Risk factors for Nipah virus infection among abattoir workers in Singapore

During 10-19 March 1999, 11 workers in 1 of 2 Singaporean abattoirs developed Nipah-virus associated encephalitis or pneumonia, resulting in 1 fatality. A case-control study was conducted to determine occupational risk factors for infection. Case patients were abattoir A workers who had anti-Nipah IgM antibodies; control subjects were randomly selected abattoir A workers who tested negative for anti-Nipah IgM. All 13 case patients versus 26 (63%) of 41 control subjects reported contact with live pigs (P=.01). Swine importation from Malaysian states concurrently experiencing a Nipah virus outbreak was banned on 3 March 1999; on 19 March 1999, importation of Malaysian pigs was banned, and abattoirs were closed. No unusual illnesses among pigs processed during February-March were reported. Contact with live pigs appeared to be the most important risk factor for human Nipah virus infection. Direct contact with live, potentially infected pigs should be minimized to prevent transmission of this potentially fatal zoonosis to humans.     

Tuberculosis Annual Report 2009--Series 6. Condition of TB (1)

The condition of tuberculosis (TB) at the time at which an individual is diagnosed with TB influences the patient's prognosis. This paper focuses on the condition of TB at the time of the diagnosis based on bacteriological status and X-ray findings. The proportion of bacteriologically confirmed cases among newly notified pulmonary TB patients increased greatly from 25.7% in 1979 to 82.7% in 2009. During this period, the proportion of far-advanced cavitary cases among pulmonary TB patients was around 2% and remained stable. This may mean that the diagnosis had come to be performed bacteriologically rather than radiologically. The proportion of bacteriologically confirmed cases among newly notified pulmonary TB patients in 2009 was studied by sex and 5-year age group. The proportion of bacteriologically confirmed cases increased with age in both male and female TB patients. In male TB patients, the proportion of cavitary cases increased in patients aged up to the end of the 50s and then decreased with age. This tendency was not observed in females. Although the proportion of cavitary cases among elderly TB patients was lower than among youths, the proportion having extensive lesions was greater than that among youths. The proportion of sputum-smear-positive cases with cavities among pulmonary TB patients aged 30-59 years was 32.9 % in male TB patients and 17.1% in female TB patients. According to occupation, this proportion was highest in "temporary workers" (52.6%) for male TB cases and "jobless/ others" (24.9%) for female TB cases, and lowest among "medical workers" in both sexes: 8.3% of male TB cases and 7.4% of female TB cases.     

Clinical and social characteristics of the patients with tuberculosis in Eastern Anatolia

Tuberculosis (TB) is an important public-health problem. The risk factors for TB are well-known. However, there may be some regional differences. In this study, we aimed to investigate the demographic characteristics and regional risk factors for TB and to discuss possible explanations for the difference. The study included totally 253 hospitalized patients (145 male and 108 female, with an average age 38+/-18) with TB (117 pulmonary and 136 extrapulmonary) between 1997 and 2004. Their demographic and clinical characteristics were reviewed. TB frequency was higher among the non-working females in urban area (38.3%). TB was also common in farmers which are male (19.8%). TB frequency was higher in the school persons including students, the teachers and the school officials (14.6%) and in the building workers compared with the other workers. There were a history of previous TB, TB exposure (mostly from family members) and associated disease in 10.3%, 14.2% and 17.4% of cases, respectively. The most encountered associated disease was diabetes. The results indicate that TB was most common among non-working females and was also increased among the men in rural areas, and schools seem to be an important source of TB transmission. Thus, an effective control program covering the treatment of cases with active disease, such as directly observed treatment, and especially preventive measures should be considered to control the disease transmission in our region.     

Pulmonary tuberculosis in allogeneic hematopoietic stem cell transplantation

Pulmonary tuberculosis (TB) is an endemic infectious disease in Taiwan. A retrospective study was conducted to define clinical manifestations and outcomes of patients with pulmonary TB among hematopoietic stem cell transplantation (HSCT) recipients. We identified eight out of 350 HSCT recipients as having pulmonary TB over a 6-year period. The relative risk of having pulmonary TB after HSCT was 13.1-fold higher than in the general population. There was a trend toward increased risk of having pulmonary TB in allogeneic HSCT as compared to autologous HSCT (4.8 +/- 1.8% vs 0, P = 0.067). All the eight patients with pulmonary TB received allogeneic HSCT and most (seven of eight patients) developed the infection during treatment for GVHD. Computed tomography of the chest was normal in one patient, with the rest showing either interstitial (two patients) or alveolar infiltrates (five patients) at the onset of pulmonary TB. The four fatal cases had an obviously shorter duration between HSCT and onset of infection. Our data suggest that pulmonary TB in HSCT recipients is not uncommon in this endemic area. Therefore, an effective strategy of prophylactic treatment for candidates and recipients of allogeneic HSCT, who may have latent pulmonary TB infection, must be developed.     

