Point-of-Care Testing for Cryptococcal Disease Among Hospitalized Human Immunodeficiency Virus-Infected Adults in Ethiopia

Cryptococcal pneumonia and meningitis in a renal transplant recipient with a false negative serum cryptococcal antigen due to postzone phenomenon

Cryptococcal infection can cause significant morbidity and mortality in immunocompromised patients. We present a patient who was diagnosed with cryptococcal meningitis and pulmonary disease in the setting of a history of renal transplantation. The diagnosis was made based on growth of Cryptococcus neoformans in blood cultures and identification of cryptococcal antigen (CrAg) in cerebral spinal fluid (CSF) using a lateral flow assay (LFA). Our case is unique since the initial serum CrAg was falsely negative due to excess cryptococcal antigen preventing the formation of antigen-antibody complexes, referred to as the postzone phenomenon. This phenomenon has been reported on CSF samples but rarely reported on serum samples in patients without an HIV diagnosis.

Contribution des diagnostics au points de service dans l’identification de la maladie à VIH avancée

BACKGROUND

Médecins Sans Frontières Belgium installed point-of-care (POC) diagnostics for the early detection of advanced HIV disease (AHD), and in its presence, TB and cryptococcosis, in six health centres (Kasai, St Ambroise, St Joseph, Libondi, Lisanga and Kimia) in Kinshasa, Democratic Republic of the Congo (DRC).

OBJECTIVE

To document their contribution to the diagnosis of these conditions.

METHOD

This is a retrospective cross-sectional study of HIV-positive adolescents and adults admitted with suspected AHD. A comparison 2 years before and 2 years after installation of POC was performed.

RESULTS

A total of 745 and 887 patients were included before and after POC, respectively. The mean age was 39.7 years (standard deviation [SD] 12.04); 66% (n = 1,077) were women. Patients with CD4 counts increased from 40.3% (n = 300) to 64.4% (n = 573) (P < 0.001). After the installation of POC, they ranged from 47.8% (Lisanga) to 97.1% (Kasai). The proportion of AHD was comparable (n = 158, 52.7% vs. n = 288, 50.3%; P = 0.779). Among patients with AHD, TB was detected in 28.5% (n = 82), of which 41.5% (n = 34) were confirmed; cryptococcosis was detected in 24.7% (n = 71), of which 9.9% (n = 7) were confirmed. Disparities between centres were observed.

CONCLUSION

The POCs have increased patient access to CD4 testing and diagnosis of AHD in the six centres in DRC. However, actions are required to improve this performance, including screening for TB and cryptococcosis.

Performance of the Colloidal Gold Immunochromatography of Cryptococcal Antigen on Bronchoalveolar Lavage Fluid for the Diagnosis of Pulmonary Cryptococcosis

Objective

This study aimed to investigate the efficacy of the colloidal gold immunochromatography method in the detection of Cryptococcus antigen in bronchoalveolar lavage fluid (BALF) for pulmonary cryptococcosis (PC) diagnosis.

Methods

A total of 111 patients with clinically suspected PC who were finally diagnosed with nonhuman immunodeficiency virus infection and hospitalized in the Ningbo First Hospital from March 2017 to December 2021 were retrospectively analyzed. All the confirmed cases were divided into two groups as follows: the PC group (33 cases) and the non-PC group (78 cases). All the patients were subjected to serum and BALF cryptococcal capsular polysaccharide antigen-lateral flow immunochromatographic assay (CrAg-LFA) and etiological culturing.

Results

In the PC group, serum CrAg-LFA was positive for 24 and negative for 9 cases, serum Cryptococcus culture was positive for 1 and negative for 32 cases, BALF CrAg-LFA was positive for 31 and negative for 2 cases, and BALF Cryptococcus culture was positive for 9 and negative for 24 cases. In the non-PC group, serum CrAg-LFA was positive for 1 and negative for 77 cases, serum culture was negative in all the cases, and both BALF CrAg-LFA and culture were negative in all the cases. The sensitivity, specificity, and accuracy of BALF CrAg-LFA for PC diagnosis were 93.9%, 100%, and 98.2%, respectively, whereas those of BALF culture were 27.3%, 100%, and 78.4%, respectively. The sensitivity and accuracy of BALF CrAg-LFA were higher than that of serum CrAg-LFA and BALF etiological culture with statistically significant differences (p < 0.05).

Conclusion

The diagnostic value of BALF CrAg-LFA for PC is superior to that of serum CrAg-LFA and BALF etiological culture.

