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“The only thing necessary for these diseases to the triumph is for good people and governments to do nothing.”

 

Monitoring the AIDS Pandemic (MAP) Network

The Status and Trends of the HIV/AIDS/STD Epidemics in Asia and the Pacific

October 1997, Manila, Philippines

Table of Contents

1. Introduction

The World Health Organization (WHO) Regional Office for the Western Pacific in Manila, Philippines, graciously hosted the first Monitoring the AIDS Pandemic (MAP) Network symposium, The Status and Trends of the HIV/AIDS/STD Epidemics in Asia and the Pacific, on 21-23 October 1997, which was an official satellite symposium of the 4th International Congress on AIDS in Asia and the Pacific.

The three-day MAP Network symposium held in Manila was the first symposium formally organized by this new global network formed in December 1996 by the AIDS Control and Prevention (AIDSCAP) Project of Family Health International, the François-Xavier Bagnoud Center for Health and Human Rights of the Harvard School of Public Health and the Joint United Nations Programme on HIV/AIDS (UNAIDS). It was the third in a continuing series of regional and global symposia that have been organized to understand the trajectory of the HIV/AIDS pandemic. Starting with the Status and Trends of the HIV/AIDS Epidemics in Africa Symposium that was held in Kampala, Uganda, in December 1995, a team of internationally recognized technical specialists in epidemiology, modeling, economics, demography, public health and international development was formed to monitor the dynamics of the HIV/AIDS pandemic and various regional epidemics. By collecting, analyzing and disseminating information on HIV/AIDS, this team of experts, which has grown rapidly over the course of two years into a global network, seeks to assist governments, organizations and the world at large to respond more actively and effectively to the challenges posed by the HIV/AIDS pandemic.

The MAP symposium in Manila brought together 40 global and regional experts, including MAP members and some specially invited participants, to achieve the following objectives:

    • To present and share information on the status and trends of the HIV/AIDS/STD epidemics in Asia and the Pacific and analyze this information in a global context;
    • To review the epidemiological and behavioral patterns among the HIV/AIDS/STD epidemics affecting the different populations in the region;
    • To identify specific data needs for monitoring and forecasting the HIV/AIDS/STD epidemics in the region; and
    • To produce and disseminate a consensus report on the current status of the HIV/AIDS/STD epidemics in Asia and on the current and projected trends for these epidemics in the region.

Because a large percentage of the world's population resides in the Asia-Pacific region, the symposium held in Manila was important in enabling MAP to focus strategically on the evolving HIV/AIDS and sexually transmitted disease (STD) epidemics in the Asian and Pacific countries, fuse current knowledge, identify gaps therein and determine topical and geographical areas for action.

The symposium began by first reviewing the global HIV/AIDS/STD situation to position the various Asia-Pacific epidemics within the worldwide context. From then on, the team concentrated on the situation in the overall region and the Western Pacific and Southeast Asian subregions, presented country-specific epidemic profiles on Australia, China, India, Japan, Malaysia, Myanmar, Philippines, and Vietnam and discussed past, present and potential future issues of relevance.

This provisional report, coauthored by the MAP Manila Symposium participants and produced in some 24 hours, reflects a consensus of the analysis, determinations, projections and recommendations brought forward during the symposium. Its aim is to provide information that can be used by international as well as local bodies to briefly review the most important aspects of the history of the HIV/AIDS epidemics in the Asia-Pacific region to date, recognize the current status of and trends within these epidemics, and take immediate action to affect the course of these epidemics in the future.

2. The Status and Trends of the HIV/AIDS/STD Epidemics in Asia and the Pacific

With a population in excess of 2.5 billion -- representing more than sixty percent of the world's population -- the Asia-Pacific region has the potential to influence greatly the course and overall impact of the global HIV/AIDS pandemic. This report examines the status and trends of HIV infection and AIDS in countries of Asia and the Pacific, a region which, for the purpose of this analysis, stretches from and includes India on the west, to Japan and island nations in the Pacific, and from China in the north, to countries forming Oceania in the south.

Epidemic patterns

The spread of HIV in this region began in the early to mid-1980s. Early infections could be traced to sexual contacts with infected persons residing outside the region, as well as some apparent further spread within the region itself. By the late 1980s, however, it had become evident that the transmission of HIV was increasing among several populations, in some cases with great velocity, and that two sets of factors strongly influenced the course of the emerging epidemics: participation in sex work and patterns of injecting drug use (IDU).

By early 1997, South and South East Asia accounted for an estimated 5.2 million (23 percent) of the 22.6 million adults and children living with HIV in the world. About one-third of adults living with HIV in the region are female. As the HIV epidemic is still relatively recent, HIV disease, including AIDS, is only beginning to emerge and the associated needs for care are rising steeply. The estimated HIV prevalence in 15 to 49 year-old populations varies from zero (DPR Korea) to one per several thousand in most countries in the region, up to 2 to 3 percent in Cambodia, Myanmar and Thailand.

