Microbiological investigations into an outbreak of Pontiac fever due to Legionella micdadei associated with use of a whirlpool

Article Abstract:

Legionella infections appear in two principal forms: legionella pneumonia (legionnaire's disease) and non-pneumonic legionellosis (Pontiac fever, PF). PF was first described in employees working in a public health building in Pontiac, MI in 1968. The responsible agents have usually been specific strains of Legionella pneumophila and L. feeleii. In many cases, the isolation of the Legionella strains has been dependent on the co-cultivation of the bacteria with specific strains of amoebae. This report describes an outbreak of PF at a resort in Lochgoilhead, Scotland. The index case and others in this large outbreak had blood serum samples which showed a 4-fold rise in titer, or a titer of greater than 1 to 256 of antibody to L. micdadei (LM). These levels showed, without a doubt, that the outbreak was indeed due to LM. Initially, routine cultures of the whirlpool waters using appropriate selective media failed to grow out the organisms. But co-cultivation with specific strains of the amoeba Acanthamoeba polyphaga, followed by incubation on selective media, subsequently produced positive isolates from whirlpool water, filter beds and the associated piping. Several strains of amoebae were isolated from the whirlpool and swimming pool filters. Culture characteristics of the amoebae, and the operating temperatures of the whirlpool, pointed to A. culbertsoni as the specific host of the causative agent responsible for this outbreak. The use of co-cultivation techniques is extremely helpful in determining the microbial cause of an outbreak, when blood tests indicate the presence of the organism and culture techniques fail to produce positive, confirming cultures. (Consumer Summary produced by Reliance Medical Information, Inc.)

Amoeba, Amoebas, Legionnaires' disease, Whirlpools, Legionellosis

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Aplastic anemia associated with organochlorine pesticide: case reports and review of evidence

Article Abstract:

Lindane is an organochlorine compound that was introduced as an insecticide in l942. Due to its long duration of biological activity, wood treated with Lindane remains ''pest free'' for many years. This compound, also known as gamma-benzene hexachloride, is used to treat scabies and pediculosis (contagious skin diseases caused by mites and lice, respectively). Lindane can be absorbed through the skin, and is predominantly stored in fatty tissue. Case histories are presented of three patients with aplastic anemia who had substantial prior exposure to organochlorine compounds. Aplastic anemia is a serious condition in which the bone marrow fails to produce adequate numbers of blood cells; affected patients generally do not respond to usual treatments for anemia. One case, a 12-year-old boy, was exposed to organochlorine during pest control efforts in his own home; the second, a 28-year-old male, used a derivative product to treat woodwork during a renovation; and the third, a 26-year-old male, was occupationally exposed. The temporal association between chemical exposure and the development of aplastic anemia supported the determination of chemical toxicity in these three cases. Lindane and pentachlorophenol were each extracted from fatty tissue of one patient. The mechanism of organochlorine toxicity on hematopoiesis (blood cell production) is discussed; organochlorine compounds or their metabolites may produce an autoimmune reaction that causes continuing bone marrow damage and, thus, aplastic anemia. More intensive record keeping of similar exposures and injuries is necessary to identify and confirm the hazard potential of these insecticides. (Consumer Summary produced by Reliance Medical Information, Inc.)

Insecticides, Organochlorine compounds, Organic chlorine compounds, Lindane, Aplastic anemia

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Neutropenia associated with X-linked agammaglobulinaemia

Article Abstract:

Immunoglobulins (also called antibodies) are special proteins that are made by cells of the immune system (the body's natural defense system for fighting infection). They play an important role in eliminating microorganisms that infect the body. X-linked (or sex-linked) agammaglobulinemia is an inherited disorder that results in abnormally low levels of immunoglobulins in the blood. Patients with this disorder have a reduced ability to fight infection and are very susceptible to infections caused by pus-forming bacteria. Also, they have abnormally low numbers of a type of white blood cell known as B lymphocytes, which are necessary for making antibodies to fight infection. The standard therapy involves treatment with immunoglobulins. This article describes the cases of six patients with this disorder. All six patients had very low levels of immunoglobulins and B lymphocytes in their blood, indicating that the function of their ability to fight infection was impaired. All of the patients had severe infections with pus-forming bacteria and had meningitis (inflammation of the brain and spinal cord membranes). The number of neutrophils (a type of white blood cell) was very low in all of the patients. This condition, neutropenia, gradually disappeared as the infection and agammaglobulinemia were treated. In the past, neutropenia has been observed in patients with agammaglobulinemia but has not been considered to be common feature of this disorder. The cases reported in this study indicate that neutropenia may be more common than previously thought. (Consumer Summary produced by Reliance Medical Information, Inc.)

Cases, Complications and side effects, Sex-linkage (Genetics), Sex linkage, Neutropenia, Agammaglobulinemia

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