WHO Essential Diagnostics List Research Articles

Availability of essential diagnostics in ten low-income and middle-income countries: results from national health facility surveys

SummaryBackgroundPathology and laboratory medicine diagnostics and diagnostic imaging are crucial to achieving universal health coverage. We analysed Service Provision Assessments (SPAs) from ten low-income and middle-income countries to benchmark diagnostic availability.MethodsDiagnostic availabilities were determined for Bangladesh, Haiti, Malawi, Namibia, Nepal, Kenya, Rwanda, Senegal, Tanzania, and Uganda, with multiple timepoints for Haiti, Kenya, Senegal, and Tanzania. A smaller set of diagnostics were included in the analysis for primary care facilities compared with those expected at hospitals, with 16 evaluated in total. Surveys spanned 2004–18, including 8512 surveyed facilities. Country-specific facility types were mapped to basic primary care, advanced primary care, or hospital tiers. We calculated percentages of facilities offering each diagnostic, accounting for facility weights, stratifying by tier, and for some analyses, region. The tier-level estimate of diagnostic availability was defined as the median of all diagnostic-specific availabilities at each tier, and country-level estimates were the median of all diagnostic-specific availabilities of each of the tiers. Associations of country-level diagnostic availability with country income as well as (within-country) region-level availability with region-specific population densities were determined by multivariable linear regression, controlling for appropriate covariates including tier.FindingsMedian availability of diagnostics was 19·1% in basic primary care facilities, 49·2% in advanced primary care facilities, and 68·4% in hospitals. Availability varied considerably between diagnostics, ranging from 1·2% (ultrasound) to 76·7% (malaria) in primary care (basic and advanced) and from 6·1% (CT scan) to 91·6% (malaria) in hospitals. Availability also varied between countries, from 14·9% (Bangladesh) to 89·6% (Namibia). Availability correlated positively with log(income) at both primary care tiers but not the hospital tier, and positively with region-specific population density at the basic primary care tier only.InterpretationMajor gaps in diagnostic availability exist in many low-income and middle-income countries, particularly in primary care facilities. These results can serve as a benchmark to gauge progress towards implementing guidelines such as the WHO Essential Diagnostics List and Priority Medical Devices initiatives.FundingBill & Melinda Gates Foundation.

Diagnosis of histoplasmosis: current status and perspectives.

Histoplasmosis is a worldwide-distributed systemic mycosis caused by the dimorphic fungus Histoplasma capsulatum. Its clinical manifestations range from subclinical or mild respiratory illness to progressive disseminated histoplasmosis (PDH), a life-threatening disease, whose accurate diagnosis is still challenging and limited in many countries, where this disease is highly endemic. In this regard, Histoplasma antigen testing is now included in the WHO Essential Diagnostics List. The final diagnosis of histoplasmosis is established by culture and/or visualization of the yeast cells by cytology or histopathology using specific stains. However, both procedures have limited sensitivity to detect the disease and cultures are time-consuming. Antibody detection assays are effective for the subacute and chronic clinical forms of histoplasmosis. However, their sensitivity is low in the immunocompromised host. Several molecular "in-house" tests were also developed and showed promising results, but none of these tests are commercially available and their standardization and validation are still pending. Antigen detection assays have high sensitivity in PDH cases and are of great value for the follow-up of patients with histoplasmosis; however, cross-reactivity with other related fungi are common. In addition, this assay is expensive and only performed in few laboratories. Novel protein antigen candidates have been recently identified and produced by DNA-recombinant techniques in order to obtain standardized and specific reagents for the diagnosis of histoplasmosis, as opposed to the unspecific antigens or crude extracts currently used. This review describes the currently available assays, highlighting their strengths and limitations and reports the latest approaches to achieve reliable and rapid diagnostic tests for histoplasmosis. KEY POINTS: • PDH causes thousands of deaths per year globally. • Rapid accurate diagnosis of PDH is unfeasible in many regions. • Fast, accurate, and low-cost diagnostic alternatives are currently under development.

Availability and Prices of WHO Essential Diagnostics in Laboratories in West Africa: A Landscape Survey of Diagnostic Testing in Northern Ghana.

We determined the availability and pricing of laboratory testing in the Northern Region of Ghana to identify current gaps with respect to the WHO's Essential Diagnostics List (EDL). A representative sample of facilities offering diagnostic testing within the Northern Region was geographically mapped and evaluated, with random sampling stratified by population density. Data were collected on testing menus, volumes, turn-around times, and out-of-pocket test prices. A total of 27 health centers and 39 clinical laboratories were surveyed between June and August 2019. Health centers offered a median of 2 of 20 tests recommended by the WHO for facilities without laboratories. The most common tests offered included point-of-care tests for malaria, HIV, and pregnancy. Clinical laboratories offered a median of 11 of 72 tests on the EDL. These facilities most commonly provided testing for malaria, HIV, pregnancy, HBsAg, urinalysis, HCV Ab, syphilis, glucose, and CBC. Urban laboratories had a total of 36 EDL tests available while rural laboratories had 12. Test prices were higher in private compared to public laboratories. National Health Insurance reimbursements were lower than out-of-pocket prices (38%), and when controlling for test price, test availability was negatively associated with this gap in reimbursement. Availability of diagnostic testing in Ghana's Northern Region is severely limited compared to the WHO's EDL. The disparity is pronounced in rural facilities. Reimbursement rates should be reset to more closely match out-of-pocket test prices in order to achieve the Universal Health Coverage target of the Sustainable Development Goals.

Effective coding is key to the development and use of the WHO Essential Diagnostics List

Effective coding is key to the development and use of the WHO Essential Diagnostics List

The World Health Organization's Essential Diagnostics List: Diagnostics for neurologic disorders.

On the recommendation of the WHO Expert Committee on the Selection and Use of Essential Medicines in 2017, the inaugural WHO Essential Diagnostics List (EDL) was published by the WHO's Strategic Advisory Group of Experts on In-Vitro Diagnostics in May 2018.1 The EDL seeks to improve global treatment by providing “a catalogue of tests needed to diagnose both the most common conditions worldwide and diseases of global importance in both primary care and advanced settings.”1,2 This first iteration of the EDL includes diagnostic tests enabling the use of medications on the WHO Essential Medicines List (EML), which has guided international policies and funding decisions for the last 4 decades.3 Yet there is little representation of neurologic treatments on the EML, including a lack of medications for dementia, multiple sclerosis, neuropathic pain, and movement disorders, as well as commonly used medications for migraine such as triptans (table).4