HIV epidemics in Asia and the Pacific are diverse, localized and have different trends over time (see Figure 1). Against this backdrop, however, it is becoming increasingly clear that the intensity of HIV epidemics associated with sex work, affecting both female sex workers and their clients, is primarily determined by the daily or weekly number of sex partners (clients) per sex worker, the frequency of use of commercial sex by men, and such other factors as the rate of regular condom use in commercial sex and the magnitude and quality of the response to the epidemics. Epidemics associated with injecting drug use have, in many situations, led to explosive outbreaks in the IDU population and then to their sexual partners (e.g., in the late 1980s in Thailand; Myanmar; the Yunnan province of China; and the Manipur state of India, Vietnam and Malaysia). The prevalence of HIV infection in IDUs in these areas reached staggering levels with prevalence reaching 50 to 90 percent within a few months.

Although HIV can spread rapidly among IDUs who share contaminated injection equipment, and then from them to their sexual partners, these epidemics have so far resulted only in limited spread of HIV to the heterosexual population at large. It may be assumed that for a variety of reasons including social isolation of some IDU populations and their sexual partners from other communities, and/or stigmatization to which they are subjected, there are only tenuous bridges between them and other sexually active adults. Strikingly, in Asia and the Pacific, HIV epidemics associated with commercial sex and those involving IDUs do not appear to fuel each other significantly. These epidemics appear to emerge and evolve almost independently from each other, as exemplified by the two concurrent HIV epidemics in Thailand, which were caused by two different subtypes of HIV, with minimum cross-over.

From a regional perspective, the magnitude and short-term trends of HIV epidemics are largely dependent on the extent of ongoing epidemics in a few countries: Cambodia, India, Thailand, Myanmar and, because of their population size, Indonesia and China. With a population close to 1 billion and multiple epidemic foci, India projects the image of a complex epidemic, involving focal outbreaks among injecting drug users and extensive HIV spread among female sex workers and their clients in several regions.

Of increasing concern in the region is the issue of blood safety and HIV transmission. In 1995, WHO/GPA estimated that less than 50 percent of blood transfusions in the region were being routinely screened for HIV. Currently in Bangladesh, virtually no screening for HIV antibodies is performed in the nearly 200,000 units of blood transfused annually. In India and Myanmar, screening of donor blood for HIV remains far from complete and measures are being taken through improved donor selection to address this issue.

Mapping the epidemics

If the HIV epidemics were analyzed on a country-by-country basis, as if HIV epidemics respected national geopolitical boundaries, most countries in the Asian-Pacific region project the reassuring image of low prevalence (proportion of adults living with HIV/AIDS) and low incidence (proportion of adults newly infected each year). Such is the case of Australia and New Zealand which, early in the epidemic, experienced sudden epidemics in men having sex with men (MSM) with a peak of incidence in the mid-1980s, followed by a rapid decline. The spread among IDUs in these two countries has been and remains limited (less than 2 percent), and heterosexual transmission remains at low levels (the prevalence of HIV among pregnant women is lower than 1 per 10,000).

Such is the case as well for Japan, where an initial dramatic outbreak of HIV infection among people with haemophilia was brought under control in the mid-1980s (see Box 1), and where other modes of transmission are only contributing minimally to a limited HIV burden in the country (less than 1 HIV-infected person per 10,000 adults in 1997). Also reassuring would be the situation in China where, in spite of increasing trends in HIV incidence in IDUs in selected southern provinces (Yunnan, Guanxi), the overall national rate of HIV prevalence in adults in this large country remains below 4/10,000 -- one tenth to one-fifth the prevalence found in Western Europe and in North America, and the spread of HIV from IDUs to their sexual partners accounts for most of the heterosexually acquired HIV infections.

Box 1
The Lingering Effect of a Controlled HIV Epidemic:
HIV infection from blood coagulation products in Japan

As of the end of August 1997, the cumulative reported number of AIDS cases in Japan was 1,657, which was still very low in Asia comparatively, even among developed countries. A little less than half of the cases (41.6 percent) are, however, those infected through blood coagulation factor products. This high percentage of hemophilia cases is still the distinctive characteristic of HIV infection in Japan and not seen in other countries in the world.

These infections resulted from transfusion of infected blood products in the early 1980s. In July 1985, the Japanese Ministry of Health and Welfare approved the usage of heat-treated blood coagulation factor products. Since the introduction of these heat-treated products, virtually no HIV infection has occurred through infected blood products. The epidemic of HIV in this population is now reflected in an increasing number of people developing AIDS and dying from the disease each year.

Almost all those infected from blood products are hemophiliacs type A or B, and the rest are related coagulopathy, such as von Willebrand disease and few cases of administrated coagulation factor for the prevention of excessive bleeding. An estimated 35 to 40 percent of hemophiliacs in Japan are infected with HIV.

Cases from blood products show a tendency to have a longer incubation period than the cases via other routes of infection. Most of these cases, however, will have the onset of AIDS in the near future. Consequently, every prefectural government in Japan is now preparing base hospitals for the treatment of AIDS. As of the end of May 1997, almost 1,300 people infected through blood products were living in Japan, accounting for 32.4 percent of the total population living with HIV in the country.

 

Less reassuring would be the estimated and projected trends in India. There, a sharp increase in the estimated number of HIV infections from a few thousand in the early 1990s to a cumulative minimum of 2.5 million in 1997, in a context of a severe gap of knowledge about prevailing risk-taking sexual behaviors, creates great uncertainty about the future course and impact of the epidemics. Yet, the 1997 national prevalence of HIV infection in adults may be between 0.2 to 0.5 percent which, on first analysis, would not place India high on the world list of "hardest hit" countries where prevalence rates may range from 10 to 25 percent.

