Human Outbreak of Trichinellosis Caused by Trichinella papuae Nematodes, Central Kampong Thom Province, Cambodia.

In September 2017, a severe trichinellosis outbreak occurred in Cambodia after persons consumed raw wild pig meat; 33 persons were infected and 8 died. We collected and analyzed the medical records for 25 patients. Clinical signs and symptoms included myalgia, facial or peripheral edema, asthenia, and fever. We observed increased levels of creatine phosphokinase and aspartate aminotransferase-, as well as eosinophilia. Histopathologic examination of muscle biopsy specimens showed nonencapsulated Trichinella larvae. A Trichinella excretory/secretory antigen ELISA identified Trichinella IgM and IgG. Biopsy samples were digested and larvae were isolated and counted. PCR for the 5S rDNA intergenic spacer region and a multiplex PCR, followed by sequencing identified the parasite as Trichinella papuae. This species was identified in Papua New Guinea during 1999 and in several outbreaks in humans in Thailand. Thus, we identified T. papuae nematodes in humans in Cambodia.

Tuberculosis and other bacterial co-infection in Cambodia: a single center retrospective cross-sectional study.

BACKGROUND: Cambodia, a lower middle-income country of about 16 million individuals in southeast Asia, endures a high burden of both tuberculosis and other lower respiratory infections. Differentiating tuberculosis from other causes of respiratory infection has important clinical implications yet may be challenging to accomplish in the absence of diagnostic microbiology facilities. Furthermore, co-infection of tuberculosis with other bacterial lower respiratory infections may occur. The objective of this study was to determine the prevalence and etiologies of tuberculosis and other bacterial co-infection and to analyze the clinical and radiographic characteristics of patients presenting with respiratory infection to a provincial referral hospital in Cambodia. METHODS: We performed a retrospective, cross-sectional analysis of laboratory and clinical data, on patients presenting with respiratory symptoms to a chest clinic of a 260-bed provincial referral hospital in Cambodia. We analyzed mycobacterial and bacterial sputum test results, and demographics, medical history and chest radiography. RESULTS: Among 137 patients whose treating clinicians ordered sputum testing for tuberculosis and other bacteria, the median age was 52 years, 54% were male, 3% had HIV infection, and 26% were current smokers. Nearly all had chronic respiratory symptoms (> 96%) and abnormal chest radiographs (87%). Sputum testing was positive for tuberculosis in 40 patients (30%) and for bacteria in 60 patients (44%); 13 had tuberculosis and bacterial co-infection (9% overall; 33% of tuberculosis patients). Clinical characteristics were generally similar across pulmonary infection types, although co-infection was identified in 43% of patients with one or more cavitary lesions on chest radiography. Among those with bacterial growth on sputum culture, Gram negative bacilli (Klebsiella and Pseudomonas spp.) were the most commonly isolated. CONCLUSIONS: Among patients with symptoms of respiratory infections whose treating clinicians ordered sputum testing for tuberculosis and other bacteria, 9% of all patients and 33% of tuberculosis patients had tuberculosis and bacterial co-infection. Greater availability of microbiologic diagnostics for pulmonary tuberculosis and bacterial infection is critical to ensure appropriate diagnosis and management.

TB-IRIS, T-cell activation, and remodeling of the T-cell compartment in highly immunosuppressed HIV-infected patients with TB.

OBJECTIVE: To investigate the impact of tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) upon immunological recovery and the T-cell compartment after initiation of TB and antiretroviral therapy (ART). DESIGN AND METHODS: We prospectively evaluated T-cell immunophenotypes by flow cytometry and cytokines by Luminex assays in a subset (n = 154) of highly immunosuppressed HIV-infected patients with TB from the Cambodian Early versus Late Introduction of Antiretrovirals randomized clinical trial. We compared findings from patients who developed TB-IRIS with findings from patients who did not develop TB-IRIS. Data were evaluated with mixed-effect linear regression, Kaplan-Meier estimates, and Wilcoxon rank-sum tests, and q-values were calculated to control for multiple comparisons. RESULTS: Development of TB-IRIS was associated with significantly greater pre-ART frequencies of HLA-DRCD45ROCD4, CCR5CD4, OX40CD4, and Fas effector memory CD8 T cells, and significantly elevated levels of plasma interleukin (IL)-6, IL-1ß, IL-8, and IL-10, and viral load. Post-ART initiation, effector memory CD4 and Fas effector memory CD4 T-cell frequencies significantly expanded, and central memory CD4 T-cell frequencies significantly contracted in patients who experienced TB-IRIS. By week 34 post-TB treatment initiation, effector memory/central memory CD4 T-cell ratios were markedly higher in TB-IRIS versus non-TB-IRIS patients. CONCLUSIONS: A distinct pattern of pre-ART T-cell and cytokine markers appear to poise the immune response of certain patients to develop TB-IRIS. Experience of TB-IRIS is then associated with long-term remodeling of the CD4 T-cell memory compartment towards an effector memory-dominated phenotype. We speculate that these pre and post-ART TB-IRIS-associated immune parameters may contribute to superior immune control of TB/HIV co-infection and better clinical outcome.

