Tuberculous Meningitis: An Endemic Cause of Intracranial Hypertension

Tuberculous meningitis (TBM) presents a complex clinical scenario, often marked by delayed recognition and high mortality. Our case involves a 27-year-old woman from Nepal with no significant medical history, presented with a two-week history of fatigue, altered consciousness, dizziness, vomiting, fever, holocranial headache, and photophobia. Initial examination revealed signs consistent with meningitis, including fever, hypertensive state, prostration, bilateral exophthalmos, sixth cranial nerve paresis, and positive Kernig/Brudzinski signs. Cerebrospinal fluid (CSF) exhibited characteristics typical of TBM: turbidity, lymphocytic-predominant pleocytosis, low glucose, and elevated protein. The patient was promptly started on meningeal doses of vancomycin, ceftriaxone, and acyclovir. However, persistent fever, neurological deterioration, and signs of increased intracranial pressure led to the decision to initiate conventional empiric treatment of tuberculosis (TB) with isoniazid, rifampicin, pyrazinamide, and ethambutol (HRZE) and dexamethasone 1 week before cultural positivity for Mycobacterium tuberculosis of CSF. The case underscores the importance of considering TBM in patients from endemic regions, interpreting CSF findings, and initiating empirical treatment in critical scenarios, contributing to a positive patient outcome despite the diagnostic challenges.

Time to Positivity Facilitates an Early Differential Diagnosis of Candida tropicalis from Other Candida species

Background

Candidemia caused by Candida tropicalis has more serious adverse consequences and an even higher mortality. Time to positivity (TTP) has been widely used to identify microbial species, resistant microorganisms and distinguish real pathogens and pollutants. However, few studies have demonstrated TTP as a presumptive diagnosis of C. tropicalis in patients with candidemia.

Patients and Methods

A retrospective study of 136 episodes of candidemia and simulated blood cultures with 314 episodes of confirmed Candida strains were applied to explore the role of TTPs in diagnosing C. tropicalis. TTPs were recorded as the shorter one if both aerobic and anaerobic vials were positive. Lastly, relationships were tested between TTPs and resistance and initial inocula concentration.

Results

For the retrospective study, the mean of TTPs for C. tropicalis from 136 patients with candidemia was significantly shorter than other Candida species. The area under the receiver operating characteristics (ROC) curve was 0.8896 ± 0.030 with a sensitivity of 92.86% and a specificity of 77.87%, respectively, indicating TTPs with a cut-off value of <25.50 h had a strong diagnostic power for C. tropicalis in patients with candidemia. Moreover, TTPs from 314 simulated blood cultures showed similar results as the retrospective study, demonstrating TTP is a powerful diagnostic tool in early diagnosing C. tropicalis in patients with candidemia. Additionally, our results showed no statistical significance between TTPs and initial inocula concentration and resistance of Candida species, suggesting initial inocula concentration does not impact TTPs, and TTPs may not be promising in predicting the resistance of all Candida species.

Conclusion

TTP can be employed to early distinguish C. tropicalis from other Candida species in patients with candidemia, which is extremely helpful to initiate empiric antifungal treatments to improve clinical outcomes.

Processing Newborn Bloodspot Screening Results for CF

Every newborn bloodspot screening (NBS) result for cystic fibrosis (CF) consists of two parts: a screening part in the laboratory and a clinical part in a CF centre. When introducing an NBS programme, more attention is usually paid to the laboratory part, especially which algorithm is most suitable for the region or the country. However, the clinical part, how a positive screening result is processed, is often underestimated and can have great consequences for the affected child and their parents. A clear algorithm for the diagnostic part in CF centres is also important and influences the performance of a CF NBS programme. The processing of a positive screening result includes the initial information given to the parents, the invitation to the sweat test, what to do if a sweat test fails, information about the results of the sweat test, the inconclusive diagnosis and the carrier status, which is handled differently from country to country. The time until the definitive diagnosis and adequate information is given, is considered by the parents and the CF team as the most important factor. The communication of a positive NBS result is crucial. It is not a singular event but rather a process that includes ensuring the appropriate clinicians are aware of the result and that families are informed in the most efficient and effective manner to facilitate consistent and timely follow-up.

