Prospective evaluation of a rapid immunochromogenic cassette test for the diagnosis of melioidosis in northeast Thailand

A prospective study was performed to compare a rapid immunochromogenic cassette test (ICT) with the indirect haemagglutination assay (IHA) and clinical rules for the diagnosis of melioidosis in an endemic area. The sensitivity and specificity of the IgG ICT was 86% and 47%, and the IgM ICT was 82% and 47%, respectively. These were similar to the results for IHA (sensitivity 73%, specificity 64%) and clinical rules (73% and 37%). ICT lacks clinical utility as a result of high background rates of positive Burkholderia pseudomallei serology in this population. Low sensitivity and specificity of clinical rules is consistent with the protean manifestations of melioidosis and clinical difficulty in identifying patients with melioidosis.     

Comparison of the protective effects of killed Burkholderia pseudomallei and CpG oligodeoxynucleotide against live challenge

Melioidosis is a fatal disease caused by Burkholderia pseudomallei. Currently there is no vaccine available. Synthetic oligodeoxynucleotides with unmethylated CpG dinucleotide motifs (CpG ODN) can stimulate vertebrate immune cells and clear certain pathogens that are susceptible to a strong Th1 response. In our previous study, pretreatment with CpG ODN alone or CpG-ODN with cationic liposomes for 2–10 or 30 days before B. pseudomallei infection in mice conferred 80–100% protection. In the present study we investigated the protective effect of CpG-ODN together with heat-killed (HK) or paraformaldehyde-killed B. pseudomallei (PP). HK or PP were used to immunize BALB/c mice twice at 15-day intervals before intra-peritoneal challenge with 5LD50 of B. pseudomallei and observed for 30 days. We found that PP could significantly protect mice (60%) with an increased survival time (24.8 ± 11.63 days) while in the HK and PBS groups, all infected mice died within 6 days. Although either CpG ODN or PP conferred significant protection, giving them in combination did not enhance it further. Serum IFN-γ levels on day-5 (before challenge) of the PP and PP + CpG ODN groups were significantly higher than those of the PBS control group. The results further support the importance of IFN-γ in host protection against B. pseudomallei and suggest further study on paraformaldehyde-killed bacteria as a component of a future B. pseudomallei vaccine.     

The effect of quicklime (calcium oxide) as an inhibitor of Burkholderia pseudomallei

Measurement of in vitro activity of quicklime against Burkholderia pseudomallei revealed that quicklime at concentrations of 10% or more was bactericidal for up to 35 d. The effect of quicklime as an inhibitor of B. pseudomallei in soil from a rice field was studied in a laboratory setting. The soil, collected from a rice field in north-eastern Thailand, was mixed with B. pseudomallei. In experiment 1, quicklime was mixed with the soil in different amounts. In experiment 2, quicklime was spread over the soil surface. In experiment 3, quicklime solution was poured onto the soil. It was found that the pH of the soil in experiment 1 was much higher than that in experiments 2 and 3. Only quicklime mixed with soil at a concentration of 40% or more (weight/weight) was effective in inhibiting the growth of B. pseudomallei for up to six weeks.     

Lipopolysaccharide from Burkholderia thailandensis E264 provides protection in a murine model of melioidosis

Burkholderia thailandensis is a less virulent close relative of Burkholderia pseudomallei, a CDC category B biothreat agent. We have previously shown that lipopolysaccharide (LPS) extracted from B. pseudomallei can provide protection against a lethal challenge of B. pseudomallei in a mouse model of melioidosis. Sugar analysis on LPS from B. thailandensis strain E264 confirmed that this polysaccharide has a similar structure to LPS from B. pseudomallei. Mice were immunised with LPS from B. thailandensis or B. pseudomallei and challenged with a lethal dose of B. pseudomallei strain K96243. Similar protection levels were observed when either LPS was used as the immunogen. This data suggests that B. thailandensis LPS has the potential to be used as part of a subunit based vaccine against pathogenic B. pseudomallei.     

Six cases of suppurative lymphadenitis caused by Burkholderia pseudomallei infection

Melioidosis, an infection caused by Burkholderia pseudomallei, is endemic in Southeast Asia and northern Australia. It can have various presentations, ranging from acute septicaemia to chronic localized infection. Uncomplicated, localized infection usually involves skin or subcutaneous tissues. Suppurative lymphadenitis caused by melioidosis has been rarely encountered by clinicians practicing in endemic areas. We encountered six cases of suppurative lymphadenitis caused by Burkholderia pseudomallei in adults who were admitted to hospital in Singapore from 1997 to 2000. The most striking difference between these patients and cases reported previously was the pattern of the lymph node involvement. In the majority of previously described patients the infected lymph nodes were in the head and neck region. By contrast, four patients in our study presented with unilateral, inguinal lymphadenitis. Another two patients presented with mediastinal lymphadenitis and prolonged fever. All patients had prompt and sustained response to therapy. Melioidosis should be considered in the differential diagnosis of suppurative, regional lymphadenitis, especially in patients who travelled to, or stayed in, an endemic area.     