Markers of cell-mediated immunity after vaccination with an inactivated, whole-cell Q fever vaccine

A clinical trial of Q fever vaccine in four South Australian abattoirs showed apparently complete protection against natural infection; however, only 50%-60% of vaccinees developed complement-fixing or immunofluorescent antibody after vaccination. Cell-mediated immunity to Coxiella burnetii antigens, as measured by an index of lymphoproliferative responses (LSI) of peripheral blood mononuclear cells, was therefore assessed. Eighty-five percent of 13 subjects with "low risk" of exposure to Q fever and with an initially negative LSI converted to a positive LSI after vaccination; conversion was noted nine to 13 days after vaccination, and positive values were obtained for at least 96 d. Only 35% of this group seroconverted. In a "high-risk" group (abattoir workers), higher rates of positive LSI (greater than 95%) and of antibody (50%-70%) were observed after vaccination; greater than 95% of vaccinees in this group, who had been vaccinated five years previously, had positive LSI values.     

Tuberculosis due to Mycobacterium bovis in the Australian population: cases recorded during 1970-1994.

OBJECTIVE: To determine the contribution of Mycobacterium bovis to active tuberculosis in the Australian population during 1970-1994, and to collate and analyse demographic data from bacteriologically proven cases. DESIGN: Summary data for tuberculosis cases notified by Australian public health agencies during 1970-1985 and 1991-1994 were obtained from the database of notifiable diseases maintained by the Department of Health and Family Services. More detailed demographic data for cases confirmed by bacteriology during 1970-1994 were supplied by the Australian Mycobacterium Reference Laboratory Network. RESULTS: At least 236 cases of bovine tuberculosis (TB) occurred in the Australian population during 1970-1994 (mean 9.4 cases; range 3-22 cases annually). The bovine strain has accounted for around 1% of Australian cases of TB during this period. Laboratory sources provided demographic data for 150 cases with positive bacteriology. For this group, the mean age was 54 years (range 22-86), and the male:female ratio was 2.4:1. The majority of cases (74%) involved pulmonary disease. Australian-born persons accounted for 68% of the total cases and typically had histories of employment in meat and/or livestock industries. CONCLUSION: M. bovis was responsible for less than 1.5% of cases of TB in the Australian population during 1970-1994. Most cases were apparently due to reactivation of infection acquired through occupational exposure. Thus, although virtual eradication of M. bovis from Australia's cattle herds has now reduced the risk of exposure, it can be expected that human cases of bovine TB will continue to be detected for years to come. The bovine strain should be considered as the possible agent of TB in foreign-born Australians.     

Fourteen-year trend of tuberculosis dynamics in the northwest of Turkey

BACKGROUND: The incidence of tuberculosis (TB) in different countries as estimated by the World Health Organization (WHO) vary from 23/100,000 and less in industrialized countries, 191/100,000 in Africa and 237/100,000 in South East Asia. OBJECTIVES: The aim of this study was to analyze the dynamics of TB in the northwest of Turkey, between 1988 and 2001. METHODS: All pulmonary TB cases reported to the National Tuberculosis Center by local TB dispensaries during 1988-2001 were analyzed. The number of new and relapsed TB cases were documented and classified according to age and type of TB (standard classification of TB patients according to disease type: pulmonary, new, smear positive; pulmonary, smear negative; relapse, and extrapulmonary). We recorded information about the prevalence of TB in different patient groups (patients with a contact history, patients who were detected in active community screening or passive case finding), TB trends in different age groups, type of TB, patients who had relapses, percentage of patients who were lost to follow-up. RESULTS: A total number of 288,996 patients were examined at Zonguldak Tuberculosis Dispensary between 1988 and 2001. Case notification rates of TB decreased over the study period. Respiratory TB was the most commonly encountered form of disease (>90%). The percentage of TB decreased in the 0- to 14-, 15- to 24-year-olds and increased in the 25- to 44- and 45- to 64-year-olds. CONCLUSION: Properly designed disease surveillance systems are critical for monitoring the TB trends so that each country can identify its own high-risk groups and target interventions to prevent, diagnose, and treat the disease.     

