Intravenous Doxycycline, Azithromycin, or Both for Severe Scrub Typhus.

BACKGROUND: The appropriate antibiotic treatment for severe scrub typhus, a neglected but widespread reemerging zoonotic infection, is unclear. METHODS: In this multicenter, double-blind, randomized, controlled trial, we compared the efficacy of intravenous doxycycline, azithromycin, or a combination of both in treating severe scrub typhus. Patients who were 15 years of age or older with severe scrub typhus with at least one organ involvement were enrolled. The patients were assigned to receive a 7-day course of intravenous doxycycline, azithromycin, or both (combination therapy). The primary outcome was a composite of death from any cause at day 28, persistent complications at day 7, and persistent fever at day 5. RESULTS: Among 794 patients (median age, 48 years) who were included in the modified intention-to-treat analysis, complications included those that were respiratory (in 62%), hepatic (in 54%), cardiovascular (in 42%), renal (in 30%), and neurologic (in 20%). The use of combination therapy resulted in a lower incidence of the composite primary outcome than the use of doxycycline (33% and 47%, respectively), for a risk difference of -13.3 percentage points (95% confidence interval [CI], -21.6 to -5.1; P = 0.002). The incidence with combination therapy was also lower than that with azithromycin (48%), for a risk difference of -14.8 percentage points (95% CI, -23.1 to -6.5; P<0.001). No significant difference was seen between the azithromycin and doxycycline groups (risk difference, 1.5 percentage points; 95% CI, -7.0 to 10.0; P = 0.73). The results in the per-protocol analysis were similar to those in the primary analysis. Adverse events and 28-day mortality were similar in the three groups. CONCLUSIONS: Combination therapy with intravenous doxycycline and azithromycin was a better therapeutic option for the treatment of severe scrub typhus than monotherapy with either drug alone. (Funded by the India Alliance and Wellcome Trust; INTREST Clinical Trials Registry-India number, CTRI/2018/08/015159.).

The role and diagnostic accuracy of serology for COVID-19.

BACKGROUND: The role and performance of various serological tests for the diagnosis of COVID-19 are unclear. This study aimed to evaluate the performance of seven commercially available serological assays for SARS-CoV-2 antibodies by testing COVID-19 cases and controls. METHODS: Adult patients with fever for > 5 days, admitted to a tertiary-care teaching hospital in South India, were enrolled prospectively between June and December 2020. SARS-CoV-2 RT-PCR confirmed patients were classified as cases, and patients with febrile illness with laboratory-confirmed alternative diagnosis and healthy participants were controls. All participants were tested with SCoV-2 Detect™ IgM ELISA kit and SCoV-2 Detect™ IgG ELISA kit (InBios International, Seattle, USA) (Inbios), SARS-CoV-2 Total and SARS-CoV-2 IgG (Siemens Healthcare Diagnostics Inc., Tarrytown, USA) (Siemens), Roche Elecsys® Anti-SARS-CoV-2 (Roche Diagnostics, Rotkreuz, Switzerland) (Roche), Abbott SARS-CoV-2 IgG (Abbott Diagnostics, IL, USA) (Abbott), and Liaison® SARS-CoV-2 S1/S2 IgG (DiaSorinS.p.A., Saluggia, Italy) (Liaison). The sensitivities, specificities, positive predictive values (PPV), negative predictive values (NPV), and accuracies were compared. RESULTS: There were 303 participants: 153 cases and 150 controls. ELISA detecting anti-S protein antibody was more sensitive (88.9% for IgG and 86.3% for IgM) than the CLIAs (82.4% for total antibodies and 76.5-85.6% for IgG). Among CLIAs, Roche IgG was most sensitive (85.6%) followed by Abbott (83%) and Liaison (83%). Abbot had the best PPV (88.8%) and was more specific (89.3%) than Liaison (82%) and Roche (82%). Siemens IgG was less sensitive (76.5%) than Siemens Total (82.4%). The specificity of all the serological assays was modest (75-90%). Antibody test positivity increased with the duration of illness reaching 90% after 10 days of illness. When cases were compared against pre-pandemic controls, the IgG gave excellent specificity (98-100%). For seroprevalence studies, InBios IgG had the best accuracy (90.8%) with 88.9% sensitivity and 97.6% specificity. CONCLUSION: The serological assays are important adjuncts for the diagnosis of COVID-19 in patients with persistent symptoms, especially in the second week of illness. The value of serological diagnostic tests is limited in the first week of illness and they provide additional value in seroprevalence studies. The diagnostic accuracy of the ELISA and CLIA platforms were comparable.

