Leptospirosis-associated acute kidney injury: penicillin at the late stage is still controversial

Efficacy and safety of antibiotics for treatment of leptospirosis: a systematic review and network meta-analysis

BACKGROUND

Leptospirosis, an important zoonotic bacterial disease, commonly affects resource-poor populations and results in significant morbidity and mortality worldwide. The value of antibiotics in leptospirosis remains unclear, as evidenced by the conflicting opinions published.

METHODS

We conducted a search in the PubMed, Web of Science, and Cochrane Library databases for studies. These studies included clinical trials and retrospective studies that evaluated the efficacy or safety of antibiotics for leptospirosis treatment. The primary outcomes assessed were defervescence time, mortality rate, and hospital stays. Subgroup analyses were performed based on whether there were cases involving children and whether there were cases of severe jaundice. Safety was defined as the prevalence of adverse events associated with the use of antibiotics. p scores were utilized to rank the efficacy of the antibiotics.

RESULTS

There are included 9 randomized controlled trials (RCTs), 1 control trial (CT), and 3 retrospective studies (RS) involving 920 patients and 8 antibiotics. Six antibiotics resulted in significantly shorter defervescence times compared to the control, namely cefotaxime (MD, - 1.88; 95% CI =  - 2.60 to - 1.15), azithromycin (MD, - 1.74; 95% CI =  - 2.52 to - 0.95), doxycycline (MD, - 1.53; 95% CI =  - 2.05 to - 1.00), ceftriaxone (MD, - 1.22; 95% CI =  - 1.89 to - 0.55), penicillin (MD, - 1.22; 95% CI =  - 1.80 to - 0.64), and penicillin or ampicillin (MD, - 0.08; 95% CI =  - 1.01 to - 0.59). The antibiotics were not effective in reducing the mortality and hospital stays. Common adverse reactions to antibiotics included Jarisch-Herxheimer reaction, rash, headache, and digestive reactions (nausea, vomiting, diarrhea, abdominal pain, and others).

CONCLUSIONS

Findings recommend that leptospirosis patients be treated with antibiotics, which significantly reduced the leptospirosis defervescence time. Cephalosporins, doxycycline, and penicillin are suggested, and azithromycin may be a suitable alternative for drug-resistant cases.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42022354938.

Acute Kidney Injury of Infectious Etiology in Monsoon Season: A Prospective Study Using Acute Kidney Injury Network Criteria

The epidemiological pattern of acute kidney injury (AKI) in tropical countries during monsoon reflects infectious disease as the most important cause. AKI is a confounding factor and may be overlooked by primary health-care providers and underreported in health statistics. The present study prospectively helps estimate the burden of disease and analyze etiology, clinical profile, and outcome in a tertiary care hospital of a metropolitan city in a tropical country. The study period included monsoon season of 2012 and 2013, a total of 8 months. AKI staging was done as per the AKI Network (AKIN) criteria. Patients were treated for primary disease. Renal replacement therapy (RRT) was given as required. Patients were followed up during hospitalization till recovery/death. Out of a total of 9930 admissions during this period, 1740 (17.52%) were for infections and 230 (2.31%) had AKI secondary to infectious diseases during monsoon. The incidence of AKI (230/1740) in infectious diseases during monsoon was 13.21%. The study population (n = 230) comprised 79.5% of males and the mean age was 40.95 ± 16.55 years. Severe AKI: AKIN Stage III was seen in 48.26% of patients and AKIN Stage I in 41.74%. The most common etiology of AKI was malaria (28.3%) followed by acute gastroenteritis (23%), dengue (16.5%), leptospirosis (13%), undifferentiated fever (10.4%), more than one etiology (5.4%), and enteric fever (3.5%). RRT was required in 44.78% of patients. Requirement for RRT was maximum in patients with more than one etiology followed by leptospirosis, malaria, dengue, and least in typhoid. The overall mortality was 12.17%. In multivariate analysis, vasopressor support and assisted ventilation were risk factors for mortality.

Changing patterns in leptospirosis: a three-decade study in Brazil

BACKGROUND

This study was conducted to investigate changes in the clinical pattern of leptospirosis over time, analyzing its clinical and laboratory presentations in a metropolitan city of Brazil.

METHOD

This was a retrospective study including all patients with leptospirosis admitted to tertiary care hospitals in Fortaleza in the northeast of Brazil, between 1985 and 2015. Patients were divided into three groups according to the year of hospital admission: group I for the years 1985-1995, group II for 1996-2005, and group III for 2006-2015. Demographic, clinical, and laboratory data were compared between the groups.

