Prevalence of Histoplasma Antigenuria among Outpatient Cohort with Advanced HIV in Kampala, Uganda

Evolving Epidemiology, Improving Diagnostic Tests and Their Importance for the Correct Diagnosis of Histoplasmosis

Histoplasmosis has traditionally been described as having discrete geographic areas of endemicity. Over the last few decades, it has become more and more clear that these areas are not accurate depictions of where histoplasmosis can occur. Our understanding of where histoplasmosis occurs has improved in recent years due to improving access to diagnostic testing and increased reporting as well as larger at-risk populations (HIV and non-HIV immune suppression) resulting in more cases. Although areas of relatively higher risk and case numbers certainly still exist, histoplasmosis has been observed in much of the world at this point. Our knowledge of the geographic distribution of histoplasmosis, though improving, remains incomplete. While diagnostic testing has traditionally been confined to visualization and/or culture in much of the world, antigen testing has emerged as an excellent tool. Unfortunately access to antigen testing has been inadequate for much of the world, but this has started to change in recent years and will likely change more dramatically in the near future, assuming ongoing positive developments in the area of lateral flow tests for antigen testing. In this review, we describe the current understanding of the geographic distribution of histoplasmosis, the current landscape of diagnostic testing, and the evolution of both areas with an eye towards the future.

Implementation of the advanced HIV disease package of care using a public health approach: lessons from Nigeria

BACKGROUND

Nigeria adapted the WHO package of care for Advanced HIV Disease (AHD) in 2020. The package includes CD4 + cell count testing to identify People Living with HIV (PLHIV) with AHD, screening and treatment of opportunistic infections, rapid antiretrovirals (ART) initiation, and intensive adherence follow-up. The national program adopted a phased approach in the rollout of the AHD package of care to learn lessons from a few representative health facilities before scaling up across the country. This study describes the process and lessons learned from the first phase of implementation.

METHODS

This was a prospective observational study, and participants were enrolled between February and September 2021. Healthcare-worker (HCW) capacity was built to implement the AHD package of care. The study population included newly diagnosed PLHIV ≥ 10 years presenting to care in 28 selected facilities across 4 states in Nigeria. Eligible participants received CD4 + cell testing at baseline. Those with CD4 + cell count < 200 cells/mm3 were subjected to a blood cryptococcal antigen (CrAg) test and urine TB lateral flow lipoarabinomannan (LF-LAM). Those with positive CrAg tests had a cerebrospinal fluid (CSF) test to confirm cryptococcal meningitis. Those negative for both blood CrAg and TB LF-LAM were rapidly initiated on ART and underwent intensive follow-up. Participants were followed up for 12 months.

RESULTS

A total of 6,781 patients were enrolled; 71% (4,812) received CD4 + cell count test, of which 41% (1,969 of 4812) had a CD4 + count < 200 cells/mm3. Approximately 81% (1,492 of 1,850) of those with CD4 + count < 200 cells/mm3 had TB LF-LAM test results documented; 25% were positive, of which 47% started TB treatment. Blood CrAg screening coverage among those with CD4 + count < 200 cells/mm3 was 88% (1,634 of 1,850), of which 5% (85 of 1,634) were positive. Cotrimoxazole preventive therapy was initiated for 65% (1,198 of 1,850) of the participants with CD4 + count < 200 cells/mm3, and 70% (966 of 1,375) of AHD patients with a negative TB LF-LAM and blood CrAg results were initiated on ART on the day of enrolment. Approximately 91% (421 of 461) of those who received viral load results at month 12 post-enrollment were virally suppressed. The retention rate and the Kaplan Meier survival probability estimate at month 12 were 65% (1,204 of 1,850) and 0.93 (CI, 0.91-0.94), respectively, for the enrolled participants.

CONCLUSION

Implementation of the AHD package of care in Nigeria has improved the diagnosis of TB and CM, and will potentially enhance the quality of care for PLHIV if sustained. Findings from this implementation were used to guide national scale-up.

