2.3.7 Situation and Trends with Respect to HIV/AIDS and Sexually Transmitted Infections (STIs)

Facts/messages: The AIDS epidemic is one of the world’s most significant current public health and development crises. In less than three decades, nearly 60 million people have been infected with HIV and more than 25 million have died of AIDS. The UNAIDS Outlook Report 2010 estimates that 2.4 – 3.0 million people were newly infected in 2008, bringing the number of people currently living with HIV to 31.1 – 35.8 million. Sub-Saharan Africa, the region most affected, is home to 67 % of all people living with HIV worldwide and 91% of all new infections among children. In this region, the epidemic has orphaned more than 14 million children. While access to treatment has increased considerably and Mother-to-Child Transmission (MCT) may be almost eliminated by 2015, 1.7 – 2.4 million AIDS-related deaths occurred in 2008. Global coverage of treatment remains low. In 2008, only 42 % of those in need of treatment had access to it, compared to 35 % in 2007. HIV-prevention programmes still fail to reach many people at risk of acquiring HIV, including sex workers, men who have sex with men and injecting drug users.

Countries are usually considered to have a generalized, rather than a concentrated AIDS epidemic if the overall prevalence rate exceeds 1 %, as is currently the case in most of Sub-Saharan Africa (except Madagascar) and the Caribbean (except Cuba), in Belize, Guyana and Suriname, some countries of Eastern Europe (Russian Federation, Ukraine and Estonia), in Sudan, Cambodia and Thailand. However, even in these countries prevalence rates can be much higher in some social groups. In Eastern Europe, for example, 62% of new infections occur among injectable drug users. In Belize, Guatemala and Honduras, prevalence is much higher among the Garífuna minority than among the general population. According to the Ugandan Ministry of Health, even though prevalence is still about 5 %, the AIDS epidemic in the country is now largely concentrated among adults, particularly those aged 35-44. These issues have to be considered in preparing the PSA.

Based on UNAIDS data, women make up 50 % of all adults living with HIV globally since the mid 1990s. In sub-Saharan Africa, the percentage has stabilized at 60 %, and in Asia, Latin America, Eastern Europe and Central Asia at around 30 %. Only in the Caribbean it is still growing; in several countries HIV is spreading faster among younger women than among younger men. One of the driving forces in the feminization of the HIV epidemic is the overlap of injecting drug use and sex work, as many women injecting drugs are also involved in sex work. This makes them more vulnerable to HIV infection because they are far more likely to share both drugs and injecting equipment. A compounding social and economic factor is women’s greater biological susceptibility to HIV infection, estimated to be almost twice as high as that of men during unprotected heterosexual intercourse.

Since 2001, there has been an extraordinary expansion of HIV programmes and funding that is beginning to bear fruit. According to the Outlook Report 2010, the HIV epidemic is stabilizing globally, although at high levels; in a number of countries in Asia, Latin America and Africa the number of new infections has fallen; and globally access to treatment has expanded significantly. These include countries where the prevalence was previously very high, such as Rwanda, Uganda and Zimbabwe, or moderate, such as Cambodia, India, Thailand and the Dominican Republic. On the other hand, prevalence is still increasing in the countries of Eastern Europe and Central Asia, in Senegal, Vietnam, Indonesia, Papua New Guinea and – to a lesser extent – in some North African and Latin American countries.

The gains are being threatened by the global economic crisis, which is likely to reduce revenues from taxes and/or donor assistance. To offset the deficit, governments may cut prevention services, especially for high risk populations, as providing prevention services for these groups often does not have much political support. This could lead to interruption of treatment and continued denial of treatment to those who need but are not yet on treatment, which would, in turn, lead to increased HIV-related mortality and morbidity. Most people who stop and do not restart antiretroviral treatment will die within one to two years. It might also cause an increase in HIV drug resistance. Finally, it would result in reduced prevention of HIV transmission.

Migration plays a key role in the spread of HIV in several parts of the world. Higher incidence of HIV correlates with good transport infrastructure and considerable internal and cross-border migration. While migration is not necessarily a health risk in itself, the conditions under which it takes place expose migrants to health risks and vulnerabilities. Migration can lead to possible risky sexual behaviour due to the disruption of former stable networks and social norms that would otherwise regulate sexual behaviour. Separation from their kin may drive migrants to engage in unsafe, casual or commercial sex, thus increasing the risk of HIV. This is particularly evident in situations of involuntary migration. Risk factors can often be linked to the legal status of migrants, which determines the conditions they face, including their level of access to health and social services. Female migrants are particularly vulnerable as they can become victims of discrimination, violence, sexual exploitation and trafficking.

