Male Circumcision and HIV Case Study

Problem Description

1.   Can you conclude from the evidence provided in the Problem Description that precedes Question 1 on pg. 24 of the case study that there is a causal relationship between the absence of circumcision and HIV infection?  Why or why not?

      Hint:  Think about the requirements for establishing cause and effect (Table 2-2).  Which of these is or aren’t met by the information?

There is a relationship between the absence of circumcision and HIV infections. The study that was conducted in the mid-1980s showed that regions that had low rates of circumcision (Zambia Lesotho, and Botswana), reported high rates of HIV infections (Hunting & Gleason, 2011). On the other hand, those that had high circumcision (Guinea, Sierra Leone, and Senegal) reported low rates of HIV infections.

Etiology/Efficacy

2.   Why were clinical trials needed to confirm the efficacy of circumcision in preventing HIV infection (why had officials delayed promoting/funding male circumcision as a method to prevent HIV infection?)?

Clinical trials were needed because the previous studies were only based on observation. Clinical trials could provide extensive standardized results out of experimentation.

3.   Describe the three randomized controlled trials conducted to study the impact of male circumcision among predominantly heterosexual males in Africa (description of subjects, what countries were chosen and why, how control and experimental groups differed, etc.).

The subjects were HIV free heterosexual volunteers who were willing to undergo circumcision. The countries chosen were South Africa, Uganda, and Kenya because they had high incidence rates of newly reported HIV infections annually. The experimental group was offered free circumcision before the trial was conducted while the control group was offered free circumcision after completion of the trial.

4.   The results of all three trials were similar. Using the Orange Farm study as an example, calculate the relative risk among those randomized to the non-circumcision comparison group (exposed to a risk factor of being uncircumcised) compared to those in the circumcision study group (not exposed to the risk factor of being uncircumcised). How do you interpret this relative risk (what does your answer mean?)?

      Hint: The relative risk can be calculated as the probability of developing HIV in the non-circumcised comparison group compared to the probability of developing HIV in the circumcised study group.  Use the data from the top of the first column on page 26. 

Non-circumcised probability= 2.1

Circumcised probability= 0.85

R.R= 2.1/0.85=2.5

The results show that there is a high risk of uncircumcised men contracting HIV disease as compared to circumcised men.

5.   Percent efficacy is the percentage of HIV infection that can potentially be prevented among men by circumcision.  Calculate the percent efficacy of circumcision, using the equation at the bottom of the first column of page 26, using the relative risk you calculated in question #4.  How do you interpret your result (what does the percent efficacy mean?)?

Percentage efficacy= [relative risk -1 /relative risk] *100

                         =       [2.5-1/2.5]*100

                          = 60%

The percent efficacy means that if circumcision is introduced in those regions, the spread of HIV infections will reduce by 60%. Thus, circumcision reduces new infections among circumcised males.

 6.  One of the criteria for establishing a contributory cause is biological plausibility.  What recent evidence provided a biological explanation for why uncircumcised males might be at greater risk for HIV infection?

The recent explanations explained that white cells that are close to the surface are many and are contained in the inner lining of the foreskin, thus, if the foreskin is not removed, the cells attract the virus. Another evidence is that uncircumcised men have ulcerative lesions that increase the risk of HIV infection.

Recommendations

7.   For an intervention to be recommended, the benefits must outweigh the harms.  Describe the benefits and harms the panel considered when deciding whether to recommend circumcision as a method of HIV prevention.

One benefit is that those undergoing circumcision had a high percentage of protection, which is, 60% from HIV infection. Therefore, circumcision lowers HIV infection rates. Secondly, during the trials, it was revealed that circumcision reduced the prevalence of genital herpes and HPV viruses.  One of the harms is if performed under unhygienic conditions, other infections associated with penile damage may occur. The second harm is that during the 6-week healing period, individuals are at high risk of HIV infection if blood contamination occurs with HIV positive people. 

8.   Using the formula found in the second column of pg. 27, calculate the percent efficacy of circumcision in both Zambia and Senegal (use the data in the first paragraph of the second column on page 27, and the relative risk you calculated in #4).    In which of the two countries is circumcision likely to have a bigger impact?

Zambia

Proportion rate without circumcision = 0.8

Relative risk= 2.5

= {[0.8*1.5] / [0.8*1.5] +1}*100

= [1.2/2.2]100

=54.5%

Senegal

Proportion rate without circumcision = 0.2

Relative risk= 2.5

= {[0.2*1.5] / [0.2*1.5] +1}*100

= [0.3/1.3]100

23.1%

If circumcision is practiced in both countries, it is likely to have a big impact in Zambia than Senegal because already the percent efficacy is 54.5% and 23.1% respectively.

9.   The panel determined that circumcision was cost-effective, based on the estimated cost of $375-$1500 to prevent one case of HIV, which is far below the cost of providing HIV drug treatment.  Condom use, however, is far cheaper than circumcision and has a better percent efficacy.  Can you think of a reason why circumcision might still be promoted and recommended over condom use even though it is more costly?

Circumcision might still be preferred because its benefits are much long-lasting than those of condoms. Additionally, condoms have not gained widespread acceptance in Africa due to culture.

Implementation

10. Describe who, when, and how factors the panel considered in developing an implementation process.  Specific points to address include: the specific population at which the intervention of circumcision is targeted (who), whether this is a primary, secondary or tertiary intervention (when), at what point of life at which the intervention should be performed (when), whether the intervention would be implemented through information, motivation, or obligation (how) and what barriers and cultural factors were considered (how).

Who – The target population was HIV negative heterosexual males because there would be reduced transmissions during the 6-week healing period.  

When – It was recommended when an adolescent is entering his adulthood because that was the dominant culture among Africans, if otherwise, it would take long before the neonatal culture is embraced.

How – The panel considered doing it through offering useful information to those willing such as circumcision is not a substitute for condoms and condoms are still vital. Barriers discussed were fear of pain, the cost associated with circumcision, and safety concerns.

Evaluation

11. What questions should the panel be prepared to ask after implementation of the intervention to evaluate the intervention’s effectiveness?

The first question is, did new HIV infections decrease after the intervention of male circumcision? The second question should be; what were the harms brought about by the intervention? Third question; did the intervention pose a threat to the social, cultural, religious, and economic factors of the regions?

Other Perspectives

12. Should circumcision be the only intervention put into practice for HIV prevention?  What other interventions might be part of a comprehensive prevention program?  Could the addition of circumcision to a comprehensive program be detrimental to prevention, and what evidence is there to support or reject this possibility?

Circumcision should not be the only intervention. Other interventions might include; advocating for condom use while offering free condoms, widespread testing to recognize high-risk individuals, and advocating for monogamous marriages rather than polygamous. The introduction of circumcision could be detrimental to prevention if its importance is overrated. The panel attributed this to people stopping using condoms, having multiple partners, and failing to take medications if circumcision was overrated.

13. Should considerable effort and resources be committed to establishing circumcision as a recommended intervention to prevent HIV in every country?  What factors should be considered in making this decision to recommend circumcision?

Yes. Some of the factors to consider include; the prevalence rate of new HIV infections, the socio-cultural beliefs of those countries, and how effective other interventions are in the countries. 

 References

Hunting, K., & Gleason, B. L. (2011). Essential case studies in public health. Jones & Bartlett Publishers.