The difference in IL-1β, MIP-1α, IL-8 and IL-18 production between the infection of PMA activated U937 cells with recombinant vaccinia viruses inserted 2004 H5N1 influenza HA genes and NS genes.

Background: The severity of avian influenza H5N1 disease is correlated with the ability of the virus to induce an over production of pro-inflammatory cytokines from innate immune cells. However, the role of each virus gene is unknown. To elaborate the function of each virus gene, the recombinant vaccinia virus inserted HA and NS gene from the 2004 H5N1 virus were used in the study. Methods: U937 cells and PMA activated U937 cells were infected with recombinant vaccinia virus inserted with HA or NS gene. The expressions of HA and NS proteins in cells were detected on immunofluorescence stained slides using a confocal microscope. The cytokine productions in the cell supernatant were quantitated by ELISA. Results: The recombinant vaccinia virus inserted with HA genes induces the production of IL-1β, MIP-1α, IL-8 and IL-18 cytokines from PMA activated U937 cells significantly more than cells infected with wild type vaccinia, whereas the recombinant vaccinia virus inserted with NS genes it was similar to that with the wild type vaccinia virus. However, there was no synergistic nor antagonistic effect of HA genes and NS genes in relation to cytokines production. Conclusion: Only the HA gene from the 2004 H5N1 virus induces IL-1β, MIP-1α, IL-8 and IL-18 cytokine productions from activated U937 cells. The same HA gene effect may or may not be the same in respiratory epithelial cells and this needs to be explored.

Fulminating influenza pneumonia in the elderly: a case demonstration.

An 82-year-old male Bangkokian with hypertension, diabetes mellitus, end-stage renal disease, and coronary artery disease for many years, was hospitalized due to deterioration of a 3-day influenza-like-illness with one-day chest oppression and respiratory failure. At the emergency room, oxygen saturation was 79% on room air Chest X-ray revealed bilateral diffuse pulmonary infiltrates. He was intubated and hemodialysis was initiated. Emergency coronary angiography revealed patent coronary artery. Sputum gram stain revealed numerous leukocytes with no bacteria. On day three of hospitalization, empiric treatment with oseltamivir and clarithromycin was administered Seventy-two hours later his clinical condition began to improve and fever subsided 7 days later Rapid test of tracheal secretion with immunofluorescence assay was positive for moderate amount of influenza A virus. Viral isolation yielded influenza A virus subtype H1N1. Review of in-patient records at this hospital using ICD-10 codes as J10 and J11 during 1995-2005, discovered 32 cases with claim diagnosis of influenza. However this is the first case with proven influenza pneumonia that was given empiric oseltamivir. Rapid deterioration of influenza-like illness due to human influenza virus in the elderly and pathogenesis of pulmonary in this case are discussed to alert physicians to recognize this dreadful illness and treat it in timely fashion.

Trends of HIV seropositivity at Siriraj Hospital: 13 year's observation from 1992-2004.

OBJECTIVE: The aim of the present report was to observe the trend of seroprevalence rates of HIV seropositivity for routine services at Siriraj Hospital for 13 years. MATERIAL AND METHOD: The prevalence rate of HIV seropositivity was analyzed in three groups of subjects: 1) patients who attended the hospital with HIV related diseases; 2) pregnant women at first visit to the antenatal care clinic; 3) emigrating workers who have applied for employment in foreign countries. RESULTS: Of the 13 year-observation, HIV seroprevalence rates in the groups of patients, pregnant women and emigrating workers was 10.6% (95%CI 8.9-12.3%), 2.0% (95%CI 1.8-2.2%) and 0.6% (95%CI 0.4-0.8%), respectively. CONCLUSION: The low prevalence of HIV seropositivity in the group of emigrating workers may be due to self selection, whereas the prevalence in pregnant women, which was rather consistent at about 2.0%, may represent the infection rate in the general population. The seroprevalence rate measured in the group of pregnant women demonstrates that Thailand should increase efforts to confine the spread of HIV infection in the community.

Specific immune response and pathological findings in BALB/c mice inoculated with recombinant BCG expressing HIV-1 antigen.

