HIV-TB Comorbidity Risk Steps:

• Identify the first infection as one that impairs immunity, increasing susceptibility to a second opportunistic disease.
• Note the second disease must amplify death risk by 15x or more compared to primary causes in affected groups.
• Recall HIV weakens the immune system, heightening TB risk dramatically in endemic areas.
• Confirm TB as a major killer in HIV patients, fitting the comorbidity pattern.

Why B is correct:

• HIV infection increases TB risk by 15-20 times; TB then raises mortality in HIV patients far beyond other causes, per WHO data on AIDS-related deaths.

Why the others are wrong:

• A: Cholera causes dehydration but does not lead to AIDS or similar comorbidity.
• C: TB does not cause AIDS; HIV causes AIDS, reversing the sequence.
• D: Malaria may co-occur with TB but lacks evidence of 15x mortality increase from TB post-malaria.

Final answer: B