RESULTS

A total of 507 patients were included. Their mean age was 37.3±15.9years and 82.4% were male. The mean time between symptom onset and admission was 7±4 days. There was a linear decrease in the levels of serum urea (190.1±92.7, 135±79.5, and 95.6±73.3mg/dl, respectively, p <0.0001) and creatinine (5.8±2.9, 3.8±2.6, and 3.0±2.5mg/dl, respectively, p <0.0001) in each decade, while levels of hemoglobin (10.31±1.9, 10.8±2.0, and 11.5±2.1g/dl, respectively, p <0.0001) and platelets (57.900±52.650, 80.130±68.836, and 107.101±99.699×10⁹/l, respectively, p<0.0001) increased. There was a tendency towards a linear decrease in mortality (22%, 14%, and 11.6%, respectively, p=0.060).

CONCLUSIONS

Leptospirosis showed significant changes over time in this region. The main changes point to a decrease in disease severity and complications, such as acute kidney injury. Mortality has decreased, being close to 11%.

In Vitro Antimicrobial Susceptibility of Pathogenic Leptospira Biofilm

Pathogenic Leptospira spp. are the causative agent of leptospirosis. Biofilm formation in leptospires is a new area of study, and its role in pathogenesis is not fully explored. As in other biofilm-forming bacteria, Leptospira biofilm may play a significant role in antibiotic resistance. In this study, the antimicrobial susceptibility of Leptospira biofilm was investigated by 96-well plate assay using Alamar Blue. Leptospira biofilm showed five to sixfold increase in resistance in all the strains used. The range of minimal bactericidal concentrations for penicillin G, ampicillin, tetracycline, and doxycycline was 1,600 U/ml, 800-1,600 μg/ml, 800-1,600 μg/ml, and 800-1,600 μg/ml, respectively. In agar substrate, the biofilm showed six- to sevenfold increase in resistance to antibiotics compared to planktonic cell. The present study emphasizes the importance of biofilm formation and its antibiotic susceptibility patterns. This could pave the way for devising appropriate strategy to prevent the occurrence of potential chronic leptospirosis in endemic areas and also during an outbreak situation.

Risk factors for intensive care unit admission in patients with severe leptospirosis: a comparative study according to patients' severity

BACKGROUND

The aim of this study is to investigate predictive factors for intensive care unit (ICU) admission among patients with severe leptospirosis.

METHODS

This is a retrospective study with all patients with severe leptospirosis admitted to a tertiary hospital. Patients were divided in ICU and ward groups. Demographical, clinical and laboratory data of the groups were compared as well as acute kidney injury (AKI) severity, according to the RIFLE criteria (R = Risk, I = Injury, F = Failure, L = Loss, E = End-stage kidney disease).

RESULTS

A total of 206 patients were included, 83 admitted to ICU and 123 to ward. Mean age was 36 ± 15.8 years, with 85.9% males. Patients in ICU group were older (38.8 ± 15.7 vs. 34.16 ± 15.9 years, p = 0.037), had a shorter hospital stay (4.13 ± 3.1 vs. 9.5 ± 5.2 days, p = 0.0001), lower levels of hematocrit (29.6 ± 6.4 vs. 33.1 ± 8.6%, p = 0.003), hemoglobin (10.2 ± 2.4 vs. 11.6 ± 1.9 g/dL, p < 0.0001), and platelets (94,427 ± 86,743 vs. 128,896 ± 137,017/mm(3), p = 0.035), as well as higher levels of bilirubin (15.0 ± 12.2 vs. 8.6 ± 9.5 mg/dL, p = 0.001). ICU group also had a higher frequency of severe AKI (RIFLE-"Failure": 73.2% vs. 54.2%, p < 0.0001) and a higher prevalence of dialysis requirement (57.3% vs. 27.6%, p < 0.0001). Mortality was higher among ICU patients (23.5% vs. 5.7%, p < 0.0001). Independent predictors for ICU admission were tachypnea (p = 0.027, OR = 13, CI = 1.3-132), hypotension (p = 0.009, OR = 5.27, CI = 1.5-18) and AKI (p = 0.029, OR = 14, CI = 1.3-150). Ceftriaxone use was a protective factor (p = 0.001, OR = 0.13, CI = 0.04-0.4).

