Hepatomegaly, splenomegaly

The clinical manifestations are listed here; hepatomegaly, splenomegaly, hyperbilirubinemia.

Generalized diffuse infection with CMV virus; the various manifestations you see here; cerebral calcifications. A big deal is made by the difference of these calcifications and toxoplasmosis, and it’s a good Board question. These are supposedly periventricular whereas in toxoplasmosis they are more diffuse. But that’s not hard and fast. The other manifestations are hemolytic anemia and interstitial pneumonia. This is a picture of a baby with severe involvement with marked petechial lesions throughout. Congenital anomalies with CMV compared to, for example rubella, actual anomalies are not that clear-cut. Cardiovascular anomalies, even though there is heart disease, it has no real pattern and it can involve all types of heart defects. Whereas with rubella you have some very specific cardiac defects. The other findings; hypospadias, gastrointestinal things such as duplications and musculoskeletal defects. But in general, the main manifestations of CMV are acute active infection involving what I showed you previously.

The diagnosis of CMV historically was looking for inclusion cells in the urine, and I’m sure nobody these days even knows what that is. That inclusion cells were epithelial cells, renal tubular epithelial cells, infected with virus and giving a typical cytopathic effect. So the main method of diagnosis is viral isolation. But the important thing in a newborn baby is you need to do this immediately. Two weeks later you don’t know whether that infection occurred after birth and therefore not a congenital infection. So one of the major things is that if you suspect congenital infection and CMV, look for virus immediately. Now in this day and age PCR can also be done as can direct antigen tests, but the definitive test is virus isolation. The places are urine, throat, CSF and really should add blood, buffy coat of the blood as well.

The next is serology. Igm we’ve gone overboard with IgM assays and the right assay IgM positive indicates recent infection and is a very useful test. But there are frequent false positives and there are occasional false negatives. The false negatives are when there are very high IgG values. But false positives actually are much more common, both in pregnant women and also occasionally in babies. So you really want to go for culture.

Leave a Reply

Your email address will not be published. Required fields are marked *