Biomedical subjects

Angkana Chaiprasert

Publications and source records attributed to Angkana Chaiprasert.

At least 19 recordsLinked to original sources

PubMed2006

Distribution of hsp65 PCR-restriction enzyme analysis patterns among Mycobacterium avium complex isolates in Thailand.

A total of 227 clinical Mycobacterium avium complex isolates from Thailand were differentiated into species and types by using PCR-restriction enzyme analysis of hsp65. The distribution of types showed the predominance of M. avium I (77%) in blood specimens, whereas M. intracellulare I was more commonly found in pulmonary specimens (44.2%). In addition, infections with M. avium were more likely to be found in younger adults (20 to 39 years old), while infections with M. intracellulare were more likely to be found in older adults (> or =60 years old). Our results provide the useful epidemiological information that some particular types have more invasive and virulent characters than others.

Adolescent↗

PubMed2006

Clinical and epidemiological analyses of human pythiosis in Thailand.

BACKGROUND: Pythiosis is an emerging and life-threatening infectious disease in humans and animals that is caused by the pathogenic oomycete Pythium insidiosum. Human pythiosis is found mostly in Thailand, although disease in animals has been increasingly reported worldwide. Clinical information on human pythiosis is limited, and health care professionals are unfamiliar with the disease, leading to underdiagnosis, delayed treatment, and poor prognosis. METHODS: To retrospectively study the clinical and epidemiological features of human pythiosis, we analyzed clinical data from patients with pythiosis diagnosed during the period of January 1985 through June 2003 at 9 tertiary care hospitals throughout Thailand. RESULTS: A total of 102 cases of human pythiosis were documented nationwide. A substantial proportion (40%) of cases occurred in the last 4 years of the 18-year study interval. Clinical presentations fell into 4 groups: cutaneous/subcutaneous cases (5% of cases), vascular cases (59%), ocular cases (33%), and disseminated cases (3%). Almost all patients with cutaneous/subcutaneous, vascular, and disseminated pythiosis (85%) had underlying thalassemia-hemoglobinopathy syndrome. Most ocular cases (84%) were associated with no underlying disease. A majority of the patients were male (71%), were aged 20-60 years (86%), and reported an agricultural occupation (75%). Regarding treatment outcomes, all patients with disseminated infection died; 78% of patients with vascular disease required limb amputation, and 40% of these patients died; and 79% of patients with ocular pythiosis required enucleation/evisceration. CONCLUSIONS: Here, we report, to our knowledge, the largest case study of human pythiosis. The disease has high rates of morbidity and mortality. Early diagnosis and effective treatment are urgently needed to improve clinical outcomes. Because P. insidiosum is distributed worldwide and can infect healthy individuals, an awareness of human pythiosis should be promoted in Thailand and in other countries.

Adolescent↗

PubMed2006

Identification of a novel 74-kiloDalton immunodominant antigen of Pythium insidiosum recognized by sera from human patients with pythiosis.

The oomycetous, fungus-like, aquatic organism Pythium insidiosum is the etiologic agent of pythiosis, a life-threatening infectious disease of humans and animals that has been increasingly reported from tropical, subtropical, and temperate countries. Human pythiosis is endemic in Thailand, and most patients present with arteritis, leading to limb amputation and/or death, or cornea ulcer, leading to enucleation. Diagnosis of pythiosis is time-consuming and difficult. Radical surgery is the main treatment for pythiosis because conventional antifungal drugs are ineffective. The aims of this study were to evaluate the use of Western blotting for diagnosis of human pythiosis, to identify specific immunodominant antigens of P. insidiosum, and to increase understanding of humoral immune responses against the pathogen. We performed Western blot analysis on 16 P. insidiosum isolates using 12 pythiosis serum samples. These specimens were derived from human patients with pythiosis who had different forms of infection and lived in different geographic areas throughout Thailand. We have identified a 74-kDa immunodominant antigen in all P. insidiosum isolates tested. The 74-kDa antigen was also recognized by sera from all patients with pythiosis but not by control sera from healthy individuals, patients with thalassemia, and patients with various infectious diseases, indicating that Western blot analysis could facilitate diagnosis of pythiosis. Therefore, the 74-kDa antigen is a potential target for developing rapid serodiagnostic tests as well as a therapeutic vaccine for pythiosis. These advances could lead to early diagnosis and effective treatment, crucial factors for better prognosis for patients with pythiosis.

