IT is easy to assume that leptospirosis and melioidosis are one disease, but with two names. However, that is far from true.
Dr Christopher Lee ... Parents should stop their kids from running around in flood water.
While both diseases are caused by bacteria, the type of bacteria and the source of the diseases are different. Leptospirosis is actually caused by bacteria found in rat urine and melioidosis by bacteria found in soil and water.
One reason for this misunderstanding could be due to fact that both the bacteria that cause the two diseases can occasionally be found in the same environment. This is shown in the recent outbreak in the Lubuk Yu recreational area near Maran, Pahang, where members of a rescue team were exposed to the groups of bacteria that cause leptospirosis (Leptospira sp.) and melioidosis (Burkholderia pseudomallei).
But it is important for us to make a distinction between the two since different treatment and prevention methods are required for both diseases.
We’ve seen this before
Both leptospirosis and melioidosis are not new diseases. Leptospirosis, for instance, is an old disease. The first fatal case of leptospirosis was reported in Malaysia in 1925 by researcher W. Fletcher. However, the incidence of leptospriosis was only five per 100,000 population in 2009, which is low compared to the incidence of dengue (136.89 per 100,000 population), TB (63.95 per 100,000 population) and malaria (24.74 per 100,000 population).
As it is also common in all countries of the tropics, Malaysia is not any worse than other country, says infectious disease physician Dr Christopher Lee. “I’m not saying it to downplay (the issue) but people shouldn’t panic over things like this. You will also get this on and off whenever there are floods,” he adds.
In the Lubuk Yu recreational area near Maran, Pahang, members of a rescue team searching for a missing man were exposed to bacteria that cause leptospirosis (Leptospira sp.) and melioidosis (Burkholderia pseudomallei).
Melioidosis, however, is rarely reported, says Health Ministry Disease Control Division Director Dr Lokman Hakim Sulaiman, when contacted via email. “Among the earliest report was by Puthuchaery SD and colleagues who published a review of 50 cases of septicaemic melioidosis in Tropical Medicine and Hygiene Journal in 1992,” he adds.
Where it’s at
As rats are the main carriers of leptospirosis, the disease goes where the rats go. However, as the bacteria can also infect a wide range of animals, people who work or come into contact with these animals (including birds, mammals and reptiles) like farmers, veterinarians, or military personnel can also be infected.
But if you have heard of the chain email message that says you can get infected if you drink from soda cans that have dried rat urine on them, Dr Lee says there is no proof that this has happened. “The Leptospira can survive for some time, but when it is dessicated, the chances for it to survive is very low. But is it zero? That would depend on how much contaminant there is in the first place,” he says.
That said, cleaning the surface of any container you drink from before you drink from it is always a good idea.
As the Leptospira is carried mainly by rats, leptospirosis goes where the rats go.
He notes that although there is a possibility of getting infected by ingesting contaminated food or water, people usually get infected through skin contact. (See SF3, How you can get infected)
Because of that, floods are typically where leptospirosis outbreaks start. When floods happen, rats drown and die. And when they die, they lost control of their bodily functions and let out urine that contaminate flood waters.
“Every time there is a flood, there is an increase in cases of leptospirosis,” Dr Lee says. That is why he often cringes when he sees children running around in flood waters. “Parents should stop their kids from running around in flood water,” he notes. Other places where people can get infections are rubbish dump sites, outdoor recreational areas and even certain households when there is rat infestation in the house.
Melioidosis, which is endemic in Asia, Southeast Asia and Northern Australia, is not carried by hosts. However, you can get infected when B. pseudomallei enters your body through burns and cuts in the skin, or through contaminated dust or water droplets you breathe in.
“It is very closely linked to rainfall,” says Dr Lee. “When it is the rainy seasen, the melioidosis rates go up. The most common areas are agricultural areas like paddy fields,” he adds. As melioidosis is linked to soil and surface water, it is more often seen in rural areas with agricultural based activities.
Fortunately, both diseases are not known to be spread from person to person.
Note the signs. Treat it early.
While leptospirosis and melioidosis can infect people of any age, gender, race, and health condition, melioidosis usually affects only those who have underlying chronic diseases such as diabetes, heart disease, kidney disease, thalassaemia, and cancer.
The good news is, a majority of people (as far as 90-95%) who get leptospirosis have no symptoms or are mildly symptomatic,” says Dr Lee. The remaining five to 10% might develop symptoms of the disease, but only a few will progress to develop serious complications of the disease, called Weil’s syndrome.
It may take about two to 10 days for initial symptoms to appear. “The most common symptom is usually initial flu-like illness,” says Dr Lee. People who are infected might develop fever for a few days and recover from it before proceeding to the second phase of the disease in the second week, where the fever returns and more severe complications appear.
“The complications are normally things like meningitis, kidney failure and jaundice,” Dr Lee says. However, there are also instances where patients develop bleeding of the lungs. Therefore, symptoms to look out for in leptospirosis include high fever, jaundice (yellowish pigmentation of the skin and eyes), headaches, chills and vomiting.
“The earlier you give antibiotics, the lesser are your chances of getting complications. There is no guarantee, obviously, but the earlier you get treated, the better off you are,” Dr Lee explains.
As for melioidosis, those who are at risk are people with co-morbidities, and diabetes is by far the most common risk factor for developing serious disease. However, like leptospirosis, early administration of antibiotics can prevent further complications in people who are at high risk of developing them.
Symptoms of melioidosis include symptoms of localised infection (ulcers, formation of pus, fever and muscle aches), acute or sudden lung infection (high-grade fever, cough, and chest pain) and acute blood infection (fever, shortness of breath and disorientation). However, when the infection has spread throughout the body, a person can also experience sudden weight loss, headaches and even seizures.
Normal, healthy people who have melioidosis generally have mild symptoms or do not develop these symptoms at all.
Prevention is key
While antibiotics can be used to treat both diseases, taking steps to avoid getting infected in the first place is still a better option.
As there is yet no vaccine that is effective for any of the two diseases, avoiding activities that expose you to the bacteria is the way to go. However, if you could not avoid them, wear protective clothing that prevents you from coming into contact with potentially contaminated water or soil.
You can also consult your doctor to find out about an antibiotic (doxycylcine) you can take one or two weeks before embarking on activities that exposes you to leptospirosis (e.g. jungle adventures and rescue work in flood-stricken areas) but this is currently not an option to prevent melioidosis.
However, if you are already exposed, it helps to be informed of the symptoms associated with both diseases so you could seek medical help promptly when you experience them.-
Star, 22/8/2010, Hidden bacteria
