The tragedy with the floods in Rio Grande do Sul has impacts in different situations. One of the concerns is the spread of diseases through contact with contaminated water, for example. The Brazilian Society of Infectious Diseases, the Gaúcha Society of Infectious Diseases and the Health Department of the State of Rio Grande do Sul, have just warned in a technical note about the danger of leptospirosis, an infectious disease caused by bacteria of the genus Leptospira, caused by contact with water , soil or food contaminated by the urine of infected animals, mainly rats.
The entities recommend chemoprophylaxis, with medical opinion, against the pathology, for individuals who have been exposed to flood water for a long time and for groups of rescuers and volunteers who have also had contact with dirty water. The technical note also contains recommendations on the most appropriate way to proceed with prophylaxis and avoid the disease.
Chemoprophylaxis is a prevention tool for infectious diseases that encompasses the use of medicines to minimize the likelihood of infections in people exposed to infectious agents. The administration of antimicrobials is generally not defined as routine conduct, but the document considers that, in high-risk situations, this intervention can be taken into consideration.
The Ministry of Health is also guided by scientific reviews and publications, such as a treatment guide published by the World Health Organization in 2003, which indicates prophylaxis with antimicrobials in occasions of great risk, as is happening in Rio Grande do Sul. The recommendation, therefore, is based on research that indicates a potential benefit in using these medications in such cases.
Events such as abnormal accumulation of water in floods are a fertile ground for the transmission of leptospirosis. The disease can manifest itself even after people can return to their homes. Another important measure is to wear boots and gloves when contact with mud or dirty water is unavoidable.
People at high risk and eligible for the use of emergency medicines are identified as follows:
– Rescue responders and volunteers with prolonged exposure to flood water when personal protective equipment is not able to prevent exposure
– People exposed to flood water for a prolonged period with careful medical evaluation of this exposure
The central drug guidance for chemoprophylaxis is the antibiotic Doxycycline. The recommended amount is 200 mg, orally, in a single dose for those who have experienced high-risk exposure (prolonged duration), and the same dosage, in this case once a week, for rescue teams and first responders. For children, the dose follows weight (4 mg per kilogram) orally, in a single dose, with a maximum established dose of 200 mg. Another alternative, which can be used under the same conditions, is Azithromycin: 500 mg for adults (single dose for people post-high-risk exposure, or once a week while exposure occurs – rescue/rescuers) and 10 mg per kilo for children, with a maximum dose of 500 mg.
Prophylaxis must be carried out under medical supervision. Even so, protection against leptospirosis is not absolute – even those who have taken the medicine can get sick. Pregnant and breastfeeding women should not use doxycycline as a preventive measure.
What is it
An infectious disease caused by a bacteria called Leptospira, present in the urine of rats and other animals, leptospirosis is transmitted to humans mainly in floods. Cattle, pigs and dogs can also become ill and spread the disease to humans.
Symptoms
Among the symptoms, many similar to those that occur with flu and dengue, for example, are fever, chills, red eyes, fatigue, headache, body aches, mainly in the calves, vomiting, diarrhea and cough. The most serious manifestations also cause jaundice (yellowing of the skin and eyes) and require specific care, usually with hospitalization. The patient may also experience bleeding, meningitis, kidney, liver and respiratory failure, which can even lead to death.
How is it transmitted
When water accumulates without drainage, rat urine, present in sewers and manholes, mixes with runoff and mud. Anyone who comes into contact with contaminated water or mud can become infected. The bacteria contained in the water enter the human body through the skin, especially if there is a scratch or wound. Contact with water or sewage sludge, contaminated lakes or rivers and wasteland, where rodents may be, also facilitates contagion. Veterinarians and animal handlers can contract leptospirosis through contact with the urine of sick or convalescent animals.
Treatment
Treatment involves medication (mainly antibiotics) and other supportive measures. The simplest cases can be dealt with on an outpatient basis, but in severe cases the disease requires hospitalization. Self-medication is contraindicated, as it can worsen the health condition.
How to prevent
Controlling leptospirosis involves adopting measures related to the environment, such as basic sanitation works (water supply, garbage and sewage), improvements to housing and the fight against rats.
In addition to avoiding contact with flood water or mud, children should also not swim or play in these waters or in places where rodents may be present. Professionals who work in cleaning mud, debris and unblocking sewage must always wear rubber boots and gloves (if this is not possible, use double plastic bags tied around their hands and feet).
2.5% sodium hypochlorite (bleach) kills leptospires and should be used to disinfect water reservoirs (one liter of bleach for every 1 thousand liters of water in the reservoir), places and objects that have come into contact with contaminated water or mud (one glass of bleach in a 20 liter bucket of water). When cleaning and disinfecting places where there has been recent flooding, it is recommended to protect your feet and hands.
To prevent the appearance of rats, it is important to properly package and dispose of trash, in addition to storing food appropriately. Disinfecting water tanks and completely sealing them are preventive measures that must be carried out periodically. Pest control is the direct elimination of animals through the use of rodenticides and needs to be carried out by trained professionals.
Anyone who has a fever, headache or body aches shortly after coming into contact with floodwaters or sewage should immediately seek the nearest health center. This is a curable disease, and early diagnosis and treatment are the best way to deal with it. In Brazil, there are around 15 thousand cases of leptospirosis registered each year.
