Be on the lookout for leptospirosis
Leptospirosis is an endemic disease in Malaysia, but may be missed as doctors are not looking for it.
Dr Yasmin Mohd Gani, an infectious diseases specialist at Hospital Sungai Buloh, said leptospirosis occurs throughout the world but has the highest prevalence in the tropics and is endemic in Malaysia. The incidence rate in Malaysia is about 20-25 per 100,000 population. “But this could be an underestimation because of poor awareness and a lack of point-of-care testing for the disease.” She was speaking at the Private Medical Practitioner's Association of Selangor and Kuala Lumpur's Annual Scientific Congress, held in Kuala Lumpur, recently.
The disease is generally biphasic in nature—with the initial bacteremic phase, followed by the immune phase which lasts from 4 to 30 days, said Yasmin. She noted that the immune phase is where the complications set in. Symptom-wise, patients usually come in with mild fevers, body aches, nausea, diarrhoea, conjunctival haemorrhage—it actually presents like a viral infection.” She added: “The ones we are more worried about are the ones who present with multi organ failure, meningitis and pulmonary haemorrhage with respiratory failure.”
The incubation period of leptospirosis is usually 10 days but can be prolonged to 30 days. “So ask for clinical history for at least until a month or so ago.”
As the disease shares symptoms with various other diseases, the differential diagnosis of leptospirosis includes ruling out of typhoid, dengue, malaria, scrub typhus, Hanta virus, influenza and melioidosis. Yasmin cautioned that, with the onset of climate change and increased population of disease vectors, the disease may see a rise in endemicity and incidence.
Treatment is straightforward and early treatment with antibiotics is essential, said Yasmin. Those presenting with severe disease are usually treated with high doses of intravenous C-penicillin while less severe cases are treated orally with antibiotics such as doxycycline, tetracycline, ampicillin or amoxicillin.
Yasmin cautioned: “If you use C-penicillin early in the course of the disease, it causes rapid deaths of the spirochetes and you know anything that causes such a rapid death of the spirochetes would lead to an anaphylactic reaction.” Therefore, she advised caution in such a situation.
Yasmin noted that third-generation cephalosporins, such as ceftriaxone and cefotaxime, and quinolones may be effective in leptospirosis treatment. However, there is a risk of Jarisch-Herxheimer reaction occurring upon initiation of antimicrobial therapy. Beyond chemotherapy, patients should be carefully monitored and be provided supportive care as appropriate. This may include dialysis and mechanical ventilation in the case of organ failure.
The zoonotic disease is caused by a spirochete carried in the renal tubules of rodents, wild animals and domestic animals. These spirochetes lay dormant in the renal tubules of rodents and intermittently shed when they urinate. Occupations considered to have a high risk of exposure to leptospirosis include plantation workers and those dealing with sewage, drainage, forestry and town cleaning. Labourers, military personnel, farmers and paddy planters are at moderate risk and school teachers and office workers are at the least risk of catching leptospirosis. A local study noted that leptospirosis affects more men than women and in particular, slum workers. These mostly fell in the age group of 30 to 39 and there was an increased incidence during rainfall. [Acta Trop 2016;157:162–168]