Staphylococcus aureus pneumonia and dengue virus co-infection and review of implications of coinfection

Severe dengue in the intensive care unit

Dengue fever is considered the most prolific vector-borne disease in the world, with its transmission rate increasing more than eight times in the last two decades. While most cases present mild to moderate symptoms, 5% of patients can develop severe disease. Although the mechanisms are yet not fully comprehended, immune-mediated activation leading to excessive cytokine expression is suggested as a cause of the two main findings in critical patients: increased vascular permeability that may shock and thrombocytopenia, and coagulopathy that can induce hemorrhage. The risk factors of severe disease include previous infection by a different serotype, specific genotypes associated with more efficient replication, certain genetic polymorphisms, and comorbidities such as diabetes, obesity, and cardiovascular disease. The World Health Organization recommends careful monitoring and prompt hospitalization of patients with warning signs or propensity for severe disease to reduce mortality. This review aims to update the diagnosis and management of patients with severe dengue in the intensive care unit.

In-hospital mortality predictors among hospitalized adults and those with chronic kidney disease with dengue

BACKGROUND

Accurately identifying risk factors that predict fatality in dengue is crucial for patient triage and clinical management. Our objective was to identify predictors of death associated with dengue and investigate the clinical characteristics and risk factors among patients with chronic kidney disease (CKD) who died from dengue.

METHODS

A multicenter longitudinal observation study conducted from 2008 to 2019.

RESULTS

A total of 1272 patients (113 who died and 1186 who recovered) diagnosed with dengue were included. Old age, CKD, and an elevated white blood cell count at hospital presentation were identified as independent predictors of in-hospital mortality among individuals infected with the dengue virus. In a subgroup analysis of 138 patients with CKD infected with dengue virus, 64 (46.3%) patients died, with 46 (33.3%) patients dying within 7 days after symptom onset. Among 64 fatal dengue patients with CKD, 34.4% were in stages 2 and 3 of kidney disease, 51.5% were in stages 4 and 5, and 14.1% had end stage renal disease as per the classification by Kidney Disease Improving Global Outcomes. Multivariate analysis revealed that initial altered consciousness, pulmonary edema, and leukocytosis during hospitalization were independently associated with in-hospital mortality in CKD patients infected with the dengue virus. Leukocytosis during hospitalization and severe hepatitis were independent risk factors for death within 7 days after dengue illness onset in CKD patients.

CONCLUSIONS

This study offers valuable insights into predictors linked to fatality in dengue and reinforces the importance of optimizing patient triage to improve the quality of care.

Viral infectious diseases severity: co-presence of transcriptionally active microbes (TAMs) can play an integral role for disease severity

Humans have been challenged by infectious diseases for all of their recorded history, and are continually being affected even today. Next-generation sequencing (NGS) has enabled identification of, i) culture independent microbes, ii) emerging disease-causing pathogens, and iii) understanding of the genome architecture. This, in turn, has highlighted that pathogen/s are not a monolith, and thereby allowing for the differentiation of the wide-ranging disease symptoms, albeit infected by a primary pathogen. The conventional 'one disease - one pathogen' paradigm has been positively revisited by considering limited yet important evidence of the co-presence of multiple transcriptionally active microbes (TAMs), potential pathogens, in various infectious diseases, including the COVID-19 pandemic. The ubiquitous microbiota presence inside humans gives reason to hypothesize that the microbiome, especially TAMs, contributes to disease etiology. Herein, we discuss current evidence and inferences on the co-infecting microbes particularly in the diseases caused by the RNA viruses - Influenza, Dengue, and the SARS-CoV-2. We have highlighted that the specific alterations in the microbial taxonomic abundances (dysbiosis) is functionally connected to the exposure of primary infecting pathogen/s. The microbial presence is intertwined with the differential host immune response modulating differential disease trajectories. The microbiota-host interactions have been shown to modulate the host immune responses to Influenza and SARS-CoV-2 infection, wherein the active commensal microbes are involved in the generation of virus-specific CD4 and CD8 T-cells following the influenza virus infection. Furthermore, COVID-19 dysbiosis causes an increase in inflammatory cytokines such as IL-6, TNF-α, and IL-1β, which might be one of the important predisposing factors for severe infection. Through this article, we aim to provide a comprehensive view of functional microbiomes that can have a significant regulatory impact on predicting disease severity (mild, moderate and severe), as well as clinical outcome (survival and mortality). This can offer fresh perspectives on the novel microbial biomarkers for stratifying patients for severe disease symptoms, disease prevention and augmenting treatment regimens.

