Bartonella seroprevalence in rural Thailand.

We estimated the prevalence of anti-Bartonella antibodies among febrile and non-febrile patients presenting to community hospitals in rural Thailand from February 2002 through March 2003. Single serum specimens were tested for IgG titers to four Bartonella species, B. henselae, B. quintana, B. elizabethae and B. vinsonii subsp vinsonii using an indirect immunofluorescent assay. A titer 21:256 was considered positive. Forty-two febrile patients (9.9%) and 19 non-febrile patients (19%) had positive serology titers to at least one Bartonella species. Age-standardized Bartonella seroprevalence differed significantly between febrile (10%) and non-febrile patients (18%, p=0.047), but did not differ by gender. Among all 521 patients, IgG titers 21:256 to B. henselae were found in 20 participants (3.8%), while 17 (3.3%) had seropositivity to B. quintana, 51 (9.8%) to B. elizabethae, and 19 (3.6%) to B. vinsonii subsp vinsonii. These results suggest exposure to Bartonella species is more common in rural Thailand than previously suspected.

Rapid diagnostic tests for dengue and leptospirosis: antibody detection is insensitive at presentation.

OBJECTIVE: To determine the performance of rapid diagnostic tests for dengue and leptospirosis that rely on detecting antibodies that may not be produced when patients present for medical treatment. METHODS: We prospectively enrolled 723 patients with undifferentiated febrile illness presenting to rural hospitals in northern and northeastern Thailand over a 1-year period. We evaluated rapid antibody detection diagnostic tests for dengue and leptospirosis on these patients. RESULTS: Sensitivity of the tests was low at the acute visit (7.6-21.5%). Sensitivity at the convalescent visit ranged from 25.8% to 81.5% and was significantly higher than at the acute visit for all tests (chi(2), P < 0.001). CONCLUSIONS: Low sensitivity of the rapid tests at presentation suggests that their utility in the acute phase of dengue and leptospirosis is limited.

Invasive infection with multidrug-resistant Salmonella enterica serotype typhimurium definitive type 104 among HIV-infected adults.

BACKGROUND: Multidrug-resistant Salmonella enterica serotype Typhimurium definitive type 104 (MRDT104), with resistance to at least ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline (R-type ACSSuT), was first detected in the United States in 1985, and the prevalence increased to account for nearly 7% of Salmonella infections in 1998. METHODS: A retrospective study of S. Typhimurium infections in an urban health care system assessed whether infection with an antibiotic-resistant strain--and specifically MRDT104--was associated with invasive disease or HIV infection. Sixty cases of S. Typhimurium infection were identified. RESULTS: Of the 50 isolates available for analysis, 30 (60%) were MRDT104. Pathogens were isolated from blood in 25 (83%) of 30 patients infected with MRDT104, compared with 10 (50%) of 20 patients who were infected with non-MRDT104 strains (P = .01). Among isolates obtained from 32 HIV-infected patients, 19 (95%) of 20 MRDT104 isolates were from blood specimens, compared with 8 (66%) of 12 non-MRDT104 isolates (P = .05). CONCLUSIONS: MRDT104 accounted for the majority of S. Typhimurium infections in this patient population, and MRDT104 infections were more invasive than non-MRDT104 infections, particularly in HIV-infected persons.

Transmission of the severe acute respiratory syndrome on aircraft.

BACKGROUND: The severe acute respiratory syndrome (SARS) spread rapidly around the world, largely because persons infected with the SARS-associated coronavirus (SARS-CoV) traveled on aircraft to distant cities. Although many infected persons traveled on commercial aircraft, the risk, if any, of in-flight transmission is unknown. METHODS: We attempted to interview passengers and crew members at least 10 days after they had taken one of three flights that transported a patient or patients with SARS. All index patients met the criteria of the World Health Organization for a probable case of SARS, and index or secondary cases were confirmed to be positive for SARS-CoV on reverse-transcriptase polymerase chain reaction or serologic testing. RESULTS: After one flight carrying a symptomatic person and 119 other persons, laboratory-confirmed SARS developed in 16 persons, 2 others were given diagnoses of probable SARS, and 4 were reported to have SARS but could not be interviewed. Among the 22 persons with illness, the mean time from the flight to the onset of symptoms was four days (range, two to eight), and there were no recognized exposures to patients with SARS before or after the flight. Illness in passengers was related to the physical proximity to the index patient, with illness reported in 8 of the 23 persons who were seated in the three rows in front of the index patient, as compared with 10 of the 88 persons who were seated elsewhere (relative risk, 3.1; 95 percent confidence interval, 1.4 to 6.9). In contrast, another flight carrying four symptomatic persons resulted in transmission to at most one other person, and no illness was documented in passengers on the flight that carried a person who had presymptomatic SARS. CONCLUSIONS: Transmission of SARS may occur on an aircraft when infected persons fly during the symptomatic phase of illness. Measures to reduce the risk of transmission are warranted.

Detection of latent tuberculosis among HIV-infected patients after initiation of highly active antiretroviral therapy.

This cross-sectional study of 110 individuals examined skin testing for latent tuberculosis infection (LTBI) after the initiation of highly active antiretroviral therapy. Skin test reactivity to one or more of four antigens was found in 98 out of 110 subjects (89%), and was maximal in those whose CD4 cell counts recovered to >= 100 cells/mm3. Skin testing is reliable for the identification or exclusion of LTBI once the CD4 cell count recovers to >= 100 cells/mm3.