Zika screening: Is looking for microcephaly enough?

July 20, 2016

A look at Brazilian Zika virus cases indicates that looking for just microcephaly may cause doctors to miss cases of congenital Zika virus infection. Plus: Why do women fare worse following cardiac arrest than their male counterparts?

A case series published in The Lancet appears to indicate that normal head circumference alone is insufficient to rule out congenital Zika virus in infants whose mothers could have been infected.

The findings reflect a review by Brazilian researchers of 1501 liveborn infants whose cases had been investigated by medical teams at the State level through February 27, 2016. The suspected Zika cases were classified into 5 categories, based on neuroimaging and laboratory results: definite cases with laboratory evidence of Zika virus infection; highly probable cases with specific neuroimaging findings and no positive results for other congenital infections; moderately probably cases with specific neuroimaging findings but other infections could not be ruled out; somewhat probable cases, which had neuroimaging findings but for which there was not enough detail provided by the local teams; and all other cases. InterGrowth standards were used to assess head circumference by gestational age. State medical teams provided information on history of rash and first week mortality.

Of the 1501 suspected cases, 899 were discarded. Of the remaining 602 cases, 76 were definite; 54 were highly probably; 181 were moderately probable; and 291 were somewhat probable of having congenital Zika virus. Among the 4 groups, the clinical, anthropometric, and survival differences were small. When compared to the 4 groups, the discarded cases had larger head circumferences (mean Z scores −1.54 vs −3.13, difference 1.58 [95% confidence interval {CI} 1.45–1.72]); lower first week mortality (14 per 1000 vs 51 per 1000; rate ratio 0.28 [95% CI 0.14–0.56]); and were less likely to have a history of rash during the pregnancy (20.7% vs 61.4%, ratio 0.34 [95% CI 0.27–0.42]). A history of rash during the third trimester was linked with brain abnormalities in spite of normal head circumference. One in 5 definite or probable cases presented with a head circumference in the normal range (above −2 SD below the median of the InterGrowth standard). Additionally one-third of definite and probable cases had no history of rash during the pregnancy.

The researchers concluded that many definite and probable cases of congenital Zika virus can be found in infants with normal heard circumference whose mothers may not have reported having a rash during pregnancy. They urged that screening criteria be updated so that affected babies aren’t missed.

NEXT: Are women more likely to survive cardiac arrest than men?


Are women more likely to survive cardiac arrest than men?

Women who are in cardiac arrest may be less likely than their male counterparts to receive life-saving treatment and also less likely to survive cardiac arrest, according to results of a new study in The Journal of the American Heart Association.

Using the Nationwide Inpatient Sample database, the researchers performed a retrospective analysis of all patients who suffered cardiac arrest between 2003 and 2012. Sex-based outcomes following cardiac arrest, rates of utilization of coronary angiography/percutaneous coronary interventions/targeted temperature management, and annual rates of cardiac rest were examined. A total of 1,436,052 discharge records were reviewed, of which 651,745 were for female patients. The study found that in comparison to men, women were not as likely to present with ventricular tachycardia/ventricular fibrillation arrests during the study period.

During the study period, the annual rate of cardiac arrest increased from 2003 to 2012 by 14.0% (Ptrend<0.001). Over the same time, the rate of ventricular tachycardia/ventricular fibrillation increased by 25.9% (Ptrend<0.001). Women were found to be less likely to undergo targeted temperature management in both ventricular tachycardia/ventricular fibrillation and pulseless electrical activity/asystole arrests, percutaneous coronary interventions, and coronary angiography than their male counterparts. Over the study period, there was a significant decrease in in-hospital mortality among women following cardiac rest (from 69.1% to 60.9%, Ptrend<0.001). However in-hospital mortality was significantly higher in women than men (64.0% vs 61.4%; adjusted odds ratio 1.02, P<0.001) especially in the ventricular tachycardia/ventricular fibrillation arrest cohort (49.4% vs 45.6%; adjusted odds ratio 1.11, P<0.001).

The researchers concluded that in spite of improving survival trends, women still face higher in-hospital mortality rates following cardiac arrest when compared to men and they are still more unlikely to receive treatment for it that could be life-saving.