Rhinofacial conidiobolomycosis: Clinical and microbiological characterisation and shift in the management of a rare disease.

BACKGROUND: Conidiobolomycosis is a rare tropical rhinofacial fungal infection which has not been well characterised. The available evidence in its management is sparse due to lack of clinical studies and the limited data on antifungal susceptibility patterns. OBJECTIVE: To analyse the clinical manifestations, antifungal treatment and outcomes of patients with conidiobolomycosis and to determine antifungal susceptibility profiles of the isolates. PATIENTS/METHODS: Retrospective analysis of data of all patients with a diagnosis of conidiobolomycosis confirmed by histopathology and culture at a tertiary care hospital from 2012 to 2019 was done. RESULTS: There were 22 patients, 21 males and one female, with a mean age of 37.1 years. Most common presenting symptom was nasal obstruction, found in 20 (90.90%) patients. Patients who presented within 12 months had a better cure rate (85%) compared to those who presented late (67%). Among the 19 patients who had a follow-up, good outcome was seen in 15 of the 17 (88.24%) patients who were on itraconazole or potassium iodide containing regimen. Of the six patients who received additional trimethoprim-sulphamethoxazole (co-trimoxazole), 67% showed good outcome with two patients showing complete cure and two patients still on treatment with significant improvement. High minimum inhibitory concentration (MIC) values were noted for azoles and amphotericin B, whereas co-trimoxazole showed lowest MIC ranges. CONCLUSION: Itraconazole and potassium iodide are reasonable first-line options for the treatment of conidiobolomycosis. Good clinical response to KI and comparatively lower MIC of co-trimoxazole are promising. Further studies are required for developing clinical breakpoints that can predict therapeutic outcomes.

Short intravenous amphotericin B followed by oral posaconazole using a simple, stratified treatment approach for diabetes or COVID-19-associated rhino-orbito-cerebral mucormycosis: a prospective cohort study.

OBJECTIVES: To evaluate the efficacy and safety of short-course intravenous amphotericin B followed by sustained release posaconazole tablets for diabetes or COVID-19-associated rhino-orbito-cerebral mucormycosis. METHODS: This prospective, pragmatic study included adults with diabetes or COVID-19-associated rhino-orbito-cerebral mucormycosis. Patients received short (7-14 days) or long (15-28 days) intravenous antifungal therapy (short intravenous antifungal treatment [SHIFT] or long intravenous antifungal treatment [LIFT], respectively) depending on the presence or absence of brain involvement. All patients received step-down posaconazole tablets, debridement, and glycemic control. The primary outcome was the treatment success at week 14, which was determined by assessing survival and the absence of disease progression through clinical evaluation and nasal endoscopy. Log-binomial regression analysis (risk ratio and 95% CI) was performed to assess factors associated with the primary outcome. RESULTS: Intravenous therapy was administered to 251 participants: SHIFT, 205 (median duration, 13 days); LIFT, 46 (median duration, 22 days). Treatment success at 3 months was 88% (217/248; 95% CI, 83-91%): SHIFT group, 93% (189/203; 89-96%); LIFT group, 62% (28/45; 47-76%). All-cause mortality was 12% (30/251): SHIFT group, 6% (13/205); LIFT group, 37% (17/46). Age (aRR [95% CI]: 1.02 [1.00-1.05]; p 0.027), diabetic ketoacidosis at presentation (2.32 [1.20-4.46]; p 0·012), glycated haemoglobin A1c (1.19 [1.03-1.39]; p 0.019), stroke (3.93 [1.94-7.95]; p 0·0001), and brain involvement (5.67 [3.05-10.54]; p < 0.0001) were independently associated with unsuccessful outcomes. DISCUSSION: Short intravenous amphotericin B with step-down posaconazole tablets should be further studied as primary treatment option for diabetes or COVID-19-associated mucormycosis in randomized controlled trials.