Marital sex among people living with HIV receiving antiretroviral treatment in Northern Thailand

Before the advent of effective antiretroviral treatment (ART), the sexuality of people living with HIV was mostly discussed in terms of risk. To assess the extent to which ART allows people living with HIV to regain a regular sexual life, we surveyed all HIV-infected people treated in four hospitals in Northern Thailand and a control group from the general population matched by sex, age and residence. Data included socio-demographic and health characteristics, frequency of sexual intercourse in the last month and condom use. Our findings indicate that people living with HIV less often live in steady partnership (50% of the HIV-infected people versus 79% of the controls). After adjusting for factors known to influence sexuality, their probability of being sexually active was estimated to be about half that of the controls. When sexually active, men had a reduced sexual activity compared to controls (2.8 intercourse in the last month versus 4.0), while levels of reported sexual activity were similar among women (2.2 versus 2.8, respectively). Consistent condom use was high among people living with HIV (66% for women and 70% for men).     

Cross-sectional relationship between HIV, lymphatic filariasis and other parasitic infections in adults in coastal northeastern Tanzania

The relationship between HIV, lymphatic filariasis, malaria (Plasmodium falciparum) and intestinal helminths (Ascaris lumbricoides, Trichuris trichiura and hookworm) was assessed in a cross-sectional study conducted in 2002 among 907 adults in Tanga Region, Tanzania. Overall prevalences were 7.9% for HIV, 43.5% for Wuchereria bancrofti-specific circulating filarial antigen (CFA), 12.3% for P. falciparum, 1.2% for A. lumbricoides, 7.1% for T. trichiura and 75.7% for hookworm. Anaemia was assessed separately for males and females and was found to be more prevalent among females (58.8%) than males (34.8%). When sex and age were controlled for, there was a statistically significant positive association between HIV and W. bancrofti (CFA) infection and between malaria and HIV, but not between malaria and W. bancrofti (CFA) infection. Hookworm infection was positively associated with W. bancrofti (CFA) infection but, surprisingly, negatively associated with HIV. Infection with HIV and hookworms, but not malaria, was associated with a significant reduction in haemoglobin concentration. These associations are likely to reflect underlying mechanisms that need to be clarified to better understand the role of co-infections in HIV pathogenesis, and vice versa.     

Quality of life among people living with HIV/AIDS in northern Thailand: MOS-HIV Health Survey

OBJECTIVES: Translation and psychometric evaluation of a Thai version of the Medical Outcomes Study HIV Health Survey (MOS-HIV) in Thailand. METHODS: A cross-sectional survey in Chiang Mai province, northern Thailand, with data collected in face-to-face interviews using a structured questionnaire designed to measure 10 scales of quality of life (QOL). We recruited 200 people with HIV/AIDS attending self-help groups in the municipal area. Standard guidelines were followed for questionnaire translation and psychometric evaluations. RESULTS: Item-level internal consistency and discriminant validity were reasonably established. Success rates were 93.8 and 97.4%, respectively. Scale-level internal consistency reliability of multi-item scales was satisfactory, ranging from 0.74 to 0.88, with all exceeding inter-scale correlations. Principal components analysis of item and scale scores identified two hypothesized dimensions of the MOS-HIV. The mental health component was strongly loaded by health distress, mental health, vitality and cognitive function scales, and physical health by role, physical and social functions, and pain scales. Respondents manifesting symptoms or reporting worsening health status scored significantly lower on all scales. CONCLUSIONS: These preliminary studies have shown the Thai version of the MOS-HIV to have psychometric properties comparable with those reported in previous surveys. Further testing and modification should make it useful as an HIV-specific QOL measure in Thailand.     

Knowledge of HIV Risk Factors Among Immigrants in Thailand

This study is based on a sample of 3,374 immigrants from Cambodia and Myanmar who worked in 17 different provinces in Thailand. Many immigrants workers had not even heard of HIV/AIDS before coming to Thailand, but most have received instruction about HIV/AIDS from some source in Thailand, and a large majority are now aware of HIV/AIDS. While immigrant workers in Thailand are fairly knowledgeable about the risk factors for HIV transmission, important gaps remain. Women, persons with less than five years of education, seafarers, agricultural workers, those who do not personally know anyone affected by HIV/AIDS, and those who have not yet received instruction in HIV/AIDS are the ones most likely to have gaps in their knowledge of HIV/AIDS risk factors.