Fishing diseased abalone to promote yield and conservation

Past theoretical models suggest fishing disease-impacted stocks can reduce parasite transmission, but this is a good management strategy only when the exploitation required to reduce transmission does not overfish the stock. We applied this concept to a red abalone fishery so impacted by an infectious disease (withering syndrome) that stock densities plummeted and managers closed the fishery. In addition to the non-selective fishing strategy considered by past disease-fishing models, we modelled targeting (culling) infected individuals, which is plausible in red abalone because modern diagnostic tools can determine infection without harming landed abalone and the diagnostic cost is minor relative to the catch value. The non-selective abalone fishing required to eradicate parasites exceeded thresholds for abalone sustainability, but targeting infected abalone allowed the fishery to generate yield and reduce parasite prevalence while maintaining stock densities at or above the densities attainable if the population was closed to fishing. The effect was strong enough that stock and yield increased even when the catch was one-third uninfected abalone. These results could apply to other fisheries as the diagnostic costs decline relative to catch value.

Shifting from presumptive to test-based management of malaria - technical basis and implications for malaria control in Ghana

The presumptive approach was the World Health Organisation (WHO) recommended to the management of malaria for many years and this was incorporated into syndromic guidelines such as the Integrated Management of Childhood Illnesses (IMCI). In early 2010 however, WHO issued revised treatment guidelines that call for a shift from the presumptive to the test-based approach. Practically, this implies that in all suspected cases, the diagnosis of uncomplicated malaria should be confirmed using rapid test before treatment is initiated. This revision effectively brings to an end an era of clinical practice that span several years. Its implementation has important implications for the health systems in malaria-endemic countries. On the basis of research in Ghana and other countries, and evidence from program work, the Ghana National Malaria Control Program has issued revised national treatment guidelines that call for implementation of test-based management of malaria in all cases, and across all age groups. This article reviews the evidence and the technical basis for the shift to test-based management and examines the implications for malaria control in Ghana.

Nonvirologic algorithms for predicting HIV infection among HIV-exposed infants younger than 12 weeks of age

BACKGROUND

Early initiation of antiretroviral therapy has been shown to reduce mortality among perinatally HIV-infected infants, but availability of virologic testing remains limited in many settings.

METHODS

We collected cross-sectional data from mother-infant pairs in three primary care clinics in Lusaka, Zambia, to develop predictive models for HIV infection among infants younger than 12 weeks of age. We evaluated algorithm performance for all possible combinations of selected characteristics using an iterative approach. In primary analysis, we identified the model with the highest combined sensitivity and specificity.

RESULTS

Between July 2009 and May 2011, 822 eligible HIV-infected mothers and their HIV-exposed infants were enrolled; of these, 44 (5.4%) infants had HIV diagnosed. We evaluated 382,155,260 different characteristic combinations for predicting infant HIV infection. The algorithm with the highest combined sensitivity and specificity required 5 of the following 7 characteristic thresholds: infant CD8 percentage >22; infant CD4 percentage ≤44; infant weight-for-age Z score ≤0; infant CD4 ≤1600 cells/µL; infant CD8 >2200 cells/µL; maternal CD4 ≤600 cells/µL; and mother not currently using antiretroviral therapy for HIV treatment. This combination had a sensitivity of 90.3%, specificity of 78.4%, positive predictive value of 22.4%, negative predictive value of 99.2% and area under the curve of 0.844.

CONCLUSION

Predicting HIV infection in HIV-exposed infants in this age group is difficult using clinical and immunologic characteristics. Expansion of polymerase chain reaction capacity in resource-limited settings remains urgently needed.