5) Brian J. Morris' second set of reviewer comments (February 25, 2011)

REVIEWER REPORT FOR REVISED VERSION OF Frisch et al. “Male circumcision and sexual function in men and women: A survey-based-crosssectional study in Denmark In my original Reviewer report I pointed out numerous factual errors, as well as the presence of distortions, bias and possible statistical errors. Few of my criticisms or suggestions for improvement has been addressed in the revised version. If the authors wish their data to be taken seriously they need to remove the erroneous statements and appearance of overt bias. Not to do so will mean that their data will be dismissed by most experts in the field. At present the manuscript remains unpublishable by any journal. The extremist views are not needed. An honest, accurate, and scholarly presentation, and a focus on the particular subject at hand, will assist in communication of data, albeit being at variance with most other research findings in this area. Moreover, the apparent bias of the authors seems to have led them to a conclusion that is not valid, when my reading of the manuscript in the context of the field leads me to quite a different conclusion.

The study involved 1,893 uncircumcised men and 103 circumcised men. As to the issue of my criticism of the authors’ statistics, it may be that a Bonferroni correction is not needed, especially given that they adjusted for confounding factors. My main concern regarding the statistics are the sheer number of predictors in their model versus the relatively small number of circumcised men and of men with difficulties.

This may be a case of overfitting … and could therefore cause instability in the model. Indeed, at the bottom of page 19 (Discussion para 10) they state that “some associations were statistically unstable because only 5% of Danish men are circumcised”. While I am concerned about possible overfitting, it is possible that the authors might have found an association, although this still depends on accurate collection and recording of the data, something that is worrisome, given the manner in which the data are discussed, where the authors immediately jump to conclusions and disparage and misrepresent the literature in this field. Their interpretation of the data is likely to be wrong and in fact less generalizable than the authors appear to think. It is, moreover, highly likely that their finding of sexual difficulties in 10 of 95 circumcised men for which data are tabulated is probably NOT due to physical factors, as I will now explain. *** A major reason for the unusual findings could be because they emanate from a population in which very few men are circumcised. If the authors thought about their research and findings, then examined the literature, they would realize that a better explanation for their findings is readily apparent. In Denmark infant circumcision is rare, being confined to Jews and possibly a small proportion of Muslims for whom age of MC is not particularly important so long as it occurs in childhood or early teens. The latter represent a small proportion of the study population, as the authors acknowledge, where they state only 8 of the circumcised men were Jewish or Muslim, with 14 men who were non-Danish being circumcised. When circumcision is performed in Denmark it is mostly to treat a medical condition caused by foreskin pathology (phimosis being one reason, and paraphimosis another). Elective MC for a non-medical reason is rare. When the authors read the references I listed and summarized in my original review, there is no evidence in the rest of the world for any adverse effect on sexual function, etc in men whose circumcision took place in early childhood (mostly infancy), nor is there any evidence of adverse function in healthy men who elect to be circumcised as adults (now confirmed at the gold

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standard level of epidemiology, the large randomized controlled trial (RCT), of which there are two. I suspect that the effect seen by the authors may be due to psychological factors. This is, moreover, supported by evidence. A study in Sydney [Mao L, Templeton DJ, Crawford J, Imrie J, Prestage GP, Grulich AE, Donovan B, Kaldor JM, Kippax SC. Does circumcision make a difference to the sexual experience of gay men? Findings from the Health in Men (HIM) cohort. J Sex Med 2008;5:2557-61] reported some associations between circumcision and sexual difficulties, but these were seen only among men circumcised AFTER infancy.

Because of their foreskin problems and associated pain and/or difficulties, they already had acquired behavioural aversions and sexual practices that meant they engaged in less penetrative sex than men with healthy penises. Since one could reasonably expect that most if not all of Frisch's sample of circumcised men might have been circumcised post-infancy for a medical reason, all that has happened in their study is that uncircumcised men with medical problems have simply switched camps, and now appear in the circumcised group. Thus the authors cannot conclude that circumcised men have sexual problems caused by their circumcision. In fact, the findings argue in favour of circumcision in infancy as a prophylactic measure to PREVENT later medical problems that then require the foreskin to be excised.

I will now point out some of the more overt errors that MUST be corrected in the different sections.

TITLE: This is misleading, since the paper does not examine sexual function in women, only sexual experience. It is, moreover, quite wrong to say “function” when function was NOT TESTED! The ‘function’ aspect was based on the authors (most likely incorrect) interpretation of their data. A title that better describes the research is: “Male circumcision and aspects of sexual intercourse in men and women: A survey-based-cross-sectional study in Denmark” The SUMMARY remains misleading.

