Methods and definitions
Reporting
Epidemiological week
Weeks start on a Sunday and end on a Saturday, 52 or 53 to a year. Week 1 is the first week with at least four days in January, so it can start in December. Epi week 37 of 2026 ran from 13 to 19 September.
Sentinel surveillance
Selected health facilities, called sentinel sites, form a network that reports on set health conditions every week. Reporting is mandatory whether or not there are cases. Jamaica has 78 sentinel sites, hospitals and health centres across the island. Health centres report syndromes only; hospitals also report additional syndromes and diseases.
Syndromic surveillance
Sentinel sites report visits by syndrome, a set of signs and symptoms, rather than by confirmed diagnosis. This allows early detection of, and response to, public health events.
On-time reports
Parish health departments submit sentinel reports by 3 p.m. on Tuesday. Reports after 3 p.m. are late. The bulletin shows each parish’s record for the last four weeks.
Hospital active surveillance
Proactive case finding by regularly reviewing medical records, laboratory reports and patient admissions, at 31 hospitals, rather than waiting for cases to be reported.
Thresholds
Mean + 2 SD
The epidemic threshold: the weekly mean plus two standard deviations.
Epidemic threshold
The mean number of cases reported per week plus two standard deviations. It is used to confirm the emergence of an epidemic, so that control measures can start.
Alert threshold
A lower line on the same charts, giving earlier warning that cases are rising.
Dengue activity levels
Weekly dengue cases are compared with the seasonal mean, which marks low activity, and the seasonal mean plus two, four and six standard deviations, which mark medium, high and very high activity.
COVID-19 positivity
Positive samples divided by all samples tested. The rate sets the level of transmission, from low to very high.
Classifying cases
Class 1 notifiable event
The highest priority, because of the potential to cause high illness and death rates. Health care providers report it immediately on suspicion to the Medical Officer of Health at their parish health department, or to the National Surveillance Unit, within 24 hours of contact, and each is investigated.
Class 2 notifiable disease
Reported weekly on a line listing to the Medical Officer of Health at the parish health department. Class 2 diseases are dengue fever, influenza and hepatitis A. While dengue is under enhanced surveillance, every suspected case is notified as Class 1.
Class 3 notifiable disease
Reported as monthly totals to the Medical Officer of Health at the parish health department; a line listing may also be used. Most are sexually transmitted or food-borne infections.
Confirmed and probable dengue
Only cases confirmed by RT-PCR are reported as confirmed. Suspected cases with a positive IgM or NS1 result, or a clinical-epidemiological link, are probable.
Clinically confirmed
Pertussis-like syndrome and tetanus are confirmed on clinical grounds.
Chikungunya and Zika
Chikungunya figures are IgM positive cases; Zika figures are PCR positive cases.
Maternal deaths
All notified deaths associated with pregnancy for the period.
Acute flaccid paralysis (AFP)
AFP is monitored to detect possible cases of polio. The indicator Jamaica reports to PAHO/WHO, to keep its certification as having eliminated polio, is detection of at least 1 case of AFP per 100,000 population under 15 years old.
Counting and revisions
Year to date (YTD)
Cumulative totals for all epidemiological weeks of the year so far, shown beside the previous year’s.
Updates to earlier weeks
Late reports are counted in the week they belong to, so figures for earlier weeks can change. The bulletin marks figures that were updated.
Dates used
Dengue cases are counted by date of symptom onset and dengue deaths by date of death.
NA
Not available.
Syndrome case definitions
The definitions sentinel sites use for weekly reporting, as the National Surveillance Manual gives them.
Undifferentiated fever
A person presenting with a body temperature of ≥38°C/ 100.4°F (or recent history of fever) without an obvious diagnosis or focus of infection. A person may also have headache, retro-orbital pain, myalgia, arthralgia, nausea or vomiting but without any symptoms fitting another syndromic definition.
Fever and rash
Fever (≥38°C or 100.4°F) (or recent history of fever) and a maculopapular rash.
Gastroenteritis
A person presenting with 3 or more loose stools within 24 hours.
Fever and respiratory symptoms (influenza-like illness)
A body temperature of ≥38°C/ 100.4°F (or recent history of fever) and cough in a previously healthy person who does not require admission.
Fever and haemorrhagic symptoms
A body temperature of ≥38°C/ 100.4°F (or recent history of fever) in a previously healthy person presenting with at least one haemorrhagic (bleeding) manifestation with or without jaundice (e.g. haematemesis or purpura or haemoptysis or melena).
Fever and neurological symptoms
Hospital sentinel sites only
A body temperature of ≥38°C/ 100.4°F (or recent history of fever) in a previously healthy person with or without headache and vomiting. The person must also have meningeal irritation, convulsions, altered consciousness, altered sensory manifestations or paralysis (except AFP).
Fever and jaundice
Hospital sentinel sites only
A body temperature of ≥38°C/ 100.4°F (or recent history of fever) in a previously healthy person presenting with jaundice.
Accidents
Any injury for which the cause is unintentional, e.g. motor vehicle accident, falls, burns, etc.
Violence
Any injury for which the cause is intentional, e.g. gunshot wounds, stab wounds, etc.
Notifying a Class 1 event
The case definitions for each Class 1 event, and the forms for notifying them, are under Resources.
Need data?
For figures not in the bulletin, send the National Surveillance Unit a data request.