Antibodies↗

PubMed2006

Intact pks15/1 in non-W-Beijing Mycobacterium tuberculosis isolates.

To determine whether intact pks15/1 is unique to the W-Beijing family, we investigated 147 Mycobacterium tuberculosis strains with different IS6110 genotypes. Intact pks15/1 was found in 87.8% of cerebrospinal fluid and 84.9% of sputum isolates. It was found not only in W-Beijing strains (approximate, equals 97%) but also in other genotypes (38.5%-100%).

Base Sequence↗

PubMed2006

One-tube multiplex PCR method for rapid identification of mycobacterium tuberculosis.

A rapid, inexpensive, simple, and accurate multiplex polymerase chain reaction (PCR) was developed in a single tube for identification of Mycobacterium tuberculosis. Assessment of sensitivity and specificity of simple PCR was performed with 116 strains of M. tuberculosis complex (MTC) and 144 strains of nontuberculous mycobacteria (NTM) compared with the biochemical method. Specific amplification of KS4, MTC-specific DNA fragment, was found in 98% (114/116) of MTC and not detected in 99% (143/144) of NTM. Amplification of the mtp40 gene revealed 95% sensitivity (100/105 strains of M. tuberculosis) and 77% specificity (not found in 119/155 mycobacterial strains). A multiplex PCR method based on the combination of KS4- and mtp40-derived primers was used for identification of M. tuberculosis. Crude DNA from slow growing mycobacteria with cream rough colonies that showed both 768-bp amplified product for KS4 and 396-bp for mtp40 was identified as M. tuberculosis whereas that from MTC gave only the 768-bp product.

Base Sequence↗

PubMed2005

Comparative evaluation of polymerase chain reaction and restriction enzyme analysis: two amplified targets, hsp65 and rpoB, for identification of cultured mycobacteria.

The increasing incidence of tuberculosis and other mycobacterial infections due to AIDS epidemic resulted in the need of rapid and accurate identification of isolated mycobacteria. The correct identification result leads to the selection of an appropriate therapeutic regimen. Polymerase chain reaction and restriction enzyme analysis (PCR-REA) has been developed since 1992 and used as the rapid method for identifying mycobacteria. Several genes or sequences have been used as an amplified target for PCR-REA. The present study aims to evaluate the potential use of PCR-REA of gene-encoding heat shock protein 65 kDa (hsp65) and beta-subunit RNA polymerase (rpoB) for the identification of mycobacteria compared with conventional biochemical identification. Two hundreds clinical isolates, consisting of 50 isolates of Mycobacterium tuberculosis and 150 isolates of nontuberculous mycobacteria (NTM), were submitted for identification using PCR-REA and biochemical method. The results demonstrated that PCR-REA identified 188 isolates of both M. tuberculosis and NTM concordantly with biochemical identification. Discordant identification results obtained from 12 isolates, comprised of 8 M. scrofulaceum, 1 M. avium complex, 1 M. malmoense, 1 M. terrae complex, and 1 M. chelonae/abscessus. Overall, the concordant percentage of results obtained from PCR-REA compared with biochemical method was 100%, 98.8%, and 83.3% for M. tuberculosis complex, rapidly growing, and slowly growing mycobacteria, respectively, and the results of hsp65 PCR-REA was in agreement with those obtained from rpoB PCR-REA. From this study, PCR-REA appears to be a simple, rapid, and reliable method for identifying mycobacteria in a routine microbiology laboratory.

Bacterial Proteins↗

PubMed2005

Detection and identification of Mycobacterium species by polymerase chain reaction (PCR) from paraffin-embedded tissue compare to AFB staining in pathological sections.

BACKGROUND: Polymerase chain reaction (PCR) is a recent, rapid and reliable method in the detection of causative organism. The authors tried to determine the possibility of using PCR technique as an alternative way to detect mycobacterial DNA from paraffin-embedded tissue to avoid repeated biopsy from the patient. MATERIAL AND METHOD: Paraffin-embedded tissue blocks, the corresponding histopathologic slides, and cultural results were retrospectively searched for according to the patient's records, the granuloma clinic, Department of Dermatology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand from 1994-2000. One hundred and thirty-one tissue blocks and slides were found but only 120 cultural results were retrieved Histologic sections were reviewed for AFB findings and PCR was done using 16S rRNA sequences to detect M. tuberculosis by one-tube nested technique and multiplex PCR for M. marinum and M. fortuitum complex. RESULTS: The causative organisms were identified by AFB staining in pathologic sections 31.29%, by PCR 35.87%, and by culture 30.00% of tested samples. The sensitivity of PCR when compared to AFB result was 29.26%, specificity 61.11% but when compared to cultural results, the sensitivity of PCR was 66.67% and AFB sensitivity was 41.66% with specificity 76.19% and 72.61% respectively. CONCLUSION: The low sensitivity of the PCR method may be due to formalin fixation, deparaffinization process, DNA extraction method, the use of 16S rRNA-based primers and the length of the expected product, and the tissue type that may have Taq polymerase inhibitor. Therefore, PCR should be used to augment the information of the conventional method in the diagnosis of mycobacterial infection.