Community seroprevalence and risk factors for SARS-CoV-2 infection in different subpopulations in Vellore, India, and their implications for future prevention.

OBJECTIVES: The aim of this study was to inform public health policy decisions through the assessment of IgG antibody seroprevalence in the population and the risk factors for SARS-CoV-2 infection. METHODS: The seroprevalence of IgG antibodies among different subpopulations at the end of the first and second waves of the pandemic was estimated. Various risk factors associated with seropositivity, including sociodemography, IgG antibodies against endemic human coronavirus, and vaccination status, were also assessed. RESULTS: For all 2433 consenting participants, the overall estimated seroprevalences at the end of first and second waves were 28.5% (95% CI 22.3-33.7%) and 71.5% (95% CI 62.8-80.5%), respectively. The accrual of IgG positivity was heterogeneous, with the highest seroprevalences found in urban slum populations (75.1%). Vaccine uptake varied among the subpopulations, with low rates (< 10%) among rural and urban slum residents. The majority of seropositive individuals (75%) were asymptomatic. Residence in urban slums (OR 2.02, 95% CI 1.57-2.6; p < 0.001), middle socioeconomic status (OR 1.77, 95% CI 1.17-2.67; p = 0.007), presence of diabetes (OR 1.721, 95% CI 1.148-2.581; p = 0.009), and hypertension (OR 1.75, 95% CI 1.16-2.64; p = 0.008) were associated with seropositivity in multivariable analyses. CONCLUSION: Although considerable population immunity has been reached, with more than two-thirds seropositive, improved vaccination strategies among unreached subpopulations and high-risk individuals are suggested for better preparedness in future.

Accuracy of Xpert MTB/RIF Ultra for the diagnosis of tuberculosis in adult patients: a retrospective cohort study.

OBJECTIVES: The value of the "trace" result in Xpert Ultra for diagnosing active tuberculosis (TB) remains unclear. Our study evaluated the diagnostic accuracy of Xpert MTB/RIF Ultra (Xpert Ultra) (Cepheid, Sunnyvale, USA) over Xpert MTB/RIF (Xpert) (Cepheid, Sunnyvale, USA) and mycobacterial culture when compared with a composite reference standard (CRS). METHODS: A retrospective single-center observational study was conducted in a tertiary care hospital in South India. Over three months, patients (aged ≥15 years) data on Xpert Ultra tests and mycobacterial culture of pulmonary and extrapulmonary samples were extracted from their electronic medical records. Patients were defined as TB cases based on the CRS criteria. Sensitivity, specificity, positive and negative predictive values of diagnostic tests were calculated by comparing them to the CRS. RESULTS: Xpert Ultra was more sensitive (87.8%) than Xpert (72.1%) and culture (44.1%). The specificity of Xpert Ultra was lower (98.1%) than those of Xpert (100%) and culture (100%). The sensitivity (92%) and specificity (100%) of Xpert Ultra were highest when performed on pus samples. CONCLUSIONS: Xpert Ultra with the trace category is superior to the conventional Xpert, and mycobacterial culture in identifying TB.

The burden of scrub typhus in India: A systematic review.

