WHO/HIV/2012.29
Annex 8: Values and Preferences report
Based on interviews with community members affected by and providers working on viral hepatitis
Background paper for WHO consultation on viral hepatitis prevention, surveillance and treatment
Acronyms and Abbreviations
3TC lamivudine
ART antiretroviral therapy ARV antiretroviral AZT zidovudine FTC Emtricitabine HBV hepatitis B virus HCV hepatitis C virus HDV hepatitis D virus
HIV human immunodeficiency virus LDSS low dead space syringe
NGO non-‐governmental organization NSP needle and syringe programs OST opioid substitution therapy PLHIV persons living with HIV PWID people who inject drugs STI sexually transmitted infections TDF tenofavir
WHO World Health Organization
Background Information
It is estimated that 350 million people are chronically infected with Hepatitis B virus (HBV); and 130-‐
170 million people are chronically infected with Hepatitis C virus (HCV).1,2 Co-‐infection with HBV and/or HCV with HIV is increasingly recognized as a major public health problem. In certain regions, up to 10% of all people living with HIV (PLHIV) are co-‐infected with chronic hepatitis B; and 25% are co-‐infected with chronic hepatitis C.3
Viral hepatitis B and C disproportionally affect people who inject drugs (PWID) as a result of unsafe injection practices. It is estimated that 1.1 million PWID have HBV and 10 million have HCV.4 The largest populations are in Eastern Europe, East Asia and South-‐East Asia. Although HBV is preventable by vaccination, the rate of vaccination among people who inject drugs is low. In addition, although both chronic HBV and HCV can be effectively treated and, sometimes cured, very few PWID access treatment because of the high cost and other barriers to accessing the health system.
Liver disease is currently one of the leading causes of morbidity and mortality in HIV-‐infected populations, particularly in settings where antiretroviral therapy (ART) access is being expanded. It is well established that HIV has a negative impact on the natural history of HBV and HCV, with a higher rate of viral persistence, and more rapid progression to fibrosis, end-‐stage liver disease and death.
Current World Health Organization (WHO) ART guidelines recommend the earlier initiation of ART in HIV-‐HBV co-‐infected individuals with chronic active hepatitis B, irrespective of CD4 count, when treatment for hepatitis B is indicated. Although guidelines for managing hepatitis B and C have been developed with high and middle-‐income countries, there are currently no global WHO clinical or programmatic guidelines.
In order to address this unmet need, WHO has been requested by countries to develop guidance on viral hepatitis prevention among PWID in low-‐income and middle-‐income countries.5
The WHO guidance will be designed to meet the needs of government, policy makers, donors, non-‐
governmental organizations, programme managers, health care providers, patient support groups and advocates supporting viral hepatitis prevention. A systematic review of the evidence has already been undertaken to inform recommendations and as a basis for this guidance.
The individual needs and challenges of the people whose lives will be affected by this guidance are best understood by those who are meeting those challenges. Through this paper, their inputs provide a personal dimension to the work of the experts participating in the technical review for the preparation of this guidance.
From December 2011-‐February 2012, a qualitative survey was conducted to collect the personal experiences and perspectives of members of civil society and service providers working on viral hepatitis in sub-‐Saharan Africa, Asia, Europe, Latin America and North America. Although the guidance will focus specifically on viral hepatitis prevention among PWID, respondents were asked a
1 WHO. Hepatitis B Fact Sheet No. 204. Geneva, WHO, 2008.
http://www.who.int/mediacentre/factsheets/fs204/en/index.html
2 WHO. Hepatitis C Fact Sheet No. 164. Geneva, WHO, 2011.
http://www.who.int/mediacentre/factsheets/fs164/en/index.html
3 Soriano V et al. Viral Hepatitis and HIV co-‐infection. Antiviral Research, Jan; 85 (1): 303-‐15, 2010.
4 Nelson et al. Global epidemiology of hepatitis B and hepatitis C in people who inject drugs: results of systematic reviews.
The Lancet, Volume 378, Issue 9791, 13 August 2011.
5 Sixty-‐third World Health Assembly, Resolution 63.18. Viral Hepatitis. WHO, Geneva, 21 May 2010.
broader range of questions e.g. on testing and treatment. The results from those questions are also presented in this report. This report documents the main issues discussed with respondents, and it will contribute to the systematic review to inform recommendations and to prepare guidance on viral hepatitis prevention among PWID.