A-1. The authors state that the study involved 5,552 men. Yet the paper provides core findings for only 95 men who were circumcised. Not stated in the Abstract is that slightly more uncircumcised men than circumcised men had “occasional difficulties”.

One would expect a continuum through to “frequent difficulties”. But this was not seen, thus raising concerns about the validity or interpretation of the findings. In fact one sees this category jump up to 11% for circumcised, compared with 4% for uncircumcised. One problem could be because of the very low ‘n’ value for the circumcised men in this category and the overfitting and thus instability in the model.

It is thus ESSENTIAL that this be stated in the Abstract.

Since only 10 circumcised men had “frequent difficulties” (total for group = 95), in Abstract lines 30-33 the authors need to state: “Although slightly more uncircumcised men had “occasional difficulties”, after adjusting for potential confounding factors 10/95 (11%) of the circumcised men reported “frequent orgasm difficulties” compared to 4% of uncircumcised men (ORadj=3.3, 95%CI=1.4–7.5).” (In this regard, the OR and 95% CIs should accord with the number of significant figures for the source data, ie, change values to two significant figures, namely, 3.3 and 1.4-7.5, respectively.)

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A-2. Then state: “Although the findings were stable in several robustness analyses the low ‘n’ value for circumcised men could mean overfitting and instability in the model”.

Making these changes might help the authors’ credibility when it comes to data presentation and a fundamental understanding of statistics.

A-3. In the Abstract the data on women needs to start a new sentence to improve readability. By definition, “dyspareunia” is painful sexual intercourse due to medical OR PSYCHOLOGICAL causes. Consideration of the latter should be given by the authors in the context of a society in which virtually all of the men are uncircumcised.

The authors’ results are, moreover, at odds with the findings of others for women in relation to MC. For example, a survey of women in Spain who had experienced sexual intercourse with the same partner before and 2 months after circumcision found no difference in general sexual satisfaction, pain during vaginal penetration, desire, and vaginal orgasm [Cortés-González et al. -- ref 56]. In a large RCT the overwhelming majority (97%) of women reported either no change (57%) or improved (40%) sexual satisfaction after their male partners had been circumcised [Kigozi et al., Ref 55]. The authors concluded that male circumcision has no deleterious effect on female sexual satisfaction, and that it might, moreover, have social benefits in addition to the established health benefits. Speculation about any possible adverse effect on female sexual satisfaction was dispelled.

A-4. The present finding that more circumcised men (38%) than uncircumcised men (28%) reported ≥10 partners (age-adjusted OR 1.6) MUST be included in the Abstract. Its omission conveys the impression that the authors are trying to hide a significant finding. An explanation for this finding could be speculated on, but would require further research. This is a very important finding and I am at a loss to know why the authors decided to omit it. In fact the Abstract at present states that “partner number… differed little …”, which is not what the authors found!

A-5. Similarly, the Abstract MUST state that there was no overall difference in sexual desire or sexual function for men of each circumcision status.

A-6. Things like “perceived importance of a good sex life” are far less important and seem to be “motherhood statements” that take up space which could be better used for findings such as those above.

A-7. As far as psychological sequelae in males are concerned, a study in Sweden (similar to Denmark re MC) reported on follow-up of 117 boys 5 years after they had been circumcised for phimosis, balanitis scarring of the prepuce, or ballooning when urinating, and found that 95% expressed complete satisfaction and the only psychological effect was slight shyness in the school change-room in 9% [Stenram A, Malmfors G, Okmian L. Circumcision for phimosis – indications and results. Acta Paediat Scand 1986;75:321-323; Stenram A, Malmfors G, Okmian L. Circumcision for phimosis: a follow-up study. Scand J Urol Nephrol 1986;20:89-92]. Could the realization that they are not like most other men in Sweden also be a contributing factor to the data for the circumcised men in the present study? And for the women, could a type of penis that they are unused to be in part behind the report by a few of the female participants of dyspaeunia?

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A-8. The Abstract’s Conclusion is very misleading and **MUST be changed**.