Recombinant BCGs (rBCGs) containing extrachromosomal plasmids with different HIV-1 insert sequences: nef, env (V3J1 and E9Q), gag p17 or whole gag p55 were evaluated for their immunogenicity, safety and persistent infection in BALB/c mice. Animal injected with, rBCG-plJKV3J1, rBCG-pSO gag p17 or rBCG-pSO gag p55 could elicit lymphocyte proliferation as tested by specific HIV-1 peptides or protein antigen. Inoculation with various concentration of rBCG-pSO gag p55 generated satisfactory specific lymphocyte proliferation in dose escalation trials. The rBCG-pSO gag p55 recovered from spleen tissues at different time interval post-inoculation could express the HIV protein as determined by ELISA p24 antigen detection kit. This result indicated that the extrachromosomal plasmid was stable and capable to express Gag protein. It was also demonstrated that rBCGs did not cause serious pathological change in the inoculated animals. The present study suggested the role of BCG as a potential vehicle for using in HIV vaccine development.

Surveillance of commensal rat and shrew populations in the Bangkok area with references to flea index as the risk indicator of plague.

Commensal rats and shrews were trapped from 47 fresh food markets in Bangkok during the two study periods in the same markets: 21st June to 28th December 1999 and 1st March to 31st May 2000. Trapping was performed using wire live traps on three consecutive nights in each period. The trapped animals were identified for taxonomic species and flea infestation. Fleas were collected, identified and counted. Four species of rodents: Rattus norvegicus, Rattus rattus, Rattus exulans and Mus musculus, and one species of shrew: Suncus murinus were trapped in comparable numbers during the two study periods. Among the 1177 animals trapped, 84.3 per cent were R. norvegicus. Regarding sex prevalence, a higher number of female animals were trapped compared to males. Almost all the fleas collected were Xenopsylla cheopis, and there were very few Ctenocephalidesfelis-felis. Flea index based on the number of X. cheopis was 0.65 for all over Bangkok. Based on the geographical area of Bangkok, the inner area had the highest rodent population and the highest flea index of 0.86. Therefore, the inner region should be the priority for sanitation improvement.

Seroprevalence of rickettsial infection in commensal rodents and shrews trapped in the Bangkok Metropolitan Area.

Murine typhus and scrub typhus are important human rickettsial diseases in Thailand. Small mammals, including many species of rodents and shrews, serve as the reservoir host of rickettsial diseases. Rickettsia typhi can be transmitted to humans by fleas causing murine typhus, while infection with Orientia tsutsugamushi causing scrub typhus in humans is transmitted by chiggers. The prevalence of rickettsial infection depends on the geographic area. The seroprevalence of antibody to R. typhi and O. tsutsugamushi was studied in commensal rodents and shrews trapped in markets in the Bangkok Metropolitan Area (BMA). R. typhi and O. tsutsugamushi antigen prepared in the yolk sac of embryonated eggs were used to determine the specific antibody in trapped animals' sera by using fluorescein isothiocyanate (FITC)-anti rat immunoglobulins as a second antibody. Antibody to R. typhi was found in 25 (5%) of 500 sera tested and no antibody to O. tsutsugamushi was detected. R. typhi antibody titer ranged from 40-1280 and was found in Rattus norvegicus (4.2%), Rattus rattus (0.4%), Rattus exulans (0.2%), and Mus musculus (0.2%) trapped in 8 of 47 markets in the BMA. R. typhi antibody was commonly found in R. norvegicus. The authors concluded that murine typhus is an important rickettsial disease and R. norvegicus is an important reservoir species of rodents found in markets of the BMA.

Lymphocyte and NK cell subpopulations in HIV seronegative Thais.

Lymphocyte subpopulations, i.e. T, B and natural killer (NK) cells including NK cell subsets which express CD16 molecules (with or without co-expression of CD56 molecules) and NK cell subsets which express CD56 molecules (with or without co-expression of CD16 molecules) were enumerated by two color-flow cytometry in a total of 125 HIV seronegative Thai adults. The study demonstrated relatively low CD4 counts in the subjects, i.e. 26.3% of them had a CD4 count of less than 500 cells/microl. In contrast, their NK cell counts were relatively high. Statistical analyses of the percentage values showed that females had significantly higher CD3 (total T cells), but lower NK cell counts as compared to males (p < 0.05). Regarding age variation, an increase of 1.1% of CD4 cells per decade was seen. It was roughly estimated that about 86% of NK cells harbored both CD16 and CD56 molecules. Collective data from several studies including the present one suggest that high NK cell counts may be a compensation for low CD4 cell counts in Mongoloid people. Thus, the role of NK cells in the defense cascade against viral infections, especially human immunodeficiency virus infections deserves further investigation.

Intracellular production of type I and type II cytokines during HIV-1 progression in Thai patients.

