In 2014-16 the United Nations (UN), World Health Organization (WHO), and UNAIDS set targets to cut new HIV infections (incidence) globally from 1.9 million in 2015 to 500,000 in 2020 and 200,000 in 2030 (Table 1). The 2030 target is a Sustainable Development Goal (SDG) – to end AIDS by 2030. Those targets promoted interventions that cut HIV transmission, but not enough to reach targets: global incidence in 2020 was 1.5 million, three times the target (Table 1). In 2021, the UN set a new target – 370,000 new infections in 2025 – with the same 200,000 target for 2030.
Table 1: Global HIV incidence targets and estimates, 2015-2030
Incidence targets, estimates
2015
2020
2025
2030
Targets
UN, WHO, UNAIDS, and Sustainable Development Goal targets set in 2014-16[1-3]
500,000
200,000*
Revised UN target set in 2021[4]
370,000
200,000
UNAIDS estimates[5]
1,900,000
1,500,000
* WHO[1] proposed reducing incidence by 90% from 2.1 million in 2010 to 210,000 in 2030.
UNAIDS’ 2021-26 strategy focuses on “reducing inequalities”[6,7] so interventions get to more people. That will help, but will it be enough to end AIDS by 2030? This blog considers what has been done and what more could be done to prevent HIV in sub-Sahara Africa and in the rest of the world. Along with continuing current programs, investigating unexplained HIV infections – in children with HIV-negative mothers, in adults with no sexual exposures to HIV – may be essential to end aids by 2030.
Missing targets in sub-Sahara Africa
Across sub-Sahara Africa, new infections peaked at 2.2 million in 1996. From 1996, incidence fell 3% per year to 1.24 million in 2015 and then slightly faster – 6% per year – to 860,000 in 2021.[5] Following sub-sections consider what happened and what could happen for three transmission paths accounting for most infections in Africa – mother-to-child, heterosexual sex, and skin-piercing medical and cosmetic procedures. After 2000, reductions in mother-to-child and sexual transmission came with policy changes championed by Kevin de Cock at the United States (US) Centers for Disease Control and Prevention (more testing),[8] Jim Kim at WHO (more anti-retroviral treatment), and Michel Sidibe, UNAIDS Executive Director, 2009-19 (more testing and treatment). After 1999, safer medical injections came with programs led by Yvan Hutin at WHO.[9]
Mother-to-child: The percentages of HIV-positive women getting drugs to protect their babies increased from nothing in the mid-1990s to 89% in Eastern and Southern Africa and 61% in Western and Central Africa in 2015, with little change to 2021 (Table 2). Annual HIV incidence in children aged 0-14 years fell circa 300,000 during 1996-2021, accounting for more than a fifth of the overall fall in incidence in sub-Saharan Africa during those years. Further reductions in mother-to-child transmission could cut remaining incidence another 10%-15%. While interrupting mother-to-child transmission is important to protect babies, children’s other risks need attention as well: during 2006-17 national surveys in eSwatini, Mozambique, South Africa, Uganda, and Zimbabwe found 6%-33% of infected babies and young children with HIV-negative mothers.[10]
Table 2: Estimated HIV incidence and interventions in Africa, 1996-2021
Intervention, incidence
1996
2010
2015
2021
Estimated incidence in sub-Sahara Africa, of which
2,200,000
1,530,000
1,240,000
860,000
Adults
1,770,000
1,240,000
1,060,000
730,000
Children aged 0-14 years
430,000
288,000
172,000
132,000
Prevention of mother-to-child transmission (PMTCT), % of HIV-positive mothers reached
Eastern and Southern Africa
0%
52%
89%
90%
Western and Central Africa
0%
29%
61%
60%
Testing: % of HIV-positive adults knowing their status
Eastern and Southern Africa
<5%
63%
81%
91%
Western and Central Africa
<5%
37%
54%
84%
Treatment as prevention: % of HIV-positive adults with suppressed viral loads
Eastern and Southern Africa
0%
20%
47%
74%
Western and Central Africa
0%
10%
26%
73%
Note: UNAIDS’ estimated incidence by age groups do not add to UNAIDS’ estimated totals. Sources: UNAIDS.[5]
Heterosexual sex:The percentages of HIV-positive adults in sub-Sahara Africa knowing their status and having suppressed viral loads hugely increased from low single digits in 1996. By 2015, roughly 3/4ths knew their status and 2/5ths had suppressed viral loads. By 2021, close to 90% knew their status and almost 3/4ths had suppressed viral loads (Table 2).
While these changes no doubt slashed sexual transmission, their impact on overall-incidence depended on the proportion of incidence in Africa through sex. Continuing high incidence in adults – despite huge increases in testing and treatment – agrees with recent evidence suggesting heterosexual sex accounts for less than half of HIV infections among adults: five studies that sequenced HIV collected from communities in Africa identified sex partners to explain only 0.3%-7.5% of infections; and in eight similar studies a median of 53% of sequence pairs linked people of the same sex (suggesting that contaminated instruments linking people of either sex accounted for more transmissions than male-female sex).[11] Furthermore, since percentages knowing their infections and having suppressed viral loads were already so high in 2021, further increases in these percentages can be expected to have only minor impact on sexual transmission, and even less on overall incidence.
