell count for anti-HIV-seropositive IDUs and the HCV genotype for HCV RNA-seropositive IDUs were measured. The seroprevalence rates of anti-HIV, anti-HCV, and HBsAg were 52.8%, 91.3%, and 15.3%, respectively. All the anti-HIV-seropositive IDUs were positive for HIV RNA. Anti-HCV seropositivity was the most important factor associated with HIV infection (odds ratio [OR], 25.06; 95% confidence intervals [CI], 8.97–74.9), followed by male gender (OR, 6.12; 95% CI, 4.05–9.39) and HBsAg seropositivity (OR, 1.90; 95% CI, 1.11–3.34). Among IDUs positive for anti-HCV, 80.7% had detectable HCV RNA. HCV viremia after HCV exposure was strongly related to HIV infection (OR, 6.262; 95% CI, 1.515–18.28), but negatively correlated to HBsAg seropositivity (OR, 0.161; 95% CI, 0.082–0.317). HCV genotype 6 was the most prevalent genotype among all IDUs (41.0%), followed by genotypes 1 (32.3%), 3 (12.8%), and 2 (5.6%). In conclusion, about half IDUs were infected with HIV and >90% with HCV infection. Male and seropositivity for HBsAg and anti-HCV were factors related to HIV infection among our IDUs. HIV was positively correlated, whereas hepatitis B co-infection was negatively correlated with HCV viremia among IDUs with HCV exposure. Different HCV molecular epidemiology was noted among IDUs.     

Occult hepatitis B virus infection among injecting drug users in the Central-West Region of Brazil

The prevalence of occult hepatitis B virus (HBV) infection was investigated in 149 hepatitis B surface antigen (HBsAg) negative injecting drug users (IDUs) in the Central-West Region of Brazil. Of these individuals, 19 were positive for HBV DNA, resulting in an occult HBV infection prevalence of 12.7% (19/149); six of these 19 individuals had anti-HBV core and/or anti-HBV surface antibodies and 13 were negative for HBV markers. All IDUs with occult hepatitis B reported sexual and/or parenteral risk behaviours. All HBV DNA-positive samples were successfully genotyped. Genotype D was the most common (17/19), followed by genotype A (2/19). These findings reveal a high prevalence of occult HBV infection and the predominance of genotype D among IDUs in Brazil''s Central-West Region.     

Use of needles and syringes in Miami and Valencia: observations of high and low availability

Two studies engaged in gathering data on injecting drug users (IDUs) employed supplementary resources to enhance their ethnographic components and compare patterns of use of needles/syringes (n/s) in two geographically similar but culturally distinct cities. Despite its policy of making n/s highly available at fair prices, Valencia, Spain, has markedly higher rates of HIV seroprevalence among its IDUs than does Miami, Florida, where possession of n/s is illegal. Ethnographically based models that track IDUs through choices of injection venues help to explain this difference. Inability of IDUs in Valencia to use their own domiciles as venues for injection contrasts sharply with problems of Miami IDUs, who have access to houses but have difficulty finding n/s. This research suggests that intervention in Valencia needs to focus on how people select places where they inject, and intervention in Miami needs to focus on improving availability of n/s.     

Characteristics of hepatitis C infection in injecting drug users in Zadar County, Croatia

The aim of the study was to determine additional risk factors that could increase the prevalence of hepatitis C (HCV) infection among injecting drug users (IDU). The study included 327 heroin addicts registered in Zadar County, Croatia. The participants were divided into two groups according to their HCV status. HCV-positive and HCV-negative study participants were compared. HCV-positive group started injecting heroin at earlier age (median 18.5 years) than HCV-negative group (median 20.0 years) (p = 0.032) and had been injecting heroin for a significantly longer period (median 5 years vs. median 4 years, respectively; p < 0.001). IDUs in HCV-positive group shared their injecting equipment significantly more often than IDUs in HCV-negative group (p < 0.001; chi2 = 32.7). The main reasons for starting drugs were curiosity, psychological reasons (depression and/or neurosis), and peer or partner pressure in HCV-positive group, and fun, curiosity, and peer pressure in HCV-negative group (p = 0.051; chi2 = 23.6). Earlier onset of heroin use, longer heroin use, sharing injection equipment, curiosity, and psychological problems as reasons for starting drugs were associated with higher prevalence of HCV infection among injecting heroin users in Zadar County.     

