Aetiology of meningitis in HIV-infected patients in a referral hospital in Phnom Penh, Cambodia

A clinical rule for the prediction of meningitis in HIV patients in the era of combination antiretroviral therapy

BACKGROUND

The diagnosis of meningitis in HIV patients is challenging due to altered immune responses. Diagnostic scoring systems were recently proposed for use in research settings to help prompt and easy differential diagnosis. The objective of this study was to create a clinical prediction rule (CPR) for meningitis in HIV-infected patients and to address the enigma of differentiating bacterial (BM), TB (TBM) and cryptococcal (CCM) meningitis based on clinical features alone, which may be enhanced by easy-to-obtain laboratory testing.

METHODS

We retrospectively enrolled 352 HIV patients presenting with neurological manifestations suggesting meningitis over the last 18 y (2000-2018). Relevant clinical and laboratory information were retrieved from inpatient records. The features independently predicting meningitis or its different types in microbiologically proven meningitis cases were modelled by multivariate logistic regression to create a CPR in an exploratory data set. The performance of the meningitis diagnostic score was assessed and validated in a subset of retrospective data.

RESULTS

AIDS clinical stage, injecting drug use, jaundice and cryptococcal antigen seropositivity were equally important as classic meningitic symptoms in predicting meningitis. Arthralgia and elevated cerebrospinal fluid Lactate dehydrogenase (LDH) were strong predictors of BM. Patients with cryptococcal antigenemia had 25 times the probability of having CCM, whereas neurological deficits were highly suggestive of TBM.

CONCLUSION

The proposed CPRs have good diagnostic potential and would support decision-making in resource-poor settings.

Spatio-temporal Distribution of Meningitis in HIV Patients in Northern Egypt (2000-2018)

BACKGROUND

Meningitis is a leading cause of death among patients living with HIV. There is no adequate tracking of the disease occurrence, distribution and etiologic agents among this risk group in Egypt, although the pattern could differ from that of the general population.

OBJECTIVES

We aimed to describe the spatio-temporal distribution of meningitis in HIV patients in a region of Northern Egypt over 18 years (2000-2018).

METHODS

We conducted a retrospective study of 352 adult HIV patients admitted to a tertiary care fever hospital with neurological manifestations suggesting meningitis. We retrieved from inpatient records all data relevant to patient demographics, clinical presentation, diagnostic work-up, results of laboratory investigations (CSF, blood, imaging), definitive diagnosis, and in-hospital mortality.

RESULTS

The overall trend of over 2 decades showed fluctuating incidence of meningitis in HIV infected patients and increasing spread into rural areas, with a uniform circulation among adult males. Cryptococcal meningitis was the most common etiologic agent (26.9%) and was associated with worse outcomes. Focal neurological deficit (38.5%), cranial nerve involvement (48.1%) were common features in TB Meningitis. The mortality was high (56.8%) and was significantly associated with low CD4+ count, advanced AIDs clinical stage and the presence of co-morbidities.

CONCLUSION

Despite the availability of cART, meningitis, particularly cryptococcal, is common in HIV/AIDS population in Egypt. Continued efforts are desperately needed to improve the outcomes of HIV-infected patients.

Clinical features vary by the aetiology of meningitis in HIV seropositive patients: A four-year study from a tertiary hospital in India

Meningitis is a serious infection of the nervous system associated with high mortality in Human Immunodeficiency Virus (HIV) seropositive individuals. Asian clinical studies describing meningitis in people living with HIV are scarce. We describe the clinical features of meningitis in 116 HIV seropositive patients from a tertiary hospital in India as a cross-sectional observational study. The mean age of the patients in our study was 35±9 years with 70.6% of them being men. Eighty-five percent of the patients had an altered sensorium during the illness. Tuberculous meningitis [82.6%] was the most common cause. Clinical features varied by aetiology. Cranial nerve deficits [40%] were common in Cryptococcal meningitis. Hydrocephalus [3%], infarcts [15.9%] and IntraCranial Space Occupying Lesions (ICSOLs) [39.1%] were common in tuberculous meningitis.

