Argentina: The Minister of Health of the Nation, Carla Vizzotti, confirmed that the samples taken from infected patients at the Luz Médica sanatorium in the capital of Tucumán and analyzed at the Malbrán Institute showed positive results for Legionella .
The Ministry of Public Health of Tucumán confirmed that there are 22 cases of bilateral pneumonia caused by the Legionella bacteria, of which six died and another five have the disease, with different degrees of severity.
The last death occurred in a patient "linked to the cluster of pneumonia cases", 81 years old and with comorbidities, who died in the last few hours. The deceased man was hospitalized "in serious condition" in the public sector, reported the provincial health portfolio.
Previously, the Ministry had announced a fifth death, in this case a 64-year-old man, also with comorbidities and hospitalized in serious condition in the public sector. While on September 3, the fourth fatal case occurred, a 48-year-old man with comorbidities affected by the same cause.
Legionella is a bacteria that can be treated with antibiotics, which usually lodges in pipes or air conditioning systems and is transmitted by inhalation. Transmission from person to person is not described. With this diagnosis, the patients will be transferred to another health center to follow their evolution, with the aim of carrying out various environmental control actions so that the building where the outbreak occurred returns to working order. It is important that the health personnel of the establishment or those who recently visited it are alert to the appearance of symptoms in order to consult early and be evaluated.
Symptoms are: fever, muscle pain, cough, headache, shortness of breath and, more rarely, diarrhea and vomiting. The Ministries of Health of the Nation and Tucumán work together to conclude the epidemiological evaluation, follow the evolution of the patients and carry out environmental control measures in the sanatorium.
WHO recommendations
- The UN agency recommends continuing laboratory controls, case identification and clinical care, contact tracing, investigation of the outbreak to identify the source(s), application of measures to prevent new infections and improving infection prevention and control measures.
- The Organization advises against applying any restrictions to travel or trade with Argentina based on the information currently available about this event.
Summary Legionella pneumophila is a Gram-negative, bacillus-shaped bacteria. It lives in stagnant waters at high temperatures and its growth is favored by the presence of organic matter. It requires oxygen to breathe and has a flagellum to move. 16 serogroups of L. pneumophila have been identified. Of the more than 30 known Legionella species, Legionella pneumophilaserogroup 1 is responsible for the majority of human infections. It is the origin of 10% of pneumonia cases, both community-acquired and hospital-acquired. In some countries it is mandatory to carry out controls for the prevention of legionellosis in facilities that use water in their operation, produce aerosols and are located inside and outside of buildings for collective use, industrial facilities or means of transport. Clinical characteristics : Legionnaires’ disease can have two different clinical presentations, Legionnaires’ disease and Pontiac fever. In the first, the disease usually manifests as pneumonia, although the clinical spectrum can vary from mild-moderate disease to severe disease with multiple organ failure. Pontiac Fever is a self-limiting disease that gives rise to a clinical picture similar to that of the flu. Diagnosis : Direct diagnostic methods include culture, direct immunofluorescence, and detection of antigen in urine. The first two methods provide low and variable sensitivity. Culture on BCYE plates is considered the reference technique for the diagnosis of Legionella infections in the laboratory. However, Legionella is a fastidious and slow-growing bacterium, and successful cultivation requires selective media and long incubation periods. On the other hand, the detection of antigen in urine has become the reference technique in most laboratories, which facilitates the process and allows an early diagnosis of legionellosis. However, these tests detect a limited number of serogroups (especially L. pneumophila serogroup 1), and antigenuria is not always present in all patients. For these reasons, urine antigen detection tests have sensitivities between 60 and 85%. Serology provides good specificity data with sensitivity close to 80% and has proven to be an ideal complement to direct detection methods. Its use is widespread in clinical diagnostic laboratories. To confirm a serological diagnosis, demonstrate seroconversion, since high titers can be found in a healthy population, although a high titer in a single serum sample together with clinical manifestations is suggestive of disease. Nucleic acid amplification is also an attractive tool for the detection of L. pneumophila genes in sputum, urine, and blood. Treatment : Antibiotics are used to combat the infection and treatment is started as soon as the disease is suspected, without waiting for confirmation by a laboratory test. |
History, load and trends
Legionella infections include Legionnaires’ disease and Pontiac fever. Legionnaires’ disease is a serious type of pneumonia (lung infection), while Pontiac fever is a milder infection that usually gets better without medical care.