A Cost Analysis of Hospitalizations for Infections Related to Injection Drug Use at a County Safety-Net Hospital in Miami,Florida

Background

Infections related to injection drug use are common. Harm reduction strategies such as syringe exchange programs and skin care clinics aim to prevent these infections in injection drug users (IDUs). Syringe exchange programs are currently prohibited by law in Florida. The goal of this study was to estimate the mortality and cost of injection drug use-related bacterial infections over a 12-month period to the county safety-net hospital in Miami, Florida. Additionally, the prevalence of HIV and hepatitis C virus among this cohort of hospitalized IDUs was estimated.

Methods and Findings

IDUs discharged from Jackson Memorial Hospital were identified using the International Classification of Diseases, Ninth Revision, codes for illicit drug abuse and endocarditis, bacteremia or sepsis, osteomyelitis and skin and soft tissue infections (SSTIs). 349 IDUs were identified for chart abstraction and 92% were either uninsured or had publicly funded insurance. SSTIs, the most common infection, were reported in 64% of IDUs. HIV seroprevalence was 17%. Seventeen patients (4.9%) died during their hospitalization. The total cost for treatment for injection drug use-related infections to Jackson Memorial Hospital over the 12-month period was $11.4 million.

Conclusions

Injection drug use-related bacterial infections represent a significant morbidity for IDUs in Miami-Dade County and a substantial financial cost to the county hospital. Strategies aimed at reducing risk of infections associated with injection drug use could decrease morbidity and the cost associated with these common, yet preventable infections.     

Seroepidemiology of viral infections among intravenous drug users in northern California.

Intravenous drug users are frequently exposed to parenterally transmitted viral infections, and these infections can spread to the general population through sexual activity. We investigated the prevalence of serologic markers for human immunodeficiency virus type 1 (HIV-1), human T-cell lymphotropic virus type I/II (HTLV-I/II), hepatitis B virus (HBV), and hepatitis C virus (HCV) in intravenous drug users and their sexual contacts. Of 585 drug users from northern California tested for these serologic markers, 72% were reactive for the antibody to HCV, 71% for the antibody to hepatitis B core antigen, 12% for HTLV-I/II antibodies, and 1% for the HIV-1 antibody. The prevalence of serologic markers for these four viruses correlated with the duration of intravenous drug use, the ethnic group, and the drug of choice. More than 85% of subjects infected with either HCV or HBV were coinfected with the other virus. All persons reactive to HTLV-I/II antibodies had antibodies for either HBV or HCV. Of 81 sexual contacts tested, 17% had evidence of HBV infection while only 6% were reactive for HTLV-I/II antibodies and 4% for the antibody to HCV. None of this group was infected with HIV-1. We conclude that HTLV-I/II and HCV are inefficiently transmitted to sexual contacts while HBV is spread more readily. Programs designed to discourage the sharing of drug paraphernalia, such as needle and syringe exchanges, should decrease the risk of parenterally spread viral infections in intravenous drug users and thus slow the spread of these infections to the general population.     

Open access clinic providing HIV-I antibody results on day of testing: the first twelve months.

OBJECTIVES--To determine the sociodemographic profile, risk category, and prevalence of HIV-I infection among people attending a clinic providing counselling, medical advice, and results of HIV-I antibody testing on the day of consultation; to determine the stage of infection and peripheral blood CD4 cell count among attenders with detectable HIV-I antibodies. DESIGN--Analysis of prospectively collected data for the 12 months from March 1989. SETTING--Same day testing clinic run by the HIV/AIDS team at an urban teaching hospital. PATIENTS--561 consecutive people choosing to attend and proceeding to HIV-I testing. RESULTS--The demand for the service caused it to run to capacity within six months. The median age of those attending was 28 years and 65% (364 patients) were male. The overall prevalence of HIV-I infection was 3.9% (22 patients). The greatest prevalence was in men reporting their primary risk as homosexual contact (11.9%, 13/109). The median CD4 cell count in the 22 patients who had detectable HIV-I antibodies was 0.31 x 10(9) cells/l (normal range 0.5 x 10(9)/l to 1.2 x 10(9)/l). Twenty of these patients were asymptomatic (Centers for Disease Control stages II or III), 14 had CD4 cell counts below 0.5 x 10(9)/l. CONCLUSIONS--There is a recognisable demand for a service providing rapid results of HIV-I antibody testing in this setting. The overall seroprevalence of 3.9% is comparable with the 5.8% reported from freestanding clinics in the United States. Most patients with HIV-I antibodies detected in this way are asymptomatic but could benefit from early medical intervention because of low CD4 cell counts.     