Methods
A qualitative study was conducted to ensure that the experiences of people living with viral hepatitis or who are service providers are considered along with the technical review of evidence that will form the basis of the guidance on prevention of viral hepatitis among PWID.
An independent consultant was hired to conduct a survey to ensure neutrality in the discussions with respondents and analysis of findings. Seventeen people were identified through international organizations and NGO networks and asked to participate in anonymous, semi-‐structured interviews regarding their personal experiences and views on hepatitis testing, HBV vaccination, prevention programs for PWID, hepatitis treatment and co-‐infection with HIV. Fourteen interviews were conducted individually by phone or Skype. One interview was conducted in person by the consultant, and two respondents provided written inputs. All participants have been tested for hepatitis and currently are involved in programmes addressing issues around hepatitis prevention and treatment access.
A semi-‐structured interview guide was developed to guide and ensure uniformity of interviews, to identify emerging themes and to facilitate analysis of findings (See Annex 1). All interviews were approximately one hour in length and most questions were open-‐ended to allow for free discussion of individual experiences, motivations, perspectives and concerns. Interviews were not recorded, but extensive notes were taken in order to ensure that respondents’ inputs were accurately reflected in the report. Verbal consent to be interviewed was obtained from all participants, and participants were free to seek clarification and to decline to answer any questions or to discuss any topics.
For the question on the rapid regimen for the HBV vaccine regimen, the consultant initially incorrectly described the rapid regimen to interview participants. After realizing her mistake, the consultant emailed the fourteen participants that she discussed this question informing them of her mistake and, based on correct information, re-‐asked the question. Twelve of the fourteen participants responded to her. These responses are presented in the results section of this report.
The consultant’s qualitative analysis of the discussions shapes the narrative sections of this report.
These are intended for consideration in the formulation of recommendations on prevention of viral hepatitis among PWID.
Topics of the interviews included:
• Hepatitis testing
• HBV vaccination
• Prevention for PWID
• Hepatitis treatment
• Co-‐infection with HIV
Demographics
Table 1. Respondent profile by gender and nationality
Africa Asia
Middle East L. America Russia / CIS Australia Europe N. America
Women -‐ -‐ -‐ 3 2
Men 1 5 2 1 3
Table 2. Respondent profile by gender and age
30-‐39 40-‐49 50-‐59
Women 3 -‐ 2
Men 2 6 4
Thirteen of the 17 of key respondents are living with HCV. Eight of the 13 people with HCV are also infected with HIV (n=6), HBV or HDV. One of the respondents is not (and has never been) infected with viral hepatitis or HIV.
Table 3. Respondent profile by gender and viral hepatitis and HIV status. One of the women respondents did not report infection with viral hepatitis or HIV.
HBV HBV
HCV HCV HCV
HIV HBV
HCV HDV
HBV HCV HDV HIV
Women -‐-‐ 1 1 1 1 -‐
Men 3 -‐ 4 4 -‐ 1
Hepatitis testing
“My doctor says I have hepatitis, but I shouldn’t worry about it.”
Participants had varying experiences with testing. The most common theme expressed by participants was a lack of knowledge by both the testing providers and participants themselves. This lack of knowledge was expressed as misinformation delivered by providers to participants in addition to participants’ own lack of knowledge about Viral Hepatitis. The timing of testing also contributed to the amount of available knowledge. For participants tested in the early 1980’s, there was less available knowledge than for those tested in the last 10 years. Many participants expressed relief that they were infected with “only” HCV and not HIV. One patient whom initially tested positive for HIV was not tested for HCV until experiencing liver problems years later. This was because he did not “fit the profile” of someone who would have HCV.
All participants were unanimous in saying that testing should be available in locations most convenient to the clients. Based on the responses from participants in different regions, it seems that this decision should be dependent on the setting. For example, some participants from developed countries said that testing should absolutely not be offered at needle and syringe programs (NSP) since PWID did not want to spend more time than necessary at these sites. On the other hand, participants from Asia recommended NSP as a setting to offer testing. Methadone and opioid substitution therapy (OST) programs were recommended provided that testing not be used as an incentive to access services. Other participants addressed that testing needs to be made available for persons who did not inject drugs also e.g. hospital hepatitis units. The overall feeling was that
viral hepatitis testing should be linked to other services, inclusive of HIV services, and should include counseling as part of the testing package.
