HL7 and FHIR in Africa: Why Health IT Interoperability Standards Matter for Cameroon Hospitals

What Is HL7 and What Is FHIR?

HL7 — Health Level 7 — is an international standards organisation founded in 1987 that develops frameworks and standards for the exchange, integration, sharing, and retrieval of electronic health information. The "Level 7" refers to the seventh layer of the OSI communications model (the application layer), indicating that HL7 standards operate at the level of the healthcare application, not the underlying network infrastructure.

FHIR — Fast Healthcare Interoperability Resources, pronounced "fire" — is HL7's most recent and most widely adopted standard, released in its current stable form as FHIR R4 in 2019. FHIR defines a set of modular building blocks called "resources" — Patient, Observation, Encounter, MedicationRequest, DiagnosticReport, and approximately 150 others — that represent discrete clinical concepts. Each resource has a defined structure, a standard set of data fields, and can be exchanged over standard web protocols (REST, JSON, XML). FHIR is designed to be implementable by modern web developers without specialist health IT knowledge, which has dramatically accelerated its adoption globally.

Why Interoperability Matters for Healthcare Delivery

Interoperability — the ability of different health information systems to exchange and use data — is not a technical nicety. It has direct consequences for patient safety and care quality.

When a patient moves between a community clinic, a district hospital, and a referral centre, their clinical history should move with them. Without interoperability, the receiving facility starts from scratch: repeating investigations, re-taking history, risking drug interactions from unknown prior prescriptions. In Cameroon, where referral chains link peripheral centres, district hospitals, regional hospitals, and the two central university teaching hospitals (CHU de Yaoundé and CHU de Douala), the absence of electronic data exchange means that paper referral letters — often incomplete, sometimes lost — are the only information transfer mechanism.

At the national level, interoperability enables individual facility records to contribute to population health databases like DHIS2, national patient registries, disease surveillance systems, and supply chain management platforms — without duplicate data entry at every level.

HL7 v2 vs HL7 v3 vs FHIR R4: Practical Differences

Understanding which version of HL7 is relevant requires a brief orientation:

For practical purposes in Africa: HL7 v2 is still widely used by laboratory analysers and legacy systems for transmitting results; HL7 v3 is largely bypassed in favour of FHIR; and FHIR R4 is the current target standard for new implementations and donor-funded digital health programmes.

Use Cases for HL7 and FHIR in Cameroon and the CEMAC Region

Several concrete use cases illustrate why these standards matter for Cameroon hospitals today and in the near future:

Laboratory Results Sharing Between Facilities

A patient's blood sample is processed at a reference laboratory in Yaoundé. Using HL7 v2 lab result messages or FHIR DiagnosticReport resources, the result is returned electronically to the ordering facility in Bafoussam — immediately, accurately, and without risk of transcription error from a phone call or paper fax.

Electronic Referral and Patient Summary

When a district hospital refers a patient to a regional hospital, the referral could include a structured FHIR document — patient demographics, active diagnoses, current medications, recent investigation results — that the receiving facility's HMS can import directly into the new patient record.

Submission of Structured Data to DHIS2

DHIS2 itself uses a REST API with JSON payloads for data import. While not strictly FHIR-compliant, DHIS2's architecture is conceptually aligned with the REST-and-JSON approach that FHIR R4 uses, making the technical bridge straightforward for systems already implementing FHIR.

National Patient Identity Matching

A unique patient identifier — linked across facilities through a national Client Registry using the HL7 FHIR Patient resource — would allow any participating facility to retrieve a patient's prior records by querying the central registry. This is the long-term vision; the infrastructure is being built incrementally in several African countries.

Donor-Funded Programme Reporting

PEPFAR, the Global Fund, and GAVI-funded programmes increasingly specify FHIR-compliant data submission as a requirement for digital health tools procured under their programmes. HMS vendors seeking to participate in these markets must demonstrate FHIR capability.

