The global diffusion of injecting drug use: implications for human immunodeficiency Virus infection


North America
Europe and Australia
Africa, Latin America and the Caribbean
Implications for research
Implications for the diffusion of injecting
Implications for the prevention of HIV infection


Author: G.V. STIMSON
Pages: 3 to 17
Creation Date: 1993/01/01

The global diffusion of injecting drug use: implications for human immunodeficiency Virus infection *

Director, and Professor of the Sociology of Health Behaviour, Centre for Research on Drugs and Health Behaviour, Department of Psychiatry, Charing Cross and Westminster Medical School, London


Long-standing patterns of drug injecting in mainly developed countries have been joined by the introduction and expansion of drug injecting in developing countries, often followed quickly by outbreaks of human immunodeficiency virus (HIV) infection. Drug injecting has been identified in 80 countries and HIV infection in 52 of these. Given the continued recruitment of new injectors where injecting is endemic, the dif- fusion of drug injecting in countries where the practice was formerly rare and the Potential for this diffusion to occur, HIV prevention must also consider interventions that discourage drug injecting. Particularly at risk are countries in drug-producing regions and along drug transit routes in Africa, south-east and south-west Asia and South America. Injecting can spread in less time than it takes to introduce HIV prevention activities. The task of the public health system will be to find a balance between activities targeted at helping current injectors change their behaviour and activities targeted at discouraging the adoption of drug injecting.


The injection of drugs occurs on a global scale and is probably increasing. Endemic patterns of drug injecting in developed countries have been joined by new patterns of injecting in developing countries, bringing with them the associated risks of HIV infection. This is occurring even though it has now been several years since the public came to be aware of acquired immunodeficiency syndrome (AIDS).

* Presentation at the Eighth international Conference on AMS1Third World Congress on Sexually Transmitted Diseases, Amsterdarn, July 1992.

Current injectors have been the main target for HIV prevention in many countries. Helping them to reduce their risk of HIV infection has been, and continues to be, an urgent public health task. But given the continued recruitment of new injectors where injecting is endemic, the diffusion of drug injecting in countries where the practice was formerly rare and the potential for this diffusion to occur, AIDS prevention must also incorporate interventions that help discourage drug injecting.

The hypodermic needle has been used by drug users for more than a century. Drug injecting (the self-injection of drugs for recreational purposes or in the furtherance of dependence) has now been identified in 80 countries (see table). Globally, a wide variety of drugs may be injected, including cocaine, amphetamines, tranquillizers, barbiturates and a variety of pharmaceutically produced opiates, of which heroin is probably the most common. WV infection among injecting drug users has been identified in 52 (over 65 per cent) of these countries.

Levels of HIV infection vary considerably. In cities in the United States of America, the prevalence of HIV infection among injectors ranges from 0 per cent to over 50 per cent. Modal prevalence at treatment sites is around 5 per cent, with the highest rates in the North-east (over 50 per cent in New York City [ 1] , intermediate rates in other Middle Atlantic cities and low rates elsewhere [ 2] ). Rates of 30 to 40 per cent have been reported for some Italian cities [3, 4], Amsterdam [ 5] , Rio de Janeiro [ 6] and Bangkok [7, 8] and 20 per cent for Denmark [ 9] . Rates of less than 10 per cent have been reported for Australia [ 10] and less than 2 per cent for much of the United Kingdom; Edinburgh (30 to 50 per cent) and London (10 to 13 per cent) are exceptions [ 11] . Rates close to zero are reported for Greece [ 12] .

North America

The United States and Canada have the longest standing endemic patterns of injecting, starting from the nineteenth century, with intravenous injecting having developed in the late 1920s and then having spread in the 1930s [ 13] . One of the first syringe-transmitted epidemics on record in the United States was an outbreak of estivo-autumnal malaria among drug injectors in New York City in 1932 [ 14] . Immediately before the Second World War about 40 per cent of the addicts seeking treatment were injecting; that figure had risen to 70 to 90 per cent by 1950 [ 13] .

The United States provides a good example of periods during which heroin use and heroin injection spread rapidly, followed by periods when prevalence levels off then by further rapid rises in incidence from the previous plateau [ 13, 15-17] . Peaks of heroin use occurred after 1945, mainly among urban minority populations. New peaks occurred between 1969 and 1972, coinciding with a plentiful supply of heroin from the French Connection * and from Mexico.

Countries and areas where injecting drug users

(and HIV) have been identified *






United States
South Africa
Czech Republic
Dominican Republic  
New Zealand
Puerto Rico
China, Taiwan Province
Hong Kong
Russian Federation
San Marino
Lao People's
Democratic Republic
United Kingdom
Yugoslavia **
Republic of Korea
Sri Lanka
Syrian Arab Republic
Via Nam

*Countries where HIV infection in injecting drug users has been diagnosed are shown in italic type.

