Local medical researchers and scientists posited that the death rate for melioidosis in the country may be higher than the figure for dengue related deaths.
Head of Genetech Research Institute, Dr. Dharshan De Silva pointed out that while some would argue that based on the rising number of cases being detected that the disease had indeed reached epidemic proportions in Sri Lanka, it was more factually accurate to say that the disease was underreported and under-diagnosed.
‘The majority of the facts and figures provided in the article come from research conducted by Senior Lecturer at the Department of Microbiology of the Faculty of Medicine of the University of Colombo, Dr. Enoka Corea and the University of Colombo.’
Burkholderia pseudomallei is the natural saprophytic soil bacterium which causes the infectious disease melioidosis. According to Dr. De Silva, the disease mostly affected farmers, in particular paddy farmers. It is suspected that it is through cut wounds and unapparent abrasions that individuals get infected. The infection is acquired accidentally, during occupational, recreational or lifestyle exposure to soil, mud or water containing the bacterium which enters the body by percutaneous inoculation (through broken skin, such as a cut), inhalation or ingestion. In most cases, the incubation period varies from a few days to weeks from the initial infection following exposure which may be asymptomatic prior to activation in a fulminant form (sudden onset).
Infection occurs in all age groups, including children and in both sexes though the highest incidence is seen in middle-aged males of 40 to 50 years, living in rural areas.
Persons with occupational exposure to soil, such as farmers and cultivators (commercial or domestic/home garden) and house or road construction workers are at special risk as are personnel in the police and defence forces. There is an increased incidence in three-wheeler drivers and motorcyclists due to exposure to dust and in persons affected by flooding. The custom of walking barefoot and of using natural sources of water for drinking and bathing in tanks and rivers may also contribute to the increased risk of infection.
A large number of cases have been found from Batticaloa and elsewhere in the districts of Kurunegala, Puttalam, Gampaha, Badulla and Kandy while cases have been reported from all the provinces. Cases are also found in Australia and Thailand.
Symptoms include fever lasting between four to six days or even longer. Patients test negatively for dengue. Apart from protracted fever, there would be an abscess or abscesses on the body of the patient. Melioidosis may involve any system and is often multifocal. Clinical presentation ranges from severe to mild and from acute to chronic.
Typical presentations include fulminant septicaemia, severe community acquired pneumonia or lung abscess, single or multiple abscesses of the superficial or deep tissues including liver, spleen, kidney and cerebral abscess, musculoskeletal disease such as abscess of the psoas muscle, septic arthritis or osteomyelitis (inflammation of bone or bone marrow), skin and soft tissue abscesses and skin infection, genitourinary infection and lymph node abscess and suppuration.
He noted that the lethal disease reduced mortality by 40 per cent to 50 per cent. There is an uptake in the disease during rainy seasons. Case clusters may be seen after severe weather events, probably due to the aerosolization of bacteria and the increased risk of inhalation. There is also a connection between having diseases like diabetes which makes one more vulnerable to melioidosis. Chronic co-morbidity and other risk factors include renal or liver disease, alcoholism, chronic lung disease and thalassemia.
“The treatment is primarily the intravenous administration of antibiotics for a long period (even up to two weeks, thus requiring hospitalization). Without curative treatment patients die”, said Dr De Silva.
He added that one cannot take antibiotics in oral (pill) form but only via injections. Patients die from septic shock resulting from sepsis. However, early diagnosis and appropriate treatment reduces morbidity and mortality considerably.
Over the past two and a half years, 1,400 such samples have been tested and 140 to 150 cases had been detected, he remarked.
The United States Army Medical Research Institute of Infectious Diseases is presently working in collaboration with Genetech in this regard.
“Previously, there was no screening and therefore the disease was not detected. Patients initially go to a general practitioner. Only later do they make their way to a base or general hospital. Earlier, the disease was misclassified. Now screening is being conducted in hospitals. The samples of those suspected to be infected are tested initially. Research assistants are sent to hospitals. They talk to the patients. If the patients consent to giving samples, then they are obtained, clinical microbiologists are notified and the suspected samples are analyzed. We have managed to save patients’, lives. We do not know the cause and how persons actually get infected. These must be reported to the epidemiology unit. We are looking at soil samples too,” Dr. De Silva said.
Senior Lecturer at the Department of Microbiology of the Faculty of Medicine of the University of Colombo, Dr. Enoka Corea who noted that Senior Professor of Microbiology of the Department of Microbiology of the Faculty of Medicine of University of Peradeniya, Prof. V. Thevanesam was a pioneer in this field, added that according to global estimates South Asia was a hotbed for the disease.
She contends that South Asia has the highest numbers for this neglected disease.