Overall, participants stated that persons who should be prioritized for HCV screening are PWID, prisoners and persons from countries where HCV (e.g. Egypt) and HBV (e.g. China) are endemic.
Prevention of onward transmission was the most common cited benefit of knowing one has HCV and/or HBV. Treatment of the disease was the second most common benefit of knowing one’s hepatitis status.
HBV Vaccination
The majority of participants have been vaccinated for HBV. Reasons cited for not being vaccinated were they have already been infected with HBV (and now have natural immunity), it was never offered to them and because they did not want to bother with something else. Although most participants were vaccinated, they still reported barriers to being vaccinated in the first place. The most common was the number of injections. Participants found that needing to return to the doctor’s office three times to complete the full course was inconvenient. It was also difficult for some participants to remember to return for those visits. All participants agreed that PWID should be prioritized to receive the HBV vaccination. It was also recommended that prisoners, migrants and other people originally from HBV or HCV endemic countries should also be prioritized for the HBV vaccine.
Prevention programs for PWID6
“It is important that programs address the importance of ALL paraphernalia being clean for HCV prevention. “
In general, most participants said that the basic harm reduction package, as recommended by WHO7, is available in their country. (The exception to this is that participants in Russia do not have access to OST.) The quality and size of the specific harm reduction programs varies by country.
There is very limited HCV focused prevention happening in any of the participants’ countries. Most of the reported HCV prevention seems to piggyback on existing HIV prevention programs. All participants were asked if they would recommend that their countries implement additional hepatitis prevention programs other than the existing programs. Participants from Russia recommended OST; and one participant from the global North recommended syringe vending and disposal machines.
“Programs that are well-‐received generally include current and former PWID. Providers do not know anything about HBV or HCV; and there is an enormous amount of stigma.”
All persons interviewed for this survey have been both recipients and/or providers of preventions services for PWID. These services include NSP as well as HIV and HCV awareness campaigns. The overarching belief is that all services must be friendly to drug users. This means that the persons providing the services should not stigmatize or infantilize the PWID accessing the services. Primarily participants from more developed countries stated that they believe current and former drug users
6 When describing which prevention programs are available for HCV prevention in their country, none of the participants cited the WHO/UNAIDS/UNODC harm reduction package. They described components included in the harm reduction package. In fact, only 50% (9/17) of those interviewed stated that they have heard of the WHO/UNODC/UNAIDS recommended HIV prevention interventions for PWID.
7 WHO, UNODC, UNAIDS. Technical Guide for countries to set targets for universal access to HIV prevention, treatment and care for injecting drug users. Geneva, WHO, 2009. http://www.who.int/hiv/pub/idu/targetsetting/en/index.html
are best suited to deliver services to PWID because they often feel stigmatized and/or judged by health care workers.
HBV vaccination for PWID -‐ Setting
Regarding the setting for vaccination, participants expressed various opinions from location to mode of service delivery. In general, it is felt that vaccination should be available at the same locations as testing. One participant suggested that vaccination also be available at STI clinics and in correctional facilities. Many participants agreed that vaccination should be linked to other services that the priority groups can easily access. In most countries, children are now being vaccinated for HBV at birth. Participants from countries who do not implement this practice questioned why their countries do not do this especially given the low price of the HBV vaccine. They suggested that vaccine implementation needs to come from the national level.
HBV vaccination for PWID -‐ Standard vs. rapid regimen
Most of the participants did not know that there is a rapid regimen for HBV vaccination. Given the choice, participants prefer a shorter regimen that is not spread out over six months. All participants, who responded to this question, stated that the length over which the vaccine is administered is a barrier to completing the vaccine regimen.
HBV vaccination for PWID: Use of incentives -‐ money or voucher
Although a few participants strongly disagreed with the use of incentives to encourage HBV vaccination, the majority of participants were in favor. However, the majority stated it is preferable that people choose to be vaccinated because they want to take care of their health.
Provision of low dead space syringes
Participants’ did not express strong feelings for or against low dead space syringes (LDSS).
Participants were most interested to know if LDSS syringes could come in different sizes and with removable needles. According to participants, one type of syringe will not fit all needs. Different drugs require different sized syringes and not all PWID prefer the same type of syringe. When sharing drugs, it is important for many to be able to remove the syringe from needle.