Other than HIV, sexually transmitted infections (STIs) involve more than 30 different sexually transmissible bacteria, viruses and parasites. Several, especially syphilis, can also be transmitted from mother to child during pregnancy and childbirth, and through blood products and tissue transfer. Common bacterial infections include gonorrhea, chlamydia, syphilis and cancroids. Viral infections include genital herpes, the human papillomavirus (HPV), hepatitis B, and the cytomegalovirus. According to 2007 WHO estimates, 340 million new cases of curable STIs (syphilis, gonorrhea, chlamydia and trichomoniasis) occur annually throughout the world in adults aged 15-49 years. In developing countries, STIs and their complications rank in the top five disease categories for which adults seek health care. Infection with STIs can lead to acute symptoms, chronic infection and serious delayed consequences. Between 10% and 40% of women with untreated chlamydial infection develop symptomatic pelvic inflammatory disease. Post-infection tubal damage is responsible for 30% to 40% of cases of female infertility. Furthermore, women who have had pelvic inflammatory disease are 6-10 times more likely to develop an ectopic (tubal) pregnancy, and 40-50% of ectopic pregnancies can be attributed to previous pelvic inflammatory disease. Infection with certain types of the human papillomavirus can lead to the development of genital cancers, particularly cervical cancer in women.

Untreated sexually transmitted infections are associated with congenital and perinatal infections in neonates, particularly in the areas where rates of infection remain high. In pregnant women with untreated early syphilis, 25% of pregnancies result in stillbirth and 14% in neonatal death – an overall perinatal mortality of about 40%. Syphilis prevalence in pregnant women in Africa, for example, ranges from 4% to 15%. Up to 35% of pregnancies among women with untreated gonococcal infection result in spontaneous abortions and premature deliveries, and up to 10% in perinatal deaths. In the absence of prophylaxis, 30% to 50% of infants born to mothers with untreated gonorrhea and up to 30% of infants born to mothers with untreated chlamydial infection will develop a serious eye infection which can lead to blindness if not treated early. The presence of an untreated infection increases the risk of both acquisition and transmission of HIV by a factor of up to 10.

Methodology: For the impacts of AIDS, the SPECTRUM software package contains two modules that facilitate the analysis, namely AIM and PMTCT. The former projects the consequences of the HIV epidemic, including the number of people living with HIV, new infections, and AIDS deaths by age and sex; as well as the new cases of tuberculosis and AIDS orphans. AIM is used by UNAIDS to make the national and regional estimates it releases every two years. The latter evaluates the costs and benefits of intervention programs to reduce transmission of HIV from mother to child through three kinds of interventions: drug treatment (seven possible options); type of delivery (vaginal or Cesarean section); and type of infant feeding (formula, breastfeeding, or mixed). Outputs include a benefit-cost ratio as well as cost-effectiveness measures such as cost per HIV infection averted. A third module explores the impact of potential HIV vaccines on the epidemic.

HIV prevalence is used to assess epidemic patterns and trends. However, due to changes in the survival period from infection to death as a result of the increased provision of antiretroviral therapy, it is becoming increasingly difficult to analyze HIV prevalence data. The incidence of HIV infection and the new infection rates over a defined time period provide a more sensitive measure of the current state of the epidemic and of programme impacts. However, while estimates of HIV prevalence are widely available from sentinel surveillance or cross-sectional studies, estimates of HIV incidence are more difficult and more costly to obtain.

In the methodology recommended by UNAIDS/WHO to obtain national HIV and AIDS estimates, the Estimation and Projection Package (EPP) (developed by the Future’s Group for UNAIDS), which has separate variants for generalized and concentrated epidemics, can be used to fit an epidemiological model to observed HIV prevalence data collected over time. EPP finds the best fitting curve that describes the evolution of adult HIV prevalence over time, and calibrates that curve based on prevalence found in any national surveys. Based on this curve, SPECTRUM uses demographic data, information on adult and child treatment coverage and assumptions about the epidemiology of HIV to generate estimates of national (adult and child) HIV prevalence, incidence, mortality and treatment needs, allowing for the effect of anti-retroviral therapy.