Given the low ‘n’ value for circumcised men, and the small proportion of circumcised men that apparently said they had “frequent orgasm difficulties” (after adjustments by the authors) the authors cannot make the statement in first line of Conclusions that “circumcision was associated with frequent orgasm difficulties” since this has a double meaning (deliberate?) and should be regarded as deceptive. Instead the authors need to communicate an unambiguous accurate message that reflects their data by instead saying “A small proportion of Danish men circumcised mostly for medical reasons could have frequent orgasm difficulties. In the female partners of circumcised men a minority reported slightly higher incomplete needs fulfilment and orgasm difficulties, while dyspareunia, although rarer, was much higher in the small subset of women who reported this. These data must be confirmed in a larger sample set. The finings may be context-specific, reflecting psychological factors in medically circumcised Danish men, and lack support from populations where circumcision occurs mostly in infancy or is elective.

In the INTRODUCTION I-1. the authors misconstrue my comment that 10% of older children and men have physiological phimosis by claiming that I only referred to Asian and Paraguayan studies, when in fact I also stated “…British, German, US and other studies of men in the late teens and adult years show rates of 9%-14% (Osmond 1953; Saitmacher 1960; Schoeberlein 1966; Ohjimi & Ohjimi 1981; Boon et al. 1989; Velazquez et al.

2003; Ben et al. 2008)”. This smacks of deliberate obfuscation, consistent with dishonesty. The authors further distort the issue by saying that prevention of pathological phimosis is an argument for circumcision, when in fact prevention of ALL forms of phimosis is a reason.

I-2. In this first paragraph they conflate two different issues: whether circumcision has benefits, and whether those benefits, when weighed against risks, are sufficient to recommend routine circumcision (i.e., automatic circumcision of all newborn boys, rather than the present elective system). Of course, most medical organizations (including the AAP, which they cite) acknowledge many of the benefits of circumcision, but perhaps admitting that would not serve the authors’ purpose so well.

I-3. Their argument that condoms can prevent various other conditions is specious and fails to recognize the reality of such use. Moreover, the biggest risk factor for penile cancer (a disease confined almost exclusively to uncircumcised men) is phimosis, something that cannot be prevented by condoms!

I-4. Even more astounding is their claim that urinary tract infections are not very much more common in uncircumcised infants. Here they cite an old paper by Van Howe, whose various meta-analyses over the years have been severely criticized as unreliable, and have even been shown to involve actual fabrication of source data in the case of one on sexually transmitted urethritis (see: Waskett JH, Morris BJ, Weiss HA. Errors in meta-analysis by Van Howe. Int J STD AIDS 2009: 20: 216-218). And why have the authors cited this old meta-analysis by van Howe, yet ignored much more recent ones, such as by Singh-Grewal et al. (Singh-Grewal D, Macdessi J, Craig J. Circumcision for the prevention of urinary tract infections in boys: a systematic

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review of randomized trials and observational studies. Arch Dis Child 2005;90;853858)? The answer would seem to be selective citation of poor quality references in order to prop up their academically weak and biased presentation.

I-5. The evidence that circumcision improves penile hygiene is irrefutable, not just obvious (see: Kalcev 1964; Oster 1968; Russell 1993; Wright 1970; Oh et al. 2002; O’Farrell et al. Int J STD AIDS 2005;16:556-9; O’Farrell et al. Int J STD AIDS 2008;19:821-23]. To quote from my original review: “Their claim that penile cancer can be prevented by good hygiene is contradicted by research - there being no scientific evidence that improved penile hygiene is effective in reducing the risk in an uncircumcised man (Moses et al. 1998). A study in California saw no correlation between penile cancer and frequency of bathing or method of cleaning the anogenital area before or after sex (Tsen et al. 2001).”

I-6. These few examples highlight the lack of credibility in the authors’ presentation.

Para 1 MUST be REMOVED. Not only is it highly biased, it is wrong. It has, moreover, no relevance to the research they are conducting. In my original review I provided an extensive set of information and references to studies that are relevant to the present research on sexual experience, function, sensation and satisfaction, and it is these that need to appear in the Introduction by way of background to the topic at hand.

I-7. In para 2 are the authors saying that ALL previous reports on sexual function are questionable? This further adds to my concerns about the credibility that readers will assign to their study should it be published in its present form. The authors seem to be their own worst enemy, because by making outrageous statements any expert reader will dismiss all of their findings as being as unreliable as their other statements.

RESULTS R-1. The reader should be told how many of the 14 men with a non-Danish background (presumably Muslim? or Jewish?) who were circumcised were amongst the 10 who had frequent orgasm difficulties. And how many of the women who reported difficulties were partners of Muslim or Jewish men? And what were the results when Muslim men and their partners were eliminated from the analyses?

