Legionnaires’ Disease (LD). The term may sound unfamiliar to Nepalis, but the type of
pneumonia LD refers to, was recently found in some patients in Kathmandu. Luckily, there have been no reports of new cases.
LD is classically thought of as pneumonia that is contacted from water sources. The bacteria, Legionella, lives in water and also inside amoebas (single cell organisms) that are found in water.
The water sources most often implicated for harbouring Legionella are shower sprays, air-conditioners, humidifiers, decorative fountains, respiratory therapy equipment and even roadside puddles which are plentiful in Nepal. Although proper chlorination of the water may help to fight off the bacteria, it is known to easily resist low levels of chlorine in the water.
The good news is that person- to-person transmission is not known to happen with this disease, meaning unlike respiratory illnesses such as viral diseases and tuberculosis, LD is not transmitted by droplet infection.
How this pneumonia got its name is an interesting story.
In the summer of 1976, at the Bellevue-Stratford Hotel in Philadelphia, USA, the American Legion (organisation of US war veterans) was holding its 58th annual convention. The water in the hotel’s air conditioning system was contaminated with Legionella and the infection quickly spread to the attendees. Presentations ranged from mild flulike symptoms to multisystem organ failure. Of the 182 people infected, 29 died.
Although Legionella was not identified until 1976, the bacteria was found in a clinical specimen from 1943. Many pneumonia outbreaks in different parts of the world that predate1976 have also been traced to Legionella on examination of archived specimens.
Worldwide prevalence reports for LD have increased with time, likely due to doctors being more aware of the disease and also the availability of better diagnostics. In countries sucha as Nepal, it is probable that LD infections may now be detected because of increased usage of air-conditioning and other environmental and behavioral reasons.
How can we detect it in a patient? If a person has pneumonia, LD has to be in the differential diagnosis and the symptoms may be very mild to life threatening as was noted in the outbreak at the meeting of the American Legion. Non-specific signs such as fever, cough, diarrhea, lethargy, and muscle pains may be the first presentations of LD.
The microbiological diagnosis is hard to make in Nepal chiefly due to lack of availability of the tests. But it is true that even in countries where facilities are available, the diagnosis of LD is very often missed because the diagnosis is not entertained and tests are not done; but even where tests are available, the current tests may not be accurate enough.
The simple antigen test in urine is the most commonly used diagnostic method and treatment starts with an antibiotic. Many of the commonly available antibiotics in Nepal such as azithromycin or the newer quinolones are usually effective against LD.
There is no vaccination against this pneumonia like there is for the more common pneumococcal pneumonia- the pneumococcal vaccine which all people over 65 are highly recommended to take once in their lifetime. The pneumococcal vaccine is available in Nepal in many hospitals and clinics.
Read also:
The humble soap, Buddha Basnyet
Nepali diarrhea, Buddha Basnyet
Confusion in the time of cholera, Mallika Aryal