Impact of a Cryptococcal meningitis diagnosis and treatment program at Lira Regional Referral Hospital in rural, Northern Uganda

In rural areas of sub-Saharan Africa, infrastructure and resources for treatment of cryptococcal meningitis (CM) are often lacking. We introduced a CM diagnosis and treatment program (CM-DTP) at Lira Regional Referral Hospital (LRRH) in rural Uganda to determine if implementing high-quality standard of care protocols would improve outcomes. Information extracted from hospital charts and clinical record forms at LRRH were used to compare diagnoses, treatments, and outcomes for all patients diagnosed with meningitis (n = 281) over a two-year period after initiation of the CM-DTP in February of 2017 to all patients diagnosed with meningitis (n = 215) in the two preceding years. After implementation of the CM-DTP, we observed increased confirmed diagnoses of CM from 22.2% (48 of 215) to 35.2% (99 of 281), (p = 0.002) among all patients diagnosed with meningitis. Among all patients treated for CM, the proportion who received standard of care treatment with amphotericin B plus fluconazole increased from 63 of 127 (49.6%) to 109 of 146 (74.7%), (p <0.001) and mortality improved from 66 of 127 (52.0%) to 57 of 146 (39.0%), (p = 0.04) after implementation of the CM-DTP. Implementation of the CM-DTP was associated with increased number of lumbar punctures and decreased use of antibiotics in patients with CM, as well as decreased mortality among patients with meningitis from all causes. Improved diagnosis, treatment, and mortality were observed following implementation of the CM-DTP. Our results demonstrate that quality treatment of CM in rural Uganda is feasible.

High prevalence of Cryptococcal antigenemia using a finger-prick lateral flow assay in individuals with advanced HIV disease in Santarém Municipality, Brazilian Amazon Basin

There is scarce information about HIV-related cryptococcosis in the Brazilian Amazon basin where laboratory infrastructure is limited. The serum cryptococcal antigen (CrAg) lateral flow assay (LFA) has simplified diagnosis of cryptococcosis and is recommended for screening in advanced HIV disease. We evaluated the prevalence of cryptococcal antigenemia using finger-prick CrAg LFA in the Brazilian Amazon basin. We enrolled a prospective cohort of outpatients and hospitalized individuals with advanced HIV disease at two centers in Santarém Municipality, Northern Brazil. All individuals were > 18 years old with advanced HIV disease, regardless of antiretroviral therapy (ART) status and with no prior or current history of confirmed cryptococcal meningitis. We tested CrAg LFA on finger-prick whole blood using an exact volume transfer pipette. From August 2018 to October 2019, 104 individuals were enrolled (outpatients 62 [60%] and hospitalized 42 [40%]). Median age was 38 years (interquartile range [IQR] 30-46), and 84 (81%) were male. Sixty-five (63%) individuals were ART-naïve. Prevalence of finger-prick CrAg LFA-positive was 10.6%; 95% CI, 5.4 to 18.1%. Prevalence of finger-prick CrAg LFA-positive among individuals without neurological symptoms was 6.0%; 95% CI, 1.7-14.6%. The number needed to test to detect one CrAg-positive individual was 9.4 persons (95% CI, 5.5-18.5). Prevalence of cryptococcal antigenemia using finger-prick whole blood CrAg LFA was high. Point-of-care approach was important for the diagnosis and screening of cryptococcosis in resource-limited settings. Screening and preemptive therapy strategy should be urgently implemented in individuals with advanced HIV disease in the Brazilian Amazon basin.

Evaluation of a Cryptococcal Antigen Lateral Flow Assay and Cryptococcal Antigen Positivity at a Large Public Hospital in Atlanta, Georgia

BACKGROUND

Cryptococcus neoformans is a major cause of morbidity and mortality among human immunodeficiency virus (HIV)-infected persons worldwide, and there are scarce recent data on cryptococcal antigen (CrAg) positivity in the United States We sought to determine the frequency of cryptococcal disease and compare the performance of a CrAg lateral flow assay (LFA) versus latex agglutination (LA) test.

METHODS

All patients from Grady Health System in Atlanta who had a serum or cerebrospinal fluid (CSF) sample sent for CrAg testing as part of clinical care from November 2017 to July 2018 were included. Percentage positivity and test agreement were calculated.

RESULTS

Among 467 patients, 557 diagnostic tests were performed; 413 on serum and 144 on CSF. The mean age was 44 years, and most were male (69%) and had HIV (79%). Twenty-four (6.4%, 95% confidence interval [CI] = 4.1-9.4) patients were serum CrAg positive, and 8 (5.8%, 95% CI = 2.6-11.2) individuals tested positive for CSF CrAg. Although overall agreement between the LA and LFA was substantial to high for CSF (κ = 0.71, 95% CI = 0.51-0.91) and serum (κ = 0.93, 95% CI = 0.86-1.00), respectively, there were important discrepancies. Five patients had false-positive CSF LA tests that affected clinical care, and 4 patients had discordant serum tests.

