Evaluation of the initial 12 months of a routine cryptococcal antigen screening program in reduction of HIV-associated cryptococcal meningitis in Uganda

A cross-sectional study evaluating the screening, diagnosis and management of advanced HIV disease at the AIDS support organization service centre in Mbarara City, Southwestern Uganda

INTRODUCTION

Uganda has made significant progress in expanding access to ART over the years, however, currently up to 50% of People Living with HIV still enroll into HIV care with Advanced HIV Disease (AHD). This study therefore seeks to evaluate the screening, diagnosis and treatment of AHD at a high volume not for profit health facility in an urban setting in Southwestern Uganda.

METHODS

A cross-sectional study utilizing secondary data from a high volume, nonprofit health facility in southwestern Uganda was conducted from April 2022 to August 2022. The analysis included patient records for 994 newly diagnosed individuals and 76 patients who were not virologically suppressed. A descriptive analysis of the data was conducted, and the two groups (newly diagnosed and non-suppressed) were compared using chi-square tests or Fisher's exact test for categorical data, as well as the Mann Whitney U test for numerical data.

RESULTS

The prevalence of AHD as defined by a CD4 + cell count below 200 cells/mm3 or WHO clinical stage 3 or 4 disease was 21.7% (216/994). The prevalence of AHD was considerably higher among males (32.5%) compared to females (13.9%) (p value < 0.001). CD4 + testing for AHD was at 74.5% (741/994) among newly enrolled patients compared to 77.6% (59/76) among virally non suppressed patients (p = 0.822). Serum CrAg testing among patients with AHD was higher among the newly enrolled HIV clients at 60.6% (131/216) compared to non-suppressed clients; 22.2% (6/27) (p < 0.001). Additionally, there was no significant difference in administration of fluconazole between the two groups (p = 0.476). Among the patients with AHD, the proportion of patient tested for TB using urine TB_LAM was higher among the newly enrolled patients (45.9%) compared to the non-suppressed clients (21.4%), and this difference was statistically significant (p = 0.010).

CONCLUSION

This study demonstrates that the prevalence of AHD remains high, and the implementation of the AHD intervention package remains sub-optimal. The Ministry of Health and partners need to strengthen implementation strategies to improve the screening, diagnosis, and management of AHD.

Systematic review on the compliance of WHO guidelines in the management of patients with advanced HIV disease in Africa: The case of cryptococcal antigen screening

BACKGROUND

The World Health Organization (WHO) recommended cryptococcal antigen (CrAg) screening for people presenting with advanced HIV disease (AHD) and for those with positive CrAg without evidence of meningitis to initiate preemptive antifungal medication. Data on the implementation of WHO recommendations regarding CrAg screening is limited. We estimated pooled prevalence of CrAg screening uptake, cryptococcal antigenemia, lumbar puncture, cryptococcal meningitis and initiation of preemptive antifungal medication from available eligible published studies conducted in Africa.

METHODS

PubMed, Cochrane Library and Embase were searched for articles published between January 2011 and December 2023. CrAg uptake was defined as percentage of eligible people (CD4 ≤ 200 cells/mm3 or WHO stage III/IV) who received cryptococcal antigen testing. Stratified analysis to compare uptake and cryptococcal antigenemia between studies that involved multiple vs single sites was performed. Using random effects models, we computed the pooled estimate of CrAg screening uptake, cryptococcal antigenemia, lumbar puncture, cryptococcal meningitis, preemptive antifungals treatment and 95% confidence intervals (CIs).

RESULTS

Ten studies with 18,820 individuals with AHD were analyzed. Overall, the pooled estimate of CrAg screening uptake was 57.1% (95% CI: 41.4-72.7). CrAg screening uptake was significantly lower among studies that involved multiple sites compared to those that involved single site, (47.3% vs 73.3%; p<0.001). Overall, the pooled prevalence of cryptococcal antigenemia was 9.6% (95% CI:6.4-12.9). Cryptococcal antigenemia was significantly lower among studies that involved multiple sites compared to those that involved single site, (9.1% vs 10.4%; p<0.001). Among those who tested positive for CrAg, 84.6% (95% CI: 54.1-99.0) received preemptive antifungal treatment, though nearly 25% did not undergo lumbar puncture, highlighting gaps in diagnostic follow-up. Six studies evaluated CrAg positive patients with lumbar puncture and the overall prevalence of lumbar puncture was 74.9% (48.0-94.8). The overall prevalence of cryptococcal meningitis was 58.1% (46.6-69.6).

CONCLUSIONS

Not screening for CrAg among people with AHD and failure to initiate antifungal medications among eligible patients with cryptococcal antigenemia presents a significant missed opportunity. Emphasis on improving CrAg screening is critical given its proven cost-effective benefits.

Screening for cryptococcal antigenemia and meningeal cryptococcosis, genetic characterization of Cryptococcus neoformans in asymptomatic patients with advanced HIV disease in Kinshasa, Democratic Republic of Congo

We evaluated the prevalence of serum and meningeal cryptococcosis in asymptomatic outpatients with advanced HIV disease (CD4 < 200 cells/mm3) in a cross-sectional screening context in Kinshasa clinics (DRC). Lumbar puncture (LP) was performed in patients with positive serum cryptococcal antigen (CrAg) test, and Cryptococcus spp. isolated from cerebrospinal fluid (CSF) were identified by MALDI-TOF-MS, and characterized using serotyping-PCR, ITS-sequencing and multilocus sequence typing (MLST). The genetic profiles obtained were then compared with those of isolates previously described in symptomatic patients in the same clinics. Forty-seven patients with advanced HIV disease out of 262 included were positive for serum CrAg (18%, 95% CI: 14.2-24.3). The prevalence of asymptomatic cryptococcal meningitis (CM) was then measured at 50% among patients with positive serum CrAg test who consented to LP (19/38). Only four CSF samples were culture positive and all were characterized as Cryptococcus neoformans, molecular type VNI and belonging to two different sequence types (ST): ST93 (3/4) and ST63 (1/4). While ST93 is also the main genomic profile described in advanced HIV disease patients with symptomatic CM in Kinshasa clinics, ST63 has not yet been identified in DRC before. It is likely that future studies involving a large number of strains will be necessary before any definitive conclusions can be drawn on the involved strains in asymptomatic patients.

Cryptococcal meningitis

Cryptococcus neoformans and Cryptococcus gattii species complexes cause meningoencephalitis with high fatality rates and considerable morbidity, particularly in persons with deficient T cell-mediated immunity, most commonly affecting people living with HIV. Whereas the global incidence of HIV-associated cryptococcal meningitis (HIV-CM) has decreased over the past decade, cryptococcosis still accounts for one in five AIDS-related deaths globally due to the persistent burden of advanced HIV disease. Moreover, mortality remains high (~50%) in low-resource settings. The armamentarium to decrease cryptococcosis-associated mortality is expanding: cryptococcal antigen screening in the serum and pre-emptive azole therapy for cryptococcal antigenaemia are well established, whereas enhanced pre-emptive combination treatment regimens to improve survival of persons with cryptococcal antigenaemia are in clinical trials. Short courses (≤7 days) of amphotericin-based therapy combined with flucytosine are currently the preferred options for induction therapy of cryptococcal meningitis. Whether short-course induction regimens improve long-term morbidity such as depression, reduced neurocognitive performance and physical disability among survivors is the subject of further study. Here, we discuss underlying immunology, changing epidemiology, and updates on the management of cryptococcal meningitis with emphasis on HIV-associated disease.