A type I to type II cytokine switch on cells of the immune system has been suggested as a critical step in the etiology of HIV infection. In this study, type I and type II cytokine production of both CD4+ and CD8+ T cells activated by superantigen were investigated in 10 healthy donors and 39 HIV-1 infected patients. Patients were divided into 3 groups based on their CD4 count (< 200, 200-500, > 500 cells/microl). Whole blood from each subject was activated by staphylococcal enterotoxin B (SEB) and anti-CD28. Intracellular cytokine stainings for proinflamatory cytokine (TNF-alpha), type I cytokines (IFN-gamma and IL-2) and type II cytokines (IL-4 and IL-5) in CD4+ and CD8+ T lymphocytes were determined by flow cytometer. Type I cytokine (IFN-gamma) expression in CD4+ T cells co-expressing with CD69 were significantly increased in HIV infected patients, particularly in patients with CD4 counts < 200 and 200-500 cells/microl (means +/- S.D. of 20.7 +/- 18.7% and 10.5 +/- 5.9%, respectively) when compared with 4.8 +/- 1.8% in the normal group (p < 0.05). But IL-2 production in both groups of patients was significantly lower than the normal (3.8 +/- 2.6% and 3.2 +/- 1.4% in patients with < 200, 200-500 cells/microl, and 5.9 +/- 1.5% in the normal group) (p < 0.05). For type II cytokines, there was no difference in all groups of subjects when IL-4 was determined. However, IL-5 production was significantly higher in patients with a CD4 count < 200 cells/microl (0.6 +/- 0.5%) than that in the normal group (0.1 +/- 0.1%) (p < 0.005). CD8+ T cells also showed higher IFN-gamma production in patients with a CD4 count < 200 cells/microl (11.9 +/- 4.7%) and 200-500 cells/microl (12.0 +/- 4.3%) than the normal group (5.3 +/- 2.5%) (p < 0.005). In contrast, IL-2 production in CD8+ T cells was low in these HIV infected patients (0.3 +/- 0.2%, 0.3 +/- 0.2%, and 0.3 +/- 0.4% in patients with < 200, 200-500, and > 500 cells/microl, respectively), which was significantly different compared to the control group (1.2 +/- 0.8%) (p < 0.05). For type II cytokines, only IL-4 production in patients with a CD4 count < 200 cells/microl (0.1 +/- 0.1%) was significantly reduced when compared to the other groups (p < 0.05). This study shows that although HIV infection alters the production of both type I and type II cytokines, it does not induce a polarized type I or type II state in the course of HIV-1 progression in Thai patients.

Prevalence of antibodies to Leptospira serovars in rodents and shrews trapped in low and high endemic areas in Thailand.

OBJECTIVE: To investigate the prevalence of antibodies to Leptospira serovars in rodents and shrews trapped in urban and rural areas in low and high endemic areas in Thailand. MATERIAL AND METHOD: A total of 1,664 serum samples were collected from rodents and shrews in areas of low and high endemicity for leptospirosis. Four areas classified by case rates (CR) per 100,000 population of leptospirosis were urban Area I Bangkok (CR = 0.07), rural Area II (CR = 0.24), rural Area III (CR = 1.97) and rural Area IV (CR = 48.20). All serum samples were investigated for antibodies to leptospires by microscopic agglutination test (MAT) using antigens from each of the 22 pathogenic serovars of Leptospira interrrogans: australis, autumnalis, ballum, bangkok, bataviae, bratislava, canicola, celledoni, copenhageni, djasiman, grippotyphosa, hardjo, hebdomadis, icterohaemorrhagiae, javanica, pomona, pyrogenes, rachmati, saigon, sejroe, tarassovi and wolffi and one non-pathogenic strain of L. biflexa serovar patoc. RESULTS: Ninety-four (5.6%) serum samples were positive for Leptospira antibodies. The most commonly detected antibodies were to serovars pyrogenes (39.1%), sejroe (19.1%), bataviae (10.0%), pomona (6.4%), autumnalis (5.5%), copenhageni (3.6%) and javanica (3.6%). The positive rates in Area I, II, III and IV were 7.6 per cent, 2.9 per cent, 4.6 per cent and 7.1 per cent, respectively. The seroprevalence in rural areas tended to increase significantly with high endemicity for leptospirosis (Chi-square for trend, p = 0.04). The seropositive rates by animal species were 39/496 (7.9%), 22/322 (6.8%), 23/492 (4.7%), 6/170 (3.5%), 4/175 (2.3%), 0/4 (0%) and 0/5 (0%) in Rattus norvegicus, Rattus exulans, Rattus rattus, Bandicota indica, Bandicota savilei, Mus musculus and Suncus murinus, respectively. There was a statistical trend between seropositive rates in R. exulans and endemicity for leptospirosis (Chi-square for trend, p = 0.04). CONCLUSION: The 5.6 per cent of rodents and shrews trapped in urban and rural areas in Thailand were reservoirs of leptospires. The results of high seroprevalence in rats also indicate the high endemicity for leptospirosis.