Adolescent↗

PubMed2005

Evaluation of polymerase chain reaction and restriction enzyme analysis for routine identification of mycobacteria: accuracy, rapidity, and cost analysis.

Polymerase chain reaction and restriction enzyme analysis (PCR-REA) of the hsp65 gene was evaluated for use as a routine identification method for identifying mycobacteria. The accuracy, rapidity, and cost were assessed compared with the conventional biochemical method. Five hundred and forty-one mycobacterial clinical isolates obtained from the Department of Microbiology, Faculty of Medicine at Siriraj Hospital, Mahidol University, were submitted for PCR-REA and biochemical identification. PCR-REA showed high concordant result with 100, 96.2, and 94.1% for identification of Mycobacterium tuberculosis, rapid- and slow-growing mycobacteria, respectively. Discordant results were obtained from 24 (4.4%) out of 541 isolates, consisting of 9 rapid growers (6 M. chelonae, 2 M. abscessus, and 1 M. fortuitum) and 15 slow growers (9 M. scrofulaceum, 2 M. gordonae, 1 M. avium, 1 M. kansasii, 1 M. malmoense, and 1 M. terrae complex). PCR-REA demonstrated not only accurate results but was also less expensive (2.1 US dollars/sample). This method was rapid with a turn-around time of 30 hours compared with 2-4 weeks for the conventional method.

Bacterial Proteins↗

PubMed2005

Treatment of tinea capitis caused by Microsporum ferrugineum with itraconazole.

A prospective, non-randomized, open clinical trial was conducted to determine the efficacy of itraconazole for treatment of Microsporum ferrugineum tinea capitis. Itraconazole capsules were given every day in continuous group and every day for 1 week on and 3-week off in pulse therapy group. Concomitant topical therapy with 2% ketoconazole shampoo was used daily. Clinical evaluation consisted of assessing the degree of hair loss, scaling, erythema, pustule, and crust. In both groups, the treatment was stopped when the clinical signs of inflammation had resolved and the mycological examination had become negative or at week 12. There were 81 patients consisted of 49 boys and 32 girls enrolled and average dose of itraconazole was 4.5 mg/kg/day. During the 16-week study period (with 4-week follow-up visit) the overall clinical severity score decreased every visit (p < 0.001). The improvement of the scores showed no statistical difference between both groups. The cumulative cure rate using combined clinical and mycological cure at week 16 in patients treated with continuous and pulse regimen was 54.3% (19/35) and 37.0% (17/46), respectively. The cumulative percentage of all cure rates including clinical cure, mycological cure and combined clinical and mycological cure of the continuous group was significantly higher than in the pulse therapy group (p < 0.001). The superior efficacy of the continuous therapy group was observed after week 8. The cumulative cure rate increased with the longer treatment duration but decreased with the larger infected area involvement (p = 0.001). All patients who were not cured showed improvement. There was no significant adverse effect. The higher dosage or the longer treatment duration of itraconazole may be required for treatment of tinea capitis from M. ferrugineum to achieve more cure rate.

Adult↗

PubMed2004

Efficacy of immunotherapy using antigens of Pythium insidiosum in the treatment of vascular pythiosis in humans.

