Leptospirosis

Leptospirosis is a neglected zoonosis caused by pathogenic spirochetes of the genus \*Leptospira\*, occurring mainly in humid tropical and subtropical regions. With over one million cases and \~60,000 deaths annually, it is among the most dangerous bacterial zoonoses worldwide. Its nonspecific onset-fever, headache, myalgia-mimics influenza, dengue, and other acute febrile illnesses, making diagnosis difficult. Delayed antibiotic treatment can lead to severe forms (in \~10% of cases) characterized by hemorrhage and multi-organ failure. In 2023, New Caledonia reported 152 cases, with 85% hospitalized and a 2.6% mortality rate. This study aims to characterize the human host response and improve patient management. \*Leptospira\* evades innate immunity, triggering a strong anti-inflammatory IL-10 response and potentially ineffective phagocytosis. However, the WHO-recommended β-lactam antibiotics induce a Jarisch-Herxheimer reaction (JHR)-an acute inflammatory response occurring within hours of treatment-in over 50% of patients (LEPJAR study, PMID:40986630), the impact of which on phagocytosis is unknown.The NEUTROLEPTO study will be conducted in New Caledonia (NC) in patients with or without leptospirosis. Clinical and biological data will be collected at the time of suspected infection and 3 hours after antibiotic administration. Specifically, immune responses will be assessed through cytokine profiling and blood cell phenotyping, as well as by transcriptome analysis of infected patients before and after antibiotic treatment.

The goal of this clinical trial is to learn if complement factor I (CFI) works to predict development of complications in participants with leptospirosis. It will also learn if plasma transfusion, hemoperfusion, and extracorporeal membrane oxygenation works to treat participants with leptospirosis. The main questions it aims to answer are: * Does a low level of CFI predict the development of lung damage in participants with leptospirosis? * Does plasma tranfusion lower the chances of participants getting lung damage from leptospirosis? * Does hemoperfusion work to remove harmful materials from the blood of participants with leptospirosis? * Does extracorporeal membrane oxygenation increase the chance of survival in participants with lung damage? Researchers will compare plasma tranfusion and hemoperfusion to conventional therapy (standard of care for leptospirosis, including antibiotics, fluids, and other treatment that the doctor deems necessary) to see if these novel therapies work to treat leptospirosis. Participants will: * Give blood samples for the study of CFI * Receive conventional therapy and/or plasma transfusion for 4 times in 2 days, OR * Receive conventional therapy and/or hemoperfusion for at least 3 days, AND/OR * Receive extracorporeal membrane oxygenation if their condition worsens

RACSMEI addresses the high burden of infectious diseases in low- and middle-income countries, including Cambodia, where limited surveillance and laboratory capacity often obscure etiologies and transmission dynamics. This knowledge gap hinders the design of effective prevention and control strategies. RACSMEI will improve understanding across multiple pathogens using a multidisciplinary One Health approach. We will answer key questions on burden, ecology, transmission and population immune status to inform targeted and culturally appropriate interventions. The project combines a nationally representative One Health survey, social-science methods, and multiplex, diverse diagnostics to efficiently test for 57 priority pathogens, including zoonotic and vector-borne agents, vaccine-preventable and elimination-targeted diseases, enteric, respiratory, and environmentally transmitted pathogens and selected neglected tropical diseases and parasites relevant to Cambodia. Mathematical modelling will reconstruct and forecast transmission dynamics and assess the potential impact of future public-health strategies. By integrating intersectoral data and innovative methods, RACSMEI will generate actionable evidence for public-health authorities, support precision One Health interventions, and help reduce disease burden in affected communities. The project also aims to ensure the transferability of methods and insights to other countries facing similar challenges.

Leptospirosis is a worldwide zoonotic diseases caused by pathogenic Leptospira spp. Human are accidental hosts, who acquired infections after exposition to animal urine, contaminated water or soil, infected tissue. Incidence of invasive leptospirosis disease causing acute kidney injury, acute respiratory distress syndrome (ARDS), myocarditis, hepatic dysfunction, hemorrhage and multi-organ failure, is globally increasing and there have been frequent outbreak situation throughout the world. Due to increasing outbreak situations and globally chances in species distributions, a worldwide surveillance in epidemiology and species distribution is urgently needed. The objective of the Leptospirosis Registry - LeptoScope is to overcome the lack knowledge on epidemiology, clinical course, prognostic factors and molecular characteristics for invasive leptospirosis disease.

So in management of Leptospirosis patients There really is no another approach to treatment. The importance of the problem was acknowledged by the researchers. As a result, this study was performed in order to The Leptospirosis Care Bundle has been used, and has been proved that its use can reduce the risk of acute renal failure.

Leptospirosis is a zoonosis found worldwide, but particularly in humid subtropical and tropical zones. It is caused by pathogenic bacteria of the Leptospira species of the spirochete family. It is estimated that there are over a million cases of leptospirosis worldwide each year, with 60,000 deaths. These figures place leptospirosis among the most dangerous bacterial zoonoses in the world. The disease affects the most disadvantaged populations, and also inflicts its burden on domestic and farm animals. To this day, however, leptospirosis remains a neglected disease, poorly understood because it has been little studied. Human leptospirosis initially presents as a febrile syndrome, with fever, headache, myalgia and joint pain. These symptoms are very similar to those observed in influenza, dengue fever and other acute febrile illnesses, making diagnosis very difficult. Delayed initiation of antibiotic therapy, a treatment recommended by the WHO, is associated with the development of severe forms of leptospirosis. Indeed, in 10% of cases, leptospirosis evolves into severe forms, which are still poorly described, but which result in haemorrhage, multivisceral failure (lungs, kidneys, liver) and a drastic increase in the case-fatality rate. In 2023, 152 cases of leptospirosis were reported in New Caledonia. Of these, 130 people (85%) were hospitalized and 4 deaths were recorded (2.6%). For patients suffering from leptospirosis, it is therefore important to be able to make the diagnosis quickly, ideally as soon as symptoms appear. It is also crucial to be able to monitor, or even prevent, the development of severe forms of the disease, to ensure optimal patient care.

Zoonoses and arboviroses refer to a group of diseases transmitted from animals to humans, either directly or indirectly (via mosquitoes, ticks or contact with contaminated environments). Most of these diseases are found in certain tropical zones, but global warming and increased international trade are modifying their geographical distribution, with a gradual trend towards temperate regions. A number of these pathogens have already been detected in Occitania, including dengue fever, West Nile, leishmaniasis and Q fever. Given the region's high mosquito population and favorable climatic conditions, other zoonoses have a strong potential to appear in the region, or may already be circulating at a low level. The study focuses on 18 pathogens selected for their potential to emerge and establish themselves in the Occitanie region: Leishmaniasis, Leptospirosis, Brucellosis, Q fever, Rickettsiosis, Tularemia, Psittacosis, Lyme disease, Tick-borne encephalitis, Hantavirus, Hepatitis E virus, Dengue virus, Zika virus, Chikungunya virus, West-Nile virus, Usutu virus, Toscana virus, Crimean-Congo haemorrhagic fever virus. The aim of the study is to find out whether patients have antibodies against these infectious agents, which would indicate that they have been exposed to them in the past, even in the absence of symptoms. Describing the circulation of these pathogens will enable to implement appropriate public health measures to avoid the risk of epidemics (mosquito control, informing professionals, etc.), as well as to assess the risk incurred in the workplace and have this risk recognized by the healthcare system.