Coinfection with dengue and hepatitis A complicated with infective endocarditis in a Yemeni patient: a case report

INTRODUCTION

Coinfection with dengue and hepatitis A is rare and challenging for physicians since their clinical features can be overlapping. These infections are self-limiting but can become complicated by subsequent infective endocarditis. We report a case of infective endocarditis following a coinfection with dengue and hepatitis A.

CASE PRESENTATION

A 17-year-old Yemeni male patient was admitted to the hospital complaining of yellowish discoloration of the skin and sclera associated with dark urine and a diffuse skin rash on the trunk and upper limbs followed by intermittent high-grade fever. Coinfection was confirmed by hepatitis A immunoglobulin M and dengue immunoglobulin M. At the time of diagnosis, white blood cells were normal, with mild neutrophilia and thrombocytopenia along with elevated C-reactive protein. Five days later, the patient was readmitted to the emergency department, complaining of high-grade fever, fatigue, myalgia, nausea, and vomiting. A systolic heart murmur was heard, and infective endocarditis was confirmed by the visualization of two vegetations on the mitral valve and coagulase-negative staphylococci after blood culture. Supportive therapies were initiated for hepatitis A and dengue fever, whereas infective endocarditis was treated with antibiotics for 4 weeks. The patient recovered completely from dengue, hepatitis A, and infective endocarditis.

CONCLUSION

In endemic areas, it is reasonable to screen for coinfection with dengue and hepatitis A since they are superimposed on each other. Subacute infective endocarditis may occur following initial dengue and hepatitis A coinfection, especially among patients with rheumatic heart disease. An echocardiogram is a pivotal workup for evaluating a patient with persistent fever of unknown origin.

Atypical Presentation of Methicillin-Susceptible Staphylococcus aureus Infection in a Dengue-Positive Patient: A Case Report with Virulence Genes Analysis

Concurrent bacteraemia in patients with dengue fever is rarely reported. We report a case of a patient who initially presented with symptoms typical of dengue fever but later succumbed to septic shock caused by hypervirulent methicillin-susceptible Staphylococcus aureus (MSSA). A 50-year-old female patient with hypertension and diabetes mellitus presented with typical symptoms of dengue fever. Upon investigation, the patient reported having prolonged fever for four days prior to hospitalization. Within 24 hours post-admission, the patient developed pneumonia and refractory shock, and ultimately succumbed to multiple-organs failure. Microbiological examination of the blood culture retrieved a pan susceptible MSSA strain. Genomic sequence analyses of the MSSA strain identified genes encoding staphylococcal superantigens (enterotoxin staphylococcal enterotoxin C 3 (SEC3) and enterotoxin-like staphylococcal enterotoxins-like toxin L (SElL)) that have been associated with toxic shock syndrome in human hosts. Genes encoding important toxins (Panton-Valentine leukocidins, alpha-haemolysin, protein A) involved in the development of staphylococcal pneumonia were also present in the MSSA genome. Staphylococcus aureus co-infections in dengue are uncommon but could be exceptionally fatal if caused by a toxin-producing strain. Clinicians should be aware of the risks and signs of sepsis in dengue fever, thus allowing early diagnosis and starting of antibiotic treatment in time to lower the mortality and morbidity rates.

Concurrent methicillin-resistant Staphylococcus aureus septicemia and pyomyositis in a patient with dengue hemorrhagic fever: a case report

BACKGROUND

Concurrent presence of dengue hemorrhagic fever (DHF), tropical pyomyositis and septicemia due to methicillin-resistant Staphylococcus aureus (MRSA) in a previously healthy person has never been reported. These three conditions even individually are potentially fatal. "Here we describe a case of a patient contracting dengue and developing DHF along with concurrent pyomyositis likely to be due to MRSA, leading to MRSA septicemia with abscesses formed by MRSA".

CASE PRESENTATION

A 44-year old previously healthy Sinhalese man presented on day 3 of the illness with fever, headache, arthralgia and myalgia and watery loose stools. His pulse rate was 76/min, blood pressure was 110/80 mmHg, while cardiovascular, respiratory and abdomen examination findings were unremarkable. The test for the dengue NS1 antigen was positive on the same day. We have diagnosed dengue and started managing him symptomatically as per the current national guidelines. The patient developed DHF with bilateral pleural effusion and ascitis. On the day 5 he developed severe myalgia, tenderness and non pitting edema of lower limbs especially in the thighs. His creatine kinase levels were high and an ultrasound scan confirmed myositis of both thighs. We suspected myositis due to dengue but investigated for possible simultaneous sepsis as well. On day 9 his blood culture became positive for MRSA. Considering the sensitivity of the bacteria intravenous vancomycin and ciprofloxacin was administered for 21 days. He developed a small abscess at the site of the first intravenous access and a large one above the ankle on the left. On day 12 the latter was drained and the pus culture yielded MRSA sensitive to the same antibiotics. The rapid test for dengue IgM was negative initially but later a positive MAC-ELISA test entrenched dengue infection. After improvement he was sent home on day 33 of the illness. He has developed two other abscesses in the proximity of the drained one and they were drained on day 57. The patient recovered.