Pattern, Clinical Characteristics, and Outcome of Meningitis among HIV-Infected Adults Admitted in a Tertiary Hospital in North Western Tanzania: A Cross-Sectional Study

Background. Limited information exists on the etiologies, clinical characteristics, and outcomes of meningitis among HIV-infected patients in Africa. We conducted a study to determine the etiology, clinical characteristics, and outcomes of meningitis among HIV-infected adults. Methods. A prospective cross-sectional hospital based study was conducted among HIV-infected patients aged ≥18 years admitted to the medical wards with symptoms and signs of meningitis. Sociodemographic and clinical information were collected using a standardized data collection tool. Lumbar puncture was performed to all patients; cerebrospinal fluid samples were sent for analysis. Results. Among 60 HIV-infected adults clinically diagnosed to have meningitis, 55 had CSF profiles consistent with meningitis. Of these, 14 (25.5%) had a laboratory-confirmed etiology while 41 (74.5%) had no isolate identified. Cryptococcus neoformans was the commonest cause of meningitis occurring in 11 (18.3%) of patients followed by Mycobacterium tuberculosis (6.7%). The in-hospital mortality was 20/55 (36.4%). Independent predictors of mortality were low baseline CD4 count and turbid CSF appearance. Conclusion. Cryptococcal meningitis is the most prevalent laboratory-confirmed etiological agent among adult HIV-infected patients with suspected meningitis admitted to medical wards in Western Tanzania. Mortality rate in this population remains unacceptably high. Improving diagnostic capacity and early treatment may help to decrease the mortality rate.

Spectrum of central nervous system disorders in hospitalized HIV/AIDS patients (2009-2011) at a major HIV/AIDS referral center in Beijing, China

OBJECTIVE

To describe the spectrum of central nervous system (CNS) disorders and the contribution of neurological immune reconstitution inflammatory syndrome (IRIS) in hospitalized HIV/AIDS patients in You'an Hospital, Beijing China.

STUDY DESIGN & METHODS

A retrospective observational study conducted over a 24-month period in You'an Hospial, a public sector referral hospital in Beijing, China. This study enrolled HIV seropositive patients who were admitted for developing new or recurrent neurological and (or) psychiatric symptoms from September 2009 to August 2011. Medical records were reviewed, demographic and clinical data were collected. Patients with peripheral neuropathy and those in delirium were excluded from this study.

RESULTS

Of the total 620 HIV/AIDS hospital admissions from September 2009 to August 2011, 60 patients (9.7%) were hospitalized for CNS complications. The diagnosis of HIV infection was made after hospital admission in 16 of the 60 patients (26.7%), and 34 of them (56.7%) were already on antiretroviral therapy (ART) at the point of admission. The median CD4 cell count in these subjects was 39 (21-133) cells/mm(3), and 93.3% (56/60) of these patients belonged to stage IV HIV disease according to World Health Organization (WHO) classification. The most frequent diagnosis in these subjects included cryptococcal meningitis (CM, n=13, 22%), cerebral toxoplasmosis (n=10, 17%), and CNS tuberculosis (n=7, 11.7%). The overall mortality was 13% (8/60) and the case-fatality rates were: cryptococcal meningitis 7.7% (1/13), cerebral toxoplasmosis 20% (2/10) and tuberculous meningitis 28.6% (2/7). Of the 34 patients who were on ART, paradoxical neurological IRIS (the conditions of their existing CNS disorders get paradoxically worse after ART because of an exuberant inflammatory response directed towards opportunistic pathogens) was diagnosed in 4 patients (11.8%), 2 of whom related to TB infection (out of 5 TB patients, 40%), and the other 2 related to CM (out of 8 patients, 25%).

CONCLUSION

Opportunistic infections, such as cryptococcal meningitis, cerebral toxoplasmosis and CNS tuberculosis were the most frequent diagnosis of CNS disease in hospitalized HIV/AIDS patients in You'an Hospital, Beijing, China. About 10% patients on ART were diagnosed as neurological IRIS in such a group of patients.