Systematic Review of Prevalence of Histoplasma Antigenuria in Persons with HIV in Latin America and Africa

Histoplasmosis is a fungal disease associated with substantial mortality rates among persons with advanced HIV disease. Our systematic review synthesized data on the global prevalence of Histoplasma--caused antigenuria in persons with HIV. We searched PubMed/Medline, Embase, and Scopus databases on January 3, 2023, to identify cross-sectional and cohort studies evaluating Histoplasma antigenuria prevalence among adults with HIV infection. We calculated point estimates and 95% CIs to summarize prevalence. Of 1,294 studies screened, we included 15. We found Histoplasma antigenuria among 581/5,096 (11%; 95% CI 11%-12%) persons with HIV and 483/3,789 persons with advanced HIV disease (13%; 95% CI 12%-14%). Among persons with HIV and symptoms consistent with histoplasmosis, Histoplasma antigenuria prevalence was 14% (95% CI 13%-15%; 502/3,631 participants). We determined that persons with advanced HIV disease, inpatients, and symptomatic persons might benefit from a systematic approach to early detection of histoplasmosis using urine antigen testing.

Frequency of fungal pathogens in autopsy studies of people who died with HIV in Africa: a scoping review

BACKGROUND

Fungal infections are common in HIV-infected individuals and significantly contribute to mortality. However, a substantial number of cases are undiagnosed before death.

OBJECTIVE

To determine the frequency of fungal pathogens in autopsy studies of people who died with HIV in Africa.

METHODS

We conducted a scoping review of autopsy studies conducted in Africa.

DATA SOURCES

PubMed, Scopus, Web of Science, Embase, Google Scholar, and African Journal Online.

STUDY ELIGIBILITY CRITERIA

The review encompasses studies published from inception to September 2023, and no language restrictions were imposed during the search process. We included studies that reported histopathological or microbiological evidence for the diagnosis of fungal infections and other pathogens.

DATA SYNTHESIS

Data were summarized using descriptive statistics and no meta-analysis was performed.

RESULTS

We examined 30 articles reporting studies conducted between 1991 and 2019, encompassing a total of 13 066 HIV-infected decedents across ten African countries. In five studies, the autopsy type was not specified. Among those studies with specified autopsy types, 20 involved complete diagnostic autopsies, whereas 5 were categorized as partial or minimally invasive autopsies. There were 2333 pathogens identified, with 946 (40.5%) being mycobacteria, 856 (36.7%) fungal, 231 (3.8%) viral, 208 (8.9%) parasitic, and 92 (3.9%) bacterial. Of the 856 fungal pathogens identified, 654 (28.0%) were Cryptococcus species, 167 (7.2%) Pneumocystis jirovecii, 16 (0.69%) Histoplasma species, 15 (0.64%) Aspergillus species, and 4 (0.17%) Candida species. Other major non-fungal pathogens identified were cytomegalovirus 172 (7.37%) and Toxoplasma gondii 173 (7.42%).

CONCLUSIONS

Invasive fungal infections occur in over one-third of people who succumb to HIV in Africa. In addition to cryptococcosis and Pneumocystis jirovecii pneumonia, integrating other priority fungal pathogen detection and management strategies into the broader framework of HIV care in Africa is recommended. This involves increasing awareness regarding the impact of fungal infections in advanced HIV disease and strengthening diagnostic and treatment capacity.

Re-estimation of the burden of serious fungal diseases in Uganda

Background

It is of utmost importance to monitor any change in the epidemiology of fungal diseases that may arise from a change in the number of the at-risk population or the availability of local data.

Objective

We sought to update the 2015 publication on the incidence and prevalence of serious fungal diseases in Uganda.

Methods

Using the Leading International Fungal Education methodology, we reviewed published data on fungal diseases and drivers of fungal diseases in Uganda. Regional or global data were used where there were no Ugandan data.

Results

With a population of ~45 million, we estimate the annual burden of serious fungal diseases at 4,099,357 cases (about 9%). We estimated the burden of candidiasis as follows: recurrent Candida vaginitis (656,340 cases), oral candidiasis (29,057 cases), and esophageal candidiasis (74,686 cases) in HIV-infected people. Cryptococcal meningitis annual incidence is estimated at 5553 cases, Pneumocystis pneumonia at 4604 cases in adults and 2100 cases in children. For aspergillosis syndromes, invasive aspergillosis annual incidence (3607 cases), chronic pulmonary aspergillosis (26,765 annual cases and 63,574 5-year-period prevalent cases), and prevalence of allergic bronchopulmonary aspergillosis at 75,931 cases, and severe asthma with fungal sensitization at 100,228 cases. Tinea capitis is common with 3,047,989 prevalent cases. For other mycoses, we estimate the annual incidence of histoplasmosis to be 646 cases and mucormycosis at 9 cases.

Conclusion

Serious fungal diseases affect nearly 9% of Ugandans every year. Tuberculosis and HIV remain the most important predisposition to acute fungal infection necessitating accelerated preventive, diagnostic, and therapeutic interventions for the management of these diseases.