Table 1. Case definitions for major infectious disease syndromes from clinic and household morbidity surveillance (HMS) in Asembo, western Kenya.

Syndrome	Clinic definition	Household definition
Acute respiratoryinfection (ARI)	(≥1 symptom): cough, difficulty breathing, chest pain, sore throat, sneezing, ear complaintsor runny nose	cough or difficulty breathing
Acute LowerRespiratoryInfection (ALRI)	cough or difficulty breathing with one of the following: elevated respiratory rate for age*(non-severe pneumonia;) or IMCI danger sign†, lower chest wall indrawing, stridor, or oxygensaturation <90% (severe/very severe pneumonia)	cough or difficulty breathing and rapid respiration for age* or chest indrawing noted on exam
Diarrhea	≥3 looser than normal stools in a 24 hour period. Severe defined as IMCI danger sign orsymptom/sign dehydration‡	≥3 looser than normal stools in a 24 hour period
Acute FebrileIllness (AFI)	documented axillary temperature ≥38.0°C without an obvious cause, defined as cough,difficulty breathing, chest pain, signs of meningitis, or bloody diarrhea (positivemalaria smear is not an exclusion)	report of fever, without evidence of another infection defined as cough or difficulty breathing or bloody diarrhea

*Elevated respiratory rate for age based on WHO Integrated Management of Childhood Illness algorithm [14]; <2 months, ≥60 breaths/minute; 2–11 months, ≥50 breaths/minute; 12–59 months, ≥40 breaths/minute.

^†IMCI danger signs are maternal report of convulsions, inability to drink or breastfeed, or vomiting everything, or on exam lethargy or unconsciousness [22].

^‡IMCI signs/symptoms of dehydration are the following: sunken eyes, slow skin pinch, restless/irritable behavior, drinking eagerly or not at all [22].