History
Legionella bacteria was discovered after an outbreak in 1976 among people who attended an American Legion convention in Philadelphia. The affected people suffered from a type of pneumonia that became known as Legionnaires’ disease.
The first identified cases of Pontiac fever occurred in 1968 in Pontiac, Michigan, among people who worked in or had visited the city’s health department. It wasn’t until Legionella bacteria was discovered after the 1976 Legionnaires’ disease outbreak in Philadelphia that public health officials were able to show that this bacteria caused both diseases.
Load and trends
The number of cases reported to the CDC has been increasing since 2000. In 2018, health departments reported approximately 10,000 cases of Legionnaires’ disease in the United States. However, due to the likelihood that not all cases will be diagnosed, this figure could represent an underestimate of the true incidence. A recent study estimated that the actual number of Legionnaires’ disease cases could be 1.8 to 2.7 times higher than reported. Generally, more cases are found in the summer and early fall, but they can occur at any time of the year.
Common causes and sources of infection
Legionella bacteria are found naturally in freshwater environments, such as lakes and streams. These bacteria can become a health concern when they multiply and spread in artificial building water systems, such as:
- Shower heads and sink faucets
- Cooling towers (structures that contain water and a fan as part of the centralized air cooling system in buildings or industrial processes)
- Whirlpool tubs
- Fountains and decorative accessories with water
- Hot water tanks and water heaters
- Complex and large piping systems
- Car and home air conditioning systems do not use water to cool the air; Therefore, they do not present a risk of multiplication of Legionella bacteria.
However, Legionella bacteria can grow in the windshield washer fluid reservoir of a vehicle (for example, car, truck, van, school bus, or taxi), particularly if the reservoir contains water rather than actual windshield washer fluid.
How it spreads
After Legionella bacteria grow and multiply in a building’s water system, the water containing them can disperse into droplets small enough for people to inhale. People can get Legionnaires’ disease or Pontiac fever when they inhale droplets containing the bacteria.
Another less common way people can get sick is by breathing in drinking water that contains Legionella bacteria. This happens when water accidentally enters the lungs while drinking. Among the people most at risk of inhaling them are those who have difficulty swallowing.
Legionnaires’ disease and Pontiac fever usually do not spread from person to person. However, this may be possible in rare circumstances.1
Signs and symptoms
People who become ill after exposure to Legionella bacteria can develop two different diseases, which together are known as legionellosis: Legionnaires’ disease and Pontiac fever.
Legionnaires’ disease
Legionnaires’ disease is very similar to other types of pneumonia (lung infection); Its symptoms include:
- Cough
- Difficulty breathing
- Fever
- Muscle pains
- Headaches
Legionnaires’ disease may also be associated with other symptoms, such as diarrhea, nausea, and confusion. Symptoms usually appear between 2 and 14 days after exposure to bacteria, but it could take longer.
Pontiac Fever
Pontiac fever is a milder infection than Legionnaires’ disease. Its symptoms, mainly fever and muscle aches, begin within a few hours to 3 days after exposure to bacteria and usually last 1 week. Pontiac fever is different from Legionnaires’ disease because people with this fever do not have pneumonia. You have symptoms, such as fever, cough, chills, or muscle aches.
People at higher risk
Most healthy people who are exposed to Legionella bacteria do not get sick. Those most at risk of getting sick are:
- People aged 50 or older.
- Smokers or ex-smokers.
- People with chronic lung disease (such as chronic obstructive pulmonary disease or emphysema).
- People who have a weakened immune system or take medications that weaken the immune system (such as after an organ transplant or chemotherapy).
- People who have cancer.
- People with underlying conditions (such as diabetes, kidney failure, or liver failure).
Prevention
There are no vaccines that can prevent Legionnaires’ disease.
Instead, the key to preventing it is to reduce the risk of Legionella bacteria multiplying and spreading. Building owners and managers can do this by maintaining building water systems and implementing Legionella controls.
