Thanaporn Hortiwakul

Kinetics of Chikungunya Infections during an Outbreak in Southern Thailand, 2008–2009

The Indian Ocean chikungunya epidemic re-emerged in Thailand in August 2008. Forty-five adults with laboratory-confirmed chikungunya in Songkhla province, Thailand were clinically assessed and serially bled throughout the acute and convalescent phase of the disease. Patient symptoms, antibody responses, and viral kinetics were evaluated using observational assessments, polymerase chain reaction (PCR), and serological assays. All subjects experienced joint pain with 42 (93%) involving multiple joints; the interphalangeal most commonly affected in 91% of the subjects. The mean duration of joint pain was 5.8 days, 11 (25%) experiencing discomfort through the duration of the study. Rash was observed in 37 (82%) subjects a mean 3.5 days post onset of symptoms. Patents were positive by PCR for a mean of 5.9 days with sustained peak viral load through Day 5. The IgM antibodies appeared on Day 4 and peaked at Day 7 and IgG antibodies first appeared at Day 5 and rose steadily through Day 24.

Consecutive cutaneous and visceral leishmaniasis manifestations involving a novel Leishmania species in two HIV patients in Thailand.

Leishmaniasis is an emerging disease in Thailand. Herein, we report on two human immunodeficiency virus (HIV)-infected patients with leishmaniasis who presented with overlapping manifestations between cutaneous and visceral leishmaniasis. Sequencing analysis of the internal transcribed spacer 1 (ITS1) of the ribosomal RNA gene showed that the species was identical to a new species recently described in Thailand. The detection of DNA of this Leishmania species in saliva may have important implications for transmission and epidemiological studies.

Toxoplasma gondii infection: What is the real situation?

The prevalence of chronic Toxoplasma infections reported in the literature varies enormously. We hypothesize that one factor could be due to the different methods used in the evaluation of infections. Serological evidence of Toxoplasma infections in 450 pregnant women (PW) and 300 HIV-infected patients (HIV) were investigated by the Sabin-Feldman dye test and two other commercial ELISA kits (kit1 and kit2). Anti-Toxoplasma IgG antibodies obtained from the Sabin-Feldman dye test, ELISA kit1 and ELISA kit2 in the PW subjects were 14.7%, 29.6% and 38.7%, and in the HIV subjects were 13%, 34.7% and 36.3%, respectively. So there were significant differences in the seroprevalences when different diagnostic tests were used (P<0.05). Regarding Sabin-Feldman dye test as the gold standard for anti-Toxoplasma antibodies detection, we found that the sensitivity and specificity of the ELISA kit1 and kit2 was in the range of their specification. However as the two ELISA kits used in our study identified a much higher prevalence of Toxoplasma infections which indicated that false positive cases were being reported. Based on results obtained, it is therefore highly recommended that research workers should be aware that the reports of serological studies in terms of high positive results should be treated with some skepticism until additional precise diagnostic tools are developed.

Characteristics, clinical outcomes and factors influencing mortality of patients with melioidosis in southern Thailand: A 10-year retrospective study

OBJECTIVE To study characteristics, clinical outcomes and factors influencing mortality of patients afflicted with melioidosis. METHODS We retrospectively analyzed 134 patients, with a microbiologically-confirmed diagnosis of melioidosis, during the period from January 2002 to June 2011 at Songklanagarind Hospital, a tertiary care hospital in southern Thailand. RESULTS The prevalence of melioidosis among admitted patients was 36.8 per 100000 in patients. The median age was 49 years and they were predominantly male. The most common underlying disease was diabetes mellitus (47.01%). The majority of cases (50%) had localized infection. The rates of multifocal, bacteremic, and disseminated infections were 12.7%, 23.1%, and 14.2%, respectively. The lungs were the most common organ afflicted, resulting in infection (24.63%). Splenic abscess as well as liver abscess accounted for 20.90% and 19.40%, respectively. A total of one eighth of the patients had septic shock at presentation. The overall mortality rate was 8.96%. The factors influencing mortality were pneumonia, septic shock, a positive blood culture for Burkholderia pseudomallei, superimposing with nosocomial infection and inappropriate antibiotic administration. CONCLUSIONS Melioidosis is not uncommon in southern Thailand. The mortality of patients with pneumonia, bacteremia and septic shock is relatively high. Appropriate antibiotics, initially, will improve outcomes.