Risk of Yersinia infection among butchers

The purpose of this study was to evaluate the risk of yersinia infection among butchers. Serum samples were collected from 146 abattoir workers, stratified into 3 groups according to exposure to swine throats and intestines. 100 healthy blood donors were used as controls. Antibodies against Yersinia enterocolitica O:3 and O:9 and Y. pseudotuberculosis I and III were measured using ELISA. Symptoms associated with yersiniosis were recorded in a questionnaire. Antibodies against Y. enterocolitica O:3 were observed more often in the sera of abattoir workers (19%), especially in butchers handling swine throats and intestines (27%), than in the sera of healthy blood donors (10%). During the 6 months preceding this study, 30-40% of the workers reported symptoms of abdominal pains and diarrhoea. However, the symptoms did not correlate with the occurrence of antibodies. One butcher had developed a yersinia-triggered prolonged reactive arthritis. Tonsil samples were collected from 120 pigs to determine the extent of yersinia contamination. Positive isolates were obtained from 54 pigs (45%). Y. enterocolitica O:3 was isolated from 31 pigs and Y. pseudotuberculosis III from 11 pigs. All of these strains shared characteristics typical for virulent strains. We conclude that yersinia infections are an occupational health risk to workers slaughtering swine in the abattoirs.     

Plasma granulysin levels and cellular interferon-gamma production correlate with curative host responses in tuberculosis, while plasma interferon-gamma levels correlate with tuberculosis disease activity in adults

Granulysin is a recently identified cytolytic protein which is expressed by human cytotoxic T-lymphocytes and natural killer (NK)-cells, and has broad antimicrobial and tumoricidal activity. Circulating granulysin levels are associated with T- and NK-cell activity, and may thus reflect protection-associated cellular immune responses. In a case-control study in Indonesia, a highly tuberculosis (TB)-endemic country, we therefore determined plasma granulysin levels in adults with active pulmonary TB before, during, and after TB treatment, both in mild/moderate-TB and advanced-TB patients, and compared these to healthy neighbourhood controls. Adults with active pulmonary TB had significantly lower plasma granulysin levels compared to controls. After 2 months of anti-TB therapy, levels in TB patients had significantly increased, reaching values similar to those in controls. Plasma granulysin levels further increased after completion of TB therapy, being significantly higher than those in controls. Plasma granulysin levels correlated inversely with TB disease activity but not with TB disease severity. In contrast, plasma interferon-gamma (IFN-gamma) levels were significantly higher in active TB cases than in controls, normalised during treatment and correlated with both TB disease activity and TB disease severity. At the cellular level, granulysin and IFN-gamma expression both correlated inversely with disease activity. Interestingly, granulysin was predominantly expressed by IFN-gamma negative T-cells, suggesting that the cellular sources of IFN-gamma and granulysin in TB are partly non-overlapping. The observation that plasma granulysin levels and cellular IFN-gamma production correlate with curative host responses in pulmonary tuberculosis points to a potentially important role of granulysin, next to IFN-gamma, in host defence against M. tuberculosis.     

Evaluation of a serologic test for the diagnosis of tuberculosis.

The ICT TB test, a new, simple, serologic diagnostic test for tuberculosis (TB), was performed on serum samples from individuals seen at an urban teaching hospital and a local health department clinic. The study population included cases of TB, disease with mycobacteria other than tuberculosis (MOTT), non-mycobacterial pulmonary disease, and healthy controls. In contrast to prior studies, we found the ICT TB test had little value in detection of new cases of TB (overall sensitivity was 20%). It had very low sensitivity (4%) in the first month of disease. The sensitivity improved in patients tested at least 3 months after clinical presentation, but still remained fairly low. The test was also positive in 30% cases of disease caused by MOTT demonstrating cross-reactivity. It was negative in all human immunodeficiency virus (HIV) positive cases of TB or MOTT. The overall specificity was 89%. At least part of the discrepancy between our results and those of previous investigators may be attributable to differences in the respective study populations, including incidence of HIV disease and duration of tuberculosis illness prior to testing.     