For countries with very little available prevalence data (less than three consistent surveillance sites) a point prevalence estimate and projection is made using spreadsheet models (the Workbook Method). The resulting point prevalence estimates for several years are entered into EPP to find the best fitting curve that describes the evolution of adult HIV prevalence over time. Incidence is then calculated from the prevalence over time, allowing for the effect of ART. Use these estimates prepared by the United Nations Joint Programme on HIV/AIDS (UNAIDS) and/or national estimates for the incidence of HIV/AIDS and the estimates by the United Nations Population Division for forecasting the future impact. UNAIDS provides online an expanded list of references on how to estimate HIV incidence.

For wider indicators on the progress of countries in the combat of HIV/AIDS, it is recommended to use one or more of the modified UNGASS indicators contained in the 2008 UNAIDS Report:

  • AIDS spending, by financing source;
  • National Composite Policy Index;
  • Percentage of donated blood units screened for HIV in a quality-assured manner;
  • Percentage of adults and children with advanced HIV infection receiving antiretroviral combination therapy;
  • Percentage of HIV-positive pregnant women who received antiretrovirals to reduce the risk of mother-to-child transmission;
  • Percentage of estimated HIV-positive incident Tuberculosis cases that received treatment for Tuberculosis and HIV
  • Percentage of women and men aged 15–49 who received an HIV test in the last 12 months and who know their results;
  • Percentage of most-at-risk populations who received an HIV test in the last 12 months and who know their results;
  • Percentage of most-at-risk populations reached with HIV prevention programmes;
  • Percentage of orphaned and vulnerable children whose households received free basic external support in caring for the child;
  • Percentage of schools that provided life skills-based HIV education within the last academic year;
  • Current school attendance among orphans and non-orphans aged 10–14;
  • Percentage of young people aged 15–24 who both correctly identify ways of preventing the sexual transmission of HIV and who reject major misconceptions about HIV transmission;
  • Percentage of most-at-risk populations who both correctly identify ways of preventing the sexual transmission of HIV and who reject major misconceptions about HIV transmission;
  • Percentage of young women and men aged 15–24 who have had sex before the age of 15;
  • Percentage of women and men aged 15–49 who have had more than one sexual partner in the past 12 months who report;
    Use of a condom during their last sexual intercourse;
  • Percentage of female and male sex workers reporting the use of a condom with their most recent client;
  • Percentage of men reporting the use of a condom the last time they had anal sex with a male partner;
  • Percentage of injecting drug users who report using a condom the last time they had sex;
  • Percentage of injecting drug users who report using sterile injecting equipment the last time they injected;
  • Percentage of young women and men aged 15–24 who are HIV infected;
  • Percentage of most-at-risk populations who are HIV infected;
  • Percentage of adults and children with HIV known to be on treatment 12 months after initiation of ARV;
  • Percentage of infants born to HIV-infected mothers.

Also try to obtain epidemiological data on the status of other STIs in the country.

The UNFPA Rapid Needs Assessment Tool for Condom Programming was developed in collaboration with the Population Council to design and test a rapid needs assessment and data-gathering tool to improve country level condom programming for HIV prevention of which condom distribution, promotion and use are important elements.

Primary Sources:

  • Health Ministries. Statistics on the number of detected cases, the number of deaths and estimated prevalence, by sex;
  • National reports for follow-up and evaluation issued by the United Nations General Assembly Special Session (UNGASS);
  • National surveillance systems.

Secondary Sources:


50  UNAIDS (2010). Methods for estimating HIV incidence. Expanded list of references. Available at: http://data.unaids.org/pub/BaseDocument/2010/epi_alert_1stqtr2010_listref_expanded_en.pdf.
51  UNAIDS (2010) EPI ALERT Introduction. UNAIDS quarterly update on HIV epidemiology / 1Q 2010.
52  UNAIDS (2010) Methods for Estimating HIV Incidence. Expanded List of References.
Available at: http://data.unaids.org/pub/BaseDocument/2010/epi_alert_1stqtr2010_listref_expanded_en.pdf