CONCLUSIONS

We found a moderately high proportion of cryptococcal disease and important discrepancies between the LA test and LFA. Clinical implications of these findings include accurate detection of serum CrAg and averting unnecessary treatment of meningitis with costly medications associated with high rates of adverse events.

Cryptococcal Immune Reconstitution Inflammatory Syndrome: From Blood and Cerebrospinal Fluid Biomarkers to Treatment Approaches

Immune reconstitution inflammatory syndrome (IRIS) presents as an exaggerated immune reaction that occurs during dysregulated immune restoration in immunocompromised patients in late-stage human immunodeficiency virus (HIV) infection who have commenced antiretroviral treatments (ART). Virtually any opportunistic pathogen can provoke this type of immune restoration disorder. In this review, we focus on recent developments in the identification of risk factors for Cryptococcal IRIS and on advancements in our understanding of C-IRIS immunopathogenesis. We overview new findings in blood and cerebrospinal fluid which can potentially be useful in the prediction and diagnosis of cryptococcal meningitis IRIS (CM-IRIS). We assess current therapeutic regimens and novel treatment approaches to combat CM-IRIS. We discuss the utility of biomarkers for clinical monitoring and adjusting treatment modalities in acquired immunodeficiency syndrome (AIDS) patients co-infected with Cryptococcus who have initiated ART.

Cryptococcal meningitis: a review of cryptococcal antigen screening programs in Africa

INTRODUCTION

Cryptococcal meningitis remains a significant contributor to AIDS-related mortality despite widened access to antiretroviral therapy. Cryptococcal antigen (CrAg) can be detected in the blood prior to development of meningitis. Development of highly sensitive and specific rapid diagnostic CrAg tests has helped facilitate the adoption of CrAg screening programs in 19 African countries.

AREAS COVERED

The biological rationale for CrAg screening and the programmatic strategies for its implementation are reviewed. We describe the approach to the investigation of patients with cryptococcal antigenemia and the importance of lumbar puncture to identify individuals who may have cryptococcal meningitis in the absence of symptoms. The limitations of current treatment recommendations and the potential role of newly defined combination antifungal therapies are discussed. A literature review was conducted using a broad database search for cryptococcal antigen screening and related terms in published journal articles dating up to December 2019. Conference abstracts, publicly available guidelines, and project descriptions were also incorporated.

EXPERT OPINION

As we learn more about the risks of cryptococcal antigenemia, it has become clear that the current management paradigm is inadequate. More intensive investigation and management are required to prevent the development of cryptococcal meningitis and reduce mortality associated with cryptococcal antigenemia.

Cryptococcal antigenemia and its predictors among HIV infected patients in resource limited settings: a systematic review

Background

Cryptococcosis is an opportunistic fungal infection that primarily affects people with advanced HIV/AIDS and is an important cause of morbidity and mortality around the globe. By far the most common presentation of the disease is cryptococcal meningitis (CM), which leads to an estimated 15–20% of all HIV related deaths worldwide, 75% of which are in sub-Saharan Africa. However, to the best of our knowledge there is quite limited reviewed data on the epidemiology of cryptococcal antigenemia in a large HIV-infected population in resource limited settings.

Methods

Articles published in English irrespective of the time of publication were systematically searched using comprehensive search strings from PubMed/Medline and SCOPUS. In addition, Google Scholar and Google databases were searched manually for grey literature. Two reviewers independently assessed study eligibility, extracted data, and assessed risk of bias. The pooled prevalence of cryptococcal antigenemia was determined with 95% confidence interval (CI).

Results

Among 2941 potential citations, we have included 22 studies with a total of 8338 HIV positive individuals. The studies were reported in ten different countries during the year (2007–2018). Most of the articles reported the mean CD4 count of the participants below 100 cells/μl. The pooled prevalence of cryptococcal antigenemia at different CD4 count and ART status was at 8% (95%CI: 6–10%) (ranged between 1.7 and 33%). Body mass index (BMI) < 18.5 kg/m², CD4 count < 100 cells, patients presenting with headache and male gender were reported by two or more articles as an important predictors of cryptococcal antigenemia.

Conclusions

Implementing a targeted screening of HIV patients with low BMI, CD4 count < 100 cells, having headache and males; and treatment for asymptomatic cryptococcal disease should be considered. Additional data is needed to better define the epidemiology of cryptococcal antigenemia and its predictors in resource limited settings in order to optimize the prevention, diagnosis, and treatment strategies.