Human pythiosis is an emerging disease in the tropical, subtropical and temperate regions of the world. It is caused by the straminipilan, fungus-like, aquatic organism Pythium insidiosum. Pythiosis occurs in localized as well as systemic or vascular forms. Most patients with arterial pythiosis usually have underlying hematologic disorders such as thalassemia and aplastic anemia/paroxysmal nocturnal hemoglobinuria (PNH) syndrome. Vascular pythiosis is characterized by ascending blood vessel infections and thrombosis of the major arteries especially those of the lower extremities. When the infection reaches a main artery, the patient usually dies within weeks. Since this pathogen is resistant to most antifungal drugs, immunotherapy was recently used to cure humans and animals with the disease. A modified P. insidiosum-antigen (PIA) formulation had already saved a young boy with life-threatening arterial pythiosis. Here, we report the therapeutic benefits of the PIA in eight patients with vascular pythiosis. Six of them had thalassemia and the other two had PNH. All of the patients had arterial occlusion of the lower limbs. P. insidiosum was isolated and identified by culture and by histopathology. All patients had evidence of active infection when immunotherapy began. After two injections of 100-200 microl of PIA (2.0mg/ml), at a 14-day interval, four patients (50%) had dramatic and complete remission. Two patients showed partial responses to PIA while the other two did not. Clinical responses correlated with the immunological reactions at the site of injection, clearance of the arteries and cytokine production. The latter included the shifting in serum levels of IL4 and IL5 to IL2 suggesting a switching from a T helper 2 (Th2) to a T helper 1 (Th1) subset. Our findings provide further evidence that immunotherapy using PIA is a safe and effective method to treat pythiosis in humans.

Adolescent↗

PubMed2004

A simple C-reactive protein measurement for the differentiation between tuberculous and malignant pleural effusion.

OBJECTIVE: The aim of this study was to determine the validity of pleural fluid C-reactive protein (CRP) concentrations and/or pleural fluid to serum CRP ratio for differentiating tuberculous pleuritis (TBP) from malignant pleural effusion (MPE) in patients presenting with lymphocytic exudative pleural effusions. METHODOLOGY: A cross-sectional study was conducted on 161 patients with pleural effusion who underwent diagnostic evaluation at Siriraj Hospital, Bangkok, Thailand, between April 2001 and March 2002. The complete biochemical analysis of pleural fluid, cultures of pleural fluid, and pathological examinations of pleural fluid and pleural tissue were performed. The CRP concentrations were then measured in stored sera and pleural fluid samples from patients with a lymphocytic exudative pleural effusion and with a definite diagnosis. RESULTS: Among the 148 patients with lymphocytic exudative pleural effusions, 55 were diagnosed with TBP, 60 with MPE, and 33 with non-specific pleuritis. Pleural fluid and serum CRP levels were significantly higher in the TBP group than in the MPE group (54.58 +/- 4.50 mg/L and 106.93 +/- 9.54 mg/L vs 12.66 +/- 3.52 mg/L and 49.66 +/- 8.84 mg/L, respectively, P < 0.001). The ratio of pleural fluid to serum CRP was significantly higher in the TBP group than in the MPE group (0.52 +/- 0.18 vs 0.30 +/- 0.16, P < 0.001). The optimum cut-off value for pleural fluid CRP level of > or =30 mg/dL had a sensitivity of 72% with 93% specificity, and the pleural fluid to serum CRP ratio cut-off value of 0.45 had a sensitivity of 60% with 89% specificity. A correlation between serum and pleural fluid CRP levels was observed in TBP patients but not in MPE patients. CONCLUSION: In patients presenting with lymphocytic exudative pleural effusion, a simple marker of raised pleural fluid CRP level may be helpful in discriminating between TBP and MPE.

Adolescent↗

PubMed2004

Mycobacterial skin infections: comparison between histopathologic features and detection of acid fast bacilli in pathologic section.

BACKGROUND: Detection of acid fast bacilli (AFB) in chronic granulomatous inflammation is an important clue for mycobacterial infection. DESIGN: A retrospective review of 104 pathologic sections (from 1994 to 2001) of suspected cases of mycobacterial (tuberculous and nontuberculous) skin infections to study histopathologic features and the correlation with the presence of AFB in the section was performed. RESULTS: All cases showed granulomatous inflammations that can be categorized into 4 types: mixed cell, suppurative, tuberculoid and palisading granuloma. AFB was found in 32 sections (30.77%). Ninety five specimens from 104 specimens were simultaneously cultured. AFB positive cases yielded higher positive cultural results, 17 from 29 cases (58.62%) compared to the AFB negative group, 23 from 66 cases, (34.85%). Mixed cell granuloma was the most common histologic feature, but suppurative granuloma was the most common histological feature (56.25%) in which AFB could be found, which was statistically significantly different from other types of granuloma. Tuberculoid granuloma was more common in the AFB negative group (20.83%) compared to the AFB positive group (9.37%) but the difference was not statistically significant. In cases that AFB could not be found, the inflammation tended to be located in the upper half of the dermis. CONCLUSION: AFB can be more frequently detected in suppurative granuloma that might be located in any portion of the dermis. This finding was not species specific.