Prevalence of cryptococcal antigenemia and cost-effectiveness of a cryptococcal antigen screening program--Vietnam

BACKGROUND

An estimated 120,000 HIV-associated cryptococcal meningitis (CM) cases occur each year in South and Southeast Asia; early treatment may improve outcomes. The World Health Organization (WHO) recently recommended screening HIV-infected adults with CD4<100 cells/mm(3) for serum cryptococcal antigen (CrAg), a marker of early cryptococcal infection, in areas of high CrAg prevalence. We evaluated CrAg prevalence and cost-effectiveness of this screening strategy in HIV-infected adults in northern and southern Vietnam.

METHODS

Serum samples were collected and stored during 2009-2012 in Hanoi and Ho Chi Minh City, Vietnam, from HIV-infected, ART-naïve patients presenting to care in 12 clinics. All specimens from patients with CD4<100 cells/mm(3) were tested using the CrAg lateral flow assay. We obtained cost estimates from laboratory staff, clinicians and hospital administrators in Vietnam, and evaluated cost-effectiveness using WHO guidelines.

RESULTS

Sera from 226 patients [104 (46%) from North Vietnam and 122 (54%) from the South] with CD4<100 cells/mm(3) were available for CrAg testing. Median CD4 count was 40 (range 0-99) cells/mm(3). Nine (4%; 95% CI 2-7%) specimens were CrAg-positive. CrAg prevalence was higher in South Vietnam (6%; 95% CI 3-11%) than in North Vietnam (2%; 95% CI 0-6%) (p = 0.18). Cost per life-year gained under a screening scenario was $190, $137, and $119 at CrAg prevalences of 2%, 4% and 6%, respectively.

CONCLUSION

CrAg prevalence was higher in southern compared with northern Vietnam; however, CrAg screening would be considered cost-effective by WHO criteria in both regions. Public health officials in Vietnam should consider adding cryptococcal screening to existing national guidelines for HIV/AIDS care.

Cryptococcus neoformans phospholipase B1 activates host cell Rac1 for traversal across the blood-brain barrier

Cryptococcus neoformans penetration into the central nervous system (CNS) requires traversal of the blood-brain barrier that is composed of a single layer of human brain microvascular endothelial cells (HBMEC), but the underlying mechanisms of C. neoformans traversal remain incompletely understood. C. neoformans transcytosis of HBMEC monolayer involves rearrangements of the host cell actin cytoskeleton and small GTP-binding Rho family proteins such as Rac1 are shown to regulate host cell actin cytoskeleton. We, therefore, examined whether C. neoformans traversal of the blood-brain barrier involves host Rac1. While the levels of activated Rac1 (GTP-Rac1) in HBMEC increased significantly upon incubation with C. neoformans strains, pharmacological inhibition and down-modulation of Rac1 significantly decreased C. neoformans transcytosis of HBMEC monolayer. Also, Rac1 inhibition was efficient in preventing C. neoformans penetration into the brain. In addition, C. neoformans phospholipase B1 (Plb1) was shown to contribute to activating host cell Rac1, andSTAT3 was observed to associate with GTP-Rac1 in HBMEC that were incubated with C. neoformans strain but not with its Δplb1 mutant. These findings demonstrate for the first time that C. neoformans Plb1 aids fungal traversal across the blood-brain barrier by activating host cell Rac1 and its association with STAT3, and suggest that pharmacological intervention of host-microbial interaction contributing to traversal of the blood-brain barrier may prevent C. neoformans penetration into the brain.

The pattern and predictors of mortality of HIV/AIDS patients with neurologic manifestation in Ethiopia: a retrospective study

BACKGROUND

Even though the prevalence of HIV infection among the adult population in Ethiopia was estimated to be 2.2% in 2008, the studies on the pattern of neurological manifestations are rare. The aim of this retrospective study was to assess the pattern and predictors of mortality of HIV/AIDS patients with neurologic manifestations.

