Table 1 Study definitions
Clinical signs | Â |
 Tachycardia | A high pulse rate for age (age: 2-11 m, > 160 beats/min; 12-47 m, > 130 beats/min; 48 m-5y, > 120 beats/min; 6-8y, > 115 beats/min; 9-12y, > 110 beats/min) [28] |
 Tachypnea | A high respiratory rate for age (age: 2-11 m, ≥ 50 breaths/min; 12-59 m, ≥ 40 breaths/min; 5-12y, ≥ 30 breaths/min) [28] |
Illnesses | Â |
 Acute respiratory infection | Presentation with at least one respiratory sign or symptom of less than 14 days and localized to the respiratory tract (upper or lower) |
 Pneumonia | A history of cough and/or difficult breathing, plus sign of (a) tachypnea OR (b) chest findings OR (c) auscultatory findings OR (d) radiologic findings [28] |
 Acute tonsillopharyngitis | Presentation with (a) pharyngeal redness and enlarged tonsils or (b) neck lymph node and enlarged tonsils or (c) tonsillar exudate, which are suggestive of bacterial infection based on the national guidelines [28] |
 Unspecified upper respiratory tract infections | Presentation with at least one respiratory sign or symptom (e.g. cough, rhinorrhoea) in the absence of features consistent with other specified respiratory illnesses |
 Acute diarrhoea | Presentation with diarrhoea (stool frequency > 3 loose or liquid stools per day on at least one day in the week prior to enrolment) lasting less than 14 days [28] |
 Meningitis | Presentation with stiff neck, positive meningeal signs, or findings on cerebrospinal fluid analysis and diagnosed by clinicians as a case of meningitis [28] |
 Sepsis | The presence of systemic inflammation response syndrome with suspected or proven infection, or with some form of organ dysfunction [29] |
 Anaemia | A low haematocrit value for age (age: 2 m, < 28%; 3-6 m, < 29%; 7-24 m, < 33%; 25 m-6y, < 34%; 7-12y, < 35%) [30] |
 Malaria | A positive blood smear microscopy for asexual stage of Plasmodium species |
 Bloodstream infections (bacteraemia/candidaemia) | A positive blood culture for pathogenic bacteria/yeast cells |
Urinary tract infection | Urine culture showing a significant bacteriuria (≥ 105 and ≥ 104 colony-forming-unit/ml of urine collected by clean catch and urethral catheterization, respectively) [31] |
 Undifferentiated fever | Cases with no identified source of infection for the fever on clinical and laboratory investigations conducted |
Outcomes | Â |
 Resolved fever | Absence of fever for 2 consecutive days prior to day 7(± 1) / day 14(± 1) as reported by caregivers or measured temperature of 36.4ºC -37.5ºC |
 Persisting fever | Fever episode within 2 days prior to day 7(± 1) / day 14(± 1) as reported by caregivers or measured temperature of ≥ 37.5ºC |
 Relapsed fever | Fever reported at day 14(± 1) in a child who had resolved fever at day 7(± 1), potentially linked to the initial febrile illness |
 Hospitalization | Admission to hospital for treatment in relation to the presenting febrile illness |
Death | Mortality within 14(± 1) days follow-up period, and potentially linked to the initial febrile illness as judged by attending clinicians |