Since it seems that 81? of the 95 men were not Muslim or Jewish, it is imperative that: (1) the reason why they were circumcised is given (was it for a medical condition?), and (2) at what age. THIS IS FUNDAMENTAL TO THE INTERPRETATION OF THE FINDINGS AND MUST BE PROVIDED. Since there are only 81 men in this category, obtaining this information should be quite easy.

Interestingly, the authors say that women whose circumcised male partner was not Jewish or Muslims had more vaginismus. As I argue, the problems might be more common in women whose male partner was circumcised for a medical condition.

Could this finding then hint at this being the case?

DISCUSSION D-1. This should address the findings only and ALL unwarranted speculation or “advice” to the world about the dangers to sexual function of MC must be removed. … ESPECIALLY when it is probably based on an erroneous interpretation of their findings and does not apply to circumcision when it is performed on males with a

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healthy penis. Thus DELETE the text: “In the present work, we focused on the possible role of the approximately 40-50 cm2 penile foreskin 22,23, which has caused more controversy than probably any other part of the human body. Before turning to the more disquieting findings”. The paper was not about a quantum of skin, but about a status, namely circumcised or not. There was no study of foreskin function, let alone the skin of the foreskin. The word “disquieting” is inappropriate as it is subjective … and probably wrong anyway.

D-2. The following too is totally wrong and misleading: “circumcised men were three times more likely than uncircumcised men to experience frequent orgasm difficulties”. The authors need to be clear and say: “10/95 circumcised men reported frequent orgasm difficulties”. They then speculate, without evidence, that these men had reduced sensitivity. Unless they conduct a proper study of this (eg, by the kind of thermal imaging carried out by Kimberly Payne et al. in Montreal referred to in my original review), then such speculation goes beyond the limits of the data.

Instead they should refer to the findings of Templeton’s group [Mao et al. 2008] cited above and state that the most likely reason is that these men had already been experiencing sexual problems because of a medical problem and that after having had a medically-necessary circumcision to treat this the psychological consequences persisted, i.e., that they had merely switched groups, and carried their sexual problem with them. This implies that the real problem is lack of circumcision, since this, by casing a medical problem, then resulted in a sexual problem. It explains why no such findings have ever been observed in men circumcised in infancy or men with a healthy penis who elected to be circumcised in adulthood. This adds to my concerns about the loaded statement referring to the large RCTs of sexual function, etc in Africa where the authors say “This is potentially problematic, considering the implausibly high levels of sexual satisfaction reported by the men in that study”. The implausibility applies more to the authors’ unsubstantiated speculation about the interpretation of their results, when a much more plausible interpretation of their results is available (ie, Mao et al.). Thus this statement MUST be deleted. Also DELETE the following text: “This suggests that reduced penile sensitivity may, at least in part, explain the difference, a situation that has been recognized by medical and religious authorities for centuries 26 and supported by recent neurophysiological studies 24,27,28. Importantly, the more frequent orgasm difficulties of circumcised men and their partners are not only a concern from a sexual pleasure perspective. The ability to achieve orgasm is a major determinant of overall sexual life satisfaction and marital satisfaction 19,29-32, and persons who rarely experience orgasm may even be a group at increased overall mortality 33. Historically, reduced penile sensitivity was not an unintended side effect of circumcision. Medieval rabbi, physician and philosopher Moses Maimonides (1135-1204) stated that circumcision was required to ‘cause man to be moderate’, because circumcision ‘weakens the power of sexual excitement’ and ‘lessens the natural enjoyment’ 26. In the 19th century, preoccupation with the dangers of phimosis, masturbation and an illdefined syndrome called spermatorrhoea gave rise to a series of preventive measures, including chastity belts, straight waistcoats, iatrogenic urethral inflammation, and other measures to reduce sexual excitability 34. These procedures eventually lost clinical relevance as circumcision grew in popularity to become the favoured method of preventing and treating the illregarded habit of masturbation 35-40.” What is said here is all debatable, or

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incorrect, has little to do with a Discussion of the data to hand, and adds to the already too long Discussion.

