Editing Leptospirosis (section)

==Signs and symptoms==
[[File:Signs and symptoms of leptospirosis.svg|thumb|upright=1.3|alt=A schematic of the human body showing the symptoms and signs of leptospirosis | Schematic depiction of the symptoms and signs of leptospirosis.]]
[[Image:Conjunctival suffusion of the eyes due to leptospirosis.jpg|thumb|alt=Human eye showing symptomatic red and yellow patches on the white of the eye | [[Conjunctival suffusion]] (red [[conjunctiva]]) together with jaundice is a specific feature of leptospirosis.]]
The symptoms of leptospirosis usually appear one to two weeks after infection,<ref name="Karpagm2020"/> but the [[incubation period]] can be as long as a month.<ref name="Haake 2015"/> The illness is [[Biphasic disease|biphasic]] in a majority of symptomatic cases. Symptoms of the first phase (acute or leptospiremic phase) last five to seven days. In the second phase (immune phase), the symptoms resolve as antibodies against the bacteria are produced.<ref name="Lane 2016"/> Additional symptoms develop in the second phase.<ref>{{cite web |title=Factsheet about leptospirosis |url=https://www.ecdc.europa.eu/en/leptospirosis/factsheet |website=European Centre for Disease Prevention and Control |access-date=5 September 2020 |language=en}}</ref> The phases of illness may not be distinct, especially in patients with severe illness.<ref name="Waggoner2016">{{cite journal |vauthors=Waggoner JJ, Pinsky BA |title=Molecular diagnostics for human leptospirosis |journal=Current Opinion in Infectious Diseases |volume=29 |issue=5 |pages=440–5 |date=October 2016 |pmid=27537829 |pmc=5127924 |doi=10.1097/QCO.0000000000000295 }}</ref> 90% of those infected experience mild symptoms while 10%&nbsp;experience severe leptospirosis.<ref name="Cagliero 2018">{{cite journal | vauthors = Cagliero J, Villanueva SY, Matsui M | title = Leptospirosis Pathophysiology: Into the Storm of Cytokines | journal = Frontiers in Cellular and Infection Microbiology | volume = 8 | issue = 204 | pages = 204 | date = 20 June 2018 | pmid = 29974037 | doi = 10.3389/fcimb.2018.00204 | pmc = 6019470 }}</ref>

Leptospiral infection in humans causes a range of [[symptom]]s, though some infected persons may have none. The disease begins suddenly with fever accompanied by chills, intense headache, severe [[Myalgia|muscle aches]] and abdominal pain.<ref name="Zoey2020"/><ref name="Haake 2015"/> A headache brought on by leptospirosis causes throbbing pain and is characteristically located at the head's bilateral [[Temple (anatomy)|temporal]] or [[Frontal bone|frontal]] regions. The person could also have pain behind the eyes and a [[Photophobia|sensitivity to light]].<!-- <ref name="Haake 2015"/> --> Muscle pain usually involves the [[Calf (leg)|calf muscle]] and the lower back.<!-- <ref name="Haake 2015"/> --> The most characteristic feature of leptospirosis is the [[conjunctival suffusion]] ([[conjunctivitis]] without [[exudate]]) which is rarely found in other [[febrile]] illnesses. Other characteristic findings on the eye include [[subconjunctival bleeding]] and [[jaundice]].<!-- <ref name="Haake 2015"/> --> A rash is rarely found in leptospirosis. When one is found alternative diagnoses such as [[dengue fever]] and [[chikungunya fever]] should be considered.<!-- <ref name="Haake 2015"/> --> Dry cough is observed in 20–57% of people with leptospirosis. Thus, this clinical feature can mislead a doctor to diagnose the disease as a respiratory illness. Additionally, [[gastrointestinal]] symptoms such as [[nausea]], vomiting, abdominal pain, and diarrhoea frequently occur. Vomiting and diarrhea may contribute to [[dehydration]].<!-- <ref name="Haake 2015"/> --> The abdominal pain can be due to [[acalculous cholecystitis]] or [[Pancreatitis|inflammation of the pancreas]].<ref name="Haake 2015"/> Rarely, the [[Lymphadenopathy|lymph nodes]], [[Hepatomegaly|liver]], and [[Splenomegaly|spleen]] may be enlarged and palpable.<ref name="Lane 2016"/>

There will be a resolution of symptoms for one to three days.<ref name="Karpagm2020"/> The immune phase starts after this and can last from four to 30 days and can be anything from brain to kidney complications.<ref name="Bennett 2015">{{cite book |last1=Bennett |first1=John E |last2=Raphael |first2=Dolin |last3=Martin |first3=J Blaser |last4=Bart |first4=J Currie | name-list-style = vanc |title=Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases|chapter=223 |date=2015 |publisher=[[Elsevier]] |isbn=978-1-4557-4801-3 |pages=2541–2549 |edition=Eighth}}</ref> The hallmark of the second phase is [[Meningitis|inflammation of the membranes covering the brain]].<ref name="Karpagm2020"/> Signs and symptoms of meningitis include severe headache and neck stiffness.<ref name="Karpagm2020"/> Kidney involvement is associated with reduced or absent urine output.<ref name="Karpagm2020"/>

The classic form of severe leptospirosis, known as Weil's disease, is characterised by liver damage (causing jaundice), [[kidney failure]], and bleeding, which happens in 5–10% of those infected.<ref name="Karpagm2020"/> Lung and brain damage can also occur. For those with signs of [[Meningoencephalitis|inflammation of membranes covering the brain and the brain itself]], [[altered level of consciousness]] can happen. A variety of neurological problems such as [[Hemiplegia|paralysis of half of the body]], [[Transverse myelitis|complete inflammation of a whole horizontal section of spinal cord]], and [[Guillain-Barré syndrome|muscle weakness due to immune damage of the nerves supplying the muscles]] are the complications.<!-- <ref name="Haake 2015"/> --> Signs of bleeding such as [[Petechiae|non-traumatic bruises at {{cvt|1|mm}}]], [[Ecchymoses|non-traumatic bruises more than {{cvt|1|cm}}]], [[Epistaxis|nose bleeding]], [[Melena|blackish stools due to bleeding in the stomach]], [[Haematemesis|vomiting blood]] and [[Pulmonary haemorrhage|bleeding from the lungs]] can also be found. Prolongation of [[prothrombin time]] in [[coagulation testing]] is associated with severe bleeding manifestation. However, [[Thrombocytopenia|low platelet count]] is not associated with severe bleeding.<ref name="Haake 2015"/> Pulmonary haemorrhage is alveolar haemorrhage (bleeding into the [[Pulmonary alveolus|alveoli]] of the lungs) leading to massive [[Haemoptysis|coughing up of blood]], and causing [[acute respiratory distress syndrome]], where the risk of death is more than&nbsp;50%.<ref name="Haake 2015"/> Rarely, [[Myocarditis|inflammation of the heart muscles]], [[Pericarditis|inflammation of membranes covering the heart]], [[Heart block|abnormalities in the heart's natural pacemaker]] and [[Arrhythmia|abnormal heart rhythms]] may occur.<ref name="Lane 2016"/>