Causes and determinants of mortality in HIV-infected adults with tuberculosis: an analysis from the CAMELIA ANRS 1295-CIPRA KH001 randomized trial.

BACKGROUND: Shortening the interval between antituberculosis treatment onset and initiation of antiretroviral therapy (ART) reduces mortality in severely immunocompromised human immunodeficiency virus (HIV)-infected patients with tuberculosis. A better understanding of causes and determinants of death may lead to new strategies to further enhance survival. METHODS: We assessed mortality rates, causes of death, and factors of mortality in Cambodian HIV-infected adults with CD4 count ≤200 cells/µL and tuberculosis, randomized to initiate ART either 2 weeks (early ART) or 8 weeks (late ART) after tuberculosis treatment onset in the CAMELIA clinical trial. RESULTS: Six hundred sixty-one patients enrolled contributed to 1366.1 person-years of follow-up; 149 (22.5%) died. There were 8.3 deaths per 100 person-years (95% confidence interval [CI], 6.4-10.7) in the early-ART group and 13.8 deaths per 100 person-years (95% CI, 11.2-16.9) in the late-ART group (P = .002). Tuberculosis was the primary cause of death (28%), followed by other HIV-associated conditions (19%). Factors independently associated with mortality in the first 26 weeks were the age, body mass index, hemoglobin, interrupted or ineffective tuberculosis treatment before identification of drug resistance, disseminated tuberculosis, and nontuberculous mycobacterial disease. After 50 weeks in the trial, the most frequent causes of death were non-HIV related or tuberculosis related, including drug toxicity; factors associated with mortality were late ART, loss to follow-up, and absence of cotrimoxazole prophylaxis. CONCLUSIONS: Despite ART introduction, mortality remained high, with tuberculosis as the leading cause of death. Reducing tuberculosis-related mortality remains a challenge in resource-limited settings and requires innovative strategies. Clinical Trials Registration. NCT00226434.

Paradoxical tuberculosis-associated immune reconstitution inflammatory syndrome after early initiation of antiretroviral therapy in a randomized clinical trial.

OBJECTIVE: To analyze cases of paradoxical tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) in the CAMbodian Early versus Late Introduction of Antiretrovirals (CAMELIA) randomized trial designed to compare early (2 weeks) versus late (8 weeks) antiretroviral therapy (ART) initiation after tuberculosis treatment onset in Cambodia (NCT00226434). METHODS: ART-naive adults with CD4 cell count of 200 cells/µl or less, newly diagnosed tuberculosis, and at least one follow-up visit after ART initiation were included in this analysis. Each case of suspected TB-IRIS was systematically validated by two physicians not involved in patients' management. Factors associated with occurrence of TB-IRIS were identified using the Cox proportional hazard model. RESULTS: Among 597 patients, 26% experienced TB-IRIS with an incidence rate of 37.9 cases per 100 person-years [95% confidence interval (CI) 32.4-44.4]. Main clinical manifestations included new or worsening lymphadenopathy (77.4%) and fever (68.4%). Chest radiograph revealed new or worsening abnormalities in 53.4%. Symptoms resolved in 95.5% of patients. Six deaths were directly related to TB-IRIS. Initiating ART early increased the risk of TB-IRIS by 2.61 (95% CI 1.84-3.70). Extrapulmonary or disseminated tuberculosis, CD4 cell count of 100 cells/µl or less, and HIV RNA concentration more than 6 log10 copies/ml were also significantly associated with higher risk of TB-IRIS. CONCLUSION: Shortening the delay between tuberculosis treatment onset and ART initiation to 2 weeks was associated with an increased risk of developing TB-IRIS. However, TB-IRIS was generally easily manageable. Given the marked reported survival advantage of early ART initiation after tuberculosis treatment onset, these data indicate that fear of TB-IRIS should not be an impediment to early ART in adults with advanced immunodeficiency in resource-limited, high burden settings.

