What is the most likely presenting symptom for a newborn whose mother is HIV positive?

In the context of a newborn whose mother is HIV positive, the most likely presenting symptom would indeed be a persistent cold, which typically manifests as respiratory symptoms such as a runny or stuffy nose, cough, or congestion. This can occur due to the infant being immunocompromised, as maternal HIV can impact the immune system of the newborn.

HIV can lead to an increased susceptibility to various infections, especially respiratory ones, because the infant may not yet have developed a robust immune response. Respiratory infections can be common in infants born to mothers with HIV, particularly if they're also facing other challenges such as low birth weight or other complications associated with HIV transmission.

The other symptoms listed, like shortness of breath or joint pain, while they may present in specific medical conditions, are not commonly associated with HIV transmission to newborns. Organomegaly, or the enlargement of organs, can occur in various conditions and may sometimes be seen in infants with congenital infections, but it is not the typical initial presentation compared to respiratory issues. A persistent cold stands out as the most likely and immediate symptom due to the relationship between HIV-related immunosuppression and the increased risk for respiratory infections in newborns.