HIV prevalence among sex workers in India varies widely from state to state, with high HIV prevalence in western and southern India to low levels of HIV in eastern and northern India. HIV prevalence among sex workers tested in Mumbai (formerly Bombay) rose from 1 to 51 percent between 1987 and 1993. Prevalence among sex workers in Calcutta was consistently low at about one percent until 1994, but there are indications that it might be rising. In Mumbai, HIV prevalence increased from two to three percent in STD clinic attendees before 1990 to 36 percent in 1994. Among antenatal clinic attendees tested in Mumbai, two percent tested positive for HIV in 1995 and around 5 percent in 1996. In Manipur, rates of HIV infection among the antenatal clinic attendees are rising.

In some countries, HIV prevalence has remained very low (less than 0.1 percent in the 15- to 49-year-old population. In the Philippines, AIDS case reporting has slowly increased to a total of 958 reported as of September 1997. HIV surveillance has found only a few cases of HIV infection among female sex workers, male STD clinic patients and men who have sex with men. Similarly, a small number of AIDS cases and low levels of HIV infection have been reported from Indonesia.

When examined through the lens of current national HIV prevalence and incidence rates, most other countries in Asia and the Pacific would conform to a pattern of low prevalence and slow HIV spread (see Figure 2).

Large-scale epidemics ahead?

Are HIV epidemics likely to expand abruptly in India, or in other countries in Asia and the Pacific? To answer this question, possible clues can be drawn from past history in several countries, including Thailand, Myanmar and Cambodia. In Thailand, information was available on IDU needle sharing practices and sex work in the country when, in the mid-1980s, HIV had not begun to spread in epidemic form. The epidemics that were predicted but insufficiently prevented did occur later in this decade, infecting an estimated 800,000 women, men and newborns by 1997. Prevalence rates in pregnant women reached 2 to 3 percent in 1995 nationwide, while rates in army recruits rose to around 4 percent in 1993, then levelled off and began to decline. In Myanmar, rates of HIV infection in IDUs, sex workers and pregnant women are similar to those found in Thailand. Consistent with an East-West gradient of HIV prevalence in Myanmar, the epicenter of the epidemics appears to lie east of the country. The analysis of geographical differentials in HIV infection rates and trends over time underscores both the deepening severity of the epidemics and the potential for national, aggregate data to mask important sub-national epidemic trends. In Cambodia, HIV spread rapidly in the early 1990s, reaching high levels in sex workers (about 40 percent HIV prevalence) and from 2 to 3 percent of the 15- to 49-year-old population (see Box 2). The evolution of the epidemic in Cambodia country illustrates the potential for HIV to spread rapidly and widely when patterns of commercial sex involve high mobility, a high sexual partner exchange rate and low condom use.

Box 2 Cambodia:
An Explosion of HIV

The Kingdom of Cambodia has seen a rapid increase in HIV infection over the past few years, giving it the likely dubious distinction of the most widespread and serious HIV epidemic in Asia. Although only about 600 AIDS cases had been reported by mid-1997, the epidemic has progressed so quickly that it is now estimated that approximately 100,000 individuals are infected with HIV. Although substantial variations exist regionally, national rates derived from 1997 serologic surveillance results indicate that approximately 40 percent of sex workers, 6 percent of police/military, and 3 percent of antenatal women are HIV-infected.

Other sexually transmitted diseases are likewise high in Cambodia, contributing to HIV spread in the country. A 1996 survey in selected cities indicated prevalence rates of gonorrhoea of 12 to 31 percent among sex workers and 2 to 6 percent among antenatal women. Similarly, syphilis rates were 4 to 24 percent in sex workers, 0 to 12 percent among police and the military, and 2 to 8 percent among antenatal women.

Despite the widespread HIV epidemic in Cambodia, there are some recent HIV prevention sucesses which may promote a slowdown. A condom social marketing program by Population Services International reports condom sales increasing from about 5 million in 1995 to 9.5 million in 1996. Behavioral surveys confirm that many of these condoms are being used for commercial sex. Men frequent sex workers in high proportions in Cambodia (about 75 percent of military/police and 37 percent of students report visiting a sex worker in the past year), but condom use has substantially increased over the past few years. However, given the state of the Cambodia's political and economic situation, these successes are fragile and continued concentration and strengthening to maintain and increase behavioral changes will be required.

 

Empirical evidence thus exists showing that sudden and sharp increases in HIV incidence can and have occurred in Asia. However, the lack of quantitative and qualitative epidemiological, behavioral and social information on the nature of and linkages between sexual networks in any of these countries rules out any reliable prediction of the future course of HIV epidemics in countries that would intuitively appear vulnerable to rapid spread. These countries include, in particular, Malaysia, Nepal and Vietnam, where rapid increases of HIV incidence in various vulnerable populations are being noted. There is an urgent need to collect and analyze systematically the information needed for the dual purpose of projecting epidemic trends and targeting prevention toward factors that seem to influence the vulnerability of the population to the further -- and possibly rapid -- spread of HIV.

