Bacteremia Salmonella

Pneumogstis carini pneumonia (PCP), the most common of the opportunistic infections, occurs in more than 80% of AIDS patients (13). Toxoplasmosis, a proto2oan infection of the central nervous system, is activated in AIDS patients when the 004 count drops and severe impairment of ceU-mediated immunity occurs. Typically, patients have a mass lesion(s) in the brain. These mass lesions usually respond well to therapy and can disappear completely. Fungal infections, such as CTyptococcalmeningitis, are extremely common in AIDS patients, and Histop/asma capsulatum appears when ceU-mediated immunity has been destroyed by the HIV vims, leading to widespread infection of the lungs, Hver, spleen, lymph nodes, and bone marrow. AIDS patients are particularly susceptible to bacteremia caused by nontyphoidal strains of Salmonella. Bacteremia may be cleared by using antibiotic therapy. 

Localized infections occur in 5% to 10% of cases with Salmonella bacteremia. Sites for extraintestinal complications of salmonellosis include endocarditis, arteritis, central nervous system, lung, bone, joints, muscle/soft tissue, splenic, and genitourinary. 

Salmonella is more likely to cause severe invasive infection in the HIV-infected population. Recurrent nontyphoidal Salmonella bacteremia is an AIDS-defining illness. 

Patients with complicated typhoid fever (i.e., metastatic foci, ileal perforation, etc.) should receive parenteral therapy with ciprofloxacin 400 mg twice daily or ceftriaxone 2000 mg once daily. Antimicrobial therapy can be completed with an oral agent after initial control of the symptoms of typhoid fever. In persons with AIDS and a first episode of Salmonella bacteremia, a longer duration of antibiotic therapy (1-2 weeks of parenteral therapy followed by 4 weeks of oral fluoroquinolone) is recommended to prevent relapse of bacteremia. 

Human disease caused by Salmonella generally falls into four categories acute gastroenteritis (enterocolitis), bacteremia, extraintestinal localized infection, and enteric fever (typhoid and paratyphoid fever), and a chronic carrier state. S. typhimurium is the most common cause of salmonellosis. Salmonellosis is a disease primarily of infants, children, and adolescents. 

Salmonella can produce bacteremia without classic enterocolitis or enteric fever. The clinical syndrome is characterized by persistent bacteremia and prolonged intermittent fever with chills. Stool cultures are frequently negative. 

It has been reported that common serotypes of Salmonella were found responsible for human bacteremia in 0.5-2.5% of culture-confirmed salmonellosis cases in the United Kingdom and in fewer than 6% in the United States. Untreated or ineffectively treated Salmonella bacteremia in humans can be fatal. There has been only one published case of a nonfatal infection by a Salmonella typhimurium DT204c resistant strain of animal origin that failed to respond to fluoroquinolone therapy (33). 

Salmonella typhi Bacteremia paratyphoid fever typhoid fever Ceftriaxone, ciprofloxacin, or cefotaxime Trimethoprim-sulfamethoxazole... 

Waisbren, B.A. Bacteremia due to gram-negative bacilli other than the Salmonella. Arch Intern Med 88 (1951) 467-488. 

Noskin GA, Clarke JT. Salmonella arizonae bacteremia as the presenting manifestation of human immunodeficiency virus infection following rattlesnake meat ingestion Rev Infect Dis 1990 12(3) 514-17. 

Specific Salmonella serotypes produce characteristic human disease. For example S. enterica serotypes Typhimurium or Enteri-tidis causes gastroenteritis, whereas serotypes Typhi or Paratyphi causes enteric fever. Clinical manifestations produced by Salmonella serotypes commonly include acute gastroeuteritis (euterocolitis), bacteremia, extraiutestiual locahzed iufectiou, euteric fever (typhoid aud paratyphoid fever), aud a chrouic carrier state. 

Common clinical manifestations of salmonella infection are diarrhea, fever, abdominal cramps. Most cases resolve within 4-7 days and the majority of patients recover without treatment. In certain cases, however. Salmonella infection may run a severe course, particularly in infants, elderly and patients with immunodeficiency. Bacteremia may develop and infection may affect multiple organs and sites with increased morbidity and mortality. 

Salmonella infections cause two distinct clinical types, the non-typhoid and typhoid type. Non-typhoid is the commonest type and presents as gastroenteritis, bacteremia or focal disease. Typhoid fever is a systemic infectious disease and follows a more severe and protracted course. 

The most common manifestation of non-typhoid Salmonella infection is gastroenteritis. Less common manifestations are bacteremia and focal disease, following a... 

Diagnosis of non-typhoid Salmonella infections is confirmed by isolation of the organism in stool culture and by blood culture in case of bacteremia. 

Respiratory symptoms, cough and hemoptysis may occur due to pulmonary infiltrates of Salmonella typhi and secondary pneumococcal infection. Bacteremia leads to focal disease, which presents with osteomyelitis, endocarditis, particularly in valvular disease, meningitis, soft-tissue abscesses, glomerulonephritis and skin lesions. CNS complications, such as meningitis, mental disturbances, delirium or depressed level of consciousness may occur in severe cases. 

Butler and colleagues demonstrated that azithromycin was effective in treating 86% of 43 bacteremic adults with typhoid fever and was as effective as chloramphenicol-treated patients (88% of 33 improved). All 83 Salmonella strains in this study were susceptible to azithromycin, and all bacteremias were cleared by day 8 of therapy in both treatment groups [259]. On the other hand, Wallace et al. reported treating four adults with typhoid fever with azithromycin [3]. All patients were bacterentic with Salmonella typhi, and three of four failed therapy. It was postulated that low azithromycin serum levels might be inadequate to treat bacteremic patients with typhoid fever. Additional studies are needed before a recommendation can be made for azithromycin as first-line therapy in typhoid fever. 

Enterocolitis Disease caused by Salmonella typhimurium and five paratyphi that invade intestinal tissue and produce bacteremia. 

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