Discovering Hope

Surveillance network tracks shift in cause of childhood diarrhea

A national vaccine surveillance program that Vanderbilt University is a part of has identified a significant shift in the most common cause of childhood diarrhea.

A study released March 21 in the New England Journal of Medicine (NEJM), finds that norovirus (sometimes called the Norwalk virus) is now the leading cause of childhood diarrhea.

Rotavirus once caused 90 percent of cases of childhood diarrhea, but rates have steadily declined since a vaccine came into widespread use in 2006.

The New Vaccine Surveillance Network (NVSN), which includes Vanderbilt, the University of Rochester and Cincinnati Children’s Hospital, tracks a number of viral illnesses and the impact of vaccination.

Kathryn Edwards, M.D., the Sarah H. Sell and Cornelius Vanderbilt Professor of Pediatrics and director of the Vanderbilt Vaccine Research Program, served as director of the Vanderbilt arm of the NVSN during this study to examine the causes of childhood diarrhea from 2008 to 2010.

“It is important to note that even though the threat of rotavirus is greatly reduced, our study shows the intensity and burden of norovirus has remained unchanged,” Edwards said.

In the NEJM study, the researchers tracked more than 141,000 children under age 5. Children with diarrhea were treated in hospitals, emergency departments and outpatient medical offices.

Lab testing confirmed the presence of norovirus and rotavirus in 1,295 cases. Norovirus was detected in 21 percent of cases, while rotavirus was identified in only 12 percent.

– by Carole Bartoo

 

Understanding bronchiolitis in children

Vanderbilt-led research published in the New England Journal of Medicine has identified the relatively unknown human metapneumovirus (MPV) as the second most common cause of severe bronchiolitis in young children.

The research spanned six years, from 2003 to 2009, and involved samples taken from more than 10,000 children under age 5. The children were hospitalized, treated in an emergency department, or seen in an outpatient clinic with a lower respiratory infection (bronchiolitis).

“We found MPV is as important a cause of respiratory illness as influenza, and caused more illness than the three common types of parainfluenza virus combined. In fact, in young children, the burden of MPV was second only to RSV (respiratory syncytial virus) as a cause of bronchiolitis,” said senior author John Williams, M.D., associate professor of Pediatric Infectious Diseases and a well-known expert in MPV research.

Researchers found MPV tends to affect more children over age 1 than RSV, and while both viral infections strike in late winter or spring, MPV has a seasonal peak that lags behind the typical peak for RSV by about a month. The authors said physicians commonly see patients with this virus, but know little about it and are trying to understand the burden of disease caused by human metapneumovirus.

MPV was first described in 2001 and there are no specific treatments or vaccines for it other than supportive care for bronchiolitis, such as oxygen, bronchodilators and intravenous fluids.

– by Carole Bartoo

 

Partnering to understand sickle cell disease

Researchers from the Monroe Carell Jr. Children’s Hospital at Vanderbilt and Aminu Kano Teaching Hospital in Kano, Nigeria, are collaborating on a study of sickle cell disease treatment for children in Nigeria.

The National Institutes of Health (NIH) awarded the project a two-year, $281,490 grant (grant No. 1R21NS080639-01). The funding will be used to investigate the effectiveness of the drug hydroxyurea as a primary prevention of stroke among children with sickle cell disease, an inherited blood disorder, in Nigeria. Stroke can be a complication in

patients with sickle cell disease. Hydroxyurea is often given to patients with sickle cell disease as part of a maintenance protocol to prevent pain episodes, another complication associated with the disease.

The principal investigators for the study are Michael DeBaun, M.D., MPH, vice chair of Clinical Research for Vanderbilt’s Department of Pediatrics and J.C. Peterson, M.D. Professor of Pediatric Pulmonology; Lori Jordan, M.D., Ph.D., assistant professor in Neurology, and Muktar Aliyu, MBBS, MPH, Dr.PH, assistant professor of Preventive Medicine in the Vanderbilt Institute for Global Health.

Nigeria has the largest burden of sickle cell disease in the world with an estimated 150,000 people living with the condition. Yet the most common therapy for the disease, recurrent blood transfusions, is not readily available. The newly funded trial could help researchers determine if hydroxyurea would prove to be an alternative treatment to frequent blood transfusions to prevent the occurrence of stroke in children at risk. Sickle cell disease is the most common cause of stroke in children.

– by Christina Echegaray