METHODS

Medical records of 347 patients (age ≥13 years) admitted to Tikur Anbesa Hospital from September 2002 to August 2009 were reviewed and demographic and clinical data were collected.

RESULTS

Data from 347 patients were analysed. The mean age was 34.6 years. The diagnosis of HIV was made before current admission in 33.7% and 15.6% were on antiretroviral therapy (ART). Causes of neurological manifestation were: cerebral toxoplasmosis (36.6%), tuberculous meningitis (22.5%), cryptococcal meningitis (22.2%) and bacterial meningitis (6.9%). HIV-encephalopathy, primary central nervous system (CNS) lymphoma and progressive multifocal leukoencephalopathy were rare in our patients. CD4 count was done in 64.6% and 89.7% had count below 200/mm3[mean = 95.8, median = 57] and 95.7% were stage IV. Neuroimaging was done in 38% and 56.8% had mass lesion. The overall mortality was 45% and the case-fatality rates were: tuberculous meningitis (53.8%), cryptococcal meningitis (48.1%), cerebral toxoplasmosiss (44.1%) and bacterial meningitis (33.3%). Change in sensorium and seizure were predictors of mortality.

CONCLUSIONS

CNS opportunistic infections were the major causes of neurological manifestations of HIV/AIDS and were associated with high mortality and morbidity. Almost all patients had advanced HIV disease at presentation. Early diagnosis of HIV, prophylaxis and treatment of opportunistic infections, timely ART, and improving laboratory services are recommended. Mortality was related to change in sensorium and seizure.

Cost-effectiveness of primary prophylaxis of AIDS associated cryptococcosis in Cambodia

Background

Cryptococcal infection is a frequent cause of mortality in Cambodian HIV-infected patients with CD4+ count ≤100 cells/µl. This study assessed the cost-effectiveness of three strategies for cryptococcosis prevention in HIV-infected patients.

Methods

A Markov decision tree was used to compare the following strategies at the time of HIV diagnosis: no intervention, one time systematic serum cryptococcal antigen (CRAG) screening and treatment of positive patients, and systematic primary prophylaxis with fluconazole. The trajectory of a hypothetical cohort of HIV-infected patients with CD4+ count ≤100 cells/µl initiating care was simulated over a 1-year period (cotrimoxazole initiation at enrollment; antiretroviral therapy within 3 months). Natural history and cost data (US$ 2009) were from Cambodia. Efficacy data were from international literature.

Results

In a population in which 81% of patients had a CD4+ count ≤50 cells/ µl and 19% a CD4+ count between 51–100 cells/µl, the proportion alive 1 year after enrolment was 61% (cost $ 472) with no intervention, 70% (cost $ 483) with screening, and 72% (cost $ 492) with prophylaxis. After one year of follow-up, the cost-effectiveness of screening vs. no intervention was US$ 180/life year gained (LYG). The cost-effectiveness of prophylaxis vs. screening was $ 511/LYG. The cost-effectiveness of prophylaxis vs. screening was estimated at $1538/LYG if the proportion of patients with CD4+ count ≤50 cells/µl decreased by 75%.

Conclusion

In a high endemic area of cryptococcosis and HIV infection, serum CRAG screening and prophylaxis are two cost effective strategies to prevent AIDS associated cryptococcosis in patients with CD4+ count ≤100 cells/µl, at a short-term horizon, screening being more cost-effective but less effective than prophylaxis. Systematic primary prophylaxis may be preferred in patients with CD4+ below 50 cells/µl while systematic serum CRAG screening for early targeted treatment may be preferred in patients with CD4+ between 51–100 cells/µl.

Cryptococcal meningitis in HIV-infected patients: a longitudinal study in Cambodia

OBJECTIVE

To describe the frequency of diagnosis of cryptococcosis among HIV-infected patients in Phnom Penh, Cambodia, at programme entry, to investigate associated risk factors, and to determine the incidence of cryptococcal meningitis.