OpenHIE: The Architecture Framework for African Health Information Exchange

OpenHIE — the Open Health Information Exchange — is a collaborative community that defines a reference architecture for national-scale health information exchange, widely adopted across sub-Saharan Africa. The OpenHIE architecture defines a set of interacting components:

• Interoperability Layer (IL) — a central health information mediator (typically OpenHIM) that routes, transforms, and validates messages between systems
• Shared Health Record (SHR) — a longitudinal patient health record repository
• Client Registry (CR) — a master patient index that assigns and resolves unique patient identifiers
• Facility Registry (FR) — a master list of all health facilities with their identifiers
• Terminology Service — a repository of standardised clinical codes (ICD-10, SNOMED, LOINC)
• Health Management Information System (HMIS) — typically DHIS2

Cameroon's national digital health architecture, under development with support from international partners, draws on OpenHIE principles. Health facilities that implement FHIR-compliant HMS platforms will be positioned to connect to this architecture as it matures — without requiring a system replacement.

Barriers to HL7/FHIR Adoption in the CEMAC Region

Despite the clear value of interoperability standards, adoption in Cameroon and the broader CEMAC region faces real barriers:

Technical capacity — implementing FHIR APIs requires software developers with specific skills. Many local HMS vendors lack in-house FHIR expertise, and the pool of health informatics professionals in Cameroon is small. Building this capacity takes time and investment.

Cost — implementing and maintaining standards-compliant interfaces adds to development and hosting costs. For small facilities or small HMS vendors, the incremental cost may be difficult to justify in the short term.

Absence of a national HIE to connect to — interoperability standards deliver maximum value when there is a functioning health information exchange to connect to. Where that infrastructure does not yet exist (or exists only partially), the incentive to invest in FHIR compliance is lower.

Data governance gaps — sharing patient data across facilities requires clear legal frameworks for patient consent, data ownership, and privacy protection. Cameroon's data protection landscape is evolving, and uncertainties may slow cross-facility data sharing even where technical capability exists.

Connectivity — standards-based data exchange over REST APIs requires reliable internet connectivity, which remains inconsistent across Cameroon, particularly outside major urban centres.

What a Cameroon HMS Must Support Today: Practical Minimum

Given the barriers above, what is the realistic minimum that a Cameroonian HMS should support now, with a credible path toward fuller interoperability?

The practical minimum includes:

• Structured data capture with standard codes — ICD-10 for diagnoses, standard laboratory test codes, standard medication names. Without structured coded data at the source, no amount of API capability produces useful interoperable output.
• DHIS2 API integration — the most immediately useful interoperability in Cameroon today, with a live national system to connect to.
• Data export in standard formats — the ability to export patient data in JSON or XML formats compatible with FHIR resources, even if a live FHIR API is not yet maintained.
• Unique patient identification — assigning and preserving a consistent patient ID within the facility, as the building block for future national patient identity linkage.
• Documented API — an HMS that provides a documented API allows future integration with national HIE components as they are deployed, without requiring the HMS to be replaced.

FHIR API Requirements for Donor-Funded Programmes

Hospitals participating in PEPFAR-funded HIV programmes, Global Fund TB or malaria grants, or GAVI-supported immunisation programmes increasingly face requirements from their programme implementing partners for electronic data submission. The PEPFAR MER (Monitoring, Evaluation and Reporting) framework and the Global Fund's information systems guidance both reference FHIR as the target standard for data exchange.

For Cameroonian facilities in donor-funded programmes, this creates a practical incentive: an HMS that can produce FHIR-formatted data submissions is increasingly a prerequisite for programme participation, or at minimum simplifies the compliance reporting burden significantly.

How OPES HMS Approaches Interoperability

OPES Health Management System is designed with interoperability as a core architectural principle, not an afterthought. The OPES data model uses ICD-10 coded diagnoses, standardised medication naming, and structured demographic fields — the prerequisite for any meaningful data exchange. The DHIS2 integration module provides the most immediately relevant interoperability for Cameroon's national reporting requirements.

OPES maintains a documented internal API that allows integration with external systems, including laboratory instruments transmitting results via HL7 v2 messages, and third-party analytics or programme management platforms. The roadmap for OPES includes FHIR R4 resource endpoints for patient, encounter, and diagnostic report data — enabling connection to national HIE infrastructure as Cameroon's digital health architecture matures.

For hospital directors evaluating HMS options, the right question about interoperability is not whether a system is "FHIR compliant" in the abstract, but whether it uses structured, coded data at the point of care, whether it can connect to DHIS2 today, and whether its architecture allows future integration without system replacement. OPES is designed to meet all three criteria — giving Cameroonian facilities a credible path from today's reporting requirements to tomorrow's interoperable health system.