Underlying Cryptococcal Diseases and the Correlation With Serum Cryptococcal Antigen Titers in Hospitalized HIV-Infected Patients Screened Positive for Cryptococcal Antigenemia

Background: The prevalence of different underlying cryptococcal diseases in human immunodeficiency virus (HIV)-infected patients screened positive for cryptococcal antigenemia and the association between cryptococcal diseases and serum cryptococcal antigen (CrAg) titers were understudied.

Methods: HIV-infected patients with CD4 < 200 cells/ul, admitted to the second hospital of Nanjing, Nanjing, China, from January 2016 to September 2019, were retrospectively analyzed. Integrated into routine HIV care, all these patients were screened for cryptococcal antigenemia with CrAg lateral flow assay. Positive patients received extensive laboratory and radiological studies to evaluate underlying cryptococcal diseases.

Results: A total of 872 HIV inpatients were screened for serum CrAg. The prevalence of cryptococcal antigenemia in the study population was 10.3% (95% CI, 8.3–12.3%), 87.6% of which with cryptococcal antigenemia had clinically cryptococcal diseases. The prevalence of cryptococcal meningitis (CM), cryptococcemia and pulmonary cryptococcosis (PC) in patients with cryptococcal antigenemia were 58.4% (95% CI, 48.0–68.9%), 50.7% (95% CI, 39.1–62.2%), and 68.5% (95% CI, 58.7–78.4%), respectively. The median (range) serum CrAg titers in severe cryptococcal diseases (CM or cryptococcemia), localized PC (without co-existing CM or cryptococcemia) and isolated cryptococcal antigenemia were 1:2560 (1:10–1:2560), 1:20 (1:2–1:320), and 1:5 (1:2–1:320), respectively. Serum CrAg titers ≥1:320 were independently associated with CM (adjusted OR 26.88; 95%CI, 8.36–86.42). Severe cryptococcal diseases were found in all patients with serum CrAg titers ≥1:640. None of the patients with serum CrAg titers ≤ 1:5 had CM.

Conclusion: The prevalence of cryptococcal antigenemia was high in HIV inpatients, supporting routine CrAg screening. Clinical cryptococcal diseases, most commonly the PC, existed in the majority of the patients with cryptococcal antigenemia. Since serum CrAg titer is correlated with cryptococcal disease severity, it may possibly guide anti-fungal treatment.

Cost-effectiveness of reflex laboratory-based cryptococcal antigen screening for the prevention and treatment of cryptococcal meningitis in Botswana

Background: Cryptococcal antigen (CrAg) screening for antiretroviral therapy (ART)-naïve adults with advanced HIV/AIDS can reduce the incidence of cryptococcal meningitis (CM) and all-cause mortality. We modeled the cost-effectiveness of laboratory-based "reflex" CrAg screening for ART-naïve CrAg-positive patients with CD4<100 cells/µL (those currently targeted in guidelines) and ART-experienced CrAg-positive patients with CD4<100 cells/µL (who make up an increasingly large proportion of individuals with advanced HIV/AIDS). Methods: A decision analytic model was developed to evaluate CrAg screening and treatment based on local CD4 count and CrAg prevalence data, and realistic assumptions regarding programmatic implementation of the CrAg screening intervention. We modeled the number of CrAg tests performed, the number of CrAg positives stratified by prior ART experience, the proportion of patients started on pre-emptive antifungal treatment, and the number of incident CM cases and CM-related deaths. Screening and treatment costs were evaluated, and cost per death or disability-adjusted life year (DALY) averted estimated. Results: We estimated that of 650,000 samples undergoing CD4 testing annually in Botswana, 16,364 would have a CD4<100 cells/µL and receive a CrAg test, with 70% of patients ART-experienced at the time of screening. Under base model assumptions, CrAg screening and pre-emptive treatment restricted to ART-naïve patients with a CD4<100 cells/µL prevented 20% (39/196) of CM-related deaths in patients undergoing CD4 testing at a cost of US$2 per DALY averted. Expansion of preemptive treatment to include ART-experienced patients with a CD4<100 cells/µL resulted in 55 additional deaths averted (a total of 48% [94/196]) and was cost-saving compared to no screening. Findings were robust across a range of model assumptions. Conclusions: Reflex laboratory-based CrAg screening for patients with CD4<100 cells/µL is a cost-effective strategy in Botswana, even in the context of a relatively low proportion of advanced HIV/AIDS in the overall HIV-infected population, the majority of whom are ART-experienced.

Magnitude of Cryptococcosis among HIV patients in sub-Saharan Africa countries: a systematic review and meta-analysis

Background

Cryptococcus is encapsulated opportunistic yeast that causes life threatening meningoencephalitis of patients with human immunodeficiency virus (HIV). The magnitude of Cryptococcosis among HIV patients varies from 1–10% in Western countries as opposed to almost a one third of HIV-infected individuals in sub-Saharan Africa where it is associated with high mortality.

