Scores of commentators, journalists and politicians heaped scorn on Pope Benedict XVI for his response in a March 17 press interview: The AIDS epidemic in Africa “can’t be resolved with the distribution of condoms: On the contrary, there is a risk of increasing the problem.”

Bonnie Erbe, writing in U.S. News & World Report, called his remark “one of the most horrifically ignorant statements.” The Lancet medical journal, which has published a number of (apparently forgotten) studies supportive of the Pope’s assertion, editorialized that his comments were “outrageous and wildly inaccurate.”

And a March 19 Washington Post editorial pontificated: “Everyone is entitled to his own opinion, but not his own facts.”

There’s rich irony here: All the ignorance, inaccuracies and subjective “facts” belong to Benedict’s detractors. The Holy Father’s contention that condoms may be counterproductive in combating the AIDS pandemic in Africa is solidly backed by a growing body of empirical research published over the past 15 years.

True believers in the core tenets of the sexual revolution — that contraceptives take all the risk out of casual sex — are baffled that a technology that works well under laboratory conditions fails miserably in real-life use. Given the fact that everyone agrees that condoms are the least effective contraceptive for pregnancy prevention, it is a mystery why condom promoters consider them the state-of-the-art best defense against HIV transmission.

There are many reasons why massive distribution of condoms fails to stop HIV transmission, including risk-compensation behavior, inconsistent use, method and user errors, and cumulative risk.

Risk compensation: A brief lesson on sunscreen, seat belts and condoms.

Risk compensation describes an interesting behavioral pattern in humans — a greater willingness to engage in potentially risky behavior when one believes his risk has been reduced through technology. For example, someone who uses sunscreen is likely to stay in the sun longer, and studies have in fact shown an increase in melanoma among sunscreen users due to their longer exposure.

After mandatory seat-belt laws were introduced in the United Kingdom, traffic fatalities surprisingly increased: “In the 23 months that followed the introduction of the U.K. seat-belt law, the number of deaths among pedestrians, cyclists, and unbelted rear seat passengers rose by 8%, 13% and 25% respectively,” due to faster and riskier driving.

John Richens et al., writing in The Lancet, then suggest three ways that a substantial increase in condom use could nevertheless fail to reduce disease transmission: “First, condom promotion appeals more strongly to risk-averse individuals who contribute little to epidemic transmission. Second, increased condom use will increase the number of transmissions that result from condom failure. Third, there is a risk-compensation mechanism: Increased condom use could reflect decisions of individuals to switch from inherently safer strategies of partner selection or fewer partners to the riskier strategy of developing or maintaining higher rates of partner change plus reliance on condoms.”

Conclusion: “A vigorous condom-promotion policy could increase rather than decrease unprotected sexual exposure, if it has the unintended effect of encouraging greater sexual activity.”

Michael Cassell and colleagues, writing in the British Medical Journal in 2006, also have focused on how risk-compensation behaviors blunt the effectiveness of new technological measures to combat the AIDS epidemic. They note the findings of many HIV researchers: that “the perception that using condoms can reduce the risk of HIV infection may have contributed to increases in inconsistent use, which has minimal protective effect, as well as to a possible neglect of the risks of having multiple sexual partners. Thus, the protective effect of promoting condoms may be attenuated at the population level and could even be offset by aggregate increases in risky sexual behavior” (emphasis added).

Cassell cites numerous studies showing that the availability of antiretroviral drugs and expanded access to treatment have resulted in significant increases in risky behavior among homosexual men and injecting drug users in Europe, the United States and Australia. Therefore, the authors stress that “behavior change” (abstinence, monogamy or fewer partners), which has proven “a feasible and effective approach to preventing new HIV infections,” must be promoted as an integral part of any HIV/AIDS prevention program.

In an interview with Christianity Today, Edward Green, director of the AIDS Prevention Research Project at the Harvard Center for Population and Development Studies, vigorously defended Pope Benedict’s contention that condoms may increase HIV transmission in Africa: “The best evidence we have supports his comments.” He adds, “There’s no evidence at all that condoms have worked as a public health intervention intended to reduce HIV infections at the ‘level of population.’ … Major articles published in Science, The Lancet, British Medical Journal, and even Studies in Family Planning have reported this finding since 2004.”

