Dengue fever: Report from the task force on tropical diseases by the World Federation of Societies of Intensive and Critical Care Medicine

Distinct inflammatory markers in primary and secondary dengue infection: can cytokines CXCL5, CXCL9, and CCL17 act as surrogate markers?

Dengue fever poses a significant global health threat, with symptoms including dengue hemorrhagic fever and dengue shock syndrome. Each year, India experiences fatal dengue outbreaks with severe manifestations. The primary cause of severe inflammatory responses in dengue is a cytokine storm. Individuals with a secondary dengue infection of a different serotype face an increased risk of complications due to antibody-dependent enhancement. Therefore, it is crucial to identify potential risk factors and biomarkers for effective disease management. In the current study, we assessed the prevalence of dengue infection in and around Aligarh, India, and explored the role of cytokines, including CXCL5, CXCL9, and CCL17, in primary and secondary dengue infections, correlating them with various clinical indices. Among 1,500 suspected cases, 367 tested positive for dengue using Real-Time PCR and ELISA. In secondary dengue infections, the serum levels of CXCL5, CXCL9, and CCL17 were significantly higher than in primary infections (P < 0.05). Dengue virus (DENV)-2 showed the highest concentrations of CXCL5 and CCL17, whereas DENV-1 showed the highest concentrations of CXCL9. Early detection of these cytokines could serve as potential biomarkers for diagnosing severe dengue, and downregulation of these cytokines may prove beneficial for the treatment of severe dengue infections.

The Emergence of Travel-related Infections in Critical Care Units

Several tropical or geographically confined infectious diseases may lead to organ failure requiring management in an intensive care unit (ICU), both in endemic low- and middle-income countries where ICU facilities are increasingly being developed and in (nonendemic) high-income countries through an increase in international travel and migration. The ICU physician must know which of these diseases may be encountered and how to recognize, differentiate, and treat them. The four historically most prevalent "tropical" diseases (malaria, enteric fever, dengue, and rickettsiosis) can present with single or multiple organ failure in a very similar manner, which makes differentiation based solely on clinical signs very difficult. Specific but frequently subtle symptoms should be considered and related to the travel history of the patient, the geographic distribution of these diseases, and the incubation period. In the future, ICU physicians may also be more frequently confronted with rare but frequently lethal diseases, such as Ebola and other viral hemorrhagic fevers, leptospirosis, and yellow fever. No one could have foreseen the worldwide 2019-up to now coronavirus disease 2019 (COVID-19) crisis caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which was initially spread by travel too. In addition, the actual pandemic due to SARS-CoV-2 reminds us of the actual and potential threat of (re)-emerging pathogens. If left untreated or when treated with a delay, many travel-related diseases remain an important cause of morbidity and even mortality, even when high-quality critical care is provided. Awareness and a high index of suspicion of these diseases is a key skill for the ICU physicians of today and tomorrow to develop.

An Approach to a Patient with Tropical Infection in the Intensive Care Unit

How to cite this article: Karnad DR, Amin P. An Approach to a Patient with Tropical Infection in the Intensive Care Unit. Indian J Crit Care Med 2021;25(Suppl 2):S118–S121.

Tropical diseases in the ICU: A syndromic approach to diagnosis and treatment

Tropical infections form 20-30% of ICU admissions in tropical countries. Diarrheal diseases, malaria, dengue, typhoid, rickettsial diseases and leptospirosis are common causes of critical illness. Overlapping clinical features makes initial diagnosis challenging. A systematic approach involving (1) history of specific continent or country of travel, (2) exposure to specific environments (forests or farms, water sports, consumption of exotic foods), (3) incubation period, and (4) pattern of organ involvement and subtle differences in manifestations help in differential diagnosis and choice of initial empiric therapy. Fever, rash, hypotension, thrombocytopenia and mild derangement of liver function tests is seen in a majority of patients. Organ failure may lead to shock, respiratory distress, renal failure, hepatitis, coma, seizures, cardiac arrhythmias or hemorrhage. Diagnosis in some conditions is made by peripheral blood smear examination, antigen detection or detection of microbial nucleic acid by PCR. Tests that detect specific IgM antibody become positive only in the second week of illness. Initial therapy is often empiric; a combination of intravenous artesunate, ceftriaxone and either doxycycline or azithromycin would cover a majority of the treatable syndromes. Additional antiviral or antiprotozoal medications are required for some specific syndromes. Involving a physician specializing in tropical or travel medicine is helpful.

Clinical and Hematological Profile of Patients with Dengue Fever at a Tertiary Care Hospital - An Observational Study

Background

Dengue is a major health issue with seasonal rise in dengue fever cases imposing an additional burden on hospitals, necessitating bolstering of services in the emergency department, laboratory with creation of additional dengue fever wards.

Objectives

To study the clinical and hematological profile of dengue fever cases presenting to a hospital.

Methods

Patients with fever and other signs of dengue with either positive NS1 antigen test or IgM or IgG antibody were included. Age, gender, clinical presentation, platelet count and hematocrit were noted and patients classified as dengue fever without warning signs (DF) or with warning signs (DFWS), and severe dengue (SD) with severe plasma leakage, severe bleeding or severe organ involvement. Duration of hospitalization, bleeding manifestations, requirement for platelet component support and mortality were recorded.

Results

There were 443 adults and 57 children between 6 months to 77 year age. NS1 was positive in 115 patients (23%). Fever (99.8%) and severe body ache (97.4%) were the commonest presentation. DF was seen in 429 (85.8 %), DFWS in 55 (11%), SD with severe bleeding in 10 (2%) and SD with severe plasma leakage in 6 cases (1.2%). Outpatient department (OPD) treatment was needed in 412 (82%) and hospitalization in 88 (18%). Intravenous fluid resuscitation was needed in 16 (3.2%) patients. Thrombocytopenia was seen in 335 (67%) patients at presentation. Platelet transfusion was needed in 46 (9.2%). Packed red blood cell (PRBC) transfusion was given in 3 patients with DFWS and 10 of SD with severe bleeding. Death occurred in 3 patients of SD with severe plasma leak and 2 patients with SD and severe bleeding.

Conclusions

Majority of DF cases can be managed on OPD basis. SD with severe bleeding or with severe plasma leakage carries high mortality. Hospitals can analyze annual data for resource allocation for capacity expansion.