An open, randomized, controlled trial of penicillin, doxycycline, and cefotaxime for patients with severe leptospirosis.

BACKGROUND: Leptospirosis is an important cause of fever in the rural tropics. Since 1996, there has been a marked increase in the incidence of leptospirosis in northeastern Thailand. Although leptospirosis generally is susceptible to antibiotics, there is no consensus regarding the optimal treatment for severe leptospirosis. METHODS: An open-label, randomized comparison of parenteral cefotaxime, penicillin G sodium (hereafter known as "penicillin G"), and doxycycline for the treatment of suspected severe leptospirosis was conducted. The study involved 540 patients admitted to 4 hospitals in northeastern Thailand. RESULTS: A total of 264 patients (48.9%) had leptospirosis confirmed by serologic testing or culture. The overall mortality rate was 5%. There were no significant differences between the antibiotics with regard to associated mortality, defervescence, or time to resolution of abnormal findings of laboratory tests either among all study participants or among the subgroup of patients with confirmed leptospirosis. A total of 132 patients had rickettsial infection diagnosed, and, for these patients, treatment with doxycycline was superior to treatment with penicillin G. CONCLUSIONS: Doxycycline or cefotaxime is a satisfactory alternative to penicillin G for the treatment of severe leptospirosis.

Etiologies of acute undifferentiated febrile illness in Thailand.

BACKGROUND: Acute pyrexia of unknown origin (Acute PUO) was reported to affect approximately 200,000-400,000 patients each year reported by the national Annual Epidemiological Surveillance Report. The patients usually present with fever of less than two-week duration and non-specific symptoms such as malaise, myalgia, headache and loss of appetite. Its mortality rate is less than 0.02 percent. It would be interesting to find the etiologies and propose a management plan if the etiologies are discovered. OBJECTIVE: This prospective epidemiologic study aimed to discover the etiologies of acute undifferentiated febrile illness in a tropical region like Thailand. SUBJECTS AND METHOD: Ten community-based hospitals were chosen as representatives in each part of Thailand to enroll patients into the study. Patients aged over two years old who presented with fever at the participating hospitals during year 1991-1993 were eligible for the study. Entry criteria of acute undifferentiated febrile illnesses (AUFI) included oral temperature over 38.3 degrees C within the last 24 hours, duration of fever ranging from 3-14 days, no specific single organ involvement by history taking and physical examination, normal or non-specific results of the following investigations: complete blood count, thick film for malaria, urinalysis and chest roentgenogram. The patients were hospitalized and a preset diagnostic protocol was performed. Other diagnostic procedures deemed necessary by attending physicians were perform. Patients were followed up within one month after hospital discharge. RESULTS: 1,240 patients were enrolled but only 1,137 case records and results of the serological tests were available for analysis. Etiologies could be found in 471 cases (38.7%). Primary bacteremia was detected in 36 cases (3.2%). E. coli, streptococci, salmonella, Enterobacter spp. and S. aureus were the five most common blood isolates. Serological studies revealed positive results for scrub typhus (7.5%), influenza (6.0%), dengue fever (5.7%), murine typhus (5.3%), enteric fever (1.9%), chikunkunya infection (1.1%), leptospirosis (1.1%) and melioidosis (0.9%). Thirteen cases succumbed (1.1%) in this study. CONCLUSION: The etiologies in the majority (61.3%) of AUFI remained unknown. Rickettsial infection, influenza and dengue fever are the most common identifiable diseases in a tropical country like Thailand especially during the rainy season. A management guideline for diagnosis and treatment of the AUFI with emphasis on primary bacteremia and antimicrobial-treatable AUFI was proposed.

Evaluation of nested PCR for the diagnosis of scrub typhus among patients with acute pyrexia of unknown origin.

A nested PCR technique was performed to detect a specific 483 bp DNA fragment of Orientia tsutsugamushi, the aetiological agent of scrub typhus, in 53 blood samples from 36 patients with acute pyrexia of unknown origin in southern Thailand. The specific primers could amplify the specific DNA from all 10 prototype strains of O. tsutsugamushi and all nine seropositive patients and three seronegative patients, while no DNA amplification was obtained with DNAs from other rickettsiae or from healthy persons or from patients with murine typhus. The specific PCR product was detectable in the blood for as long as 22 days after the onset of disease in patients without specific treatment and 27 days after receiving a single dose of doxycycline. Thus, nested PCR may be more sensitive than the serological test for diagnosis of scrub typhus and prolonged persistence of O. tsutsugamushi DNA in patients' blood was demonstrated despite clinical recovery of the patients.