Green reports that in eight or nine African countries, HIV has declined and, in every case, “there’s been a decrease in the proportion of men and women reporting multiple sexual partners. Ironically, in the first country where we saw this, Uganda, HIV prevalence decline stopped in 2004, and infection rates appear to be rising again. … in part because emphasis on interventions that promote monogamy and fidelity has weakened significantly, and earlier behavior changes have eroded. … [and] foreign donors have persuaded Uganda to put even more emphasis on condoms.”

In his 2003 book, Rethinking AIDS Prevention: Learning From Successes in Developing Countries, Green cites numerous studies finding “higher rates of STD or HIV infections among inconstant condom users than among condom nonusers. … And, of course, condom use is inconsistent far more often than it is consistent, virtually everywhere.”

He explains that condoms “might give some men a somewhat greater sense of security than warranted by actual condom effectiveness. This might lead to more risky sexual behavior than men might practice if condoms were not available.”

He adds that in the real world “Third World situations, where use may not be correct, or condoms may be of poor or deteriorated quality, made of non-latex, or the wrong size [leading to slippage or tearing], protection may be actually less than 80%, even when use is consistent, which is rare.”

Cumulative risk exposure with condoms is overlooked.

Cumulative risk is a simple concept: One’s risk of infection increases with increasing numbers of condom-“protected” exposures. J. Thomas Fitch et al. (2002) note that “an intervention that is 99.8% effective for a single episode of intercourse can yield an 18% cumulative failure rate with 100 exposures.” As applied to condoms, Green gives a straightforward illustration of cumulative risk: With “repeated exposures to an infected partner, such as a man visiting a sex worker [sic] in Nairobi or Johannesburg once a month, the man will likely be infected within five months, even with consistent condom use.”

Due to cumulative risk, R. Gordon noted in 1989 that condoms provide inadequate risk reduction for individuals, as it is statistically quite likely that a condom user who engages in casual sex or sex with people likely to be infected with HIV/AIDS will eventually become HIV infected, as well.

What works?

James Shelton, a USAID senior medical scientist, co-authored a 2004 study in the British Medical Journal explaining the “crucial role” of partner reduction in reducing HIV/AIDS transmission. Partner reduction was critical in Uganda and elsewhere. While he does not dismiss the role of condoms in specific circumstances, he cautions: “Even though prospective studies have shown that condoms reduce risk by about 80%-90% when always used, in real life they are often used incorrectly and inconsistently. They should therefore not be advertised in a manner that leads to overconfidence or risky behavior.”

Also in 2004, Tim Allen of the London School of Economics and Suzette Heald of Brunel University collaborated on an article explaining how the early aggressive promotion of condoms doomed efforts to curb HIV/AIDS in Botswana, while the resistance to condom promotion in Uganda fostered behavior changes that dramatically reversed the epidemic in Uganda.

Although the reproductive “rights” and pharmaceutical industries continue to propagate the conventional wisdom that widespread consistent condom use is the key to halting the transmission of HIV/AIDS, approximately 150 experts signed a statement — again in The Lancet — in 2004 calling for a “common ground,” evidence-based approach to preventing the sexual transmission of HIV/AIDS with primary emphasis on behavior-modification in generalized epidemics.

The lead authors, Daniel Halperin et al., prioritize interventions according to their effectiveness in dealing with the target audience and the type of epidemic (generalized, as in sub-Saharan Africa, or one mainly among “commercial sex workers [sic]” and their clients in Thailand and Cambodia):

“When targeting young people … the first priority should be to encourage abstinence or delay of sexual onset. … After sexual debut, returning to abstinence or being mutually faithful with an uninfected partner are the most effective ways of avoiding infection.”

They continue: “When targeting sexually active adults, the first priority should be to promote mutual fidelity with an uninfected partner as the best way to assure avoidance of HIV infection. The experience of countries where HIV has declined suggests that partner reduction is of central epidemiological importance in achieving large-scale HIV incidence reduction.”

Once again, science has proven the wisdom of Church teaching on abstinence before, and faithfulness within, marriage. Once again, Benedict was right!

Susan Wills is assistant director

for education and outreach in

the U.S. bishops’ Secretariat

of Pro-Life Activities.