Utility of serum Galactomannan in diagnosing COVID-19 patients with suspected IPA: an observational study in resource limited settings

OBJECTIVE

To study the utility of Galactomannan (GM) antigen as a screening marker for diagnosing invasive pulmonary aspergillosis (IPA) in coronavirus disease 2019 (COVID-19) patients.

PATIENTS AND METHODS

The serum samples from patients with severe COVID-19 diseases admitted to the Critical Care Unit were collected on the 5th day of admission for GM screening. The samples were analysed by enzyme linked immune sorbent assay (ELISA) and GM index of more than 1 was considered as positive. All GM positive patients were serially followed until discharge or death.

RESULTS

The GM was raised in serum of 12 out of 38 patients, indicating an incidence of possible COVID-19 associated IPA (CAPA) in 31.57% of patients. The median age of these CAPA patients was 56.5 years, males were significantly more affected than females. The inflammatory marker serum ferritin was raised in all 12 patients (median value of 713.74 ng/ml), while IL-6 was raised in 9 patients (median value of 54.13 ng/ml). None of these patients received antifungals. Their median length of hospital stay was 20 days (IQR: 12, 34 days). All these patients succumbed to the illness.

CONCLUSIONS

The serum GM appears to be sensitive diagnostic tool to identify early IPA in COVID-19 patients and pre-emptive antifungal therapy could play a role in salvaging these patients.

Impact of COVID-19 on the cerebrovascular system and the prevention of RBC lysis

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) uses Angiotensin- converting enzyme 2 (ACE2) receptors to infect host cells which may lead to coronavirus disease (COVID-19). Given the presence of ACE2 receptors in the brain and the critical role of the renin-angiotensin system (RAS) in brain functions, special attention to brain microcirculation and neuronal inflammation is warranted during COVID-19 treatment. Neurological complications reported among COVID-19 patients range from mild dizziness, headache, hypogeusia, hyposmia to severe like encephalopathy, stroke, Guillain-Barre Syndrome (GBS), CNS demyelination, infarcts, microhemorrhages and nerve root enhancement. The pathophysiology of these complications is likely via direct viral infection of the CNS and PNS tissue or through indirect effects including post- viral autoimmune response, neurological consequences of sepsis, hyperpyrexia, hypoxia and hypercoagulability among critically ill COVID-19 patients. Further, decreased deformability of red blood cells (RBC) may be contributing to inflammatory conditions and hypoxia in COVID-19 patients. Haptoglobin, hemopexin, heme oxygenase-1 and acetaminophen may be used to maintain the integrity of the RBC membrane.

Revisiting the Woolly wolf (Canis lupus chanco) phylogeny in Himalaya: Addressing taxonomy, spatial extent and distribution of an ancient lineage in Asia

Of the sub-species of Holarctic wolf, the Woolly wolf (Canis lupus chanco) is uniquely adapted to atmospheric hypoxia and widely distributed across the Himalaya, Qinghai Tibetan Plateau (QTP) and Mongolia. Taxonomic ambiguity still exists for this sub-species because of complex evolutionary history anduse of limited wild samples across its range in Himalaya. We document for the first time population genetic structure and taxonomic affinity of the wolves across western and eastern Himalayan regions from samples collected from the wild (n = 19) using mitochondrial control region (225bp). We found two haplotypes in our data, one widely distributed in the Himalaya that was shared with QTP and the other confined to Himachal Pradesh and Uttarakhand in the western Himalaya, India. After combining our data withpublished sequences (n = 83), we observed 15 haplotypes. Some of these were shared among different locations from India to QTP and a few were private to geographic locations. A phylogenetic tree indicated that Woolly wolves from India, Nepal, QTP and Mongolia are basal to other wolves with shallow divergence (K2P; 0.000-0.044) and high bootstrap values. Demographic analyses based on mismatch distribution and Bayesian skyline plots (BSP) suggested a stable population over a long time (~million years) with signs of recent declines. Regional dominance of private haplotypes across its distribution range may indicate allopatric divergence. This may be due to differences in habitat characteristics, availability of different wild prey species and differential deglaciation within the range of the Woolly wolf during historic time. Presence of basal and shallow divergence within-clade along with unique ecological requirements and adaptation to hypoxia, the Woolly wolf of Himalaya, QTP, and Mongolian regions may be considered as a distinct an Evolutionary Significant Unit (ESU). Identifying management units (MUs) is needed within its distribution range using harmonized multiple genetic data for effective conservation planning.