**Territory of the former Yugoslavia.

After 1972, when the French Connection was severed and the Government of Turkey banned opium production, imports came from Mexico, and there was a new peak of heroin use around 1976. After 1976, the Mexican poppy eradication programme was operational and the supply of heroin was reduced, only to be supplanted later on by heroin from south-east and south-west Asia [ 18] .

In the United States, the National Institute on Drug Abuse con- servatively estimates that in 1990 over 700,000 people in that country injected drugs including heroin an d cocaine, and that over 3.33 million people have injected at some time in their lives [ 19] . Injecting prevalence rates are extremely high in some localities: in the Bronx, a borough of New York City, it is estimated that 17 per cent of all males aged 25-44 are injectors. It is further estimated that 5 to 13 per cent of all men in this age group in the Bronx are IRV-positive [ 20] .

Europe and Australia

In Europe and Australia, drug injecting began to spread in the late 1960s. In western Europe injecting was initially adopted in creative circles (jazz musicians, bohemians and students), but the practice spread rapidly to other social groups in the early 1970s, with the market having been served by illicit heroin from south-east Asia [ 21] . Political upheavals in the Islamic Republic of Iran in 1979 led to a further flow of heroin to Europe, and heroin smoking and injecting both increased in the early 1980s [ 22] . Injection became associated with poorer and disadvantaged social groups. Such a shift, from middle class innovators to poorer groups, has been encountered in other parts of the world.

The rapid diffusion of injecting is illustrated by a case study of a community at Edinburgh [ 23] , where there had been little injecting before 1979. The Europe-wide proliferation of heroin injecting was reflected there in the peak incidence of new injectors between 1979 and 1984. Edinburgh also illustrates the rapid spread of IRV infection in networks of new injectors. Based on the analysis of stored blood samples, the number of new HIV-positive injectors was highest in 1984. Those who started injecting in the peak years of injecting incidence were more likely than those who started earlier or later to eventually become HIV -positive.

*Laboratories mainly in and around Marseille producing heroin for large-scale shipment to the United States, particularly New York City.

Europe, Australia and North America continue to have new recruits to drug injecting. In the United Kingdom in 1991, 15 per cent of newly notified injecting addicts were under 21 years of age [ 24] . New patterns of injecting are spreading as well: for example, occasional amphetamine injection may be as widespread as heroin injection in some countries. Anabolic steroid injection is encountered among some people in sports [ 25] .

In Europe, drug injecting is likely to spread to new areas and social groups where it has hitherto been uncommon. This is particularly the case in eastern Europe and the former Soviet Union, as a consequence of political and economic changes, the lifting of travel restrictions, the existence of drug trading routes through the area and the legacy of military involvement in Afghanistan.

Most countries lack good epidemiological information, and national estimates of drug injecting must be treated with extreme caution. It is estimated that there may be upwards of 75,000 drug injectors in the United Kingdom [ 26] , although this estimate is not much more than an informed guess. More reliably, it is calculated that at Glasgow 1.5 per cent of the population aged 15-55 injects drugs [ 27] . There may be as many as 8,000 injectors in the Netherlands, 100,000 in Italy and 100,000 in Poland [ 28] , [ 29] . In Australia there may be 30,000-60,000 regular users of heroin, another 60,000 occasional users and an unestimated number of amphetamine injectors [ 30] .

While such estimates are suspect, many countries can provide some profile of injecting populations. Current European Community studies attempt to gain comparable international data on drug-injecting populations and HIV infection. Data for Europe from the European Community collaborative study on HIV infection show that male injectors tend to outnumber female injectors by two or three to one and that injectors tend to be young: most started injecting in the years immediately after leaving school and are, on average, in their late twenties [ 31] .

Africa, Latin America and the Caribbean

In Africa, Egypt has a history of intravenous drug use since the 1920s [ 32] . Injecting appears to be uncommon in other African countries, but there are some recent reports of this practice from Nigeria, and it may be occurring in Senegal, South Africa and Tunisia. In Mauritius, an island country in the Indian Ocean, heroin use spread rapidly in the 1980s in connection with the country's status as a drug transit country.

In the Caribbean and Central America, injecting on a small scale is reported from a number of countries, including the Dominican Republic

and Honduras. In Puerto Rico, which has a high rate of HIV infection, the practice is linked with that of injecting populations in New York City [ 33] . In South America, cocaine injecting has been reported in Argentina, Brazil (there is extensive injecting at Rio de Janeiro) [ 6] and Venezuela, and to a lesser extent in Chile and Paraguay.