Psychosocial interventions
It was generally felt by most participants that there is too much misinformation about viral hepatitis among both health care workers and PWID. Respondents were generally in favor of psychosocial interventions, if they were done well. PWID need more information on prevention, re-‐infection and treatment. Participants feel it is extremely important that accurate information is shared appropriately.
Other participants were less optimistic. As one participant said, “PWID don’t need to be ”told” about behavior change. When they have a clean needle, they use a new needle.” In fact, most PWID want to have a new needle and use their own needle. They prefer not to share. It is not like a chillum where sharing implies something brotherly.”
Many respondents stated that psychosocial interventions should not be provided at needle and syringe programs. The general feeling is that when respondents attend NSPs, the goal is to get new needles and leave, not linger and receive additional services. Participants did not specify a setting that would be better suited for receiving psychosocial interventions. As expressed for other
interventions, psychosocial interventions also need to be done in a non-‐discriminatory way by people with whom PWID are comfortable.
Peer based interventions
As stated by one participant, “Peers are defined as a person who has a connection with the community and are accepted by drug users.” The overwhelming majority of participants stated strongly that peer-‐based interventions are key in providing services, especially to PWID.
Respondents said that having other peers deliver services improves the atmosphere of service delivery because peers, generally, do not discriminate towards other peers, which contributes greatly to their acceptance by and success with PWID.
7. Treatment of Viral Hepatitis
Over half of those with HCV have been treated for their HCV. Those who originally had genotypes 3 and 4 all successfully cleared their HCV with treatment. Among those who had genotype 1, only half successfully cleared their HCV with treatment. Reported side effects for those who underwent treatment seemed to vary in severity by genotype. Those with genotype 1 reported more adverse side effects than those with genotype 3.
All participants reported that HCV treatment is available in their countries. However, cost and accessibility are barriers. Even in countries where HCV treatment is provided for free by the government, not all people do or are willing to access treatment. Anecdotal stories from participants state that many PWID do not want to enter the health system due to stigma felt by providers, uneven quality of services and/or fear that they will be reported to the police. In some countries, even though the treatment is available, it is extremely difficult to see a doctor who specializes in HCV and can prescribe the treatment. Many doctors are apprehensive to prescribe HCV treatment due to all the side effects associated with interferon, which can complicate the physicians’
management of the patient. Two participants stated they are waiting for the new (and supposedly better) HCV treatment to become available before initiating treatment. In countries where HCV treatment is not provided by the government, the cost is prohibitively expensive
Should WHO develop HCV treatment guidelines?
All participants strongly agree that WHO should develop HCV treatment guidelines. Participants say this would be “…a powerful policy tool and blueprint for countries to use.” In addition, due to fears that the price of new drugs will be out of reach for those in low and middle income countries, it is regarded as much more important that WHO has an official stance on HCV treatment.
Co-‐infection with HIV and HBV/HCV
“Disease progression is accelerated for both diseases when co-‐infected.”
“Better to do complete HCV treatment before initiating ART.”
“Priority for ART should be given to co-‐infected people.”
At the advice of their physicians, two of the participants, both from Asia, delayed initiating HIV treatment until after completing their HCV treatment. The same two participants were also advised that it would be best to treat their HCV when their HIV viral load was above 300.
Of the participants interviewed, six are co-‐infected with HIV and HCV. Although he never failed any of his regimens, one participant changed his ART regimen six times since he began ART due to complications with his liver. Another participant had to change one of his antiretroviral (ARV) medications once due to side effects and a third participant has been on the same ART regimen since 2008.
Approximately half of all interviewed had relatively low general knowledge on (treatment) affecting people co-‐infected with HIV and HCV/HBV. Those with low knowledge readily admitted that they need more information on the issues affecting people co-‐infected with HIV and viral hepatitis.
Should all people with viral hepatitis initiate ART treatment irrespective of their HIV CD4 count?
WHO is currently reviewing the evidence regarding whether all people with viral hepatitis should initiate HIV treatment irrespective of CD4 count Not all of the participants have enough knowledge to answer this questions authoritatively.
Those participants with more knowledge feel that, in general, people co-‐infected with (chronic) HBV and HIV should start initiate ARTs irrespective of their CD-‐4 count provided they are on a therapy that includes TDF + 3TC/FTC. One participant pointed out that it is critical to test people for HBV before initiating ART because this should affect the ART regimen chosen.
