Global health is often hampered by the fact that not enough specimens get to testing sites in a timely manner. A review article in Clinical Infectious Diseases describes two approaches that improved the process of specimen referral in areas of the world with limited resources.
To fully prepare for disease outbreaks, experts have placed increasing importance on improving the efficiency of laboratory networks and disease surveillance systems. “However, it will be an uphill task to establish functional laboratories at all tiers of the healthcare systems in developing countries,” according to the study’s authors.
“Strengthening specimen referral networks is critical to serve the entire healthcare delivery system and establish preparedness strategies for effective disease control and prevention,” they said. This coordinated approach involves the safe transfer of a patient specimen from a resource-scare lab or health facility to a facility with the capability to conduct the needed test(s) and provide timely, reliable results.
Such systems require a platform strategy that enables them to address a number of different disease programs. The platform comprises a tiered laboratory structure that “reflects varying complexity of tests performed in each tier, with decreasing test complexities toward the lower tier within a country healthcare structure,” the authors explained.
The review authors describe two models for developing these types of referral networks. One of the models, used in Ethiopia and Haiti, is based on a decentralized approach, whereas a model in Uganda, employed a centralized approach.
Both systems led “to reduced turnaround time and retain flexibility for integrating different specimen types,” the authors said.
The Ethiopian model was pilot tested in two locations, using a tiered laboratory approach to transfer specimen results back and forth between a central private laboratory, the International Clinical Laboratory in Addis Ababa, to a series of Ministry of Health laboratories. Specimen samples included dried blood spots to test for early infant HIV diagnosis (EID), plasma for viral load, sputum for tuberculosis, whole blood for CD4, and hematology, and serum for chemistry to monitor antiretroviral load.
The approach, which evolved from a pilot project to the establishment of referral network system across all regions in Ethiopia, “reduced the one-way distance from referral sites to testing laboratory from an average of 80 km to 32 km, with a 60% cost savings,” the authors reported.
In other similar systems, Haiti’s decentralized system led to a more than 180% rise in enrollment of immunodeficiency virus treatment programs. Access to CD4 cell count testing also rose by 315%. Another network in Vietnam had success in improving access to tuberculosis testing and treatments.
Uganda’s centralized model used a “hub and spoke” system, in which the Central Public Health Laboratories (CPHL) in Kampala served as the central point or “hub” for collecting specimens from the “spokes,” or referring sites.
The referral network was able to reduce costs by 62%, dramatically reducing turnaround time for both EID and tuberculosis testing from 1 to 2 months to 5 to 10 days, and from 21 days to 3 days, respectively. “The success of the hub-and-spoke specimen referral network model made it possible to include other specimen types for CD4, viral load, hematology, chemistry, tuberculosis, and outbreak-related specimens,” the authors said.
All of these results suggest that “a platform strategy will create a network effect that will benefit multiple disease programs,” the authors concluded.
Any type of referral system needs tailoring to fit the needs of a specific local population, David W. Dowdy, MD, of the Johns Hopkins Bloomberg School of Public Health, wrote in a related editorial. What the review article authors provide is “an important first step, illustrating how specimen referral systems can be effectively implemented in resource-limited, high-burden settings,” Dowdy noted.
Successfully implementing these types of networks requires more proactive efforts from the infectious disease community, he emphasized.
“It is no longer sufficient to understand how specimen referral systems can work, nor to argue in the abstract about why they are important,” Dowdy said. “We must undertake formal studies to quantify the benefits of specimen referral systems and demonstrate their value for money.”