Populations of affinity

The analysis of HIV epidemic trends in the region becomes more meaningful when a focus is placed on populations whose cultural and social affinity and networks transcend geopolitical borders. A new geography of HIV/AIDS in the region then emerges that helps recognize the foci of intense HIV spread. (See the map, Figure 3.) These include large metropolitan areas in western and southern India (Mumbai, Tamilnadu) (see Box 3); the India/Nepal border area; the larger "Golden Triangle," which reaches out to Northern Thailand, eastern Myanmar, but also encompasses the areas of Manipur in India and Yunnan in China; and the Mekong delta area, which includes Cambodia and southern Vietnam. To gain better understanding of the dynamics of HIV epidemics, factors of affinity between populations as well as mobility patterns must be explored and mapped.

Box 3
India: An uncertain future

With more HIV infections than any other country in the world, India gives the impression that HIV infection is common and that there is a severe epidemic in the country. However, the estimated 2.5 million HIV infections should be considered in the context of the close to 970 million population of India. The prevalence of HIV is about 0.3 percent, a rate much lower than many other countries in the Asia-Pacific region.

In India, HIV infection is not evenly distributed throughout the country. While it is true that HIV has now been reported from all except one of the 32 states and Union Territories, the infection is actually highly localized.

 

As the pie chart shows, almost half the total 4,828 cases of AIDS reported so far are from the state of Maharashtra, and of these 80 percent are from Mumbai city. The state of Tamilnadu contributes another 22 percent. It is worth noting that 21 of the 32 states add only 4 percent of the total AIDS cases reported. The state of Manipur, which contributes 6 percent to the total, reports that all the cases of AIDS recorded so far are in IDUs. There are an estimated 25,000 IDUs in the state, which borders on the "Golden Triangle," and at last estimate the HIV prevalence in this group varied from about 50 to a staggering 80 percent.

Another group showing high HIV prevalence is that of long-distance truck drivers and their helpers. It has been shown that this group has a steadily increasing prevalence. In Chennai (Madras) a seroprevalence of close to 10 percent has been reported.

These data bring out the fact that it is often misleading to consider a country as a homogenous entity as far as HIV/AIDS is concerned. Many countries have more than one epidemic, often at different stages of development and in different communities and regions. An appreciation of this fact is important in planning suitable interventions.

 

The potential for continued spread of HIV/AIDS in Asia and the Pacific is real and requires determined and sustained prevention efforts. Several countries have already experienced intense HIV epidemics in certain population groups or, in some cases, in the population at large. In these countries, including India, Thailand, Myanmar and Cambodia, the individual impact of HIV has begun to be felt as AIDS has imposed new demands on the health care systems. It is essential that countries reinforce their prevention and care efforts in order to enhance their response to the existing HIV/AIDS challenge. In addition, countries should make every effort to collect and analyze the information needed to assess and monitor the evolving potential for large-scale HIV epidemics.

Recognizing the threat of emerging or fast-growing epidemics in certain populations is essential to an early and effective response. Acknowledging the possibility that, in other populations, rapid and extensive spread of HIV may not occur is equally crucial as policy and decision makers may, on the basis of this information, orient efforts and resources towards people who are most at risk.

Figure 1. HIV Penetration into Asian and the Pacific Countries

Countries with epidemic spread

Current HIV Epidemic Trends

Main Populations Affected

Projected HIV Epidemic Trends

 .

HIV incidence

HIV prevalence

 .

(3-5 Years)

Australia

Low and decreasing

Low and stable

MSM

Decline

Cambodia

High and increasing rapidly

High and increasing

Individuals with high and moderate risk heterosexual behavior

Sustained upward trend

China

Low except in Yunnan

Low and increasing

IDU

Increasing

India

Moderate and increasing(significant regional variation)

Still low but increasing(significant regional variation)

Individuals with high-risk heterosexual behavior and IDUs

Increasing

Malaysia

Moderate and increasing

Low and increasing

Principally IDUs but increasing among individuals with high risk sexual behavior

Increasing

Myanmar

High and increasing

High and increasing

Individuals with high-risk heterosexual behavior, IDUs and their spouses

Increasing

New Zealand

Low and decreasing

Low and stable

MSM and IDU

Decline

Papua New Guinea

Moderate and increasing

Low but increasing

Individuals with high-risk heterosexual behavior

Slowly increasing

Thailand

Moderate and stabilising in specific groups

High but stabilizing

IDUs and individuals with high and moderate risk heterosexual behavior

Tending to stabilize

Vietnam

Moderate and increasing

Still low but increazing

Principally IDUs but increasing among individuals with high risk sexual behavior

Increasing

 

 

Countries with low transmission

Current HIV Epidemic Trends

Main Populations Affected

Projected HIV Epidemic Trends

 .

HIV incidence

HIV prevalence

 .

(3-5 Years)

Bangladesh

Low

Low

Individuals with high-risk heterosexual behavior

Slowly increasing

Indonesia

Low

Low

MSM, Bisexual and high-risk heterosexual behaviour

Slowly increasing

Japan

Low

Low

Previously blood product related, currently sexual

Slowly increasing

Hong Kong

Low

Low

MSM

Slowly increasing

Nepal

Low except in IDUs

Low except in IDUs

Individuals with high-risk heterosexual behavior and IDUs

Slowly increasing

Philippines

Low

Low

Individuals with high-risk heterosexual behavior

Slowly increasing

Singapore

Low

Low

MSM, IDUs

Slowly increasing

Sri Lanka

Low

Low

Individuals with high-risk heterosexual behavior and MSM

Slowly increasing

 

Figure 2. HIV Distribution Among Selected Asian And Pacific Populations

The following countries in the region have minimal spread of HIV infection: Bhutan, Brunei, DPR Korea, Macao, Mongolia, Pacific Island countries and areas, Republic of Korea.