Human T-lymphotropic virus type I seroprevalence among Japanese Americans.

The epidemiology of human T-lymphotropic virus type I (HTLV-I) infection is not well defined in Japanese Americans. This impairs using approaches that could reduce viral transmission and monitor carriers for the disease. Using enzyme-linked immunosorbent assay and p21e recombinant Western blot testing, HTLV-I antibody was measured in unlinked samples from Japanese-American patients at 4 physicians'' offices in San Francisco, California. Of 442 patients, 4 (0.9%; 95% confidence interval 0.25%, 2.3%) were confirmed seropositive, all with an HTLV-I rather than an HTLV-II pattern on Western blot. Seroprevalence was highest among the issei or immigrant generation (3/230 or 1.3%) compared with the second-generation nisei (1/191 or 0.5%) or third-generation sansei (0 of 17). Prevalence did not differ by age or sex, although the number of positive subjects in each subgroup was small. Of 88 patients with familial origins in endemic areas of southern Japan, none were seropositive. In this sample of Japanese Americans, HTLV-I seroprevalence was lower than in residents of endemic southern Japan but higher than among American blood donors. The prevalence was most similar to that in nonendemic areas of Japan. The public health implications of HTLV-I infection among Japanese Americans are discussed.     

Human T-lymphotropic virus type I (HTLV-I) and tropical spastic paraparesis or HTLV-I-associated myelopathy in Hawaii.

Tropical spastic paraparesis or human T-lymphotropic virus type I (HTLV-I)-associated myelopathy is a degenerative encephalomyelopathy with pyramidal tract dysfunction affecting the lower extremities. It is associated with HTLV-I infection and found primarily in the Caribbean region and in southwestern Japan. Five cases of tropical spastic paraparesis (or HTLV-I-associated myelopathy) in Hawaii are reported. All five patients were born in Hawaii; four are women. Each of the patients has parents who were from HTLV-I-endemic areas of Japan. Two of these patients had serum antibodies to HTLV-I. Five of six of the spouses and children of the seropositive patients were also seropositive. Viral cultures of lymphocytes from both seropositive patients and two of the three seropositive children were positive for HTLV-I. None of the five patients had a history of antecedent blood transfusion, multiple sexual partners, or intravenous drug use. There is no evidence of adult T-cell leukemia or lymphoma in any of the patients or their families. Given the increasing seroprevalence of HTLV-I in the United States, clinicians need to be alert to new cases of this disorder.     

Human T-cell lymphotropic virus type I infection and disease in the Pacific basin.

Human T-cell lymphotropic virus type I (HTLV-I), the cause of adult T-cell leukemia/lymphoma (ATLL) and HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP), is widespread in the Pacific basin. Modes of virus transmission include blood transfusion (and intravenous drug use), breast milk, and sexual intercourse. High prevalences of HTLV-I infection and disease occur among the inhabitants of southwestern Japan and among first- and second-generation (issei and nisei) Japanese-Americans in the Hawaiian Islands. Other Pacific populations with high prevalences of HTLV-I infection include several remote groups in West New Guinea, Papua New Guinea, the Solomon Islands, and Vanuatu, which have had no contact with Japanese or Africans. By contrast, Micronesian and Polynesian populations, even those with prolonged contact with Japanese, exhibit low prevalences or no evidence of HTLV-I infection. Low prevalences of infection are also found in Australia, except among some aboriginal populations. Changing patterns of HTLV-I infection and disease are no better exemplified than in Japan, where striking reductions in transfusion-acquired infection and subsequent development of HAM/TSP have followed the institution of nationwide screening of blood donors for HTLV-I infection. Furthermore, virus transmission from mother to infant by means of infected breast milk has been markedly curtailed in HTLV-I-hyperendemic regions in Japan by interrupting the practice of breast feeding by HTLV-I-infected mothers. The next frontier of HTLV-I research is in Melanesia, where highly divergent sequence variants of HTLV-I have been discovered.     

