Clinical presentation and response to treatment of novel influenza A H1N1 in a university-based summer camp population.
BACKGROUND
Little is known about the clinical presentation and course of novel H1N1 influenza in summer camps.


OBJECTIVE
To describe the clinical course and evaluate the effect of influenza treatment in a summer camp population.


METHODS
Two large influenza outbreaks occurred in university-based residential camps between May 21 and August 2, 2009. Through active daily surveillance, medical evaluation at symptom onset, and data collection during isolation, we describe the clinical course of a large outbreak of novel H1N1 influenza.


RESULTS
Influenza-like illness (ILI) was documented in 119 individuals. Influenza A was confirmed in 66 (79%) of 84 samples tested. Three early samples were identified as novel H1N1. ILI cases had an average age of 15.7 years and 52% were male. Sixty-three were treated with oseltamivir or zanamivir, which was initiated within 24h of diagnosis. Cough, myalgia and sore throat occurred in 69, 64 and 63% of cases, respectively. The highest temperature over the course of illness (T(max)) occurred within 48h after symptom onset in 87.5% of individuals. Average T(max) was 38.4 degrees C (range 36.1-40.2 degrees C). Among confirmed influenza cases, 69% defervesced by 72h and 95% defervesced by 96h. Defervescence at 72h was not different in the treated and untreated groups (p=0.12).


CONCLUSIONS
Novel H1N1 generally has a mild, self-limited course in healthy adolescent campers. Defervescence occurred within 72h and was unaffected by treatment.
Tsalik
Ephraim L
EL
Duke University Medical Center, Department of Internal Medicine, Durham, NC 27710, USA.
Hendershot
Edward F
EF
Sangvai
Devdutta G
DG
Cunningham
Hannah M
HM
Cunningham
Coleen K
CK
Lopez-Marti
Maria G
MG
Purdy
William K
WK
Woods
Christopher W
CW
Caram
L Brett
LB
D000293:Adolescent; D000998:Antiviral Agents / Q000627:therapeutic use; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000302:isolation & purification*; D007251:Influenza, Human / Q000188:drug therapy* / Q000453:epidemiology / Q000473:pathology* / Q000821:virology; D008297:Male; D053139:Oseltamivir / Q000627:therapeutic use; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology; D053243:Zanamivir / Q000627:therapeutic use
D000998:Antiviral Agents; D053139:Oseltamivir; D053243:Zanamivir