CONCLUSIONS

When dengue patients develop symptoms and signs of myositis, prompt investigations for pyomyositis and the treatment can save lives.

Fatal case of co-infection with dengue virus and Neisseria meningitidis during a dengue epidemic in the state of Rio de Janeiro, Brazil

INTRODUCTION

Dengue and meningococcal disease are caused by two different agents: a flavivirus and a Gram-negative bacterium, respectively. The first symptoms of both diseases can be indistinct and a rapid and accurate diagnosis is crucial, considering that both diseases are associated with high morbidity and mortality, representing a major public-health problem in Brazil.

CASE PRESENTATION

We report a fatal case of co-infection of dengue virus (DENV) and Neisseria meningitidis in a 54-year-old patient. The serum tested positive for DENV NS1 antigen, and N. meningitidis serogroup C was detected by nspA-PCR. Following the initial positive result for DENV infection, rRT-PCRwas performed and DENV-4 was confirmed.

CONCLUSION

Our report highlights the importance of accurate differential diagnosis during periods of high circulation of DENV, in order to provide adequate management and an improved outcome.

The outcomes of patients with severe dengue admitted to intensive care units

Outcomes of adult patients with dengue infections requiring intensive care unit (ICU) admissions remain unclear. We assessed the clinical manifestations and prognostic factors of patients critically ill with severe dengue.This retrospective study was done in a tertiary referral hospital with 96 adult ICU beds. All of the patients with laboratory-confirmed severe dengue infections and admitted to the ICU were enrolled between July 31 and November 31, 2015, during the large outbreak period. The medical records of all the recruited patients were reviewed for the following information: age, gender, clinical manifestations, disease severity scores, underlying conditions, laboratory examinations, and outcomes. The primary endpoint was to find the predictors of ICU mortality.During the study period, 4787 patients with dengue infections required ICU admission. One hundred forty-three (2.99%) were critically ill (mean age: 69.7 years). Hypertension (n = 90, 62.9%) and diabetes mellitus (n = 70, 49.0%) were the 2 most common underlying diseases. Eighty critically ill patients (55.9%) had cobacterial infections, and 33 had cobacteremia. The hematologic system failed most often, followed by thoracic and cardiovascular systems. Fever was the most common presentation (n = 112; 78.3%), followed by anorexia (n = 47; 32.9%) and abdominal pain (n = 46; 32.2%). Overall, 33 patients died (mortality rate: 23.1%). Multivariate analysis showed that ICU mortality was significantly associated with lower Glasgow Coma Scale (GCS) scores, lower platelet counts before ICU discharge, and more organ failures.The number of severe dengue patients who require ICU admission remains high. The mortality rate was associated with lower GCS scores, lower platelet counts, and more organ failures. In addition, more than half of the critically ill dengue patients had comorbid bacterial infections.

Bacterial coinfections in dengue virus disease: what we know and what is still obscure about an emerging concern

PURPOSE

Dengue virus is the most frequent arthropod-borne viral infection worldwide. Simultaneously to the growth of its incidence, cases of bacterial coinfection in dengue have been increasingly reported. The clinical course of dual infections may worsen for reciprocal interactions and delays in the diagnosis, so that clinicians should be aware of this eventuality. Therefore, we reviewed literature to provide an overview of the epidemiological, clinical, and physiopathological issues related to bacterial coinfections and bacteremia in dengue.

METHODS

Clinical studies and case reports regarding bacteremia and bacterial coinfections in dengue and the interactions between the pathogens published on PubMed were reviewed.

RESULTS

We found 26 case reports, only 3 studies on concurrent bacteremia and 12 studies reporting data on bacterial coinfections in dengue. According to the three available studies, the 0.18-7 % of dengue infections are accompanied by concurrent bacteremia, while the 14.3-44.4 % of dengue-related deaths seem associated to bacterial coinfections. Comorbidities, advanced age, and more severe dengue manifestations could be risk factors for dual infections. A longer duration of fever and alterations in laboratory parameters such as procalcitonin, hyponatremia, leukocyte count, and renal function tests can raise the suspicion.