Morphine effects on HTLV-I infection in the presence or absence of concurrent HIV-1 infection

Human T-cell leukemia virus type I (HTLV-I) infection is emerging as an important complication in HIV infection and AIDS in injecting drug users. HIV-1 and HTLV-I share a common host in CD4+ T lymphocytes. However, the result of HIV-1 infection is the decimation of this cell population, whereas a hallmark of HTLV-I infection is the inappropriate proliferation of infected cells. Combined epidemiologic data suggest that HTLV-I infection is enhanced during concurrent HIV-1/HTLV-I infection; however, there are currently no in vitro studies focusing on the effects of drugs of abuse on retrovirus coinfection. We have found that in an in vitro coinfection system (HIV-1 + HTLV-I), morphine treatment further enhanced the levels of HTLV-I p19. In addition, indicators of in vitro infection by cell-free HIV-1 were reduced by morphine treatment in both single and dual in vitro infection experiments. Interleukin 2 levels in the affected cultures were found to increase with combined HTLV-I infection and morphine treatment. These in vitro results indicate the need to further explore the activity of HTLV-I within opiate-treated cells, as this oncoretrovirus appears to be especially sensitive to morphine-induced alterations to its host cell environment.     

Anti-nef antibodies and other predictors of disease progression in HIV-1 seropositive injecting drug users.

A cross-sectional and retrospective longitudinal study has been conducted in three Italian infectious disease centres to evaluate the role of anti-nef antibodies and other markers (HIV-1 p24 antigen, p24 Ag; Beta 2-microglobulin, B2-M; and number of CD4+ lymphocytes) as predictors of disease progression in HIV seropositive injecting drug users (IDUs). The selected patients were: 1) HIV-seropositive IDUs in different stages of HIV infection; 2) HIV-seropositive IDUs who had developed AIDS, from whom serial serum samples were available during the asymptomatic stage, and 3) HIV seropositive IDUs who remained asymptomatic through a follow-up period of the same duration as the patients who developed AIDS. Absence of anti-nef antibodies was associated with symptomatic HIV infection. A significant association between the absence of anti-nef antibodies, the presence of p24 Ag, high levels of B2-M, a number of CD4+ lymphocytes less than 500/ml at first visit and disease progression was found. Subjects who were persistently positive for antibody to nef were less likely to develop AIDS than those who were transiently or persistently negative. This difference was statistically significant (p = 0.03). The results of this study show that absence or disappearance of anti-nef antibodies may be used as predictor of disease evolution in HIV seropositive IDUs. This study also confirms the usefulness of other markers, such as p24 Ag, B2-M and number of CD4+ lymphocytes previously shown to be predictive of rapid disease progression for predicting the course of HIV seropositive IDUs.     

Prevalence of hepatitis-B surface antigen among blood donors and human immunodeficiency virus-infected patients in Jos, Nigeria

Information is very scarce on the prevalence of hepatitis-B virus (HBV) infection among blood donors and patients with human immunodeficiency virus (HIV) infection in Nigeria. Hepatitis-B surface antigen (HBsAg) ELISA was used to determined the prevalence of HBsAg among 175 blood donors (aged 20-40 years) and 490 HIV-infected patients (aged 17-60 years) in Jos, Nigeria. Twenty-five (14.3%) of the blood donors and 127 (25.9%) of the HIV-infected individuals were HBsAg seropositive, indicating a higher HBV infection among HIV-infected persons than among healthy blood donors. A slightly higher HBsAg seroprevalence was recorded in the males (14.6%) than females (12.9%) of the blood donors. Among the HIV-infected patients, the males had considerably higher HBsAg seroprevalence than the females (31.8 vs 22.1%) with the highest prevalence of HBsAg occurring in the 51-60 years age group (44%), followed by those of 31-40 years (28.2%). Results confirmed the high endemicity of HBV infection in Jos, Nigeria and the significantly greater prevalence of HBV infection among HIV-infected patients than among blood donors.     

Hepatitis B infection among patients attending a sexually transmitted diseases clinic in Rio de Janeiro, Brazil

Hepatitis B virus (HBV) has a low endemicity in Rio de Janeiro, Brazil. Sexual transmission must play an important role in this virus, but the prevalence and risk factors have never been properly investigated. The aim of this paper is to determine the prevalence and risk factors for HBV infection in patients attending a Sexually Transmitted Diseases Clinic of the Universidade Federal Fluminense, from the State of Rio de Janeiro, Brazil. In a retrospective study, HBV seroprevalence was investigated in 440 patients. Serum of each patient was assayed for antibodies against hepatitis B core antigen (anti-HBc), hepatitis B surface antigen (HBsAg) and antibodies against hepatitis B surface antigen (anti-HBs). Demographic and risk factor data were extracted from clinic notes. The overall seroprevalence of exposure markers for HBV (anti-HBc, HBsAg and anti-HBs) were 13%, 3.4% and 8.5% respectively. Homo/bisexual behaviour, anal intercourse, HIV infection, positive serology for syphilis and blood transfusion were predictors of the HBV exposure. Among demographic data, age and place of birth were associated with the anti-HBc seropositivity.     