Earlier versus later start of antiretroviral therapy in HIV-infected adults with tuberculosis.

BACKGROUND: Tuberculosis remains an important cause of death among patients infected with the human immunodeficiency virus (HIV). Robust data are lacking with regard to the timing for the initiation of antiretroviral therapy (ART) in relation to the start of antituberculosis therapy. METHODS: We tested the hypothesis that the timing of ART initiation would significantly affect mortality among adults not previously exposed to antiretroviral drugs who had newly diagnosed tuberculosis and CD4+ T-cell counts of 200 per cubic millimeter or lower. After beginning the standard, 6-month treatment for tuberculosis, patients were randomly assigned to either earlier treatment (2 weeks after beginning tuberculosis treatment) or later treatment (8 weeks after) with stavudine, lamivudine, and efavirenz. The primary end point was survival. RESULTS: A total of 661 patients were enrolled and were followed for a median of 25 months. The median CD4+ T-cell count was 25 per cubic millimeter, and the median viral load was 5.64 log(10) copies per milliliter. The risk of death was significantly reduced in the group that received ART earlier, with 59 deaths among 332 patients (18%), as compared with 90 deaths among 329 patients (27%) in the later-ART group (hazard ratio, 0.62; 95% confidence interval [CI]; 0.44 to 0.86; P=0.006). The risk of tuberculosis-associated immune reconstitution inflammatory syndrome was significantly increased in the earlier-ART group (hazard ratio, 2.51; 95% CI, 1.78 to 3.59; P<0.001). Irrespective of the study group, the median gain in the CD4+ T-cell count was 114 per cubic millimeter, and the viral load was undetectable at week 50 in 96.5% of the patients. CONCLUSIONS: Initiating ART 2 weeks after the start of tuberculosis treatment significantly improved survival among HIV-infected adults with CD4+ T-cell counts of 200 per cubic millimeter or lower. (Funded by the French National Agency for Research on AIDS and Viral Hepatitis and the National Institutes of Health; CAMELIA ClinicalTrials.gov number, NCT01300481.).

Anti-tuberculosis drug resistance and HIV co-infection in Phnom Penh, Cambodia.

The objective of this study was to observe the prevalence of drug resistance in Mycobacterium tuberculosis isolates in HIV associated tuberculosis co-infected patients in Phnom Penh City. The isolates of M. tuberculosis were collected during active laboratory-based surveillance. Of the 98 isolates studied, M. tuberculosis resistance to isoniazid was seen in 23.5%, resistance to rifampicin was seen in 16.3% and multidrug-resistance (MDR-TB) was seen in 5.1%. Our findings reveal an alarmingly high level of resistance to isoniazid and rifampicin, and confirms the need for drug susceptibility testing to guide treatment in patients with culture positive tuberculosis.

Predictors of pneumocystosis or tuberculosis in HIV-infected Asian patients with AFB smear-negative sputum pneumonia.

OBJECTIVES: To identify predictors of Pneumocystis jiroveci pneumonia (PCP) or pulmonary tuberculosis (TB) in acid-fast bacillus smear-negative HIV-infected patients and to develop clinical prediction rules. DESIGN: A cohort study conducted in consecutive hospitalized Asian patients. METHODS: Multivariate analyses were performed on the Cambodian sample to determine clinical, radiological, and biological predictors of PCP or TB at hospital admission. The Vietnamese sample was kept for independent validation. RESULTS: In Cambodia, the gold standard technique for TB and PCP were fulfilled in 172 (27 cases) and 160 (84 cases) patients, respectively. For TB, independent predictors included the following: headache [odds ratio (OR) 3.0; 95% confidence interval (CI) 1.04 to 8.6], localized radiological opacity (OR 5.8; 95% CI 1.9-17.9), and mediastinal adenopathy (OR 10.1; 95% CI 3.5 to 29.0); and for PCP: resting oxygen saturation <90% (OR 3.3; 95% CI 1.3 to 8.5 for resting arterial oxygen saturation >or=80%; and OR 9.1; 95% CI 1.8 to 44.5 for resting arterial oxygen saturation <80%), trimethoprim-sulphamethoxazole prophylaxis (OR 0.1; 95% CI 0.04 to 0.6), and diffuse radiological shadowing (OR 7.0; 95% CI 2.7 to 18.6). PCP risk predicted by a score based on these 3 factors ranged from 3% to 92% (Cambodia). When tested on Vietnamese patients (n = 69, 38 with PCP), the score maintained correct predictive ability (c-index = 0.72) but with poor calibration. CONCLUSIONS: The PCP score could provide a useful clinical tool to identify PCP among acid-fast bacillus smear-negative pneumonia and start specific therapy.