Imported Melioidosis in South Korea: A Case Series with a Literature Review

Objectives

Melioidosis is a potentially fatal infectious disease caused by the environmental anaerobic Gram-negative bacillus Burkholderia pseudomallei. Melioidosis is endemic to areas of northern Australia and Southeast Asia. With increasing international travel and migration, imported cases of melioidosis are being reported regularly. Here, we summarize the 11 cases of melioidosis reported in South Korea from 2003 to 2014.

Methods

Tracing epidemiological investigations were performed on every patient reported to the National Surveillance System since 2011. A systematic literature search was performed to identify melioidosis cases that occurred prior to 2011.

Results

The overall fatality rate was 36.4%. All the patients had visited Southeast Asia where melioidosis is endemic. The stay in the endemic region ranged from 4 days to 20 years. Of the seven patients who developed initial symptoms after returning to South Korea, the time interval between returning to South Korea and symptom onset ranged from 1 day to 3 years. The remaining four patients developed symptoms during their stay in the endemic region and were diagnosed with melioidosis in South Korea. Seven (63.6%) patients possessed at least one risk factor, all of whom were diabetic. Pneumonia was the most frequent clinical manifestation, but the patients showed a wide spectrum of clinical features, including internal organ abscesses, a mycotic aneurysm of the aorta, and coinfection with tuberculosis.

Conclusion

An early diagnosis and initiation of the appropriate antibiotics can reduce the mortality of melioidosis. Consequently, increased awareness of the risk factors and clinical features of melioidosis is required.     

Clinical presentation of melioidosis in Queensland, Australia

A retrospective study was performed on culture-positive patients (n = 57) with melioidosis presenting to the Townsville Hospital to define the epidemiology of the disease in Queensland, Australia. Mortality was 25% (n = 14) with a 9% (n = 5) relapse rate. At presentation, primary organs involved included the lungs (58%; n = 33), genitourinary system (11%; n = 6), skin and soft tissue (9%; n = 5), bone and joints (4%; n = 2), central nervous system (4%; n = 2), mycotic aneurysm (2%; n = 1) and peritonitis (2%; n = 1). No focus of infection could be identified in 12% of cases (n = 7). There was no significant difference in the clinical presentation of melioidosis in Queensland compared with the Northern Territory. Regional trends in the clinical presentation of melioidosis in Australia compared with Southeast Asia were confirmed. Risk factors for disease included diabetes (42%), excess alcohol consumption (42%), chronic lung disease (26%), immunosuppressive drug use (12%), renal disease (11%), malignancy (7%) and autoimmune disease (5%). No risk factors were identifiable in 18% of cases. The presence of multiple risk factors for melioidosis was not significantly associated with increased mortality (P > 0.05).     

Factors associated with tuberculosis treatment default among HIV-infected tuberculosis patients in Thailand

Ensuring completion of tuberculosis (TB) treatment remains a major public health problem. In HIV-infected patients, TB is the most common severe opportunistic infection. Few studies have evaluated risk factors for TB treatment default in HIV-infected patients. We conducted a prospective, observational study of HIV-infected TB patients in Thailand. Patients underwent standardised evaluations at the beginning of TB treatment, at the end of the intensive phase and at the end of TB treatment. TB treatment outcomes were assessed according to WHO guidelines. The analysis was limited to patients who defaulted or who had treatment success. Of the 554 patients analysed, 61 (11%) defaulted. In multivariate analysis, factors associated with TB treatment default included incarceration history [adjusted odds ratio (AOR) 2.0, 95% CI 1.1-3.7), smoking (AOR 2.3, 95% CI 1.3-4.1) and having a symptom complaint score >15 (AOR 3.4, 95% CI 1.4-8.0); one marker of wealth, namely owning a refrigerator, was protective (AOR 0.4, 95% CI 0.2-0.8). Default during TB treatment was a significant problem in HIV-infected patients. Reducing default may require enhancing services for patients with a history of incarceration or smoking and designing patient-centred systems to address poverty and patient wellness.     

Chlorination and pH of drinking water do not correlate with rates of melioidosis in the Northern Territory, Australia

Prompted by 2 outbreaks of melioidosis with fatalities linked to culture-positive drinking water, we theorized that there may be a correlation between low drinking water pH or lack of chlorination and the rate of melioidosis in rural communities in tropical Australia. However, following adjustment for rainfall, such associations were not apparent in a multivariate regression model.     

High prevalence of toxinogenic Clostridium difficile in Nigerian adult HIV patients

Clostridium difficile is the most commonly identified bacterial cause of nosocomial and HIV-related diarrhea. In many developing countries, antibiotic access is unregulated. Nigeria has the third highest HIV burden worldwide. Due to perceptions of low prevalence and resource incapacity, patients with diarrhea are not tested for toxinogenic C. difficile infection (CDI). In this pilot study which included 97 HIV-positive patients at two hospitals in Nigeria, the estimated prevalence of CDI was 43% and 14% for in-patients and out-patients respectively. HIV-positive out-patients were more likely to have toxinogenic CDI than non-HIV out-patients (P = 0.007, Fisher's exact test).     