Molecular and epidemiologic characteristics of HIV-infection outbreak in the Irkutsk region

The genetic analysis of the variants of human immunodeficiency virus of type 1 (HIV-I) circulating among drug addicts in the Irkutsk region was carried out. The results of serological tests and comparative evaluation of electrophoretic mobility of heteroduplexes (HMA) revealed that all 74 samples under study belonged to subtype A. Genetic differences between these viruses did not exceed 2%. Thus, it was the variant of subtype A prevalent in CIS countries which caused the outbreak of HIV infection among drug addicts in the Irkutsk region, but not viruses of subtypes B, C or A/E typical for this risk group in relatively nearby China.     

Infection with HIV and hepatitis C virus among injecting drug users in a prevention setting: retrospective cohort study

Objectives: To estimate the incidence of HIV and hepatitis C virus and risk factors for seroconversion among a cohort of injecting drug users. Design: Retrospective cohort study. Setting: Primary healthcare facility in central Sydney. Subjects: Injecting drug users tested for HIV-1 antibody (n=1179) and antibodies to hepatitis C virus (n=1078) from February 1992 to October 1995. Main outcome measures: Incidence of HIV-1 and hepatitis C virus among seronegative subjects who injected drugs and underwent repeat testing. Demographic and behavioural risk factors for hepatitis seroconversion. Results: Incidence of HIV-1 among 426 initially seronegative injecting drug users was 0.17/100 person years (two seroconversions) compared with an incidence of hepatitis C virus of 20.9/100 person years (31 seroconversions) among 152 injecting drug users initially negative for hepatitis C virus. Incidence of hepatitis C virus among injecting drug users aged less than 20 years was 75.6/100 person years. Independent risk factors for hepatitis C virus seroconversion were age less than 20 years and a history of imprisonment. Conclusions: In a setting where prevention measures have contributed to the maintenance of low prevalence and incidence of HIV-1, transmission of hepatitis C virus continues at extremely high levels, particularly among young injecting drug users.

Key messages

• The prevalence and incidence of hepatitis C virus is high, while the prevalence and incidence of HIV remains low among injecting drug users
• Young age and history of imprisonment are risk factors for acquisition of hepatitis C virus infection
• HIV prevention strategies have been relatively ineffective in preventing hepatitis C virus infection in this population
• The role of imprisonment in the acquisition of hepatitis C infection should be further investigated

     

Mathematical modelling of hepatitis C treatment for injecting drug users

Hepatitis C virus (HCV) is a blood-borne infection that can lead to progressive liver failure, cirrhosis, hepatocellular carcinoma and death. In developed countries, the majority of HCV infections are transmitted via injecting drug users (IDUs). Despite effective antiviral treatment for HCV, very few active IDUs are treated. Reluctance to treat is partially due to the risk of reinfection. We develop a mathematical model of HCV transmission amongst active IDUs, and examine the potential effect of antiviral treatment. As most mathematical models of interventions utilise a treatment function proportional to the infected population, but many policy implementations set fixed yearly targets for specific numbers treated, we study the effects of using two different treatment terms: annually treating a proportion of infecteds or a fixed number of infecteds. We examine the behaviour of the two treatment models and find different bifurcation behaviours in each case. We calculate analytical solutions for the treatment level needed for disease clearance or control, and observe that achievable levels of treatment can result in control or eradication across a wide range of prevalence levels. Finally, we calculate the sensitivity of the critical treatment threshold to the model parameters, and find that for a given observed prevalence, the injecting duration and infection risk play the most important role in determining the treatment level needed. By contrast, the sensitivity analysis indicates the presence (or absence) of immunity does not alter the treatment threshold. We conclude by discussing the public health implications of this work, and comment on the importance and feasibility of utilising treatment as prevention for HCV spread amongst IDUs.