For HCV, it was agreed that there is not the same amount of evidence. For example, some participants mentioned that it is not preferable to use nevirapine or zidovudine as treatment for people co-‐infected with HCV since these drugs can damage the mitochondria and/or interact with ribavirin for people on HCV treatment. However, two of the respondents stated that they are on ART regimens that include these two ARV medications.
Conclusion
Seventeen individuals shared very personal stories for the purposes of these interviews. To varying degrees, they stated they are hopeful that WHO is looking at the prevention of viral hepatitis among PWID.
Annex 1. Example of the semi-‐structured interview guide
Viral Hepatitis: Semi-structured interview M / F
Provider / community member / both Age
Region
1. Qualitative interview introduction Length: 45-60 minutes
Primary goal: To see things the way you see them… more like a conversation with a focus on your experience, your opinions and what you think or feel about the topics covered
2. Verbal consent
Would you like to participate in this interview?
Verbal Consent was obtained from the study participant Verbal Consent was NOT obtained from the study participant 3. Background Information
Overview:
Invite interviewee to briefly tell me about him/herself: General information about background… mostly about experiences and perspectives on issues surrounding HCV, HBV and co-infection with HIV.
If the interviewee openly identifies as having been tested for viral hepatitis or has viral hepatitis, probe with the next questions.
Been through testing - serostatus not disclosed Been through testing - serostatus positive Been through testing - serostatus negative
4. Hepatitis testing experience
Can you tell me about your HBV / HCV testing experience?
• Where tested
• Was your experience with testing positive or negative?
o Why?
• If you have not been tested, than why not?
o What conditions/support would need to be in place to make you more inclined to test?
Where should HBV/HCV testing be available?
• Linked to other services?
o Which ones: Vaccination? Treatment? Other?
In your opinion, who should be prioritized for HBV and HCV screening? Any particular groups?
What do you see as the benefit of knowing you have HBV? HCV?
• Change in behavior: Alcohol use? Sharing syringes? Other?
• Assess if people know that HCV/HBV diagnosis may impact HIV treatment regimen
• Better information at country level re: how many people have viral hepatitis (VH) (improve surveillance) 5. HBV Vaccination
Availability of HBV vaccine
• Have you been vaccinated?
o Why were you vaccinated?
§ Can you tell me about your experience? Positive or negative? Why?
o Where were you vaccinated
o Do you think people should get vaccinated?
§ If so, who in particular?
• If you have not been vaccinated, than why not?
o What conditions/support would need to be in place to make you more inclined to be vaccinated?
• Barriers to vaccination?
o Stigma? Health care workers attitude?
o What could improve setting for vaccination?
Setting
Where should vaccination take place?
• Linked to other services? Which ones: Testing? Treatment? Other?
Who should be prioritized for HBV vaccination?
What are your opinions/feelings about the HBV vaccine regimen?
• Length of time: the different regimens – standard vs. accelerated
• Ability to adhere to regimen Opinion on use of incentives?
• What type?
o Probe for money and voucher
In your opinion, who should be prioritized for HBV vaccination? Any particular groups?
6. Prevention – for PWID
What kinds of viral hepatitis prevention programs for PWID exist in your country?
Would you recommend other prevention programs?
• If yes, which ones?
What is your experience with prevention programs?
- Recipient? Provider?
- Which ones?
- Opinion?
Are you aware of the 9 prevention interventions that have been recommended by the UN (WHO/UNODC/UNAIDS) for HIV prevention?
1. Needle and syringe programmes (safe use and safe injecting) noting higher intensity coverage and paraphernalia needed and type of syringes 2. Opioid substitution therapy
3. HIV testing and counselling
4. HIV care and antiretroviral therapy for IDU 5. Prevention and treatment of STI
6. Condom programme
7. Outreach; information, education and communication for IDUs and their sexual partners 8. Hepatitis diagnosis, treatment and vaccination
9. Tuberculosis prevention, diagnosis and treatment
WHO is looking at additional prevention interventions in addition to the above 9. Examples include (see below) 1. Types of syringes
2. Psychosocial interventions provided by health services or peer driven to reduce injecting risk behaviour for HBV and HCV transmission.
3. HBV vaccination for PWID
Probe if they have heard of these interventions?
