Season of Leptospirosis

If you have been exposed to flood waters, you can take an antibiotic called doxycycline as a prophylaxis or preventive measure against the disease.

What is leptospirosis? How does it differ from the other infections that are common during the rainy season? —estudio_ errnad@gmail.com

Leptospirosis is one of the infectious diseases prevalent in our country during the rainy season. Most of these infections, such as typhoid fever, salmonellosis, shigellosis, hepatitis A, and cholera, are food-borne— they only occur when we ingest food and water that have been contaminated by floodwater. Leptospirosis is a little different. It can be acquired, aside from ingesting contaminated food or water, by simply wading or swimming in floodwaters.

Leptospirosis cases are on the rise in the Philippines

The last three years have witnessed a dramatic increase in the incidence of leptospirosis in our country. Historically, the disease afflicts about 680 Filipinos and results in 40 deaths annually. But in 2016, 1,673 cases of the disease were recorded nationwide. This figure increased by 49 percent (i.e., 2,495) in 2017, and out of these, 261 resulted in death. This year, as of the end of June, more than one thousand cases of the disease have already been recorded nationwide, with more than a hundred deaths. Hit hardest is Metro Manila, accounting for more than a third of the reported cases, with more than 50 deaths. These numbers are projected to markedly swell in the next few months because, traditionally, the peak incidence of leptospirosis has been during the months of July to October.

Leptospirosis and floods

Leptospirosis is caused by a bacterium called Leptospirainterrogans. It is primarily an infection of lower animals, such as rats (the most common source of human infection in the Philippines) and other rodents, cattle, pigs, horses, and dogs. But in these animals, the bacteria rarely cause symptomatic disease, thus the animals serve as healthy carriers. The bacteria are excreted by infected animals with

their urine. We humans get infected with the bacteria when we swallow food or water, or when our skin or mucosal surfaces (e.g., of the eyes or nose) get in contact with water that has been contaminated with the urine of infected animals.

Outbreaks of leptospirosis in humans are common during the rainy season because the rains wash off the leptospira bacteria from the surface of urine-contaminated soils. The bacteria then collect in floodwaters and infect us when we wade or swim in these floodwaters. Leptospirosis is serious in 10 percent of cases

Leptospirosis is generally a benign, self-limiting illness that is characterized by flu-like symptoms that appear two days to four weeks after exposure. But in about 10 percent of cases, it complicates resulting in inflammation of vital organs such as the brain, liver, kidneys, and lungs. The severe form of leptospirosis, known as Weil’s disease, is characterized by bleeding and kidney failure. It has a high mortality rate.

When to see a doctor

If you have been exposed to floodwaters, seek medical consultation if you experience at least two of the following symptoms: myalgia (muscle pain), calf tenderness, conjunctival suffusion (i.e. very red eyes), chills, abdominal pain, headache, jaundice (yellowing of the skin or eyes), and oliguria (i.e., no or little urination). How to prevent leptospirosis

You can prevent leptospirosis by simply refraining from wading or swimming in floodwaters and wearing protective clothing, including rubber boots and gloves, if contact with floodwaters is inevitable.

Additionally, if you have been exposed to floodwaters, you can take an antibiotic called doxycycline as a prophylaxis or preventive measure against the disease. The antibiotics, however, are not 100 percent effective. In any case, the Philhealth guidelines in its use among adults are as follows (note: the antibiotic is not recommended for pregnant and lactating women):

• Low-risk exposure—those individuals with a single history of wading in flood or contaminated water without wounds, cuts, or open lesions on the skin: Doxycycline 200 mg single dose within 24 to 72 hours from exposure.

• Moderate-risk exposure—those individuals with a single history of wading in flood or contaminated water and the presence of wounds, cuts, or open lesions on the skin, or accidental ingestion of contaminated water: Doxycycline 200 mg once daily for three to five days to be started immediately within 24 to 72 hours from exposure.

• High-risk exposure—those indi- viduals with continuous exposure (those having more than a single exposure, or several days, such as those residing in flooded areas, rescuers, and relief workers) of wading in flood or contaminated water with or without wounds, cuts, or open lesions on the skin. Swimming in flooded waters especially in urban areas infested with domestic/sewer rats and ingestion of contaminated water: Doxycycline 200 mg once weekly until the end of exposure. Note: Email inquiries on health matters tomedical_notes@yahoo.com