It consists of three parts: A (clinical findings), B (epidemiological factors), and C (lab findings and bacteriological data). Since the original Faines criteria only included culture and MAT in part C, which is difficult and complex to perform, the modified Faines criteria was proposed in 2004 to include ELISA and slide agglutination tests which are easier to perform. In 2012, modified Faines criteria (with amendment) was proposed to include shortness of breath and coughing up blood in the diagnosis. In 2013, India recommended modified Faines criteria in the diagnosis of leptospirosis. Prevention
Rates of leptospirosis can be reduced by improving housing, infrastructure, and sanitation standards. Rodent abatement efforts and flood mitigation projects can also help to prevent it. Proper use of personal protective equipment (PPE) by people who have a high risk of occupational exposure can prevent leptospirosis infections in most cases.There is no human vaccine suitable for worldwide use. Only a few countries such as Cuba, Japan, France, and China have approved the use of inactivated vaccines with limited protective effects. Side effects such as nausea, injection site redness and swelling have been reported after the vaccine was injected. Since the immunity induced by one Leptospiraserovar is only protective against that specific one, trivalent vaccines have been developed. However, they do not confer long-lasting immunity to humans or animals. Vaccines for other animals are more widely available.Doxycycline is given once a week as a prophylaxis and is effective in reducing the rate of leptospirosis infections amongst high-risk individuals in flood-prone areas.
Other rapid screening tests have been developed such as dipsticks, latex and slide agglutination tests.The microscopic agglutination test (MAT) is the reference test for the diagnosis of leptospirosis. MAT is a test where serial dilutions of patient sera are mixed with different serovars of Leptospira. The mixture is then examined under a dark field microscope to look for agglutination. The highest dilution where 50% agglutination occurs is the result. MAT titres of 1:100 to 1:800 are diagnostic of leptospirosis. A fourfold or greater rise in titre of two sera taken at symptoms onset and three to 10 days of disease onset confirms the diagnosis. During the acute phase of the disease, MAT is not specific in detecting a serotype of Leptospira because of cross-reactivity between the serovars. In the convalescent phase, MAT is more specific in detecting the serovar types. MAT requires a panel of live antigens and requires laborious work. Molecular tests
Leptospiral DNA can be amplified by using polymerase chain reaction (PCR) from serum, urine, aqueous humour, CSF, and autopsy specimens. It detects the presence of bacteria faster than MAT during the first few days of infection without waiting for the appearance of antibodies. As PCR detects the presence of leptospiral DNA in the blood it is useful even when the bacteria is killed by antibiotics. Imaging
In those who have lung involvement, a chest X-ray may demonstrate diffuse alveolar opacities. Diagnostic criteria
In 1982, the World Health Organization (WHO) proposed the Faines criteria for the diagnosis of leptospirosis.