Methodology

By using key terms “Cryptococcosis among HIV patients in sub-saharan Africa countries”, articles that published in different journals from 2010–2017 searched on Pub-Med and Google scholar database. Those freely accessible and included the prevalence of Cryptococcosis in the result section, their PDF file was downloaded and the result extracted manually and presented in table. Articles that did not report the prevalence of Cryptococcosis, with a study design otherthan cross sectional, or a sample size less than 100, and those duplicated in the same study area and period by the same authors were excluded. The article selection followed the PRISMA guidelines and meta- analysis was performed using OpenMeta(analyst).

Results

The overall pooled magnitude of Cryptococcosis among HIV patients in sub saharan African countries was 8.3% (95%CI 6.1–10.5%). The highest prevalence was from Uganda (19%) and the least was from Ethiopia at 1.6%. There was 87.2 % of substantial heterogeneity among the studies with p-value<0.001. The symmetry ofthe forest plot showed that there was little publication bias. The most commonly used method for diagnosis of Cryptococcosis was lateral flow assay and latex agglutination test and culture was the least method employed.

Conclusion

The overall pooled magnitude of Cryptococcosisis high among HIV patients in sub-Saharan African countries. The studies showed substantial heterogeneity, and little publication bias. Most of the studies relied on LFA & LA that showed the scarcity of facilities for fungal culture. Therefore, paying attention to screening HIV patients; those with signs and symptoms of meningitis may help to reduce the loss of HIV patients.

Mortality from HIV-associated meningitis in sub-Saharan Africa: a systematic review and meta-analysis

INTRODUCTION

HIV-associated cryptococcal, TB and pneumococcal meningitis are the leading causes of adult meningitis in sub-Saharan Africa (SSA). We performed a systematic review and meta-analysis with the primary aim of estimating mortality from major causes of adult meningitis in routine care settings, and to contrast this with outcomes from clinical trial settings.

METHODS

We searched PubMed, EMBASE and the Cochrane Library for published clinical trials (defined as randomized-controlled trials (RCTs) or investigator-managed prospective cohorts) and observational studies that evaluated outcomes of adult meningitis in SSA from 1 January 1990 through 15 September 2019. We performed random effects modelling to estimate pooled mortality, both in clinical trial and routine care settings. Outcomes were stratified as short-term (in-hospital or two weeks), medium-term (up to 10 weeks) and long-term (up to six months).

RESULTS AND DISCUSSION

Seventy-nine studies met inclusion criteria. In routine care settings, pooled short-term mortality from cryptococcal meningitis was 44% (95% confidence interval (95% CI):39% to 49%, 40 studies), which did not differ between amphotericin (either alone or with fluconazole) and fluconazole-based induction regimens, and was twofold higher than pooled mortality in clinical trials using amphotericin based treatment (21% (95% CI:17% to 25%), 17 studies). Pooled short-term mortality of TB meningitis was 46% (95% CI: 33% to 59%, 11 studies, all routine care). For pneumococcal meningitis, pooled short-term mortality was 54% in routine care settings (95% CI:44% to 64%, nine studies), with similar mortality reported in two included randomized-controlled trials. Few studies evaluated long-term outcomes.

CONCLUSIONS

Mortality rates from HIV-associated meningitis in SSA are very high under routine care conditions. Better strategies are needed to reduce mortality from HIV-associated meningitis in the region.

The Burden of Fungal Infections in Ethiopia

The burden of severe fungal infections (FIs) is not well addressed in Ethiopia. We have estimated the burden of FIs from multiple demographic sources and by searching articles from PubMed. Opportunistic FIs were estimated using modelling and 2017 national HIV data. The burdens of chronic pulmonary aspergillosis (CPA) and allergic bronchopulmonary aspergillosis (ABPA) were estimated by using the prevalence of asthma, chronic obstructive pulmonary disease, and annual the incidence of tuberculosis. Of the 105,000,000 estimated Ethiopian population, 610,000 are thought to have HIV infection. Our estimation of HIV-related FIs were: 9900 cryptococcal meningitis (CM), 12,700 Pneumocystis jirovecii pneumonia (PCP), 76,300 oral and 56,000 oesophageal candidiasis cases. A remarkable 7,051,700 4–14-year-olds probably have tinea capitis and 1,469,000 women probably have recurrent Candida vaginitis. There were 15,200 estimated CPA cases (prevalence) and 11,500 invasive aspergillosis (IA) cases (incidence). Data are scant, but we estimated 5300 candidaemia and 800 Candida peritonitis cases. In conclusion, approximately 8% of Ethiopians suffer from FIs annually, mostly schoolchildren with tinea capitis. IA, CM and PCP are the major causes of fungal deaths. The absence of CD4 count is challenging the identification of HIV patients at risk of opportunistic FIs. There is a pressing need to improve FI diagnosis, probably including national surveillance.