METHODS

We analysed individual monitoring data from 11,970 HIV-infected adults enrolled between 1999 and 2008. We used Kaplan-Meier naïve methods to estimate survival and retention in care and multiple logistic regression to investigate associations with individual-level factors.

RESULTS

Cryptococcal meningitis was diagnosed in 12.0% of the patients: 1066 at inclusion and 374 during follow-up. Incidence was 20.3 per 1000 person-years and decreased over time. At diagnosis, median age was 33 years, median CD4 cell count was 8 cells/μl, and 2.4% of patients were receiving combined antiretroviral therapy; 38.7% died and 34.6% were lost to follow-up. Of 750 patients alive and in care after 3 months of diagnosis, 85.9% received secondary cryptococcal meningitis prophylaxis and 13.7% relapsed in median 5.7 months [interquartile range 4.1-8.8] after cryptococcal meningitis diagnosis (relapse incidence=5.7 per 100 person-years; 95%CI 4.7-6.9). Cryptococcal meningitis was more common in men at programme entry (adjusted OR=2.24, 95% CI 1.67-3.00) and fell with higher levels of CD4 cell counts (P<0.0001).

CONCLUSIONS

Cryptococcal meningitis remains an important cause of morbidity and mortality in Cambodian HIV-infected patients. Our findings highlight the importance of increasing early access to HIV care and cryptococcal meningitis prophylaxis and of improving its diagnosis in resource-limited settings.

Prevalence, determinants of positivity, and clinical utility of cryptococcal antigenemia in Cambodian HIV-infected patients

OBJECTIVES

To determine the prevalence, determinants ofpositivity, and clinical utility of serum cryptococcal polysaccharide (CPS) antigen testing among HIV-infected patients in 2004 in Cambodia, an area highly endemic for cryptococcosis.

METHODS

All HIV-infected patients with a CD4+ count <200 cells/mm3 attending 1 of 2 Phnom Penh hospitals for the first time were systematically screened for serum CPS. Patients with positive test results were further investigated to identify those with cryptococcal meningitis (CM), pulmonary cryptococcosis, or isolated positive cryptococcal antigenemia (IPCA).

RESULTS

The median (interquartile range [IQR]) CD4+ count of 327 enrolled patients was 24 (IQR: 8 to 65) cells/mm3. The prevalence of cryptococcal infection was 59 (18.0%) of 327 cases, of which 41 were CM and 10 were IPCA. In the absence of serum CPS detection, 17 (28.8%) of 59 cryptococcal infections would have been missed on the day of consultation. In patients with no specific symptoms of meningoencephalitis, the prevalence of positive serum CPS detection was 32 (10.8%) of 295 cases. Countryside residence (adjusted odds ratio [AOR] = 3.6), headache (AOR = 3.2), body mass index <15.4 kg/m2 (AOR = 3.4), CD4+ count <50 cells/mm3 (AOR = 4.0), and male gender (marginally, AOR = 2.1) were all independently associated with a positive test results.

CONCLUSION

Serum CPS screening among AIDS patients with a CD4+ count <100 cells/mm3 is useful in areas highly endemic for cryptococcosis, allowing early diagnosis and treatment of this opportunistic infection.

Microbial translocation of the blood–brain barrier

A major contributing factor to high mortality and morbidity associated with CNS infection is the incomplete understanding of the pathogenesis of this disease. Relatively small numbers of pathogens account for most cases of CNS infections in humans, but it is unclear how such pathogens cross the blood-brain barrier (BBB) and cause infections. The development of the in vitro BBB model using human brain microvascular endothelial cells has facilitated our understanding of the microbial translocation of the BBB, a key step for the acquisition of CNS infections. Recent studies have revealed that microbial translocation of the BBB involves host cell actin cytoskeletal rearrangements, most likely as the result of specific microbial-host interactions. A better understanding of microbial-host interactions that are involved in microbial translocation of the BBB should help in developing new strategies to prevent CNS infections. This review summarises our current understanding of the pathogenic mechanisms involved in translocation of the BBB by meningitis-causing bacteria, fungi and parasites.