In Japan, the injecting of amphetamine was widespread between 1946 and 1956, and it is estimated that up to 2 million people were involved [ 34-36] . The injecting of amphetamines and heroin continues on a lesser scale up to the present. Heroin injecting has been practised in Hong Kong since the 1950s.

What is significant for AIDS, however, is that drug injecting is a recent phenomenon in many countries, especially in south-cast Asia, having first appeared only in the mid - 1980s in China, India, Lao People's Democratic Republic, Myanmar, Nepal, Sri Lanka and Viet Nam [ 37] , [ 38] .

Injecting is now spreading in countries that are mostly poor and that are either in drug-producing areas or along drug transit routes. In many countries the recent rapid spread of injecting has been followed by major outbreaks of HIV infection, for example throughout the urban, rural and hill - tribe areas of Thailand, in Manipur State in north - east India, in Ruili in southern China and in Myanmar [ 8] , [ 39] , [ 40] .

Heroin, which is the most commonly injected drug and one that can be rapidly adopted, provides a model for understanding the potential diffusion of drug use and injecting. Heroin is made from opium, at the rate of about I kg heroin from 10 kg opium, and most of the opium grown for conversion to heroin comes from three parts of the world: the Golden Crescent, in south-west Asia, which comprises parts of Afghanistan, Iran and Pakistan; the Golden Triangle, in south-east Asia, which is the area where the Lao People's Democratic Republic, Myanmar and Thailand meet, and Mexico [ 18] .

Most heroin is now produced in refineries in or near growing areas for reasons of cost or because of law enforcement and political conditions. The local refining and distribution of heroin has created local markets for the drug, which was originally intended exclusively for export.

The development of heroin injecting in Thailand is an early example of the way in which the practice can evolve. Heroin use there paralleled the trade in heroin for United States servicemen in Viet Nam and the growth of world heroin markets generally. In the two decades after the late 1950s, users in Thailand switched from opium smoking to heroin smoking and then to heroin injection [ 41] . HIV infection was first noted among injectors in 1987, after which the infection prevalence. rate increased rapidly to 40 to 50 per cent [ 8] .

Manipur State in north-east lndia is a more recent example. Manipur has a long international border with Myanmar, the world's largest producer of heroin. There was a dramatic increase in injecting in the 1980s, and by 1990 there were an estimated 15,000 injectors, 1.3 per cent of the population [ 39] , [ 42] , [ 43] . Most heroin use is found along Highway 39, a heroin transit route originating at the Myanmar border and running north to Nagaland State. Although HIV screening began in July 1986, the first HIV positive cases were found only in September 1989; by June 1990, however, the HIV-positive rate in tested injectors was 55 per cent.

A third example is Madras. The smoking of "brown sugar" heroin imported from the Golden Crescent began in 1983 among middle-class youth and students and by 1986 had spread to slum areas. Injecting, which began in 1987, was at first confined to Sri Lankan Tamils and people from the north-east of India. Three factors propelled the shift to injecting. First, 'brown sugar' heroin became scarce following police action against Sri Lankan militants after the assassination of Rajiv Ghandi. Secondly, some local doctors sold injections of buprenorphine (brand name Tidigesic in India) as a cure for addiction, unwittingly introducing users to the practice of injecting. Thirdly, migration from Manipur facilitated the importation of injectable-grade heroin from the Golden Triangle. Injecting is now practised in many sectors of Madras society" The link with Manipur suggests that HIV infection will soon appear among injectors in Madras.

Implications for research

It is clearly difficult to arrive at a detailed global epidemiology for injecting. Few researchers have attempted to estimate the size of drug-injecting populations. Prevalence is rarely measured directly. There are major problems in trying to investigate an illicit activity. Most countries can only estimate trends and relative prevalence by means of multiple indicators. Information can be pieced together from statistics on arrests, convictions and drug seizures; hospital data; data from drug treatment programmes; hepatitis incidence; drug -related deaths; registers of known "addicts"; and surveys of special populations [ 44] , [ 45] . Even so, differences in terminology, case definition and counting procedures and a lack of specificity about the route of administration make overall assessment difficult. Statistical modelling has sometimes been used: an example is the use of capture-recapture techniques [ 27] , [ 46] , [ 47] . These borrow from studies of animal populations and predict population size from the overlap between two or more samples of the population. Many of these techniques are beyond the reach of developing countries resources.

Research must focus on the dynamics of drug-injecting populations, including recruitment to injection, the spread of injecting to new population groups, the movement between different modes of administration, the length of time exposed to risk of HIV infection through drug injecting, and trends in rates of cessation from drug injecting. The history of injecting and its social and cultural aspects must also be studied. Such information is needed for estimating populations at risk, for planning and assessing HIV prevention activities and for allocating resources to the care and treatment of HIV-positive injectors.