Respiratory syncytial virus-associated lower respiratory tract infection in under-5-year-old children in a rural community of central Thailand, a population-based study.

The population-based cohort study on the epidemiology of respiratory syncytial virus (RSV)-associated lower respiratory tract infection (LRI) (RSV-LRI) was conducted in Takhli district from November 1998 to February 2001. The incidence of RSV-LRI was 12.6/1,000 child-year and 5.8/ 1,000 child-year during the first and second year, respectively. RSV accounted for 35.8 per cent of all LRI cases during the first year and significantly decreased to 17.5 per cent during the second year. Three-quarters of RSV-LRI occurred among children under 2 years old (76.6% during the first year and 62.2% during the second year). Most of RSV-LRI in both years occurred from July to October. Risk factor for morbidity of RSV infections were age less than or equal to 2 years (OR = 2.38, 95% CI = 1.22-4.67 p = 0.009) and sleeping with more than 3 persons in the patient's bedroom (OR = 2.92,95% CI = 1.42-6.00, p = 0.002). Most RSV-LRI (63.9%) were clinically diagnosed as having pneumonia. No RSV-LRI deaths were detected. During the first year, RSV subtype B was predominate, in contrast to the second year when subtype A was more predominate. Further research to determine the annual change in subtype of RSV-LRI and correlation of severity of disease with specific subtypes needs to conducted in order to prepare for the future introduction of a vaccine.

Acute viral lower respiratory infections in children in a rural community in Thailand.

The present study was conducted as a population based cohort in a rural community of Amphoe Takhli, Nakhon Sawan province for the determination of the prevalence of acute viral lower respiratory infection (ALRI) in pediatric cases under 5 years of age from November 1998 to February 2001. There were 472 ALRI episodes during the study period; and there were 5 cases who contracted ALRI twice. The etiologic agents were determined by indirect immunofluorescence (IIF) test using specific monoclonal antibodies for the staining of exfoliated cells in nasopharyngeal aspirate (NPA) samples. The slides of fixed cells were prepared by Takhli Hospital and posted in ambient temperature to the Virology Laboratory, Siriraj Hospital where they were stained and examined. Among 472 episodes of ALRI, 170 (36.0%) viral agents were found. Viral agents were associated with 41.4 per cent of all pneumonic cases. Respiratory syncytial virus (RSV) was the most common virus observed in the present study; and it was also the most common virus associated with pneumonia and bronchitis. RSV subgrouping was performed directly in NPA samples by IIF test using a panel of subgroup specific monoclonal antibodies. RSV subgroup B predominated over subgroup A in the first study year, and it was vice versa in the second year. Overall, more cases of subgroup B were found which was in contrast to what the authors had reported in the previous study. Prevalence of RSV was seasonal dependent, the epidemic was seen during the rainy season with peaks in August or September of each year. As the method of viral identification was limited to IIF only, therefore, fewer viruses were detected. Parainfluenza viruses were detected as the second most common viral agent, the viruses spread during early summer with peaks in February or March of each year. However, its association with croup could not be demonstrated which may be due to the insensitivity of IIF in the diagnosis of non-RSV infection. Nevertheless, in terms of feasibility to investigate the disease in a rural area, IIF is economic, convenient and rapid; and gives enough information for the nationwide plan of a health care development system.

Antiplatelet transfusion in dengue haemorrhagic fever during pregnancy: A case report.

Dengue, an important mosquito-borne flavivirus infection, is endemic in South-East Asia. We report here on a pregnant patient with an unusual presentation of dengue haemorrhagic fever. After diagnosis of dengue haemorrhagic fever, the patient was given platelets and antiplatelet transfusion was occurred. Labor was delayed by conservative, symptomatic and supportive management. The condition of the patient improved and she gave birth to a healthy baby. The history, investigation, diagnosis and treatment of the patient are discussed.

Findings of toxoplasma antibody at Siriraj Hospital.

The evaluation of commercial haemagglutination test kit for the incidence of toxoplasma antibody at Siriraj Hospital from 1985 to 1987 was 0.94 percent. The prevalence among 184 healthy persons, 92 patients with fever of unknown origin and 43 patients who had clinical symptoms like toxoplasmosis was 0.5, 1.1 and 2.3 percent respectively. The total prevalence of T.gondii antibodies among patients was 1.5 percent. This study confirms the presence of T.gondii in the country, although the test has some limitations for detecting recent toxoplasmosis.