 

 

Country

IDU*

HET**

MSM***

Australia

+

+

++

Bangladesh

+

+

+

Cambodia

+

+++

+

China
- Yunnan Prov.
- Hong Kong
- Rest of China


+++
+
++


+
+
+


+
++
+

India
- West & South
- Central & East
- Northeast


+
+
+++


+++
+
+


+
+
+

Indonesia

+

+

++

Japan

+

+

+

Laos

+

+

+

Malaysia

+++

++

++

Myanmar

+++

++

++

Nepal

+++

++

++

Papau New Guinea

+

++

+

Philippines

+

+

+

South Korea

0

+

+

Sri Lanka

0

+

+

Thailand

+++

++

+

Vietnam

+++

+

+

 

 

 Chart legend:

+++

high or rapidly growing

++

relatively low or plateauing

+

not a major component

0

no evidence of spread

*

IDU: Injecting drug users

**

HET: Heterosexual men and women

***

MSM: Men having sex with men

 

 

 

3. Risk and vulnerability

There are three factors that appear to play a crucial role in HIV transmission in the Asia and Pacific region: female sex work, substance use and mobility. Female sex workers and their clients have been a major factor in the heterosexual transmission of HIV in Thailand, Cambodia and parts of India and Myanmar. Separate but explosive epidemics have been seen in some IDU populations in Thailand, Myanmar, Manipur (India), and Malaysia. And mobile populations, particularly at national borders, are at higher risk of HIV acquisition due to the fact of being away from home and community, and the anonymity and loneliness of traveling. The following three sections focus on monitoring the HIV epidemics in these vulnerable populations.

3.1 Female Sex Work in the Asia-Pacific Region

The numbers of commercial sex workers

Female sex workers operate in all countries in the region, but it is important to know how large the sex-worker population may be to adequately interpret surveillance results. It is believed that in some countries, rapid increases in the number of sex workers have resulted from significant political, social or economic changes.

The number of female sex workers in countries can range from a few thousand to a few hundred thousand. Thailand, for example, has approximately 80,000 to 100,000 female sex workers -- an estimate that only recently has gained consensus. In most countries, however, validated estimates of the numbers of sex workers are almost non-existent. Without such numbers, interpretation of surveillance results, policy commitment, planning, intervention designing, and resource allocation are extremely difficult (see Box 4).

Box 4
How Many Sex Workers?

Most estimates of the numbers of female sex workers are either restricted to a subset of licensed commercial sex establishments or ad hoc unvalidated "guesstimates." In Dhaka, Bangladesh, estimates of the number of sex workers frequently quoted range from 3,000 to 100,000. It is impossible to anticipate the scale of services and funds and nature of interventions needed without more meaningful numbers.

One promising direct estimation method being used in Thailand, Laos, Nepal and Taiwan developed by the Thai Red Cross and the East-West Center is the method of comprehensive geographic mapping of sex work sites and types. In Thailand, this method has now been adopted by the Ministry of Public Health for their annual survey of sex work. In several areas, the method has detected up to 50 percent more sites than estimates by using the conventional method of referral by STD patients. In other countries, population estimates have been generated through innovative applications of capture-recapture techniques. In Dhaka, CARE/Bangladesh recruited and trained sex workers to assist in "capturing" street sex workers throughout the city by handing out different colored cards for 24 hours on two different days within a fortnight.

 

All estimates need regular updating and validation but these two approaches are worthy of replication in other settings. Neither method can work without the trust and involvement of sex workers themselves.

 

Diversity

The nature of sex work and the profile of sex workers vary enormously within and between countries. There are female and male sex workers, and those that work full-time, part-time or seasonally. Sex workers may operate in a variety of settings such as brothels, bars, massage parlors, street corners, restaurants, etc. Sex workers operating in government-registered establishments exist in a few countries such as the Philippines, in contrast to the freelance sex workers in most countries of this region. There are also commercial sex areas that are highly organized, such as in Indonesia, as opposed to those with bonded or sex workers imprisoned in underground settings. There are women in brothels who cannot refuse sex with customers and those in massage parlours or bars who have more freedom of decision.

For surveillance purposes, sex work can be characterized by work conditions, methods of recruitment, number of clients per week, price, how clients are contacted, where sex takes place, types of clients, existence of employers or agents. Despite these diversities, some types of sex workers are more visible and/or more easily brought to the attention of government or public health officials. These are usually the sex workers who are the subjects of epidemiological studies presented without acknowledging the fact that they represent only a subset of all sex workers. Without a clear understanding of these diversities, effective surveillance cannot be designed or implemented.

Sex workers and HIV

Frequency of exposure to HIV infection through sexual intercourse is the key factor for transmission of HIV among sex workers. In many countries, a significant proportion of sex workers is infected with HIV. The rates might vary from less than 1 percent to 40 percent or higher in some settings (see Table 1).

