diff --git a/src/data/repositories/utils/DiseaseOutbreakMapper.ts b/src/data/repositories/utils/DiseaseOutbreakMapper.ts
index 660ce1fb..67a09203 100644
--- a/src/data/repositories/utils/DiseaseOutbreakMapper.ts
+++ b/src/data/repositories/utils/DiseaseOutbreakMapper.ts
@@ -74,23 +74,34 @@ export function mapTrackedEntityAttributesToDiseaseOutbreak(
             ),
             laboratoryConfirmation: {
                 date: new Date(getValueFromMap("laboratoryConfirmationDate", trackedEntity)),
-                na: getValueFromMap("laboratoryConfirmationNA", trackedEntity) === "true",
+                na:
+                    getValueFromMap("laboratoryConfirmationNA", trackedEntity) === "true"
+                        ? false
+                        : true,
             },
             appropriateCaseManagement: {
                 date: new Date(getValueFromMap("appropriateCaseManagementDate", trackedEntity)),
-                na: getValueFromMap("appropriateCaseManagementNA", trackedEntity) === "true",
+                na:
+                    getValueFromMap("appropriateCaseManagementNA", trackedEntity) === "true"
+                        ? false
+                        : true,
             },
             initiatePublicHealthCounterMeasures: {
                 date: new Date(
-                    getValueFromMap("initiatePublicHealthCounterMeasuresNA", trackedEntity)
+                    getValueFromMap("initiatePublicHealthCounterMeasuresDate", trackedEntity)
                 ),
                 na:
-                    getValueFromMap("initiatePublicHealthCounterMeasuresDate", trackedEntity) ===
-                    "true",
+                    getValueFromMap("initiatePublicHealthCounterMeasuresNA", trackedEntity) ===
+                    "true"
+                        ? false
+                        : true,
             },
             initiateRiskCommunication: {
                 date: new Date(getValueFromMap("initiateRiskCommunicationDate", trackedEntity)),
-                na: getValueFromMap("initiateRiskCommunicationNA", trackedEntity) === "true",
+                na:
+                    getValueFromMap("initiateRiskCommunicationNA", trackedEntity) === "true"
+                        ? false
+                        : true,
             },
             establishCoordination: new Date(
                 getValueFromMap("establishCoordination", trackedEntity)
@@ -165,7 +176,7 @@ function getValueFromDiseaseOutbreak(
 ): string {
     switch (key) {
         case "RTSL_ZEB_TEA_EVENT_id":
-            return diseaseOutbreak.eventId.toString();
+            return diseaseOutbreak.eventId?.toString() || "";
         case "RTSL_ZEB_TEA_EVENT_NAME":
             return diseaseOutbreak.name;
         case "RTSL_ZEB_TEA_HAZARD_TYPE":
@@ -213,7 +224,7 @@ function getValueFromDiseaseOutbreak(
         case "RTSL_ZEB_TEA_LABORATORY_CONFIRMATION":
             return diseaseOutbreak.earlyResponseActions.laboratoryConfirmation.na ? "true" : "";
         case "RTSL_ZEB_TEA_SPECIFY_DATE1":
-            return diseaseOutbreak.earlyResponseActions.laboratoryConfirmation.date.toISOString();
+            return diseaseOutbreak.earlyResponseActions.laboratoryConfirmation.date?.toISOString();
         case "RTSL_ZEB_TEA_APPROPRIATE_CASE_MANAGEMENT":
             return diseaseOutbreak.earlyResponseActions.appropriateCaseManagement.na ? "true" : "";
         case "RTSL_ZEB_TEA_SPECIFY_DATE2":
diff --git a/src/domain/entities/ValidationError.ts b/src/domain/entities/ValidationError.ts
new file mode 100644
index 00000000..68ea0518
--- /dev/null
+++ b/src/domain/entities/ValidationError.ts
@@ -0,0 +1,11 @@
+export type ValidationErrorKey =
+    | "field_is_required"
+    | "field_is_required_na"
+    | "detected_before_emerged"
+    | "notified_before_emerged";
+
+export type ValidationError = {
+    property: string;
+    value: unknown;
+    errors: ValidationErrorKey[];
+};
diff --git a/src/domain/entities/disease-outbreak-event/DiseaseOutbreakEvent.ts b/src/domain/entities/disease-outbreak-event/DiseaseOutbreakEvent.ts
index 20275af3..07861bb2 100644
--- a/src/domain/entities/disease-outbreak-event/DiseaseOutbreakEvent.ts
+++ b/src/domain/entities/disease-outbreak-event/DiseaseOutbreakEvent.ts
@@ -6,6 +6,7 @@ import { OrgUnit } from "../OrgUnit";
 import { Id, NamedRef } from "../Ref";
 import { RiskAssessment } from "../risk-assessment/RiskAssessment";
 import { Maybe } from "../../../utils/ts-utils";
+import { ValidationError, ValidationErrorKey } from "../ValidationError";
 