Their opinion / view?
Probe
1. There is insufficient evidence to recommend providing LDSS rather than HDSS in needle distribution programs at this stage.
o How do you react to this?
o Is this acceptable?
o What should be the message?
2. There is no evidence that psychosocial interventions reduce HCV/HBV transmission.
o How do you react to this?
o Is this acceptable?
o What should be the message?
3. HBV vaccination recommendations
a. Short course schedule to maximize adherence combined with higher dose of vaccine for each injection to maximize immune response b. Immediate on site availability of HBV vaccine at programs providing HBV vaccine or working closely with PWID populations.
c. Where appropriate and available, modest monetary incentives can be used to increase completion and received second short rates o How do you react to this?
o Is this acceptable?
o What should be the message?
7. Treatment of Viral Hepatitis
Explore thoughts about viral hepatitis treatment Explain that these guidelines will not address treatment of VH alone. Can mention TDF based ART will treat HBV.
.
For each topic, differentiate between HBV and HCV treatment.
• If you have viral hepatitis, have you been treated?
o Why/ why not?
o What was your experience with it?
§ Side effects, adherence, other problems?
• Is treatment widely available in your country?
o Where?
o Quality of services?
o Accessibility, cost?
o Acceptability of service delivery?
Do you think WHO should develop HCV treatment guidelines…?
8. Co-infection with HIV and HBV/HCV – for all co-infected, not only PWID
Explain that this guidance in development will focus on the treatment of HIV in patients co-infected with HBV/HCV.
For ART treatment initiation and regimen, it is important to assess co-infection. -- Focus on questions that relate to this --- Are you co-infected with HIV and HBV/HCV?
• Are you on ART?
• If yes: has having viral hepatitis affected your ART regimen o If yes, how/why?
• Any additional side effects to ART regimen because of (or thought to be because of) co-infection?
Explore
• Knowledge of issues
• Knowledge of Treatment issues: has this affected your regimen?
WHO is currently reviewing the evidence regarding whether all people with VH should initiate HIV treatment irrespective of CD4 count.
• HBV?
• HCV?
• Opinion on this?
• Is this realistic in your setting?
o Availability, access?
• What about in the context of low and middle-income countries?
o Effect on the clinical and eligibility criteria?
Annex 2. Results of Values and Preferences survey as related to the PICO questions from the guidelines
Question 1: Should a rapid HBV vaccination regimen versus a standard HBV vaccination regimen be used among PWID?
The values and preferences study found the most common reported barrier to HBV vaccination to be the length of time between injections. Approximately half of all participants found returning three times over the course of 6 months to be a barrier fro vaccine completion. Most participants were not aware of the rapid regimen for HBV vaccination. Given the choice, participants prefer to have the regimen delivered over a shorter length of time.
Question 2: Should incentives for HBV vaccination completion versus no incentives be used among PWID?
The values and preference survey found the majority of respondents in favour of incentives for increasing vaccination rates, although some were strongly against. Vouchers (for food or transport) were raised as an alternative to money as an incentive. The majority stated it was preferable that people choose to be vaccinated because they want to take care of their health.
Question 3: Should low dead space-‐syringes versus high dead space syringes be provided to PWID?
Participants’ did not express strong feelings for or against LDSS. Participants were most interested to know if LDSS syringes could come in different sizes and with removable needles. According to participants, one type of syringe will not fit all needs. Different drugs require different sized syringes and not all PWID prefer the same type of syringe. When sharing drugs, it can be important to be able to remove the syringe from the needle
Question 4: Should psychosocial interventions versus no psychosocial interventions be used among PWID?
The values and preferences survey found. Respondents were generally in favor of psychosocial interventions, if they were done well. PWID need more information on prevention, re-‐infection and treatment. Participants feel it is extremely important that accurate information is shared appropriately. Participants did not specify a setting that would be better suited for receiving psychosocial interventions.
Question 5: Should peer based interventions versus no peer based interventions be used among PWID?
The overwhelming majority of participants stated strongly that peer-‐based interventions are key in providing services, especially to PWID. As stated by one participant, “Peers are defined as a person who has a connection with the community and are accepted by drug users.” Respondents said that having other peers deliver services improves the atmosphere of service delivery because peers, generally, do not discriminate towards other peers, which contributes greatly to their acceptance by and success with PWID.
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