BACKGROUND: Scrub typhus, a vector-borne zoonotic infection caused by the bacteria Orientia tsutsugamushi, is one of the most common and clinically important rickettsial infections worldwide. An estimated one million cases occur annually with a high case fatality rate. Although scrub typhus is a major public health threat in India, the burden and distribution remains unclear. We aimed to estimate the burden of scrub typhus in India. METHODOLOGY: We performed a systematic review of published literature on scrub typhus from India to extract information on epidemiology, morbidity, and mortality. Important databases were searched using keywords and appropriate combinations. We identified observational, interventional, and population-based studies and extracted the data to evaluate the number of cases diagnosed using serology or PCR and the number of deaths due to scrub typhus. We conducted a systematic narrative synthesis to summarize included studies. PRINCIPAL FINDINGS: In the last decade, there were 18,781 confirmed scrub typhus cases reported in 138 hospital-based studies and two community-based studies. IgM ELISA was used in 122 studies to confirm the cases in majority (89%). The proportion of scrub typhus among acute undifferentiated febrile illness (AUFI) studies was 25.3%, and community seroprevalence was 34.2%. Ninety studies had data published on multiple organ involvement out of which 17.4% of cases had multiple organ dysfunction syndromes, 20.4% patients required ICU admission, and 19.1% needed ventilation. The overall case-fatality rate was 6.3%, and the mortality among those with multi-organ dysfunction syndrome was as high as 38.9%. CONCLUSION/SIGNIFICANCE: Scrub typhus, a common acute febrile illness in India causing severe morbidity, accounts for a large number of deaths. The burden of the disease has been underappreciated. Early diagnosis and prompt treatment can significantly reduce complications and mortality. Establishing good surveillance and instituting appropriate control measures are urgently needed.

Performance of molecular and serologic tests for the diagnosis of scrub typhus.

Diagnosis of scrub typhus, caused by the bacterium Orientia tsutsugamushi, is challenging because of the overlap of its non-specific symptoms with other infections coupled with the lack of sufficient data on the performance of diagnostic tests. Early diagnosis of scrub typhus is crucial to improve outcomes and this study evaluates the diagnostic performance of various tests. The present study aims at assessing the accuracy of various rapid diagnostic tests, serologic tests, and nucleic acid amplification methods on well-characterized patient samples. Adult patients with acute febrile illness and manifestations suggestive of scrub typhus confirmed by positive PCR in the blood, eschar or tissue were characterized as cases. Patients with acute febrile illness and a confirmed alternate etiology such as culture-confirmed typhoid, smear/PCR positive for malaria, PCR/NS1 antigen positive for dengue, PCR positive for influenza, PCR/MAT positive for leptospirosis, PCR positive for spotted fever were characterized as controls with other infections. The healthy controls consisted of subjects from the same geographic region. We performed the following tests on blood samples for scrub typhus and calculated the sensitivity, specificity, positive predictive value, and negative predictive value: (1) Quantitative real time PCR using 47kDa gene (qPCR); (2) Conventional PCR using 56kDa gene (cPCR); (3) Loop-mediated isothermal amplification assay (LAMP assay); (4) Immunofluorescence assay (IFA); (5) Enzyme-linked immunosorbent assay (ELISA); (6) Weil-Felix test(WF test); and (7) Immunochromatographic Rapid Diagnostic Test (RDT).Among the 316 participants, 158 had confirmed scrub typhus (cases) and 158 were controls. ELISA and RDT detecting Orientia tsutsugamushi specific IgM antibodies had excellent discriminative potential with sensitivities and specificities of 92%, 94% and 92%, 92% respectively. The sensitivity and specificity of IFA were found to be 95% and 74% respectively. IgM serology had a false positivity rate of 8% with other acute febrile illnesses such as dengue, leptospirosis and spotted fever due to the nonspecific binding of the pentavalent IgM. LAMP assay had 91.7% sensitivity and 77.2% specificity while qPCR provided excellent sensitivity (97%) and perfect specificity. In conclusion, ELISA and RDT detecting Orientia tsutsugamushi specific IgM antibodies have excellent sensitivity and specificity while the accuracy of IFA is suboptimal for the diagnosis of scrub typhus. Given its perfect specificity and superior sensitivity, qPCR is preferred for diagnostic confirmation in reference laboratories particularly for diagnosis of early disease with less than 7 days duration. This study provides a comprehensive evaluation of all currently available diagnostic tests for scrub typhus.