The hyperinfection syndrome (HS) caused by Strongyloides stercoralis has a high mortality rate (15% to 87%). A variety of risk factors and predisposing conditions have been described, including new immunosuppressive therapies; HTLV-1 infection; cadaveric transplantation; immune reconstitution syndrome; haematological malignancies (especially lymphoma); tuberculosis; malnutrition secondary to chronic Strongyloides diarrhoea; international travel and immigration. Inhibition of Th2 cell-mediated, humoral or mucosal immunity is associated with HS. HS is more frequently seen in HTLV-1 than HIV patients. In AIDS, there is an increase in Th2 cytokines, while in HTLV-1 infection there is a decrease in the Th2 response, leading to an increased risk of autoinfection. Corticosteroid use remains the most frequent risk factor for HS. A number of ELISAs are useful for diagnosis and post-treatment evaluation. Once diagnosed, the disease may be managed effectively with anthelminthic drugs, including ivermectin. HS causes diverse symptoms and signs, with unusual manifestations leading to misdiagnosis and medical errors related to healthcare providers' lack of familiarity with the condition. HS is an example of an emerging tropical infection migrating to developed countries and requiring greater clinician awareness.

SUMMARY Humans encounter mycobacterial species due to their ubiquity in different environmental niches. In many individuals, pathogenic mycobacterial species may breach our first-line barrier defenses of the innate immune system and modulate the activation of phagocytes to cause disease of the respiratory tract or the skin and soft tissues, sometimes resulting in disseminated infection. Cutaneous mycobacterial infections may cause a wide range of clinical manifestations, which are divided into four main disease categories: (i) cutaneous manifestations of Mycobacterium tuberculosis infection, (ii) Buruli ulcer caused by Mycobacterium ulcerans and other related slowly growing mycobacteria, (iii) leprosy caused by Mycobacterium leprae and Mycobacterium lepromatosis, and (iv) cutaneous infections caused by rapidly growing mycobacteria. Clinically, cutaneous mycobacterial infections present with widely different clinical presentations, including cellulitis, nonhealing ulcers, subacute or chronic nodular lesions, abscesses, superficial lymphadenitis, verrucous lesions, and other types of findings. Mycobacterial infections of the skin and subcutaneous tissue are associated with important stigma, deformity, and disability. Geography-based environmental exposures influence the epidemiology of cutaneous mycobacterial infections. Cutaneous tuberculosis exhibits different clinical phenotypes acquired through different routes, including via extrinsic inoculation of the tuberculous bacilli and dissemination to the skin from other sites, or represents hypersensitivity reactions to M. tuberculosis infection. In many settings, leprosy remains an important cause of neurological impairment, deformity, limb loss, and stigma. Mycobacterium lepromatosis, a mycobacterial species related to M. leprae, is linked to diffuse lepromatous leprosy of Lucio and Latapí. Mycobacterium ulcerans produces a mycolactone toxin that leads to subcutaneous tissue destruction and immunosuppression, resulting in deep ulcerations that often produce substantial disfigurement and disability. Mycobacterium marinum, a close relative of M. ulcerans, is an important cause of cutaneous sporotrichoid nodular lymphangitic lesions. Among patients with advanced immunosuppression, Mycobacterium kansasii, the Mycobacterium avium-intracellulare complex, and Mycobacterium haemophilum may cause cutaneous or disseminated disease. Rapidly growing mycobacteria, including the Mycobacterium abscessus group, Mycobacterium chelonei, and Mycobacterium fortuitum, are increasingly recognized pathogens in cutaneous infections associated particularly with plastic surgery and cosmetic procedures. Skin biopsies of cutaneous lesions to identify acid-fast staining bacilli and cultures represent the cornerstone of diagnosis. Additionally, histopathological evaluation of skin biopsy specimens may be useful in identifying leprosy, Buruli ulcer, and cutaneous tuberculosis. Molecular assays are useful in some cases. The treatment for cutaneous mycobacterial infections depends on the specific pathogen and therefore requires a careful consideration of antimicrobial choices based on official treatment guidelines.

Immunocompromised persons are the most vulnerable population at risk for developing life-threatening clinical syndromes associated with strongyloidiasis, such as hyperinfection syndrome (HS) or dissemination. This review focuses on describing Strongyloides infection in the immunocompromised host, including immune response against this infection, analyzing the cases with HS published during the past 4 years in the United States, and describing the most sensitive diagnostic tools and the most effective treatment for each clinical syndrome. Strongyloidiasis is becoming an important parasitic disease in the United States, especially in the immunocompromised immigrant population. Because the transplant population is particularly at risk for developing HS, both recipients and donors should be screened for Strongyloides. Clinicians should also be aware that the development of HS can follow unexpectedly a few days after appropriate anthelminthic therapy. Highly sensitive screening tests are still not available in the major tertiary medical centers. Parenteral ivermectin has been used in some severe cases. Further therapy developments and improving diagnostic tools are warranted.