Assessment of Nipah virus transmission among pork sellers in Seremban, Malaysia

Between September 1998 and May 1999, 265 cases of encephalitis were reported from among those involved in pig rearing. A few cases were also reported among abattoir workers. This raised questions of the risk of transmission among those who handled raw pork. A serosurvey was conducted among pork sellers in Seremban town, which is about 20 km from one of the pig rearing areas which had reported cases of encephalitis. It was found that out of the 28 pork sellers tested, only one tested positive for Nipah virus antibodies and that this pork seller also worked in an abattoir in the same district, removing the urinary bladders from slaughtered pigs. Based on these findings, it was concluded that the risk of transmission of the virus from handling raw pork appeared to be low.     

Clinical features of abdominal tuberculosis

The clinical features of 81 cases of abdominal tuberculosis (TB) are presented. The peritoneum was involved in 41 patients, the ileocecal area in 17, the anorectal area in 16, and mesenteric glands in 8. There was one case each involving the liver and sigmoid colon. Most patients were young women. The tuberculin reaction was significant in 83% of patients tested, and 54% had evidence of TB elsewhere. Tuberculous peritonitis was more common in native North American Indians and presented as an acute abdomen, abdominal tumor, or cirrhosis. Asians developed the majority of ileocecal and mesenteric lymph node disease and were frequently diagnosed as having Crohn's disease, appendicitis, or cancer. Anorectal cases presented with fistulae or abscesses and usually had concomitant pulmonary TB. The disease was fatal in five patients (6%), four of whom were diagnosed only after death. One noncompliant patient had a relapse. All other patients were cured after receiving treatment.     

Tuberculosis control of construction workers living in Hanba

Construction workers living in temporal quarters, HANBA, rarely have opportunity to receive the routine health screening program such as that for general inhabitants organized by the local government or that for permanent employees by the employer. Long delay in detecting TB and high drop-out rate from TB treatment among them have been reported. We carried out the following interventions to cope with the problems: In 1999 and 2000, we organized TB screening with X-ray and further examination in the same day when necessary among workers in 6 HANBA in Chiba City. A total of 382 workers were screened, and they also received structured interviews to assess their health-related behaviors and conditions. Four active pulmonary TB cases were detected, and the incidence of 1,047/1,000,000 was forty times higher than that of Chiba City. All four patients were treated and cured. According to the experiences through our intervention, we developed the following recommendations on TB control of construction workers living in HANBA: 1) A system carry out the health examination routinely in the HANBA should be provided, and its implementation be supervised by the public health center and the Labor Standards Inspection Office. 2) It is necessary to guarantee worker's minimum living conditions and medical treatment, and for this regular purpose, close cooperation should be established between clinical service providers and public health, social welfare, and work management authorities. 3) We should start "DOTS" (Directly Observed Treatment Short-Course) not only to the patients in the hospital but also to the outpatients and in the HANBA. To control TB among those workers, further effort is necessary to motivate them to receive basic regular health screening program that is provided in free of charge in Japan.     

Preferential recruitment of phagocytes into the lung of patients with advanced acquired immunodeficiency syndrome and tuberculosis

Limited data are available on the cellular and immunocytological characteristics of bronchoalveolar lavage (BAL) fluid in individuals infected with the human immunodeficiency virus (HIV) and pulmonary tuberculosis (TB). The immune host response against tuberculosis in early HIV-infection may differ from that in later stages of HIV disease, as is strongly suggested by different clinical and radiographic patterns. We studied the cellular elements in the lungs of 15 HIV-infected patients with advanced immunosuppression and pulmonary tuberculosis (TB/AIDS). The findings were compared with data from four other groups: 1) 15 HIV-seronegative patients with pulmonary TB; 2) 12 HIV-seropositive TB patients without previous AIDS-defining illnesses and with CD4+ >200 cells mm(-3); 3) five AIDS patients without pulmonary lesions; and 4) five healthy controls. BAL fluid and differential cell counts, as well as lymphocyte subsets, were determined. Despite a low CD4/CD8 ratio, the TB/AIDS group had a higher absolute number of CD8+ lymphocytes in the BAL fluid than the other groups. Alveolar macrophages and neutrophils were significantly increased in TB/AIDS patients compared to control groups. The number of eosinophils was increased in TB/HIV--patients but not in TB/AIDS patients. We conclude that tuberculosis in late stage HIV-infected patients has a distinct inflammatory cell profile, suggesting an enhanced compensatory mechanism that amplifies the unspecific inflammatory reaction.     