Condom promotion, an old story, cannot explain differences over time. The potential impacts of other interventions aimed at sexual risks – voluntary medical male circumcision (VMMC) and pre-exposure prophylaxis (PrEP)[12,13] – are limited by how much sexual transmission remains after testing, treatment, and condoms. Furthermore: VMMC programs circumcise many people who would have been circumcised otherwise; many say circumcision harms men; and multiple studies have found women not interested in PrEP (eg, in Kenya[14]).
Skin-piercing events in health care and cosmetic services: Blood safety (testing blood before transfusing) in sub-Sahara Africa took a leap forward with US support from 2003.[15] Beginning in 1999, WHO’s Safe Injection Global Network (SIGN) campaigned for injection safety. Estimated numbers of unsafe injections per year in sub-Sahara Africa fell by circa 90% from the 1990s to 2011-15 (260-520 million in the 1990s, calculated as 50% of 1-2 injections per person for a population of 520 million[16]; 40 million in 2011-15, calculated as 3.3% of 1.18 injections per person for a population of 910 million[17]).
More testing of transfused blood and fewer unsafe injections no doubt reduced HIV transmission during health care. However, there are enough other skin-piercing risks in medical and cosmetic services (dental care, infusions, catheters, manicures, tattooing, etc) to explain continuing high levels of blood-borne transmission in Africa.
The best way to prevent medical and cosmetic procedures transmitting HIV is to investigate unexplained infections. People who see an unexplained infection and realize that whatever caused it may be infecting others can initiate informal local investigations. For example, in 2014, a village leader in Roka, Cambodia, realized he had an unexplained HIV infection. He urged relatives and neighbors to go for tests, which found more infections.[18] Media attention brought a government investigation that identified 242 with HIV from health care. Similarly, a private doctor in Ratodero, Pakistan, identified several unexplained infections in early 2019. Publicity brought a government investigation that by early 2023 had found circa 2,800 children and hundreds of adults with HIV from health care.[19] Publicity from investigations promotes safe practices and warns people to beware blood-borne risks.
Anal sex among MSM and unsafe injections among IDU: UNAIDS estimates 10% of incidence in sub-Sahara Africa in 2021 was in MSM and IDU (7% in MSM including transgender women born male; and 3% in IDU). The interventions UNAIDS proposes for MSM and IDU (treatment as prevention, PrEP, condoms, sterile injection equipment, etc.) are on target. However, impact on overall incidence may be small, not only because working with MSM and IDU is challenging, but also because 10% may overstate their share of Africa’s incidence. If MSM and IDU had 10% of Africa’s infections, per capita incidence from those risks in Africa (0.0075%/year, calculated as 10% of 860,000 infections in 1.12 billion people) would higher than in the rest of the world, which seems unlikely (0.006%/year, calculated as 62% of 640,000 infections in 6.65 billion people).[20,21]
Missing targets in the rest of the world
In the rest of the world (excluding sub-Sahara Africa) new HIV infections in adults peaked in the 1990s and then fell circa 4% per year to 2010. During 2010-21, adult incidence fell more slowly, at 0.3% per year, with major differences by regions (eg, falling in Asia and the Pacific, but increasing in Eastern Europe and Central Asia). Following subsections consider interventions and incidence for five risks, four of which UNAIDS addresses (mother-to-child, MSM, heterosexual sex, and IDU) and a fifth that UNAIDS ignores (medical and cosmetic skin-piercing procedures).
Table 3: HIV incidence and interventions in the rest of the world, 1996-2021
Incidence, interventions
2010
2015
2021
Estimated adult incidence
610,000
600,000
590,000
Testing: % of HIV-positive adults knowing their status (three regions with most infections)
53%, 73%, no estimate
62%-82%
Treatment as prevention: % of HIV-positive adults with suppressed viral loads (three regions with most infections)
20%, 45%, no estimate
48%-64%
Note: Adult incidence adds UNAIDS’ estimates for each regions outside sub-Sahara Africa. Source: UNAIDS.[5]
Mother-to-child: According to UNAIDS, outside sub-Sahara Africa, incidence in children aged 0-14 years was 3% of total incidence for all ages in 2021. In the two regions that account for most children’s incidence, Asia and the Pacific and Latin America, 49% and 63%, respectively, of HIV-positive women got drugs to protect their babies in 2021, with little change from 2015. Reaching and treating more HIV-positive pregnant women could bring modest reductions in overall incidence.