Candida auris in critically ill patients: Emerging threat in intensive care unit of hospitals

Candida auris has emerged as the multi-drug resistant non-albican candida species in critically ill patients admitted to intensive care units (ICU) causing bloodstream and other infections. It has often been misidentified as Candida famata, Candida sake, Rhodotorula glutinis, or Saccharomyces cerevisiae and Candida haemulonii by automated identification systems. We, in this study, discuss three patients who acquired Candida auris infection after 15 to 20days of their stay in medical ICU. Medical equipment, use of multiple antibiotics, and poor hand hygiene are the most probable predisposing factors attributing to its colonization at multiple anatomical sites leading to bloodstream infection. Candida auris might substantially contaminate the environment of colonized or infected patients making its eradication difficult. Patient screening for Candida auris, especially during prolonged ICU stays, along with strict infection prevention and control strategies needs to be adopted to break its persistence.

Challenges in culture-negative cases of Madurella mycetomatis: A case report re-accentuating PCR as an essential diagnostic tool

Identification of dematiaceous fungi responsible for black-grain mycetoma has remained cumbersome and time consuming for years leading to delayed diagnosis and thereby increased agony to patients. Moreover, difficult morphology of some of these fungi demanding enough expertise for species identification in addition to culture-negativity has often led to misdiagnosis and hence inapt treatment to the patients. We report the identification of Madurella mycetomatis from culture-negative black granules discharged from foot nodular lesions of a 27 years old male using PCR followed by sequencing of the internal transcribed spacer region. The patient's lesions were successfully treated using a combination of itraconazole (200mg) and terbinafine (250mg), confirming our diagnosis. Our case study proves the clinical value of PCR as the best, rapid and accurate diagnostic method for the identification of Madurella mycetomatis and related fungi, particularly in culture-negative cases.

[A comparative analysis of various antigenic proteins found in Haemonchus contortus--a review]

Many innovative researches on the development and introduction of recombinant vaccines against many economically important parasites were carried out in the 20th century. Research continues to hold promise with the development of immunological and molecular approaches for control of these parasites and in this regard it has already been seen that blood-sucking parasites such as Haemonchus contortus and Ostertagia ostertagi are susceptible to control by vaccines containing "novel" or "concealed" antigens. Haemonchus contortus is primarily pathogenic to sheep and its blood-feeding behaviour causes effects ranging from mild anaemia to mortality in young animals. Current means of control which are dependent on repeated treatment with anthelmintics are responsible for the increasing drug resistance of this parasite. Together with the growing concern of residual chemicals in the environment and food chain, this has led to attempts to better understand the biology of the parasite with an aim to develop alternate means of control, including the development of molecular vaccines. More problematic and also important is the formulation and delivery strategy to induce expulsion of this parasite, using vaccines containing recombinant "conventional" antigens. Tremendous progress has been made in the last decade in identifying several antigens from Haemonchus contortus which in their native form stimulate useful levels of protective immunity. Vaccines have been developed against H. contortus using 'novel' gut antigens from the parasite, but variable responsiveness of the host sheep has resulted in varying degrees of protection which are stimulated by these vaccines. Computer models have also been used to simulate vaccine efficacy in worm control and have yielded good results. This review will try to summarise the protective efficacy and also the molecular properties of principal candidate antigens which are expressed by this parasite. The review will try to cover the aspirations, current success, limitations and problems faced by researchers in the control of this economically important parasite.