Cost-effectiveness of reflex laboratory-based cryptococcal antigen screening for the prevention and treatment of cryptococcal meningitis in Botswana

Background: Cryptococcal antigen (CrAg) screening for antiretroviral therapy (ART)-naïve adults with advanced HIV/AIDS can reduce the incidence of cryptococcal meningitis (CM) and all-cause mortality. We modeled the cost-effectiveness of laboratory-based "reflex" CrAg screening for ART-naïve CrAg-positive patients with CD4<100 cells/µL (those currently targeted in guidelines) and ART-experienced CrAg-positive patients with CD4<100 cells/µL (who make up an increasingly large proportion of individuals with advanced HIV/AIDS). Methods: A decision analytic model was developed to evaluate CrAg screening and treatment based on local CD4 count and CrAg prevalence data, and realistic assumptions regarding programmatic implementation of the CrAg screening intervention. We modeled the number of CrAg tests performed, the number of CrAg positives stratified by prior ART experience, the proportion of patients started on pre-emptive antifungal treatment, and the number of incident CM cases and CM-related deaths. Screening and treatment costs were evaluated, and cost per death or disability-adjusted life year (DALY) averted estimated. Results: We estimated that of 650,000 samples undergoing CD4 testing annually in Botswana, 16,364 would have a CD4<100 cells/µL and receive a CrAg test, with 70% of patients ART-experienced at the time of screening. Under base model assumptions, CrAg screening and pre-emptive treatment restricted to ART-naïve patients with a CD4<100 cells/µL prevented 20% (39/196) of CM-related deaths in patients undergoing CD4 testing at a cost of US$2 per DALY averted. Expansion of preemptive treatment to include ART-experienced patients with a CD4<100 cells/µL resulted in 55 additional deaths averted (a total of 48% [94/196]) and was cost-saving compared to no screening. Findings were robust across a range of model assumptions. Conclusions: Reflex laboratory-based CrAg screening for patients with CD4<100 cells/µL is a cost-effective strategy in Botswana, even in the context of a relatively low proportion of advanced HIV/AIDS in the overall HIV-infected population, the majority of whom are ART-experienced.

Identification of Cryptococcus antigen in human immunodeficiency virus-positive Turkish patients by using the Dynamiker® lateral flow assay

Cryptococcus neoformans causes life-threatening meningoencephalitis, particularly in human immunodeficiency virus (HIV)-positive individuals with low CD4 levels (<100 cells/μL). Although the burden of cryptococcal meningoencephalitis (CM) in Turkey is low (0.13 cases per 100 000 persons), asymptomatic individuals at risk of cryptococcosis should be screened for antigenemia to prevent the disease and/or promote early CM diagnosis. A lateral flow assay (LFA) is used to detect Cryptococcus antigen (CrAg) in cerebrospinal fluid and serum. We determined Cryptococcus antigenemia prevalence in serum samples of HIV-positive and HIV-negative adult patients by using Dynamiker® CrAg-LFA, a point-of-care dipstick test. Patients' demographic data, CD4 count, HIV-RNA levels and anti-retroviral therapy status were recorded. CrAg was detected in 28 (11%) of 254 HIV-positive patients screened but not in 100 HIV-negative control individuals; a significant difference was observed in the CrAg-LFA positivity rate between HIV-positive and HIV-negative groups (x²  = 11.970; P < .05). In CrAg-positive patients, the median CD4 level was 666 cells/μL (115-1344 cells/μL), with a median viral load of 23 copies/mL (0-3.69 × 10⁶  copies/mL). In HIV-positive CrAg-negative patients, the median CD4 level was 633 cells/μL (31-2953 cells/μL) and the median viral load was 12 copies/mL (0-1.95 × 10⁶  copies/mL; P > .05). Results indicate that HIV-positive patients with both low (<200 cells/μL) and high (>200 cells/μL) CD4 counts should be screened for asymptomatic cryptococcal antigenemia. HIV-associated asymptomatic cryptococcosis is not uncommon in Turkey, which warrants systematic screening. Updated strategies for CM prevention among HIV-positive patients should be used even in non-endemic countries.