Even where HIV infection has not yet spread extensively, STD infection is often very high among sex workers. For example, in one brothel area in Bangladesh, 95 percent of 466 sex workers tested positive to antibodies for genital herpes virus and 60 percent for syphilis, although HIV was not detected among any of them. With the progression of the epidemic, HIV tends to increase where other STDs are present.

HIV, STD, and behavioral surveillance

Systematic, continuous and quality sentinel surveillance of HIV and STD will provide not only the indications of an emerging epidemic but its progress over time as well. This will benefit policy formulation, planning and resource allocation. For sex workers, confidentiality, community participation and protection against stigmatization should be integral components of surveillance activities. STD services should also be provided as part of the surveillance package. However, if serosurveillance is to be used for monitoring success of intervention programs, it must be accompanied with behavioral surveillance (see Section 4.2) because HIV prevalence may not decline for several years despite successful interventions. Behavioral surveillance results can also be used to direct the detailed design of prevention activities with special emphasis on specific sub-groups within sex worker populations.

Table 1. HIV prevalence among various sex worker populations in Asia

Study group

HIV prevalence

Thailand, sentinel sites in all provinces, brothel-based and "indirect" female sex workers, 1996

18.8 %

Cambodia, 2,906 female sex workers, various sites throughout the country, 1996

40%

Myanmar, NAP sentinel survey of 2 sites, sample (n=200), 1996

25%

Philippines, 6,084 registered female sex workers, 10 cities, 2 rounds of testing, 1996

0.13%

Vietnam, 8,178 female sex workers in 20 provinces, 1996 (median rate)

0.5%

Laos, 216 male and female bar workers in one town, 1995

0%

Indonesia, national seroprevalence study of high-risk groups, 12, 418 registered prostitutes, 1991-2

0.02%

Singapore, 738 brothel-based female sex workers, 1992

0%

 

Improving surveillance of HIV/AIDS among sex workers

There is no doubt that commercial sex played or is playing a crucial role in the heterosexual transmission dynamic in Thailand, Cambodia, Myanmar and large parts of India. It remains to be seen whether similar experiences will be repeated in countries which at present have little evidence of extensive HIV infection among sex workers. The following are issues and suggested recommendations based on these observations in the region:

    • Surveillance of sex workers can place an emphasis on sex workers as the "cause" of an HIV epidemic and can, therefore, result in a backlash producing greater discrimination and more support for prohibitive policies leading to an increase in the vulnerability of this population to HIV. Thus, surveillance should be accompanied by clear policies on non-discrimination and supportive prevention interventions.

 

    • In many areas of Asia, the high prevalence of HIV detected from surveillance activities has not been translated into resources for programs targeting this group. Even when resources are allocated, funding is often not utilized or restricted to awareness programs that do not necessarily change behavior.

 

    • Future efforts in surveillance should attempt to document the distribution and characteristics of female and male sex workers. Such information would lead to a recognition of the biases inherent in the continued use of "captured" groups of sex workers for epidemiological and behavioral surveillance. It would also permit a more meaningful measurement of the variations of condom use and the rates of partner exchange between and within types of sex work.

 

    • Better estimates of the numbers of sex workers are also needed. These should also take into account the types of sex work and the diverse settings that influence the negotiating power of sex workers for condom use. Current estimates using geographic, capture-recapture or ad hoc approaches need to be validated.

 

    • Focalized surveillance, if possible, is likely to be more useful for intervention design and to permit a more careful analysis of the behaviors and sexual networks of sex workers so that more informed decision-making regarding interventions can occur.

 

    • More attention is also needed on the types of indicators to be measured in the behavioral surveillance of sex workers and potential male clients as well as other methodological issues such as reducing selection bias and increasing the truthfulness of responses.

 

3.2 Substance Use: Patterns and Impact on HIV Transmission

There are many aspects to the nexus of drug use and HIV infection, but globally and in Asia, the direct contribution of HIV transmission by the reuse of contaminated injecting equipment among people injecting illicit drugs, and the indirect contribution of sexual and vertical transmission from this core group far outweigh other aspects. In most of Asia, people who choose to use drugs that are not socially sanctioned are treated as entirely outside society, enemies even of the social structure. What does this mean for HIV/AIDS and drug use? For the majority of injecting drug users (IDUs), it means that lip-service is paid to the principles supposedly learned through the course of the epidemic: in relation to IDUs and the risks of HIV transmission, issues such as human rights, peer education, community participation, and legal and social change are unachievable fictions.

Patterns

Patterns of use of illicit drugs are becoming globalized and "standardized". What were fairly simple equations have largely gone, to be replaced by complex global production and distribution networks, diversified marketing, new and emerging markets - a highly dynamic and thriving scene. Drug control efforts are almost always not one pace, but two, three or even more behind the market. Racism and colonialism continue to be fundamental determing aspects of the global drug trade, both licit and illicit, as they have been for centuries.