Granuloma↗

PubMed2003

Diagnostic value of gastric aspirate smear and polymerase chain reaction in smear-negative pulmonary tuberculosis.

OBJECTIVE: The aim of this study was to determine the validity of acid-fast bacilli (AFB) smear and polymerase chain reaction (PCR) from gastric aspirates for the diagnosis of smear-negative pulmonary tuberculosis. METHODOLOGY: A cross-sectional study was conducted in a university hospital. One hundred and nine patients with suspected pulmonary tuberculosis in whom either sputum smears were negative or who were not producing sputum were recruited to the study. All patients underwent gastric aspiration after an overnight fast followed by standard fibreoptic bronchoscopy. Specimens were subjected to AFB smear, culture, and pathological examination. PCR was performed on culture filtrate after 1 week of incubation. RESULTS: Eight patients did not complete the follow-up schedule. Of the 101 patients with final outcomes, a diagnosis of pulmonary tuberculosis from microbiological evidence was established in 54 patients. The gastric aspirate smear, PCR, or either one of them was positive in 34, 30, and 39 tuberculosis patients, respectively. There were 13 false positive smears from 47 non-tuberculosis patients, with five resulting from non-tuberculous mycobacteria (NTM). The PCR was falsely positive in eight patients, five of whom had previous histories of tuberculosis. The overall sensitivity, specificity, positive predictive value, and negative predictive value of gastric aspirate examination by combined smear and PCR were 72, 58, 66, and 64%, respectively. CONCLUSIONS: Gastric aspiration is a useful tool for the diagnosis of smear-negative pulmonary tuberculosis warranting institution of antituberculosis treatment. Interpretation of the results should be cautious in those who have had tuberculosis in the past or who have been at risk for acquisition of NTM.

Adolescent↗

PubMed2003

Nontuberculous mycobacterial skin infections: clinical and bacteriological studies.

OBJECTIVE: Nontuberculous mycobacterial (NTM) skin infections were analysed in terms of clinical manifestation in different species to provide clues for the clinical diagnosis and sensitivity patterns of these species were studied for planning appropriate therapy. DESIGN: A retrospective study was performed in 123 suspected cases of NTM infections from January 1994 to December 2000. NTM infection was documented by culture result of the infected tissue obtained by skin biopsy. Drug susceptibility test was done as requested. RESULT: Rapid growers (M. fortuitum-chelonae) were found in 26 cases (65%) and M. marinum was responsible for 12 cases (30%) and caused only localized skin lesions on arms or legs as indurated plaque, Disseminated skin infections manifested as multiple abscesses were found in 2 cases caused by M. avium in an HIV-infected male patient and mixed infection of M. szulgai and M. terrae in an immunocompetent female patient after a dental procedure. Both sexes were affected equally in overall number but male predominated in M. marinum infection and females predominated in rapid growers. All ages can be affected but most cases were middle aged. Scrofuloderma-like cervical lymphadenitis and cutaneous abscesses were the common manifestation of rapid grower infections. Hyperkeratotic verrucous plaques (tuberculosis verrucosa cutis-like) and sporotrichoid lesions were the common manifestations of M. marinum infection. M. marinum is sensitive to minocyclin, clarithromycin, amikacin, rifampicin and ethambutol and a good clinical response was obtained with doxycyclin 100 mg orally twice a day for 3 months. Clarithromycin and amikacin showed in vitro activity against the same strain of M. fortuitum but most strains of rapid growers resisted antituberculous drugs and also various antibiotics. CONCLUSION: Clinical manifestations can be used as clues for diagnosis. Medical therapy is recommended for M. marinum infection and surgical treatment is recommended for rapid growers.

Adolescent↗

PubMed2003

Thrombocytopenic purpura associated with miliary tuberculosis.

The authors report a case of thrombocytopenia associated with miliary tuberculosis. The patient was a 28-year-old woman who was admitted because of massive upper gastrointestinal hemorrhage and acute respiratory failure. Chest radiographs revealed diffuse bilateral reticulonodular infiltration and complete blood count was significant for severe thrombocytopenia. Bone marrow biopsy was performed to investigate the cause of thrombocytopenia and demonstrated multiple tiny caseating granulomas suggesting miliary tuberculosis (TB). She received anti-TB therapy and a short course of steroid with good response. Platelet count returned to normal limit within 10 days. Although isolated thrombocytopenia is uncommon in TB, it is still important to consider TB in the differential diagnosis of thrombocytopenia, particularly in patients with abnormal chest radiographs. Bone marrow examination is very helpful in this situation.

