Avaliação do hemograma, da velocidade de hemossedimentação (VHS) e da proteína C reativa (PCR) como preditores diagnósticos da síndrome febril de caráter infeccioso

Abstract

Fever is the oldest and most frequent sign/symptom in the entire field of medicine. It is present in all ages and comprises all medical specialties. Currently, are known more than 200 causes of fever, being the etiology infectious the most common. The fever can be short term – more related to viral etiology -, and long-term, more frequently caused by bacteria, protozoa and, fungi. When excessively prolonged, it is more linked to structural factors, such as autoimmune diseases and neoplasms. The extension of etiology poses fever as a challenge most of the time. The hemogram, in turn, is the most requested exam in the medical routine due to its wide utility, since it can provide more than 20 parameters for analysis, enabling to perform a broad clinical evaluation and monitor the evolution of cases. Hemogram is very useful in the assessment of fever syndrome, as it shows a reactional state in response to infectious diseases, mainly if added to the evaluation of inflammatory tests, including the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). This study aimed to evaluate the application of the hemogram, ESR and CRP combined with clinical-epidemiological factors and time of illness as diagnostic predictors of infectious fever syndrome. We evaluated 319 patients with fever syndrome of infectious origin, being 77 of bacterial causes, 113 of viral causes, and 129 parasitic etiology, aged between 18 and 60 years old, who were attended at the Unified Medical Care Sector of Evandro Chagas Institute, between the period from 02/2018 to 01/2020. Another 213 healthy individuals were included in the study as control group. For data analysis, we used Microsoft Office Excel (2007), Biostat 5.0 (2007), SPSS Statistics 17.0 (2010), GraphPad Prism 9.0.0 Release Notes (2020), and Rv 3.5.2 (2018) software. We applied the Odds ratio (OR) to assess chances; Kruskal-Wallis for variance; Youden index for the cutoff points between variables, and ROC curve (AUROC) for accuracy. The p-value < 0.05 was considered statistically significant. The results revealed that the bacterial diseases have as characteristics in hemogram the increase in the number of neutrophils, which reflects in the numerical increase of leukocytes; In contrast, the viral diseases are characterized by the numerical reduction of lymphocytes, mainly of neutrophils, with reflection on the total number of leukocytes defined as leukopenia; the parasitic diseases assumed an intermediate profile between bacterial and viral, marked by the numerical normality of white blood cells, thus resembling the control group. However, the mean of lymphocytes was higher than in the other diseases, including the control group. In general, in bacterial diseases, there is an increase in ERS, and especially in CRP, which are also increased in parasitic diseases; but in viral diseases, these tests tend to be numerically normal, being similar to the control group in this aspect. Therefore, the inflammatory tests are increased in bacterial and parasitic diseases, but mainly in the first-mentioned, and are normal in viral diseases. Diseases such as malaria, visceral leishmaniasis, typhoid fever, HIV, and Epstein-Barr virus infections can be identified by findings peculiar to them observed in hemogram. We concluded that the numerical values of the hemogram, as well as the levels of ESR and CRP, combined with clinical and epidemiological factors and to the time of illness can predict groups of diseases and even predict specific diseases causative of infectious fever syndrome.