Amphetamines are flooding into Thailand and beyond from China and Myanmar. Developing countries are all becoming major illicit drug consumers. New producers are springing up -- Opium production has started again within the borders of China and in Afghanistan opium production has risen rapidly to hold second rank globally among illicit opium producers. The transition from little use of a certain drug in a particular community, to its widespread availability and use orally or nasally, and then to its injection -- followed by epidemics of HIV -- can be extremely rapid, as is exemplified by recent history. This pattern has been so common and so predictable that we must recognize it as the norm, even if we do not fully understand the dynamics of the process. Shifts from smoking or inhaling opium to injecting heroin as a result of "crackdowns", increasing price or decreasing purity of available drug have been seen in many countries. Furthermore, cocaine injecting, if it becomes prevalent in the region, is problematic because of the greater frequency of injecting and the increased social and personal disorganization of the user. This places a further barrier in the way of achieving safer injecting behavior.

We must also recognize the role misguided attempts to control drug use have played in accelerating these processes. The rise in heroin use in India, Thailand, Hong Kong and Laos all date from the institution of anti-opium laws. Prisons in some ways are exemplars of the impact of current policies at national levels: even where there has been successful behavior change in the community, this has not happened in prisons.

Impact on HIV transmitted through injections

The diffusion of HIV among IDUs in South East Asia has been well described. Epidemics that can literally be called explosive have been documented among IDUs in Thailand, Myanmar, Malaysia, Vietnam and China, with prevalences reaching 60 to 90 percent within a few months of the appearance of the first case, and often forming epicenters for wider diffusion of the HIV epidemic. Prevalences of 60 percent or more have been described among young IDUs within their first two years of injecting. Several communities in Asia have now had HIV among IDUs for so long that they are now in the grip of multiple ongoing epidemics: of drug use and its consequences, injecting drug use, resulting HIV infection among IDUs, their sexual partners and their children, AIDS and tuberculosis. The tragedy is that these epidemics are totally predictable and preventable, and we know exactly how to prevent them. The scientific evidence on this point is unassailable (see Box 5).

There are certain places in Asia that now have uncontrolled epidemics of HIV infection that began as explosive epidemics among IDUs, taking the community from one with no HIV infection to one with a large pool of sexually active infected people in a matter of months. These include epidemics that could have been prevented by timely and relatively inexpensive interventions at an early stage, if, and only if, the conceptual leap had been taken that people who inject drugs are human and worth caring about.

Education and advocacy is needed on a much larger scale to influence those authorities concerned nationally and internationally with drug control and drug demand reduction. Efforts should be made to involve them more as partners in prevention of HIV among IDUs, building on the memorandum of understanding between UNAIDS and the United Nations Drug Control Program (UNDCP), for instance, at program level, and empowering and assisting NGOs and communities to advocate and influence national policy and the practices of public security and police.

Globally, there are relatively few programs and very few countries that have as a prime concern the prevention of HIV infection among IDUs. There are far more programs and policies that are oriented toward drug demand reduction, with the prevention of HIV among drug users or in association with drug use tacked on as a subsidiary aim.

Direction for Enhanced Surveillance and Monitoring in IDUs

Most of the information about HIV risk among IDUs comes from captive treatment or incarcerated populations, which are often not representative of the wider community of drug users. Increased investigation of risks and HIV dynamics in these so-called -- hidden populations -- is necessary. A detailed understanding of transmission from core groups of IDUs to their sexual partners and children is urgently needed in Asia to demonstrate the central role IDUs can play in national epidemics and to increase the justification for early and intense action.

In addition, better enumeration or estimation of populations at risk (i.e., those currently injecting drugs, or sex partners of IDUs) and populations coming to be at risk, and a better understanding of the dynamics of drug consumption and social organization of drug use are all necessary for targeting interventions effectively.

Incidence data, in particular, are also necessary from a range of sources to counter the potential for misunderstandings about the interpretation of available prevalence data. Potential sources for incidence data may include drug rehabilitation centers and prisons where recidivism is high and testing is mandatory (as in many Asian countries). While simple conceptually, obtaining these data may be difficult since it may require substantial negotiations with the appropriate authorities.

Finally, a process for categorization and analysis of laws relating to drug use, country by country, and their impact (potential or real) on both drug use and HIV transmission among IDUs is necessary to develop appropriate interventions. Prevention programs should be specifically aimed at reducing transmission of HIV among IDUs based on harm reduction principles. Evidence-based interventions should be the focal point to prevent HIV transmission among IDUs in Asia. In evaluating programs for their effect in decreasing HIV transmission, there is an absolute need for epidemiologically sound outcomes, especially incidence data, and a need for appropriate analysis of the factors underlying trends in risks or transmission.

Box 5
The Need for Harm Reduction

The principles of harm reduction are increasingly being applied to stem the emerging epidemic of HIV among injecting drug users in Asia and the Pacific, through a range of different programs including:

  • needle and syringe exchange programs (NSEPs)
  • methadone maintenance therapy
  • sale of clean injecting equipment through pharmacies and other outlets
  • peer support and outreach programs.

Of these, NSEPs are becoming accepted as an important, relatively inexpensive tool to prevent the spread of HIV among injecting drug users, and there is a growing body of evidence to support their effectiveness. For example, a 1993 review by the Institute for Health Policy Studies in the U.S. showed NSEPs were associated with decreases in sharing of injecting equipment. Recently, an ecological association was demonstrated between the presence of NSEPs in a city and a flat or declining trend in HIV seroprevalence among IDUs as compared with increasing trends for cities without NSEPs.