Brief Report: Point of Care Cryptococcal Antigen Screening: Pipetting Finger-Prick Blood Improves Performance of Immunomycologics Lateral Flow Assay

BACKGROUND

Cryptococcal antigen (CrAg) screening at the point of care could improve cryptococcal meningitis prevention where laboratory resources are limited. We evaluated the accuracy of Immunomycologics (IMMY, Norman, OK) CrAg lateral flow assay (LFA) using different techniques at point of care.

SETTING

Two tertiary-level hospitals in Johannesburg and a community health clinic in Soweto, South Africa.

METHODS

A case-control diagnostic validation study and a prospective clinic-based implementation study using the IMMY CrAg LFA on finger-prick blood. Accuracy, using direct application of LFA to sample, or pipette to transfer sample to diluent, and reading after 10 and 20 minutes, was compared with laboratory-based plasma testing.

RESULTS

The validation study tested 64 CrAg-positive and 152 CrAg-negative patients with no symptoms or signs of meningitis, identified by routine laboratory screening, recruited by convenience sampling. Consecutively diagnosed HIV-infected adults (n = 654) were included in the implementation study. Sensitivity was 82% and 20% when the LFA was read 10 minutes after direct application to finger-prick blood in the validation and implementation studies, respectively. Using a pipette to transfer blood and reading after 20 minutes improved sensitivity to 100%, while retaining 100% specificity, in both studies.

CONCLUSIONS

Although the IMMY CrAg LFA performs well when applied directly to finger-prick blood for diagnosing cryptococcal meningitis, this technique may not provide adequate volume to detect low concentrations of CrAg when screening asymptomatic patients. Using a pipette to transfer larger volumes of blood to diluent before CrAg LFA testing and reading results after 20 minutes is a more reliable point-of-care method.

The epidemiology of febrile illness in sub-Saharan Africa: implications for diagnosis and management

BACKGROUND

Fever is among the most common symptoms of people living in Africa, and clinicians are challenged by the similar clinical features of a wide spectrum of potential aetiologies.

AIM

To summarize recent studies of fever aetiology in sub-Saharan Africa focusing on causes other than malaria.

SOURCES

A narrative literature review by searching the MEDLINE database, and recent conference abstracts.

CONTENT

Studies of multiple potential causes of fever are scarce, and for many participants the infecting organism remains unidentified, or multiple co-infecting microorganisms are identified, and establishing causation is challenging. Among ambulatory patients, self-limiting arboviral infections and viral upper respiratory infections are common, occurring in up to 60% of children attending health centres. Among hospitalized patients there is a high prevalence of potentially fatal infections requiring specific treatment. Bacterial bloodstream infection and bacterial zoonoses are major causes of fever. In recent years, the prevalence of antimicrobial resistance among bacterial isolates has increased, notably with spread of extended spectrum β-lactamase-producing Enterobacteriaceae and fluoroquinolone-resistant Salmonella enterica. Among those with human immunodeficiency virus (HIV) infection, Mycobacterium tuberculosis bacteraemia has been confirmed in up to 34.8% of patients with sepsis, and fungal infections such as cryptococcosis and histoplasmosis remain important.

IMPLICATIONS

Understanding the local epidemiology of fever aetiology, and the use of diagnostics including malaria and HIV rapid-diagnostic tests, guides healthcare workers in the management of patients with fever. Current challenges for clinicians include assessing which ambulatory patients require antibacterial drugs, and identifying hospitalized patients infected with organisms that are not susceptible to empiric antibacterial regimens.

CD4 Cell Count Threshold for Cryptococcal Antigen Screening of HIV-Infected Individuals: A Systematic Review and Meta-analysis

Background

Current guidelines recommend screening all people living with human immunodeficiency virus (PLHIV) who have a CD4 count ≤100 cells/µL for cryptococcal antigen (CrAg) to identify those patients who could benefit from preemptive fluconazole treatment prior to the onset of meningitis. We conducted a systematic review to assess the prevalence of CrAg positivity at different CD4 cell counts.

Methods

We searched 4 databases and abstracts from 3 conferences up to 1 September 2017 for studies reporting prevalence of CrAg positivity according to CD4 cell count strata. Prevalence estimates were pooled using random effects models.

Results

Sixty studies met our inclusion criteria. The pooled prevalence of cryptococcal antigenemia was 6.5% (95% confidence interval [CI], 5.7%-7.3%; 54 studies) among patients with CD4 count ≤100 cells/µL and 2.0% (95% CI, 1.2%-2.7%; 21 studies) among patients with CD4 count 101-200 cells/µL. Twenty-one studies provided sufficient information to compare CrAg prevalence per strata; overall, 18.6% (95% CI, 15.4%-22.2%) of the CrAg-positive cases identified at ≤200 cells/µL (n = 11823) were identified among individuals with a CD4 count 101-200 cells/µL. CrAg prevalence was higher among inpatients (9.8% [95% CI, 4.0%-15.5%]) compared with outpatients (6.3% [95% CI, 5.3%-7.4%]).