D-3. In para 4 of the Discussion the word “amputate” MUST be deleted. This is emotive and wrong. It does not belong in a scientific article. The correct word is ‘excision’ or ‘removal’. In the next part of sentence the word ‘abundance’ also needs to be removed as there is no evidence that the foreskin contains any more nerve endings than adjacent parts of the penis, and without an extensive discussion of the proportion of different types of sensory receptors and what their function is this sentence comes across as ‘loaded’. Really this whole sentence needs to be removed because the authors state what is in effect an old hypothesis that has now been disproven by numerous research studies, as listed in my original report. In the next sentence REMOVE “Nevertheless, some authors maintain that” and simply state the findings, ie, “There is …”. In what then follows the authors cite selectively and laboriously when they should cite succinctly and do so for a larger breadth of findings by citing the publications I listed in my original report. Neurological tested by Masters & Johnson found no difference (as simple as that! … no need for 4 lines of text to state what?). The authors complain that Masters and Johnson used only 35 circumcised men and later talk about “underpowered studies”, yet in their own study here they make claims of “frequent orgasm difficulties’ based on an n of 10. Thus all of this paragraph is incredibly biased. The authors must write in a scholarly, balanced and inclusive manner if they want to be judged as credible. At present this all comes across as a rabid rant.

D-4. In para 5 more poor quality studies are cited by the authors. For example, the Korean study (ref 49) has been criticized on numerous grounds and has no credibility, yet the authors have ignored the reference I provided previsouly [Willcourt R. Critique of: 'The effect of male circumcision on sexuality' by Kim KD, Pang M. BJU Int 2006;99:619-622. BJU Int 2007:99:1169-1170] that undermines that study.

Similarly Sorrells et al. (ref 28) has been debunked based on a proper analysis of the data presented in that paper [see Waskett JH, Morris BJ. Fine-touch pressure thresholds in the adult penis. (Critique of Sorrells ML, et al. BJU Int 2007;99:864869). BJU Int 2007:99:1551-1552]. My comments illustrate the poor quality of the authors’ presentation of the literature in the field. They choose weak, old, superseded and/or discredited studies, often in books or low-ranked journals.

D-4. In para 6 a more direct presentation of the findings in the papers discussed would be in order. This should also state that most of the circumcised men in these studies had been circumcised at birth, and their lack of a difference in sexual problems compared with uncircumcised men supports the hypothesis that the present authors’ findings that problems may be confined to a small subset of men who are circumcised for a medical condition.

D-5. In para 8, it is quite incorrect to say that no explanation was provided for the decline in sexual problems over the 2 years of the trial in both the intervention (MC) arm and the control arm. In this study the men were much younger than in the other RCT that examined sexual function, etc, and it was stated that this change was due to maturation and acquisition of improved sexual experience over the two years involved in the trial. See the paper and accompanying editorial/review(s) at the time.

Thus DELETE “The authors provided no explanation for this remarkable decline in sexual problems over time but felt reassured by”. “The sentence

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“Measurement problems and drop out of men who experienced sexual problems during follow-up but were reluctant to report them in a personal interview with representatives of the circumcision team need consideration” is far too speculative and cannot be justified, so MUST BE DELETED. Similarly, please DELETE the sentence: “As pointed out by others, bias needs consideration in these African studies because interviewers were not blinded to participants’ circumcision status 52”, especially so because of the appalling, highly criticized, very biased review that it appears in (i.e., ref 52). The authors need to state the findings at the last time point of the trials, as at 12 months it could be argued that a tiny proportion of the intervention arm men could still be undergoing healing from their circumcision.

D-6. The first sentence is incorrect, especially since one of the studies cited is a large RCT by some of the best researchers in the field, so can hardly be said to be ‘questionable’ or ‘overtly flawed’. This sentence needs to be either re-worded so as to convey an accurate message or BETTER DELETED, since each of the references cited is discussed in the text that follows, so is redundant. The Iowa study by Wlliamson & Willamson is misrepresented. In fact women who had only ever had sex with men who were uncircumcised stated that they preferred the appearance of the circumcised penis. Please re-read this and the other references and re-write in a much more dispassionate manner. The sentence about the O’Hara study is quite well said.

The last sentence must definitely be DELETED: “This is potentially problematic, considering the implausibly high levels of sexual satisfaction reported by the men in that study 50“ The only reason that it might be implausible in the opinion of the authors is that this large RCT of men with a healthy penis who elected to be circumcised either at the beginning or the end of the trial disagrees with their findings on medically circumcised men in Denmark.