Although NSEPs have been available since the late 1980s in countries such as Australia and Canada, their introduction to users in Asia has occurred more recently. Asian examples include, among others, the programs run by the Lifesaving and Lifegiving Society in Khatmandu, Nepal, and the Shalom Project in Manipur in northern India. NSEPs in and of themselves do not guarantee reduced incidence, since for this to happen, the need for sharing injecting equipment must be eliminated or substantially reduced.

In some cities in Canada, for example, the prevalence of HIV remained stable in IDUs following the introduction of NSEPs in the late 1980s, but prevalence rates recently have risen dramatically. Reasons for this are unclear, but probably include a shift in the pattern of drug use from heroin injection to cocaine-injecting together with limitations ofof service provision at NSEP sites. This shows that NSEPs must do more than just provide clean injecting equipment; they must provide IDUs with access to the other elements of harm reduction such as peer counseling and education, provision of condoms and safe sex information, social support, and referral to medical care and/or drug treatment services (i.e., methadone maintenance). Indeed, it is not so much the NSEP itself that can prevent HIV infection amongst IDUs, but the supportive legal and social environment in which NSEPs can exist and flourish. The creation of this environment is an integral part of the development of a harm reduction approach and it requires one major conceptual step -- admission of IDUs to the human race.

 

3.3 Mobility, HIV and the Clustering of the HIV Epidemic in Asia

Population Mobility in Asia

Populations in Asia are moving across land and sea borders in increasing numbers. International trade and commerce supports this growth in population mobility, which is also facilitated by the growing number of international highways and construction of new bridges. As in Africa, truckers on international land routes move vast quantities of goods between mainland countries. For example, at one international border between India and Nepal, more than 3,000 trucks cross daily. Also occurring in Asia are high levels of maritime trade, and seamen on fishing vessels travel widely in the region, enabling the transmission of HIV to populations in areas where the virus was formerly unknown.

State of Knowledge

In Africa, mobility has been demonstrated to be an independent risk factor for the spread of HIV. Therefore, extremely mobile population groups such as travelers, fishermen, traders and migrant workers tend to have high HIV prevalence. In Asia, evidence exists showing a similar association between population mobility and vulnerability to HIV. Prevalence of HIV among travelers and fishermen in Thailand and India is higher than in the general population, approximating rates found in male STD patients.

The fact of being away from home, family and community, and the anonymity and loneliness of traveling are factors that increase vulnerability to HIV acquisition. Since opportunities for casual sex may occur frequently en route, itinerant people may adopt high-risk behavior that otherwise might not occur. Current evidence indicates that the environment in well-traveled border crossing areas and international fishing ports in several Asian countries fosters more risk-taking behavior than in other trade towns.

Crossing land or sea borders often requires overnight stays, leaving the individual with idle time and opportunities to visit drinking and gambling establishments and brothels. HIV surveillance data for female sex workers, male STD clinic patients and young males in four countries in the region -- Thailand, Myanmar, Cambodia and Vietnam -- show a clustering of high prevalence sites around international borders and ports (see Figure 4). The map included in the accompanying box shows the distribution of higher and lower HIV prevalence by sentinel site, with clustering of HIV infection along the Thai-Myanmar, Thai-Cambodia, Cambodia-Vietnam and Vietnam-China borders.

Opportunities for Prevention

HIV prevention interventions targeted to border crossing areas could take advantage of the idle time of travelers waiting for border clearance. Such interventions could include those focused on behavior change, provision of sexually transmitted infection (STI) services and access to affordable condoms. Structural interventions, including advocating for policy change to improve the process of border crossing and shorten the waiting time, might help reduce opportunities for high risk-behavior.

Recent cross-border interventions have documented that their effectiveness relies on their service provision on both sides of the border. Those that involve communities passing through and residing at border sites as well as NGOs/PVOs with the ability to work transnationally supported by local governments offer more opportunities for success. Private sector businesses and institutions, such as transport and shipping companies as well as corporations, have a vested interest in ensuring safer environments for their labor force passing through or residing in cross-border areas and offer the potential for collaboration and resource support.

The behavioral and epidemiological patterns found among mobile populations in cross-border areas are poorly known. Investigative study, including ethnographic research, is needed to provide better understanding of the risk environments populations encounter as they pass through or reside in these areas. Border crossings in Indochina and South Asia require urgent prevention and care interventions.

Interventions to reduce the vulnerability of populations traversing cross-border areas are urgently needed because mobile groups can serve as "bridges" between high-risk and low-risk populations, thereby creating the potential for a widespread diffusion of HIV. Well-traveled border towns and ports are also gateways and catchment areas for many different types of travelers passing through them and are, therefore, appropriate and convenient sites for intervention.

 

4. Monitoring the HIV/AIDS Epidemics

Methods for the monitoring of the HIV/AIDS pandemic in the Asia-Pacific region are, in general, no different from methods used in other regions. However, a diversity of HIV epidemics in this region requires adapting HIV/AIDS surveillance methods to measure Asian Pacific HIV/AIDS/STD patterns and prevalence levels. The following sections describe HIV sentinel, behavioral and STD surveillance in the Asia-Pacific region. In addition, the uses and limitations of HIV/AIDS modeling for forecasting and scenario development in this region are described.