Combat zone work

OH4 records periods of combat zone service for a patient. It captures start and end dates of deployment, the entry date, and a unique identifier. It supports veteran health screening, exposure tracking, and benefits eligibility workflows.

Set the start and end dates for the deployment:

from zato.hl7v2.v2_9 import OH4

oh4 = OH4()
oh4.set_id = '1'
oh4.combat_zone_start_date = (
    '20150301'
)
oh4.combat_zone_end_date = '20160901'
oh4.entered_date = '20240601'

The combat_zone_unique_identifier field uses the EI datatype:

from zato.hl7v2.v2_9 import OH4, EI

oh4 = OH4()
oh4.combat_zone_unique_identifier = EI(
    entity_identifier='OH4-2024-001',
    namespace_id='MAIN'
)

Omit the end date to indicate the deployment is still active:

from zato.hl7v2.v2_9 import OH4

oh4 = OH4()
oh4.set_id = '1'
oh4.combat_zone_start_date = (
    '20230901'
)
oh4.entered_date = '20240101'

The action_code field accepts standard HL7 action codes:

from zato.hl7v2.v2_9 import OH4

oh4 = OH4()
oh4.set_id = '1'
oh4.action_code = 'AD'

oh4_del = OH4()
oh4_del.set_id = '2'
oh4_del.action_code = 'DE'

Zato connects to any system that speaks HL7v2 over MLLP or FHIR over REST. This includes Epic, Cerner, Meditech, Allscripts, and other EHR platforms.

Yes, Zato has built-in MLLP support for sending and receiving HL7v2 messages. MLLP channels handle the framing protocol automatically.

Zato supports HL7 v2.9, which is backward compatible with earlier versions including v2.3, v2.5, and v2.7. Standard segments and datatypes are available as typed Python classes.

Yes. Zato handles both HL7v2 and FHIR natively, so you can parse v2 messages and build FHIR resources with IG-specific extensions in the same service. Typed Python classes are available for both protocols, including extensions from US Core, UK Core, Da Vinci, and other Implementation Guides.