CONCLUSIONS

Despite the real burden and consequences of this emerging concern is still not computable accurately due to the lack of a significant number of studies on large cohorts, clinicians need a greater awareness about it to early recognize warning signs, to properly use available diagnostic tools and to readily start antibiotic treatment able to prevent worsening in mortality and morbidity.

Laboratory-acquired dengue virus infection by needlestick injury: a case report, South Korea, 2014

Background

Dengue fever is one of the most dominant vector-borne diseases, putting approximately 3.9 billion people at risk worldwide. While it is generally vector-borne, other routes of transmission such as needlestick injury are possible. Laboratory workers can be exposed to dengue virus transcutaneously by needlestick injury. This is the first case, to our knowledge, of dengue virus infection by needlestick injury in a laboratory environment. This paper evaluates the risk and related health concerns of laboratory workers exposed to dengue virus.

Case presentation

We evaluated a 30-year-old female laboratory worker exposed to the dengue virus by needlestick injury while conducting virus filtering. During admission, she showed symptoms of fever, nausea, myalgia, and a characteristic maculopapular rash with elevated aspartate aminotransferase (AST) of 235 IU/L and alanine aminotransferase (ALT) of 269 IU/L. She had been diagnosed by a positive nonstructural protein 1 (NS1) antigen (Ag) rapid test one day prior to symptom onset along with positive immunoglobulin M (IgM) enzyme-linked immunosorbent assay (ELISA) on the ninth day of symptom onset. Reverse transcription polymerase chain reaction (RT-PCR), also conducted on the ninth day, was negative. After proper symptomatic treatment, she recovered without any sequelae. As a result of thorough epidemiologic investigation, it was determined that she had tried to recap the needle during the virus filtering procedure and a subsequent needlestick injury occurred.

Conclusions

In the context of health promotion of laboratory workers, we suggest that the laboratory biosafety manual be revised and reinforced, and related prevention measures be implemented. Furthermore, health authorities and health care providers in Korea should be fully informed of proper dengue fever management.

Cavity Forming Pneumonia Due to Staphylococcus aureus Following Dengue Fever

While visiting Malaysia, a 22-year-old previously healthy Japanese man developed myalgia, headache, and fever, leading to a diagnosis of classical dengue fever. After improvement and returning to Japan after a five day hospitalization, he developed productive cough several days after defervescing from dengue. Computed tomography (CT) thorax scan showed multiple lung cavities. A sputum smear revealed leukocytes with phagocytized gram-positive cocci in clusters, and grew an isolate Staphylococcus aureus sensitive to semi-synthetic penicillin; he was treated successfully with ceftriaxone and cephalexin. This second reported case of pneumonia due to S. aureus occurring after dengue fever, was associated both with nosocomial exposure and might have been associated with dengue-associated immunosuppression. Clinicians should pay systematic attention to bacterial pneumonia following dengue fever to establish whether such a connection is causally associated.

Stable Expression and Characterization of an Optimized Mannose Receptor

The mannose receptor (MR) is a macrophage surface receptor that recognizes pathogen associated molecular patterns (PAMPs) from a diverse array of bacterial, fungal and viral pathogens. Functional studies of the MR are hampered by the scarcity of human cell lines that express the receptor. Current model systems available for the study of MR biology often demonstrate low levels of expression and do not retain many of the classical MR properties. Although several laboratories have reported transient and stable expression of MR from plasmids, preliminary data from our laboratory suggests that these plasmids produce a protein that lacks critical domains and is often not stable over time. In this current report we describe the generation and characterization of a novel human codon-optimized system for transient and stable MR expression. Rare codons and sequences that contribute to mRNA instability were modified to produce mRNA that is qualitatively and quantitatively improved. Confocal imaging of the transient and stably expressed optimized receptor demonstrates a distribution consistent with previous reports. To demonstrate the functional characteristics of the optimized receptor, we further show that the introduction of codon-optimized MR plasmid can confer MR-associated phagocytosis of S. aureus to non-phagocytic HeLa cells. We show that three molecules participate in the engagement and internalization of S. aureus. MR was found to colocalize with Toll-like receptor 2 (TLR2) and Rab5 following exposure to pHrodo-stained S. aureus, suggesting cooperation among the three molecules to engage and internalize the bacterial particle. This study describes a transfection capable, optimized MR receptor with functional characteristics similar to the wild type receptor and further demonstrates a new system for the continued study of MR biology and function.