Rodents as vectors of human leptospirosis
Leptospirosis is a corkscrew shaped that is known as one of the most widespread bacterial zoonoses in the world. Symptoms range from mild flu to severe multi-organ failure and fatal pulmonary hemorrhagic syndrome. In which the key factors of these diseases are from stray animals, poor sanitation, rodents, heavy rainfall and flooding. Many regions have been increasingly exposed to leptospirosis infection due to climate change, global warming, poverty and high urban density. Rodents are the main animal reservoir in urban settings mainly involved in pathogenic transmission. Moreover, a high prevalence in rodent population occurs in major cities such as in Baltimore, Tokyo and Copenhagen. In Italy sporadic cases of leptospirosis have been often related to river flooding. This study focused on molecular survey of rodents in the city of Palermo, Italy.
Human leptospirosis cases
Two cases in 2009 of leptospirosis in Palermo during spring and fall seasons and there were 22 locations monitored. A rodent is the main reservoir for leptospirosis related to heavy rainfall and flooding in urban streets and riverbanks. During street floods individual were potentially in contact with water contaminated by infected rodent urine. So, the risk of infection is high but because of good hygienic conditions and economic wellness severe symptoms is rare. It is also possible that periodic exposures to serovars leave the immune competent population more resistant to infection. Other cases also in Northern Italy an elderly woman has a fatal infection after river flooding occurs.
Based on molecular testing leptospirosis are positive in all species of wild rodents living in almost all areas in the city. Mice and rats are the natural source for this pathogenic infection. The main common problem in Palermo, Italy is the urban street floods from heavy rains and waste accumulation. In which the city is represented by almost ten thousand stray dogs feeding on garbage. Previously, a patient was in contact with contaminated water in street flood after violent cloudburst. Waste collection also is one of the problem in Palermo that eventually facilitates the increased of rodent population.
High prevalence of leptospirosis occurs in mild wet climate, flooding of urban streets and socio-economic problems. Other Italian cities has presence of simultaneous risk factors for leptospirosis, and thus, a major concern from this underestimated zoonosis should be considered by public health authorities and clinicians particularly for elderly and immune-compromised individuals. However, severe symptomatic cases are referred to hospitals and the true prevalence of infection is probably not evaluated.
Source: Prepared by Joan Tura from Journal of Infection and Public Health
Volume 11, Issue 2, March–April 2018, Pages 209-214