Implications for the diffusion of injecting

Injecting is spreading to new social groups for reasons connected with economic, political and social conditions and changes, drug control strategies, and local. cultural contexts and traditions. More needs to be known about the factors that facilitate the diffusion of injecting.

Recent history suggests that proximity to drug production and to trading routes appears to be one important predictor for the spread of drug use and of injecting. Based on this hypothesis, the potential for drug injecting to spread, mainly in developing countries, can be identified.

One vulnerable region is Africa. A major route for the trade of heroin between Asia and Europe and North America runs through Nigeria [ 48] , [ 49] . Enforcement efforts against transport and travellers originating in Nigeria have helped to shift trade routes to the C6te d'Ivoire, Zambia and Zimbabwe. Some growing of poppies is now reported in Benin and Cameroon [ 50] . Nigeria is a growing consumer of heroin, but there is as yet only a little injection. However, given the popularity of injections in medical treatment in Africa, heroin injection may spread in this region.

South-east and south-west Asian countries are particularly vulnerable. They contain much of the world's poverty and much of its heroin production. It is likely that injection will spread in Bangladesh, Cambodia, parts of China, India, the Lao People's Democratic Republic, Pakistan and Viet Nam as other routes in the region are made difficult. As much as 30 per cent of the heroin from the Golden Triangle now passes through China to Beijing, Shanghai and other seaports and cities with airports for expert to Europe and North America [ 38] . Drug injecting occurs in the Ruili area in Yunnan Province, which has an easy border crossing into Myanmar. In 1990, of the 16,383 local residents who had been tested, 398 (2.4 per cent) were HIV -positive, most of them drug injectors [ 40] , [ 51] . The southern borders, in Asia, of the Commonwealth of Independent States are shared with heroin-producing countries, and opium production appears to be spreading in countries such as Uzbekistan [ 50] .

Elsewhere in Asia, Pakistan is a major heroin refining and transit area for opium grown in Afghanistan. The smoking of "brown sugar" heroin became common in the 1980s, but there is as yet only a little injecting. However, the injection of drugs for medical treatment is commonplace, and this may contribute to the spread of drug injecting.

The third vulnerable area is South America. Local cocaine production and distribution have led to serious local cocaine problems, and there is some cocaine injecting; indeed, in Brazil this is found in association with HIV infection [ 52] . Cocaine injection could spread, particularly along drug transit routes. Also significant is that the cocaine cartels in Colombia and Venezuela are experimenting with poppy growing and heroin production [ 53] , and there are reports of heroin injecting in Colombia.

Implications for the prevention of HIV infection

The final issue arising from this global assessment concerns HIV prevention. Much has been learned since the mid-1980s about working with current injectors to help them reduce their risk of HIV infection [ 54] . However, HIV prevention also needs to focus on potential injectors.

Countries where injecting is endemic are still seeing new recruits to injecting, and injecting is spreading to new population groups. In other countries, particularly poor ones, injecting can spread in less time than it takes to introduce HIV prevention activities. Many countries urgently need to assess the risk that injecting will develop or spread and the need to institute appropriate public-health-based HIV intervention activities before the problem overtakes the response. The World Health Organization can play an important role by advising countries how to do this.

The challenge for countries where drug injecting is endemic, and for those where it is new or has the potential to spread, is to include within HIV prevention programmes measures to discourage injecting. The task of the public health system will be to find a balance between activities targeted at helping current injectors change their behaviour and activities targeted at discouraging drug injecting.

Some Governments may wrongly assume that demand reduction acti- vities will suffice to prevent the spread of injecting. In southern China the response of the authorities was savage and dramatic. In Yunnan in 1990, the 150th anniversary of the opium war between Britain and China was celebrated with a mass rally at which 40 drug of fenders were sentenced and executed [ 55] . What happened in both Africa and Asia illustrates the potential negative consequences of law enforcement: effective enforcement in one area can drive drug problems and drug injecting into new areas.

Much creative thought must be given to the appropriate public health approach to this task. Some interventions that have been developed for the prevention of HIV infection in current injectors might be adapted: for example, peer educators as well as the careful use of national and local media and culturally relevant outreach initiatives [56-581. Such inter- ventions are distinguished by their attempt to meet drug injectors on their own terms and territory and to work with them collaboratively rather than coercively. HIV prevention workers will need to develop appropriate working relations with police and law enforcement agents in order to avoid actions that would promote rather than discourage injecting. In pursuing public health goals, the relative harm from different modes of drug administration may have to be considered, including the merits of making available non-injectable preparations if this would prevent transitions to injecting. Interventions will have to be appropriate to the needs of potential injectors and acceptable to them, and they must avoid further repression, marginalization and stigmatization.



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