Final answer:
Thrush that does not respond readily to treatment is an indicator of HIV infection in a newborn exposed to HIV in utero, as it suggests a compromised immune system which is a characteristic of HIV.
Step-by-step explanation:
A male newborn has been exposed to HIV in utero. Among the findings that support the diagnosis of HIV infection in the newborn, thrush that does not respond readily to treatment is indicative. While findings like delay in temperature regulation, continued bleeding after circumcision, and hypoglycemia within the first day of birth may be concerning, they are not specific to HIV infection. Oral thrush, or candidiasis, is a common opportunistic infection in HIV-infected individuals and is caused by the fungus Candida albicans. Infants with HIV may present with severe, persistent thrush that can be resistant to typical antifungal treatments. The presence of difficult-to-treat thrush in an infant known to have been exposed to HIV in utero is, therefore, a strong indicator of actual HIV infection.