Conclusions

The findings of this review support current recommendations to screen all PLHIV who have a CD4 count ≤100 cells/µL for CrAg and suggest that screening may be considered at CD4 cell count ≤200 cells/µL.

High Cryptococcal Antigen Titers in Blood Are Predictive of Subclinical Cryptococcal Meningitis Among Human Immunodeficiency Virus-Infected Patients

Background

High mortality rates among asymptomatic cryptococcal antigen (CrAg)-positive patients identified through CrAg screening, despite preemptive fluconazole treatment, may be due to undiagnosed cryptococcal meningitis.

Methods

Symptoms were reviewed in CrAg-positive patients identified by screening 19233 individuals with human immunodeficiency virus infection and CD4 cell counts <100/µL at 17 clinics and 3 hospitals in Johannesburg from September 2012 until September 2015, and at 2 hospitals until June 2016. Cerebrospinal fluid samples from 90 of 254 asymptomatic patients (35%) and 78 of 173 (45%) with headache only were analyzed for cryptococcal meningitis, considered present if Cryptococcus was identified by means of India ink microscopy, culture, or CrAg test. CrAg titers were determined with stored blood samples from 62 of these patients. The associations between blood CrAg titer, concurrent cryptococcal meningitis, and mortality rate were assessed.

Results

Cryptococcal meningitis was confirmed in 34% (95% confidence interval, 25%-43%; 31 of 90) of asymptomatic CrAg-positive patients and 90% (81%-96%; 70 of 78) with headache only. Blood CrAg titer was significantly associated with concurrent cryptococcal meningitis in asymptomatic patients (P < .001) and patients with headache only (P = .003). The optimal titer for predicting cryptococcal meningitis was >160 (sensitivity, 88.2%; specificity, 82.1%); the odds ratio for concurrent cryptococcal meningitis was 34.5 (95% confidence interval, 8.3-143.1; P < .001).

Conclusions

About a third of asymptomatic CrAg-positive patients have concurrent cryptococcal meningitis. More effective clinical assessment strategies and antifungal regimens are required for CrAg-positive patients, including investigation for cryptococcal meningitis irrespective of symptoms. Where it is not possible to perform lumbar punctures in all CrAg-positive patients, blood CrAg titers should be used to target those most at risk of cryptococcal meningitis.

Cryptococcal Lung Infections

Cryptococcus is among the most common invasive fungal pathogens globally and is one of the leading causes of acquired immunodeficiency virus-related deaths. Cryptococcus neoformans and Cryptococcus gattii are the most clinically relevant species and account for most cryptococcal disease. Pulmonary manifestations can range from mild symptoms to life-threatening infection. Treatment is tailored based on the severity of pulmonary infection, the presence of disseminated or central nervous system disease, and patient immune status. Amphotericin B and flucytosine followed by fluconazole remain the standard agents for the treatment of severe cryptococcal infection.

Looking for fungi in all the right places: screening for cryptococcal disease and other AIDS-related mycoses among patients with advanced HIV disease

PURPOSE OF REVIEW

As HIV treatment programmes scale up to meet the UNAIDS 90-90-90 goals, care must be taken to start antiretroviral treatment safely in patients with advanced disease (CD4 counts <200 cells/μl) who are simultaneously at risk for opportunistic infections and immune reconstitution inflammatory syndrome. Invasive fungal diseases pose a great threat at this critical time point, though the development of inexpensive and highly accurate rapid diagnostic tests has changed the approach HIV programmes are taking to reduce the high mortality associated with these opportunistic infections. This article summarizes recent advances and findings in fungal opportunistic infection diagnostics with a focus on screening to prevent cryptococcal meningitis.

RECENT FINDINGS

Cryptococcal antigen (CrAg) screening using a lateral flow assay platform is cost-effective and feasible to implement as either a laboratory reflex or point-of-care test. Recent CrAg screening pilots have elucidated the varying prevalence of cryptococcal antigenemia across geographic regions, which may aid programme planning. Evidence from recently completed clinical trials provides a strong motivation for the use of CrAg titer to refine treatment options for patients with subclinical cryptococcal disease.

SUMMARY

Although several operational barriers to programme effectiveness still need to be addressed, the utility of CrAg screening using inexpensive and accurate antigen assays has been demonstrated in real-world HIV programmes, paving the way for development and testing of other fungal opportunistic infection screening strategies and for an integrated advanced HIV disease testing package to reduce AIDS mortality and ensure safe antiretroviral treatment initiation.