Year : 2017 | Volume
: 9 | Issue : 1 | Page : 1--2
State of the globe: Impracticality of clinical scores in acute undifferentiated fever: A global challenge
Vivek Chauhan1, Suman Thakur2,
1 Department of Medicine, Dr. RPGMC, Kangra, Himachal Pradesh, India
2 Department of Microbiology, Dr. RPGMC, Kangra, Himachal Pradesh, India
Department of Medicine, Dr. RPGMC, Kangra - 176 001, Himachal Pradesh
|How to cite this article:|
Chauhan V, Thakur S. State of the globe: Impracticality of clinical scores in acute undifferentiated fever: A global challenge.J Global Infect Dis 2017;9:1-2
|How to cite this URL:|
Chauhan V, Thakur S. State of the globe: Impracticality of clinical scores in acute undifferentiated fever: A global challenge. J Global Infect Dis [serial online] 2017 [cited 2017 Feb 24 ];9:1-2
Available from: http://www.jgid.org/text.asp?2017/9/1/1/199993
Dengue is rapidly becoming a global challenge as the number of countries affected increased from 36 to 64 in just 8 years (1999–2007). India, in 2009, reported 100 deaths among 16,000 cases of dengue. Dengue infections have variable presentation and up to 87% have been shown to be asymptomatic or minimally symptomatic, and in the absence of testing facilities, the real figures could be manifold. Dengue has four serotypes that have all been documented in India. Infection with a particular serotype leads to a lifelong immunity to that serotype. First or primary infection is mildly symptomatic and rarely requires hospitalization while the secondary infection with another serotype is responsible for most cases with severe clinical manifestations.,, The dengue illness has been divided into febrile phase (lasting 2–7 days), critical phase (3rd–7th day), and recovery phase (8th day onwards). In critical phase, capillary permeability leads to rise in hematocrit along with falling platelets and defervescence of fever. Most patients recover after 48 h but some progress to hemorrhages, multiple organ dysfunction, and shock. The knowledge about previous dengue infection in a febrile individual, indicated by the IgG antibodies, is more valuable than the confirmation of dengue infection itself. We have to be vigilant if it is a secondary infection with preformed IgG antibodies detectable during the febrile phase as these are more likely to develop severe manifestations during critical phase. There are no absolute markers, during the febrile phase, to guess who is going to progress to dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS). The WHO has enlisted warning signs that include: abdominal pain or tenderness, persistent vomiting, clinical fluid accumulation, mucosal bleed, lethargy, restlessness, liver enlargement >2 cm, and increasing hematocrit with falling platelets. Diagnosis of dengue, during the 1st week of illness, relies mainly upon detection of NS1 antigen using ELISA which is not available in most parts of India. Since most cases of primary dengue and mildly symptomatic secondary dengue go unreported, most patients who present to the hospitals are those with severe manifestations and require close monitoring for development of DHS and DSS. Hematocrit and tourniquet test are suggested to diagnose DHS in its early stages and checked repeatedly, during treatment and observation.
The clinical picture of severe dengue can be confused with scrub typhus, leptospirosis, malaria, typhoid, and bacterial sepsis, and all of these have peaking during June–October. Malaria is easy to diagnose, using a rapid card test and microscopy, whereas leptospirosis and scrub typhus are difficult to diagnose during the first 5 days of illness as IgM antibodies take 1 week to appear. Clinically, eschar is a pathognomonic sign for scrub typhus, and very high bilirubin with mild elevation of transaminases favors leptospirosis (Weil's disease). Patients with fatal hemorrhagic fever variant of leptospirosis can be difficult to differentiate from DHF. Luckily, this variant has only been reported from few sites in India that include Andaman islands and Gujarat, so its diagnosis does not pose many challenges.
Practically, in the absence of rapid diagnostic tools to diagnose dengue, scrub typhus, and leptospirosis, during the first 5 days of illness, physicians have to rely upon their own clinical sense. Mitra et al. have proposed a clinical score, based on their analysis of data from 201 dengue cases and 188 scrub typhus cases, to differentiate between dengue and scrub typhus. Although their attempt looks attractive with a sensitivity and specificity of 85% and 77%, respectively, to differentiate dengue from scrub, do we really need to do that? Since scrub typhus is treatable with doxycycline, physicians are unlikely to apply a score that labels even one case of scrub typhus as dengue. Withholding doxycycline in false-negative cases for scrub typhus may have disastrous consequences. In places where dengue, scrub typhus, and leptospirosis are endemic during monsoons, the best treatment regimen is a combination of injectable ceftriaxone and oral doxycycline that covers for infections such as scrub typhus, leptospirosis, typhoid, and bacterial sepsis. We also should keep in mind that multiple infections in endemic areas are always possible, so treatment based upon clinical scores may be dangerous in such patients.
Validation of the proposed clinical score by Mitra et al. is still to be done, so we advise our readers not to withhold the time-sensitive treatments such as doxycycline and ceftriaxone in patients who have been labeled as dengue based on this clinical score alone, till this score is validated. Authors have themselves mentioned in their limitation section that they did not use polymerase chain reaction-based confirmation of dengue cases neither had they used gold standard immunofluorescence assay to confirm scrub typhus. Furthermore, the authors have not made it clear what percentage of their dengue patients was primary infections, DHF or DSS. Just by varying the proportion of primary infections, DHF and DSS in their data set can change the elements of the score. Furthermore, exclusion of age, eschar, and bleeding manifestations from their score may appear confusing. A test recommended by the WHO, i.e., tourniquet test, should have been included as it can diagnose hemorrhagic manifestations and is recommended in resource poor settings for early diagnosis of DHF.
To conclude, while the attempt to design a clinical score seems attractive, the clinical applicability may be limited. Still, some take home messages for us, from the study by Mitra et al. to say that dengue is a more likely cause of acute undifferentiated fever compared to scrub typhus if the patient is young, has leukocyte counts <4000/mm 3, hemoconcentration manifest by hemoglobin >14, high transaminase levels, bleeding manifestations, saturation of oxygen >90%, no eschar, and a normal sensorium. We would like to repeat that even in the absence of eschar, doxycycline must be given to all patients of acute undifferentiated fever in typhus endemic regions, during monsoons along with the injectable ceftriaxone to cover for leptospirosis and enteric fever as mixed infections are not uncommon.
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