Dr. María Alt. Santana Acosta
Physician and Bioanalyst- Hematologist / Microbiologist – Professor of the Central University of the East -San Pedro de Macoris, Rep Dom
Leptospirosis, also called Weil’s disease or Canicola fever, is a zoonotic bacterial disease caused by leptospires, bacteria encompassed in spirochetes. The reservoir of this disease is made up of wild and domestic animals, mainly rodents, but each serovar has preferential reservoirs such as: rats for L. icterohaemorrhagiae, pigs for L. pomona, cattle for L. hardjo, dogs for L. .canicola
Many other mammals are capable of maintaining brief carrier states. There are other serovars that infect reptiles and amphibians and are generally considered not to affect humans, although suspected cases have been observed in Barbados and Trinidad.
The distribution of leptospirosis is worldwide, except for the polar regions. It is the most extensive zoonosis in the world and occurs in developed and developing countries, both in rural and urban areas, although it is more widespread in countries with a tropical climate, due to the greater survival of the microorganism in hot and humid environments. Likewise, the disease presents a certain seasonality, with more cases occurring in summer and autumn in temperate countries and during rainy seasons in hot countries.
It is difficult to estimate the prevalence of the disease, due to the lack of data in general. The best known high-risk areas include Brazil, China, the Caribbean, India, the Pacific Islands, Malaysia, the Seychelles, Sri Lanka, Thailand, and Vietnam. There are around 100,000 human cases per year and about 1000 deaths per year worldwide
In January 2019, the Australian government declared an outbreak of leptospirosis, a disease transmitted through water contaminated by the urine of animals, following the death of four people this month.
While in the Dominican Republic the Weekly Epidemiological Bulletin 01 From 12/30/2018 to 01/05/2019 This week four (4) suspected cases of leptospirosis were reported, three (3) alive and one deceased. The live cases correspond to two men and a woman aged 49, 57 and 58, residing in the municipalities of Santo Domingo Oeste, Higüey and San Juan. This week’s death corresponds to a 73-year-old woman, housewife occupation, who was taken to a regional reference health center 5 days after the clinical picture began, died half an hour after arriving at the emergency room.
During the last four weeks, 23 cases have been reported, including two (2) disease-related deaths (case fatality = 8.7%). During this period the highest frequency of cases resides in the O Metropolitan region.
Leptospires pathogenic for humans belong to the species L. interrogans, of which at least 23 serogroups have been identified, in turn divided into more than 200 serovars. The most identified serovars are: L. icterohaemorrhagiae, L. canícola, L. autumnalis, L. hebdomidis, L. australis, L. pomona, and L. herdjo
Severe cases (Weil syndrome) are characterized by hepatic impairment with jaundice, impaired kidney function, confusion, and hemorrhagic diathesis, due to damage to the capillary endothelium causing generalized vasculitis.
The severity depends on the infecting serovar and factors of the infected host, reaching a lethality of up to 20% in severe cases.
The suspected diagnosis is made by clinical and epidemiological conditions, but it is a difficult diagnosis, which hinders the fight against the disease. The diagnosis is confirmed by the detection of specific antibodies and by the isolation of leptospires in the blood in the first 7 days, in the CSF from the 4th to the 10th day and / or in the urine from the 10th day.
Transmission occurs mainly by direct contact with blood, urine or tissues of infected animals, which penetrate the host’s skin if it is exsicated or through mucous membranes. Transmission by contact with material contaminated by urine from affected animals is also possible. The microorganism survives for a long time in water, which makes it an important transmission vehicle when swimming in contaminated water, as well as through contact with wet soil or contaminated vegetation (especially sugarcane has been implicated). Infection by ingestion of contaminated food and, rarely, by inhalation of aerosol droplets of contaminated liquids has been described.
The risk of transmission increases after periods of heavy rains, as water saturates the environment and leptospires from the soil pass directly into surface waters.
The incubation period is approximately 10 days, with limits between 4 and 19 days. The period of transmissibility from the reservoir to man or, rarely, person-to-person, lasts as long as leptospires are excreted in urine, which generally lasts a month in sick humans and long in animals.
The preventive measures that we can take: inform the population about the mode of transmission of the disease. Use of footwear and gloves to avoid direct contact with stagnant water or mud. Do not ingest beverages in cans directly, serve them in a glass and then drink them
Bibliography ./ Ministry of Public Health General Directorate of Epidemiology National Epidemiological Surveillance System Boletin un, 1
Regional Office for the Americas of the World Health Organization PAHO
Dr. María Alt. Santana Acosta