HIV and AIDS, stigma and AIDS support groups: Perspectives from women living with HIV and AIDS in central Thailand

In this paper, community attitudes toward women living with HIV and AIDS at the present time from the perspectives of women in Thailand are examined. We also look at strategies women use in order to deal with any stigma and discrimination that they may feel or experience in the community. The paper is based on our larger study of the experiences of women living with HIV and AIDS and their participation in clinical trials. In late 2007 and early 2008 we carried out a number of in-depth interviews with women living with HIV and AIDS in central Thailand. We find that women living with HIV and AIDS still deal with stigma and discrimination in their everyday life. However, from the women's narratives, we also find more positive attitudes from local communities. Some women deal with stigma and discrimination by joining and participating in HIV and AIDS support groups that have emerged in response to the AIDS epidemic in Thailand. We argue that women are not passive victims, but that they act in their own agencies to counteract any negativity they might encounter.     

Monitoring of Plasmodium vivax sensitivity to chloroquine in vitro in Thailand

The sensitivity of Plasmodium vivax to chloroquine in vitro was investigated in patients admitted to the Bangkok Hospital for Tropical Diseases, Thailand, between September 2001 and May 2002. Of 42 isolates, 34 were successfully tested for parasite sensitivity to chloroquine in vitro; the results showed a significant decrease in sensitivity compared with data published in 1989 and 1995: the IC50 and IC90 were 187.2 and 1217.9 ng/mL blood, respectively, an approximate 4-fold decrease in sensitivity in comparison with other data from the past 2 decades. A number of in vitro tests were performed simultaneously using both WHO microplates and our own laboratory-prepared pre-dosed microplates under the same conditions and there was no significant difference between the results.     

Spatiotemporal patterns of malaria incidence in northern Thailand

We present a detailed analysis of long-term time series of malaria incidence in northern Thailand. Positive cases for Plasmodium falciparum and P. vivax have been recorded monthly from 1977-2002 at 13 provinces in the region. Time series statistical methods are used to examine the long-term trends and seasonal dynamics of malaria incidence at regional and provincial scales. Both malarial types are declining throughout the region, except in the two provinces that share a large border with Myanmar. The rate of decline in P. vivax has decreased across the region since the end of the 1980s, and this may be a signal of developing resistance or changing vector potential. Both species display a two-peak annual seasonality that may be attributed to patterns of vector occurrence, farming practice and migration of individuals across international borders. In a number of provinces, the importance of the first seasonal peak has grown in recent years, possibly owing to increases in vector densities. The medium-term fluctuations of both species exhibit a clear spatial organisation. There is some evidence of a subtle close to 4-year super annual cycle in P. falciparum, which we suggest is driven by extrinsic factors relating to the climate of the region.     

Melioidosis in a rural community of Western Province, Papua New Guinea

A prospective study was conducted to determine the significance of melioidosis in the Balimo district of Western Province, Papua New Guinea. During 1998, after the establishment of laboratory procedures and increasing local clinical awareness, the disease was found in 1.8% (95% CI 0.37-5.1%) of individuals presenting with fever refractory to standard treatment. The clinical incidence was 20.0 per 100,000 population (95% CI 12.2-30.9). The median age of culture-confirmed cases was 9.5 years (interquartile range 8.3-14.8 years). The seroprevalence of 747 community children in the region tested was 8.2% (95% CI 6.2-10.4%). Most individuals presented during the rainy season with a febrile disease refractory to standard treatment, sometimes mimicking tuberculosis. Some family clustering was apparent. All patients with bacteraemic melioidosis died, but treatment with the available conventional therapies of chloramphenicol, co-trimoxazole or doxycycline resulted in survival and cure in six patients with subacute/localised melioidosis. Further studies are needed to ascertain the local epidemiology and why children appear particularly at risk, as well as to establish the true extent of melioidosis in Papua New Guinea.     

泰国艾滋病防控策略研究及经验分析

目的 分析泰国艾滋病防控成效取得的成功经验。 方法 从疾病防控的组织管理、防控策略的实施路径、防控成效几个方面进行分析。 结果 2000年以来,泰国有效控制了艾滋病的流行趋势,并成为亚洲第一个阻断母婴传播的国家。 结论 泰国过去几十年在艾滋病预防和应对方面的成功归功于政府清晰的政策承诺、完善的信息系统、有效的价格调节机制、治疗的全民覆盖和所有有关部门的良好合作。