Single dosage of doxycycline for prophylaxis against leptospiral infection and leptospirosis during urban flooding in southern Thailand: A non-randomized controlled trial

This study was conducted to investigate the protective efficacy of a single dosage of 200 mg doxycycline against leptospiral infection and leptospirosis and associated risk factors among residents exposed to flooding in southern Thailand. Of 641 participants, 600 received doxycycline while 41 did not. Twenty two participants were infected with Leptospira and six developed leptospirosis. Having a laceration wound was significantly associated with leptospiral infection (odds ratio [OR] = 37.20; P < 0.001) and leptospirosis (OR = 18.24; P = 0.003) whereas exposure to flood more than 3 h per day was associated with only leptospiral infection (OR = 3.70; P = 0.038). Seventeen participants who received doxycycline and five who did not, were infected with Leptospira, resulting a protective efficacy of 76.8% (95% confidence interval [CI] = 34.3%-92.0%). Four who received doxycycline and two who did not, developed leptospirosis, resulting a protective efficacy of 86.3% (CI = -9.8%-98.2%). Among the participants with laceration wound, the protective efficacy for leptospiral infection was 92.0% (CI = 81.2%-96.6%) and for leptospirosis was 95.6% (CI = 78.2%-99.3%). Among the participants exposed to flood water less than or equal to 3 h per day, the protective efficacy for leptospiral infection was 89.2% (95% CI 63.6%-96.67%). A single dosage of 200 mg doxycycline for prophylaxis might be effective for preventing leptospirosis among flood victims with laceration wound after recent flood exposure.

A possible origin population of pathogenic intestinal nematodes, Strongyloides stercoralis , unveiled by molecular phylogeny

Humans and dogs are the two major hosts of Strongyloides stercoralis, an intestinal parasitic nematode. To better understand the phylogenetic relationships among S. stercoralis isolates infecting humans and dogs and to assess the zoonotic potential of this parasite, we analyzed mitochondrial Cox1, nuclear 18S rDNA, 28S rDNA, and a major sperm protein domain-containing protein genes. Overall, our analyses indicated the presence of two distinct lineages of S. stercoralis (referred to as type A and type B). While type A parasites were isolated both from humans and dogs in different countries, type B parasites were found exclusively in dogs, indicating that the type B has not adapted to infect humans. These epidemiological data, together with the close phylogenetic relationship of S. stercoralis with S. procyonis, a Strongyloides parasite of raccoons, possibly indicates that S. stercoralis originally evolved as a canid parasite, and later spread into humans. The inability to infect humans might be an ancestral character of this species and the type B might be surmised to be an origin population from which human-infecting strains are derived.

Outcomes of Patients with Melioidosis Treated with Cotrimoxazole Alone for Eradication Therapy

We retrospectively reviewed a 10-year experience of administration of cotrimoxazole alone in 31 patients compared with 109 patients who received conventional eradication therapy (cotrimoxazole plus doxycycline). The baseline characteristics, the clinical manifestations, the initial intravenous antibiotic treatments, and the mean duration of eradication therapy between the two groups were similar. The culture-confirmed recurrences among the patients who received cotrimoxazole alone and those who received the conventional regimen were not significantly different (1/31 [3.2%] versus 5/109 [4.5% odds ratio = 0.69 [95% confidence interval [CI] = 0.08-6.17]). Gastrointestinal side effects were more common among the conventional regimen group (28/109 [25.7%] versus 2/31 [6.5%], P = 0.02) and the proportion of patients who could complete at least 20 weeks of therapy without having switched to the other regimen was significantly lower (91/109 [83.5%] versus 31/31 [100.0%] P = 0.01). Cotrimoxazole alone is as effective as and better tolerated than cotrimoxazole plus doxycycline for the eradication treatment of melioidosis.

Multiple Cutaneous Nodules in an HIV-Infected Patient

1 Medical Science Program, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand, 2 Division of Infectious Diseases, Department of Internal Medicine, Faculty of Medicine, Prince of Songkla University, Songkhla, Thailand, 3 Department of Parasitology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand, 4 Division of Dermatology, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand, 5 Medical Sciences, National Institutes of Health Ministry of Public Health, Nonthaburi, Thailand, 6 Excellence Center for Emerging Infectious Diseases, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand