Leptospirosis diagnosis among patients suspected of dengue fever in Brazil

Abstract

Background: The early symptoms of leptospirosis and dengue fever are difficult to distinguish and can cause diagnostic confusion. Due to the large dengue epidemics that has occurred in Brazil in recent years, it is possible that cases of leptospirosis were unreported. Therefore, we performed a retrospective study to detect leptospirosis in patients who were tested for dengue, but whose laboratory diagnoses were negative. Methods: Sera samples from 2,017 patients from 48 cities located in the central region of São Paulo state, Brazil, were studied. All samples were subjected to the microscopic agglutination test (MAT), 305 of which were taken from patients five days or less since the onset of symptoms, and were additionally subjected to real-time polymerase chain reaction (PCR). Results: The overall prevalence of leptospirosis cases was 21 (1.04%), with 20 through MAT (18 for Icterohaemorrhagiae and two for the Cynopteri serogroup) and one through PCR (amplicon sequencing compatible with Leptospira interrogans ). According to previously established criteria, eight cases of leptospirosis were classified as “confirmed” and 13 as “probable”. The Brazilian notification system for health surveillance had no records for 16 patients positive for leptospirosis and, thus, they were considered unreported cases. Statistical analyses revealed that the prevalence of leptospirosis was higher in men (1.56%) than in women (0.56%), and the mean age was higher in positive patients (43.7 years) than in negative ones (32.3 years). Conclusion: The results indicated that patients suspected of dengue fever had evidence of leptospirosis or Leptospira infection, and most of these cases were unreported in the Brazilian notification system. The high burden of dengue may contribute to the misdiagnosis of leptospirosis, and health professionals should increase their awareness of leptospirosis as an important differential diagnosis of patients with suspicion of dengue.

Clinical profile, management and outcome of patients with leptospirosis during the times of COVID-19 pandemic: A prospective study from a tertiary care centre in South India

“…In a study by Suputtamongkol et al, there was no difference between doxycycline, penicillin and cefotaxime with respect to mortality and time to improvement [35]. The use of penicillin, ceftriaxone and doxycycline in different studies range from 34-100%, 28-100% and 8-48% respectively [11,22,24,28,30,32,33,35,36,[42][43][44]. Penicillin, ceftriaxone and doxycycline was used in 16%, 87% and 90% of the patients, respectively.…”

Immunological and Molecular Diagnostic Techniques for Leptospirosis: An Update

“…The real-time RT-PCR produced 5.6 cycle threshold of positive detection earlier than convectional PCR when the same DNA samples were analyzed in parallel indicating enhanced detection by RT-PCR [21]. The efficacy of real time PCR for the daignosis of leptosprisos has been reported by Fornazari and co-investigators [24]. Recently, Perez and co-workes [25] mentioned that new multiplex qPCR is a dependable tool to diagnose Leptospira infections.…”