There is a better understanding of risk factors, clinical manifestations and complications, novel diagnosis tests and effective treatment, which together should help reduce the morbidity and mortality of these infections.

The geographic range and complexity of this disease are increasing.

Background Recent trials with dexamethasone and hydrocortisone have demonstrated benefit in patients with coronavirus disease 2019 (COVID‐19). Data on methylprednisolone are limited. Methods Retrospective cohort of consecutive adults with severe COVID‐19 pneumonia on high‐flow oxygen (FiO2 ≥ 50%) admitted to an academic centre in New York, from 1 March to 15 April 2020. We used inverse probability of treatment weights to estimate the effect of methylprednisolone on clinical outcomes and intensive care resource utilization. Results Of 447 patients, 153 (34.2%) received methylprednisolone and 294 (65.8%) received no corticosteroids. At 28 days, 102 patients (22.8%) had died and 115 (25.7%) received mechanical ventilation. In weighted analyses, risk for death or mechanical ventilation was 37% lower with methylprednisolone (hazard ratio 0.63; 95% CI 0.47‐0.86; P = .003), driven by less frequent mechanical ventilation (subhazard ratio 0.56; 95% CI 0.40‐0.79; P = .001); mortality did not differ between groups. The methylprednisolone group had 2.8 more ventilator‐free days (95% CI 0.5‐5.1; P = .017) and 2.6 more intensive care‐free days (95% CI 0.2‐4.9; P = .033) during the first 28 days. Complication rates were not higher with methylprednisolone. Conclusions In nonintubated patients with severe COVID‐19 pneumonia, methylprednisolone was associated with reduced need for mechanical ventilation and less‐intensive care resource utilization without excess complications.

The performance of Fas2-ELISA for the diagnosis of Fasciola hepatica infection in children living in areas of high endemicity for fascioliasis in the Peruvian Andes is analyzed. Fas2-ELISA is based on the detection of circulating IgG antibodies elicited in infected individuals against a F. hepatica antigen termed Fas2. The study was conducted in three Andean localities, Huertas-Julcan in Junin, Asillo in Puno, and Cajamarca, with a total population of 634 children in an age range 1 to 16 years old. Child fascioliasis prevalence was 21.1% in Huertas-Julcan, 25.4% in Asillo, and 24% in Cajamarca, estimated by coprological inspection. The seroprevalence of F. hepatica infection, determined by Fas2-ELISA, was 27.8% in Huertas-Julcan, 44.6% in Asillo, and 29.1% in Cajamarca. The overall sensitivity of Fas2-ELISA was 92.4%, the specificity 83.6%, and the negative predictive value 97.2%. No association between OD(450) Fas2-ELISA and infection intensity measured by egg counting was observed. Results show that Fas2-ELISA is a highly sensitive immunodiagnostic test for the detection of F. hepatica infection in children living in human fascioliasis endemic areas.

An observational descriptive study was conducted in a Shipibo-Conibo/Ese'Eja community of the rainforest in Peru to compare the Kato-Katz method and the spontaneous sedimentation in tube technique (SSTT) for the diagnosis of intestinal parasites as well as to report the prevalence of soil-transmitted helminth (STH) infections in this area. A total of 73 stool samples were collected and analysed by several parasitological techniques, including Kato-Katz, SSTT, modified Baermann technique (MBT), agar plate culture, Harada-Mori culture and the direct smear examination. Kato-Katz and SSTT had the same rate of detection for Ascaris lumbricoides (5%), Trichuris trichiura (5%), hookworm (14%) and Hymenolepis nana (26%). The detection rate for Strongyloides stercoralis larvae was 16% by SSTT and 0% by Kato-Katz, but 18% by agar plate culture and 16% by MBT. The SSTT also had the advantage of detecting multiple intestinal protozoa such as Blastocystis hominis (40%), Giardia intestinalis (29%) and Entamoeba histolytica/E. dispar (16%). The most common intestinal parasites found in this community were B. hominis, G. intestinalis, H. nana, S. stercoralis and hookworm. In conclusion, the SSTT is not inferior to Kato-Katz for the diagnosis of common STH infections but is largely superior for detecting intestinal protozoa and S. stercoralis larvae.