 export type HazardType =
     | "Biological:Human"
@@ -38,7 +39,7 @@ type EarlyResponseActions = {
 };
 
 export type DiseaseOutbreakEventBaseAttrs = NamedRef & {
-    eventId: number;
+    eventId: Maybe<number>;
     created: Date;
     lastUpdated: Date;
     createdByName: Maybe<string>;
@@ -52,12 +53,12 @@ export type DiseaseOutbreakEventBaseAttrs = NamedRef & {
     emerged: DateWithNarrative;
     detected: DateWithNarrative;
     notified: DateWithNarrative;
-    earlyResponseActions: EarlyResponseActions; //TO DO : mandatory field
+    earlyResponseActions: EarlyResponseActions;
     incidentManagerName: string;
     notes: Maybe<string>;
 };
 
-type DiseaseOutbreakEventAttrs = DiseaseOutbreakEventBaseAttrs & {
+export type DiseaseOutbreakEventAttrs = DiseaseOutbreakEventBaseAttrs & {
     createdBy: Maybe<TeamMember>;
     mainSyndrome: NamedRef;
     suspectedDisease: NamedRef;
@@ -76,7 +77,45 @@ type DiseaseOutbreakEventAttrs = DiseaseOutbreakEventBaseAttrs & {
  **/
 
 export class DiseaseOutbreakEvent extends Struct<DiseaseOutbreakEventAttrs>() {
-    static validateEventName() {
-        //TO DO : Ensure event name is unique on event creation.
+    //TODO: Add required validations, this is an example:
+    static validate(data: DiseaseOutbreakEventBaseAttrs): ValidationError[] {
+        const validationErrors: ValidationError[] = [
+            {
+                property: "detected_date" as const,
+                errors: DiseaseOutbreakEvent.validateDateDetectedBeforeEmerged(data),
+                value: data.id,
+            },
+            {
+                property: "notified_date" as const,
+                errors: DiseaseOutbreakEvent.validateDateNotifiedBeforeEmerged(data),
+                value: data.id,
+            },
+        ];
+
+        const filteredValidationErrorsWithErrors = validationErrors.filter(
+            v => v.errors.length > 0
+        );
+
+        return filteredValidationErrorsWithErrors.length ? validationErrors : [];
+    }
+
+    static validateDateDetectedBeforeEmerged(
+        data: DiseaseOutbreakEventBaseAttrs
+    ): ValidationErrorKey[] {
+        return data.detected.date &&
+            data.emerged.date &&
+            data.detected.date.getTime() < data.emerged.date.getTime()
+            ? ["detected_before_emerged"]
+            : [];
+    }
+
+    static validateDateNotifiedBeforeEmerged(
+        data: DiseaseOutbreakEventBaseAttrs
+    ): ValidationErrorKey[] {
+        return data.notified.date &&
+            data.emerged.date &&
+            data.notified.date.getTime() < data.emerged.date.getTime()
+            ? ["notified_before_emerged"]
+            : [];
     }
 }