D-7. The sentence “Consequently, our findings of increased rates of orgasm difficulties in circumcised men and of increased rates of a variety of sexual troubles among their spouses are potentially relevant to millions of people around the world” must be deleted because it makes an invalid assumption (not supported by the field of research), namely that their findings on 10 men circumcised for medical reasons are also relevant to men with a healthy penis and infant males, and for the women the findings for a society with a very low rate of MC also apply to societies where MC is more common.

D-8. The statement “Other assets include the large size of our study” is incorrect, as the large size refers only to uncircumcised men. The circumcised men were too few for reliable data to be generated. As such the findings are more in the realm of “hypothesis generating” than “hypothesis proved”. Studies in a very much larger cohort are required, as well as in others settings geographically, and in populations where most men are circumcised in infancy, and ones in which most men choose to be circumcised in the absence of a medcial problem that necessitates the procedure. After the last sentence tha authors need to state the limitations of studying a Danish population because MC is so rare, and then only a sign that the man has had medical problems, or is a member of a religious minority that practices MC. Although the authors state that the findings were not the result of unadjusted cultural or religious factors, the study would have to examine the issue of medical MC as explaining the findings. This might not be possible, however. If so a conclusion about the cause of ‘orgasm difficulties’ can only be speculated on.

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D-9. The last para of the Discussion should be DELETED. It goes way beyond the data obtained, is self-indulgent and may parts of it are wrong for the reasons stated in my report. Deletion will also shorten the overly long Discussion.

Should the authors wish to continue to seek publication of their findings in a scientific journal I implore them to re-read the extensive comments in my original peer-review.

Conclusions: In line 2, change ‘warranted’ to ‘essential’.

Given the more plausible interpretation of the data the authors’ suggestion that their findings might inform doctors or parents of baby boys should state in addition “of the wisdom of circumcising them in infancy before problems develop that might adversely affect their sex life as adults”, not to mention “conferring a lifetime of protection from conditions caused by lack of circumcision”.

The last sentence “Additionally, since it appears from our study that both men and women may have fewer sexual problems when the man is uncircumcised, and because preputial plasties may sometimes serve as suitable alternatives to standard circumcision, our study may stimulate a more conservative, tissue-preserving attitude in situations where foreskin pathology requires surgical intervention” is wrong, irrelevant and dangerous advice, having no place in the context of the present manuscript and MUST BE DELETED..

AUTHORS’ RESPONSE The authors provided a Response to a small number of the comments I made in my original report. Most of these need no comment, having been adequately covered in my report above. However, their last statement confirms my view that the authors have no aptitude or understanding of epidemiology or much knowledge of the field of MC. They say that the USA has a high rate of MC and a high rate of HIV, but in Scandinavian countries MC is low and so is HIV, so this means MC offers no protection against HIV in industrialized countries. Firstly, they do not state the rates in each country/region. They would then have to state the rate in HETEROSEXUAL adults, injecting drug users, and MSM who are receptive only, MSM who are insertive-only, and perhaps those MSM who engage in each. They would then need to break these down into circumcised and uncircumcised. Such comparisons are available for the USA (but few other parts of the world except for Sub-Saharan Africa, India and to a lesser extend parts of South East Asia and South America). The US data clearly shows lower HIV prevalence in men who are circumcised. Since no credible source these days would refute the protection afforded by MC against HIV, it stands to reason that the high MC rate in the USA has kept HIV infections amongst the majority heterosexual population to levels much lower than it would otherwise be the case if MC was rare, as in Denmark. One also has to realize that the USA experienced some of the first cases of HIV infection outside of Africa. HIV was brought to the USA via Haiti. The history goes something like this: HIV appeared first in Sub-Saharan Africa, quite likely in the Belgian Congo, in the 1930s or 40s

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[Holmes EC. When HIV spread afar. Proc Natl Acad Sci USA 2007; 104: 1835118352]. From there HIV subtype B moved to Haiti between 1961 and 1970 [Gilbert MT, Rambaut A, Wlasiuk G, Spira TJ, Pitchenik AE, Worobey M. The emergence of HIV/AIDS in the Americas and beyond. Proc Natl Acad Sci USA 2007; 104: 1856618570]. This is a period when many Haitians returned to their home country after the Congo’s independence from Belgium. It spread within Haiti for some years before dispersing elsewhere in the world between 1966 and 1972. The Americas were probably the first after Haiti to be recipients. HIV circulated cryptically in the USA for about 12 years before AIDS was recognized as a new disease in 1981. The emergence of a pandemic variant of subtype B was an important turning point in the history of AIDS, but its spread was likely driven by ecological rather than evolutionary factors.