Adult↗

PubMed2002

Scrofuloderma and Sweet's syndrome.

BACKGROUND: In recent years, the rare association of Sweet's syndrome with nontuberculous mycobacterial lymphadenitis has been reported. OBJECTIVE: To report the clinical, demographic, and bacteriologic data and association with Sweet's syndrome of 18 patients with scrofuloderma and scrofuloderma-like condition caused by nontuberculous mycobacterial infections seen during the past 7 years (1994-2000). METHODS: In all patients, a biopsy specimen was obtained for histopathologic and microbiologic studies. Patients from whom Mycobacterium tuberculosis and nontuberculous mycobacteria were isolated from the culture of skin biopsy specimens were included. Deep fungal infection was excluded by the lack of a fungal element in histologic section and cultural methods. The patients were treated with antimicrobials or antituberculous drugs according to the causative species. RESULTS: Eighteen cases of scrofuloderma (nine male, nine female; mean age, 36.9 years) were found among 104 patients with cutaneous tuberculosis and nontuberculous mycobacterial cutaneous infections. Sixteen of the 18 cases had lymphadenitis as the underlying focus of scrofuloderma: 15 cases occurred in the cervical group and one case in the inguinal area. One case drained from the soft tissue and one from the paranasal air sinus. Five cases had multiple episodes of Sweet' s syndrome during the course of treatment. Most cases in this group (four of the five) were middle-aged women with cervical lymphadenitis, and the most common species were rapid growers. CONCLUSIONS: Age, sex, and the site of infection may have some influence on the association with Sweet's syndrome in nontuberculous mycobacterial infections.

Adult↗

PubMed2002

Infection due to nontuberculous Mycobacterium other than MAC in AIDS patients at Siriraj hospital during 1998-2000: saprophyte vs pathogen.

HIV is a major health problem in Thailand. These patients are vulnerable to opportunistic infections, especially Mycobacterium tuberculosis and MAC infection. However, NTM was considered a rare disease in Thailand before the AIDS era. In this study, there were 38 HIV seropositive patients with NTM (other than MAC) identified from clinical specimens during the 3 year period 1998-2000 at Siriraj Hospital, which has a higher prevalence than the previous report. Among these patients, 29 cases were likely to have had definite infection from NTM, 5 cases possibly had NTM as a pathogen, and 4 cases had NTM as colonization. The most common site of infection was the lung (87%) and most common symptoms were cough (62.2%), fever (34.2%), weight loss (42.1%), and lymphadenopathy (5.3%). The outcome was poor because many NTM are not susceptible to standard medication for tuberculosis which is the empirical treatment for the majority of HIV seropositive patients with a clinical finding suspected of mycobacterial infection. The fatality rate was as high as 58.6 per cent. Awareness of NTM as a potential pathogen in HIV seropositive patientsand adjustment of medications even before the availability of culture results may improve the outcome of treatment of NTM infection in HIV seropositive patients.

AIDS-Related Opportunistic Infections↗

PubMed2002

Mycobacterium avium complex in HIV-infected Thai children.

Of the 169 human immunodeficiency virus (HIV)-infected children being cared for at Siriraj Hospital from January 1998 to September 2000, 10 had Mycobacterium avium complex (MAC) infection; seven had disseminated disease and three had MAC pneumonia. Nine children were in the advanced stage of HIV disease at the time of diagnosis with the median CD4 count of 7 cells/mm3 and 127 cells/mm3 and the median age of 65 months and 63 months in disseminated MAC and MAC pneumonia respectively. None of these children had received prior chemoprophylaxis. Common clinical findings included prolonged fever, weight loss, lymphadenopathy, hepatosplenomegaly, diarrhea, anemia and leukopenia. The outcome of MAC infection was poor, with a mortality rate of 60 per cent. In in vitro susceptibility testing, clarithromycin was the least resistant drug. With the incidence rate of 2.15 per 100 person-years, the high rate of antimicrobial resistance, and the poor outcome, primary chemoprophylaxis for MAC infection in conjunction with effective antiretroviral therapy should be considered for Thai children in the advanced stage of HIV infection.

AIDS-Related Opportunistic Infections↗