Clinical features and etiology of pneumonia in acid-fast bacillus sputum smear-negative HIV-infected patients hospitalized in Asia and Africa.

OBJECTIVES: To determine the main causes of acid-fast bacillus sputum smear-negative pneumonia in Asian and African HIV-infected patients DESIGN AND SETTING: A prospective multicenter study (ANRS 1260) of consecutive hospitalized patients in tertiary hospitals in Phnom Penh, Ho Chi Minh City, Bangui and Dakar. INTERVENTION: Use of the same clinical, radiological and biological methods at the four sites; regular quality controls of participating laboratories; final review of medical records by experts. Similar criteria used to establish diagnoses. RESULTS: In all 462 patients were enrolled, 291 in Asia and 171 in Africa. The median CD4 cell count was 25 cells/microl. Radiological opacities were diffuse in 42% of patients and localized in 45%. Fiberoptic bronchoscopy was performed in 354 patients, at similar rates in the four sites. A definite and/or probable diagnosis was obtained in 375 patients (81%). Pneumocystis jiroveci pneumonia, bacterial pneumonia, AFB sputum smear-negative tuberculosis and other infections (fungi, parasites, atypical mycobacteria) were diagnosed in respectively 47, 30, 17 and 12% of Asian patients and 3, 48, 26 and 5% of African patients. CONCLUSION: In South-east Asia, acid-fast bacillus smear-negative pneumonia is caused by a wide variety of pathogens. When possible, fiberoptic bronchoscopy must be performed rapidly if clinical data are not highly suggestive of bacterial pneumonia, Pneumocystis jiroveci pneumonia or tuberculosis. In contrast, in Africa, bacterial pneumonia and tuberculosis are responsible for the large majority of cases. Fiberoptic bronchoscopy should be restricted to patients with clinical and/or radiological findings not suggestive of bacterial pneumonia or tuberculosis, antibiotic failure, and three consecutive negative sputum smears.

A first report of pulmonary melioidosis in Cambodia.

Melioidosis has never been officially reported from Cambodia. Here we report two cases, a 58-year-old male (case 1) and a 49-year-old female (case 2) who presented with respiratory illnesses featuring multiple lung abscesses. The sputum culture of both patients, taken in the framework of a laboratory-based study on aetiologies of (sub-)acute respiratory infections among hospitalized patients in southern Cambodia, grew Burkholderia pseudomallei. The most striking aspect of these case stories was the extent of the delays in diagnosis. Presenting with a 1-month history of respiratory symptoms, case 1 was first suspected of tuberculosis (TB) infection, and then misdiagnosed as 'metastatic lung cancer' in Phnom Penh, Cambodia. Case 2 suffered from pulmonary infections for >10 years, during which time she was treated for TB four times. Neither patient ever produced acid-fast-bacilli (AFB)-positive sputum. Following our laboratory confirmation, the patients were traced for re-admission. Under the 'classical' trimethoprim sulphamethoxazole, chloramphenicol and doxycycline treatment, their clinical status improved considerably within 2 weeks. The two study cases illustrate issues relating to the misdiagnosis of melioidosis in Cambodia; an unfamiliarity of clinicians with the disease, which is associated with a high prevalence of TB. Therefore, a heightened awareness of melioidosis among clinicians would have a substantial impact on public health as the non-septicaemic form of the disease is potentially treatable with antibiotics that are available in Cambodian public hospitals.