Sex, including MSM and heterosexual sex: UNAIDS estimates that 82% of HIV incidence outside sub-Sahara Africa in 2021 came from sex – 44% in MSM (including transsexuals) and 38% in heterosexuals. Most of those infections come from three regions: Asia and the Pacific, Eastern Europe and Central Asia, and Latin America.
For those three regions, UNAIDS estimates 48%-64% of HIV-positive adults had suppressed viral loads in 2021 (Table 3). Because people with suppressed viral loads almost never transmit through vaginal or anal sex, increasing percentages of adults with suppressed viral loads no doubt reduced sexual transmission during 2010-2021. However, since overall incidence fell only 3% during that period, UNAIDS may have been overestimating sexual transmission. Because countries with the best information on HIV risks (in Western Europe, North America, and East Asia) report large percentages of infections in MSM, overestimates of HIV from sex are more likely for heterosexuals than for MSM. Ignoring problems with estimates, some further reductions in sexual transmission could be achieved by extending treatment, especially to MSM with new infections.
IDU: UNAIDS estimates IDU accounted for 18% of incidence in the rest of the world, with big differences between the three regions with the most incidence — 4% in Latin America, 12% in Asia and the Pacific, and 39% in Eastern Europe and Central Asia. Cross-country comparisons suggest these rates can be reduced, but proven interventions (eg, getting IDUs to use sterile injection equipment, opioid treatment) can be hard to implement due to controversies about policies and difficulties reaching and working with IDUs.
Skin-piercing events in health care and cosmetic services: Where most infections are in MSM and IDUs, several times more men than women are infected. For example, across Western and Central Europe and North America, 3.2 men are infected for every woman (according to UNAIDS estimates for 2021).[5] Even higher ratios are common in countries with low HIV prevalence; for example, Australia has a sex ratio of 7.1 and 0.1% adult prevalence.
On the other hand, low ratios of men to women infected in many countries outside sub-Sahara Africa suggest many women and some men are getting HIV from non-IDU skin-piercing procedures. The two regions that account for roughly 2/3rds of infections outside sub-Sahara Africa have much lower male-female ratios compared to Western Europe and North America. In Eastern Europe and Central Asia, with 1.1% adult prevalence, the sex ratio is 1.9 overall, but lower in many countries, including 1.0 in Ukraine. Similarly, the sex ratio in Asia and the Pacific is 1.7, but lower in many countries, including 0.7 in Papua New Guinea and 0.9 in Cambodia. The Caribbean region, with 1.2% adult prevalence (the highest outside sub-Sahara Africa) has a sex ratio of 1.0.
UNAIDS’ silence about HIV infections from unsafe health care ignores a lot of evidence. As of 2011-15, WHO experts estimated that 6.7% of injections in Southeast Asia, 2.9% in Europe, and 9.8% in the Eastern Mediterranean were unsafe.[16] During 1986-2021, scores of investigations outside sub-Sahara Africa uncovered small to large outbreaks from unsafe medical procedures, including twelve with more than 100 to an estimated 100,000 HIV infections.[10]
Conclusion: Africa could lead
Considering the annual rate at which HIV incidence has been falling since 2015, there is little chance that targets – 370,000 new infections in 2025 and 200,000 in 2030 – will be achieved with UNAIDS’ current strategy. Much of the potential impact from treatment and testing has already been realized. Other interventions in UNAIDS’s strategy will help, but not enough.
To meet targets, something must be done about HIV transmission through skin-piercing procedures in health care and cosmetic services. The best way to reduce such transmission is to investigate unexplained infections. Based on experiences to date, WHO, UNAIDS, donors, and many governments are unlikely to lead. If and when the African general public takes the lead to investigate unexplained infections in several communities, it will likely take several more years for public awareness to roll back blood-borne transmission in Africa. Investigations in Africa could encourage the public and governments in other regions to investigate as well. If investigations in Africa begin in the next several years, and if other investigations and programs progress, HIV incidence around the world could fall to 200,000 by 2030 or not long after. Without investigations, targets are out of reach.
14. Kinuthia J, Pintye J, Abuna F, et al. Pre-exposure prophylaxis uptake and early continuation among pregnant and post-partum women within maternal and child health clinics in Kenya: results from an implementation programme. Lancet HIV2020; 7: e38-e48.
15. Mili FD, Teng Y, Shiraishi RW, et al. New HIV infections from blood transfusions averted in 28 countries supported by PEPFAR blood safety programs, 2004‐2015. Transfusion 2021; 61: 851-861. Available at: https://onlinelibrary.wiley.com/doi/epdf/10.1111/trf.16256 (accessed 19 May 2023).
16. Kane A, Lloyd M, Zaffran M, et al. Transmission of hepatitis B, hepatitis C and human immunodeficiency viruses through unsafe injections in the developing world: Model-based regional estimates. Bull World Health Organ 1999; 77: 801-7. Available at https://pubmed.ncbi.nlm.nih.gov/10593027/ (accessed 16 May 2023).
Bloodborne HIV: Don't Get Stuck! 