CONCLUSIONS

Independent risk factors for ICU admission in leptospirosis include tachypnea, hypotension and AKI. Ceftriaxone was a protective factor for ICU admission, suggesting that its use may prevent severe forms of the disease.

Live imaging of bioluminescent leptospira interrogans in mice reveals renal colonization as a stealth escape from the blood defenses and antibiotics

Leptospira (L.) interrogans are bacteria responsible for a worldwide reemerging zoonosis. Some animals asymptomatically carry L. interrogans in their kidneys and excrete bacteria in their urine, which contaminates the environment. Humans are infected through skin contact with leptospires and develop mild to severe leptospirosis. Previous attempts to construct fluorescent or bioluminescent leptospires, which would permit in vivo visualization and investigation of host defense mechanisms during infection, have been unsuccessful. Using a firefly luciferase cassette and random transposition tools, we constructed bioluminescent chromosomal transformants in saprophytic and pathogenic leptospires. The kinetics of leptospiral dissemination in mice, after intraperitoneal inoculation with a pathogenic transformant, was tracked by bioluminescence using live imaging. For infective doses of 10⁶ to 10⁷ bacteria, we observed dissemination and exponential growth of leptospires in the blood, followed by apparent clearance of bacteria. However, with 2×10⁸ bacteria, the septicemia led to the death of mice within 3 days post-infection. In surviving mice, one week after infection, pathogenic leptospires reemerged only in the kidneys, where they multiplied and reached a steady state, leading to a sustained chronic renal infection. These experiments reveal that a fraction of the leptospiral population escapes the potent blood defense, and colonizes a defined number of niches in the kidneys, proportional to the infective dose. Antibiotic treatments failed to eradicate leptospires that colonized the kidneys, although they were effective against L. interrogans if administered before or early after infection. To conclude, mice infected with bioluminescent L. interrogans proved to be a novel model to study both acute and chronic leptospirosis, and revealed that, in the kidneys, leptospires are protected from antibiotics. These bioluminescent leptospires represent a powerful new tool to challenge mice treated with drugs or vaccines, and test the survival, dissemination, and transmission of leptospires between environment and hosts.

Leptospirosis is a worldwide neglected disease caused by the pathogenic bacterium named Leptospira interrogans. Some rodents, such as rats, do not get sick from leptospirosis and constitute a reservoir. They carry leptospires in their kidneys and excrete the bacteria in the environment. L. interrogans are mobile and penetrate their hosts through abraded skin or mucosa. Infected humans may develop mild to severe leptospirosis, potentially leading to death. Leptospires are difficult to cultivate and to genetically manipulate, impairing the study of leptospirosis. Here, we constructed bioluminescent leptospires, and monitored infection in live mice by tracking bioluminescence. In the first days after infection, a rapid dissemination and growth of bacteria was observed in the blood circulation, followed around one week after the infection by their apparent disappearance. However, the leptospires reemerged and multiplied in the kidneys, to reach sustained levels three weeks after infection. The use of antibiotics showed that antibiotic-susceptible L. interrogans are very difficult to eradicate once they are settled in the kidneys. Mice infected with bioluminescent leptospires represent a pertinent model to study leptospirosis. These bioluminescent leptospires are novel tools that will be useful to test the efficacy of treatments or vaccines against leptospirosis.

Acute kidney injury-epidemiology, outcomes and economics

Acute kidney injury (AKI) is a widespread problem of epidemic status. Compelling evidence indicates that the incidence of AKI is rapidly increasing, particularly among hospitalized patients with acute illness and those undergoing major surgery. This increase might be partially attributable to greater recognition of AKI, improved ascertainment in administrative data and greater sensitivity of consensus diagnostic and classification schemes. Other causes could be an ageing population, increasing incidences of cardiovascular disease, diabetes mellitus and chronic kidney disease (CKD), and an expanding characterization of modifiable risk factors, such as sepsis, administration of contrast media and exposure to nephrotoxins. The sequelae of AKI are severe and characterized by increased risk of short-term and long-term mortality, incident CKD and accelerated progression to end-stage renal disease. AKI-associated mortality is decreasing, but remains unacceptably high. Moreover, the absolute number of patients dying as a result of AKI is increasing as the incidence of the disorder increases, and few proven effective preventative or therapeutic interventions exist. Survivors of AKI, particularly those who remain on renal replacement therapy, often have reduced quality of life and consume substantially greater health-care resources than the general population as a result of longer hospitalizations, unplanned intensive care unit admissions and rehospitalizations.