Legal considerations have to refer to the local legal system..... In our system it would be difficult to implement a control program for a specific group - In our constitution there is a "principle of equality" and defining groups easily can be seen as (political) discrimination. Only strong arguments allow discrimination.
The ethical aspects can be discussed using the bioethics framework: beneficience, maleficience, authonomy and justice. Justice can have a link to the principle of equality. A program should produce benefits - there has to be strong evidence for that if you take this potential benefit (for the individual? , or for society?) as an argument to restrict individual authonomy. Nearly all medical interventions have also some risk of doing harm. So imposing harm with overriding authonomy makes the system liable for this harm. That's also a link to the legal considerations. The bioethics framework can be operationalized by conducting a survey and giving the situation at it is in the 4 domains a numerical weight and then do the same with a value judgement to the changes of the programs implementation. Then - in a spider web diagram - you can visualize the change and can calculate the changing area. Helps to compare different strategies.
I find the chapter on infectious diseases in the Nuffield Council on Bioethics report titled 'Public health: ethical issues' very useful. This chapter doesn't focus on low literacy populations in particular but it provides a useful overview of ethical issues related to vaccination (for e.g. is it ethical to introduce a quasi-mandatory vaccination scheme that requires all children to be fully immunised before they can be admitted to school), surveillance (for e.g. the tension between patient confidentiality and the need for accurate estimates of disease burden in the case of potentially stigmatising diseases like HIV and other STIs), issues like quarantine in the case of epidemics/pandemics and implications for individual freedoms. There is a UK focus but many of the ethical issues are generalisable to other contexts including those like the one you describe. The pdf version of the chapter can be downloaded at this link:
If you are new to ethical frameworks in public health, I would highly recommend the second chapter in this report as well which provides an excellent overview of these: