Where there is no laboratory, a urine patch test helps diagnose meningitis

Prevalence and mortality of cryptococcal disease in adults with advanced HIV in an urban tertiary hospital in Sierra Leone: a prospective study

Background

The global annual estimate for cryptococcal disease-related deaths exceeds 180,000, with three fourth occurring in sub-Saharan Africa. The World Health Organization (WHO) recommends cryptococcal antigen (CrAg) screening in all HIV patients with CD4 count < 100/μl. As there is no previous published study on the burden and impact of cryptococcal disease in Sierra Leone, research is needed to inform public health policies. We aimed to establish the seroprevalence and mortality of cryptococcal disease in adults with advanced HIV attending an urban tertiary hospital in Sierra Leone.

Methods

A prospective cohort study design was used to screen consecutive adult (18 years or older) HIV patients at Connaught Hospital in Freetown, Sierra Leone with CD4 count below 100 cells/mm³ from January to April 2018. Participants received a blood CrAg lateral flow assay (IMMY, Oklahoma, USA). All participants with a positive serum CrAg had lumbar puncture and cerebrospinal fluid (CSF) CrAg assay, and those with cryptococcal diseases had fluconazole monotherapy with 8 weeks followed up. Data were entered into Excel and analysed in Stata version 13.0. Proportions, median and interquartile ranges were used to summarise the data. Fisher’s exact test was used to compare categorical variables.

Results

A total of 170 patients, with median age of 36 (IQR 30–43) and median CD4 count of 45 cells/mm³ (IQR 23–63) were screened. At the time of enrolment, 54% were inpatients, 51% were newly diagnosed with HIV, and 56% were either ART-naïve or newly initiated (≤ 30 days). Eight participants had a positive blood CrAg, giving a prevalence of 4.7% (95% CI: 2.4–9.2%). Of those with a positive CrAg, CSF CrAg was positive in five (62.5%). Five (62.5%) CrAg-positive participants died within the first month, while the remaining three were alive and established on ART at 8 weeks.

Conclusion

A substantial prevalence of cryptococcal antigenaemia and poor outcome of cryptococcal disease were demonstrated in our study. The high mortality suggests a need for the HIV programme to formulate and implement policies on screening and pre-emptive fluconazole therapy for all adults with advanced HIV in Sierra Leone, and advocate for affordable access to effective antifungal therapies.

Utility of urine reagent strips in cerebrospinal fluid analysis: An aid to bedside diagnosis of meningitis

Context

The provision of initial treatment to a patient with suspected meningitis depends greatly on early recognition and rapid diagnostic evaluation of cerebrospinal fluid (CSF) leukocytes, proteins, and glucose. The diagnosis is time critical and timely intervention has an implication on the prognosis and outcome. Reasonably, sound laboratorial setups are not available in our country in the primary health-care level and, even in the settings where they are available, long waiting periods precede the availability of results.

Aims

We conducted this study to emphasize the role of urine reagent strip test as a rapid diagnostic tool in CSF analysis.

Settings and Design:

This is a prospective single-blinded study on 100 consecutive CSF samples received with in 1h of tap.

Subjects and Methods

All the 100 samples were subjected to definitive test being CSF microscopy and biochemical analysis of proteins and sugar and index test being a semi quantitative analysis of CSF leukocytes, proteins, and sugar by urinary reagent strips.

Statistical Analysis Used

The diagnostic accuracy of the reagent strip for different cutoff levels was estimated and tabulated in the form of sensitivity, specificity, positive predictive value, negative predictive value, and likelihood ratio.

Results

77% of cases were in the pediatric age group and 23% cases were adults. The sensitivity and specificity for leukocytes by the strip method for ≥15 cells/cumm were 89.28% and 98.61%, respectively, which increased to 100% with an increase in the counts. The reagent strip test had a sensitivity of 85.71% and a specificity of 95.65% for the protein levels >30 mg/dl which increased to 100% with an increase in protein levels. The reagent strip test for glucose was highly specific (100%) but less sensitive.

Conclusions

The results indicate that urine reagent strip is instrumental in bedside CSF analysis and has a future stand in the diagnosis of meningitis.

Utility of the urine reagent strip leucocyte esterase assay for the diagnosis of meningitis in resource-limited settings: meta-analysis

OBJECTIVE

Diagnosis of bacterial meningitis often requires cytometry, chemistry and/or microbiologic culture capabilities. Unfortunately, laboratory resources in low-resource settings (LRS) often lack the capacity to perform these studies. We sought to determine whether the presence of white blood cells in CSF detected by commercially available urine reagent strips could aid in the diagnosis of bacterial meningitis.

METHODS

We searched PubMed for studies published between 1980 and 2016 that investigated the use of urine reagent strips to identify cerebrospinal fluid (CSF) pleocytosis. We assessed studies in any language that enrolled subjects who underwent lumbar puncture and had cerebrospinal fluid testing by both standard laboratory assays and urine reagent strips. We abstracted true-positive, false-negative, false-positive and true-negative counts for each study using a diagnostic threshold of ≥10 white blood cells per microlitre for suspected bacterial meningitis and performed mixed regression modelling with random effects to estimate pooled diagnostic accuracy across studies.

RESULTS

Our search returned 13 studies including 2235 participants. Urine reagent strips detected CSF pleocytosis with a pooled sensitivity of 92% (95% CI: 84-96), a pooled specificity of 98% (95% CI: 94-99) and a negative predictive value of 99% when the bacterial meningitis prevalence is 10%.

CONCLUSIONS

Urine reagent strips could provide a rapid and accurate tool to detect CSF pleocytosis, which, if negative, can be used to exclude diagnosis of bacterial meningitis in settings without laboratory infrastructure. Further investigation of the diagnostic value of using protein, glucose and bacteria components of these strips is warranted.