Prevalence of pulmonary tuberculosis among HIV-infected persons in a home care program in Phnom Penh, Cambodia.

SETTING: Phnom Penh, Cambodia. OBJECTIVE: To determine the burden of active pulmonary tuberculosis among an HIV-infected cohort and the proportion of drug-resistant strains, using active case-finding adapted to a home care setting. DESIGN: Cross-sectional study. Measures include the prevalence of culture-confirmed Mycobacterium tuberculosis, utilizing a single spot sputum specimen; the proportion of pulmonary TB, detected and undetected; proportion of cases resistant to isoniazid, rifampicin, ethambutol, streptomycin; and the diagnostic value of symptoms. RESULTS: Of 441 persons surveyed, 41 (9%) had active pulmonary TB by culture; 29 were smear-positive (71%), and only one case was on treatment. The total burden of pulmonary TB was 12% (54/441), with a ratio of undetected to detected cases of 3:1. Primary isoniazid resistance was detected in six new cases (15%); no MDR-TB was identified. Symptoms were not predictive of active pulmonary disease. Mortality was high among those not surveyed (20%) and those found to have TB (49%). CONCLUSIONS: Tuberculosis is epidemic in this HIV-infected population. Active case-finding yielded three times the number of cases already detected and should be considered where resources allow. However, effective passive case detection and improved coordination of TB and HIV care programs are required to address HIV-associated TB morbidity and mortality.     

Active case finding of pulmonary tuberculosis and HIV infection among prisoners of South Gujarat: A cross sectional study

BackgroundIn a close knit congregation such as prison, Tuberculosis (TB) and HIV can be major health problems. However, their prevalence in Indian prisons is under reported. This study aimed at adopting a camp based, active case finding approach to identify cases of TB, HIV and at risk prisoners in a central prison of South Gujarat.MethodsA multidisciplinary team of public health experts, pulmonologists, social workers and lab technicians conducted a week-long camp to screen 1665 prisoners for TB using clinical examination, sputum smear for AFB, CBNAAT and Chest X-Ray and for HIV through Rapid Antigen Testing.ResultsMajority of participants (1392, 84%) were under trail prisoners, having spent an average of 1.4 years in prison. About 2.9% of participants had previous history of TB, of whom only 59% had completed treatment. About 14% of participants were underweight. Weight reduction was found to be significant in first five years of imprisonment. Of all participants, 3.6% were found to have diabetic range of blood sugar. Seven new active, drug sensitive pulmonary TB cases and three new cases of HIV infection were identified. All new cases of TB, HIV and increased blood sugar levels were linked to treatment.ConclusionCamp based approach is effective in active case finding of pulmonary TB and predisposing factors such as malnourishment, Diabetes and HIV among prisoners. Routine screening of all prisoners at the time of entry and monthly thereafter in a camp based approach should be adopted to identify TB and at risk prisoners.     

Pleural tuberculosis in the United States: incidence and drug resistance

BACKGROUND: Pleural tuberculosis (TB) should be considered in any patient with a lymphocytic pleural effusion. The diagnostic approach is under debate. Knowledge of pleural TB epidemiology would be beneficial. To help clarify pleural TB epidemiology, we analyzed US national TB surveillance data for 1993 to 2003. METHODS: We compared pleural TB to pulmonary TB (where each was reported as the major site of TB disease, and no additional sites of disease were reported). Applicable statistical tests were performed; p < 0.05 was considered to be significant. RESULTS: From 1993 through 2003, 7,549 cases of pleural TB and 156,779 cases of pulmonary TB were reported (in 2003: pleural TB, 536 cases; pulmonary TB, 10,551 cases). The annual proportion of pleural TB was relatively stable (median rate, 3.6%; range, 3.3 to 4.0%) compared to that for pulmonary TB, which steadily decreased (average annual decrease, 0.9%; p < 0.01). Pleural TB occurred significantly more often than pulmonary TB among persons >/= 65 years old (30.4% vs 23.3%, respectively; p < 0.01), and it occurred significantly less often among children < 15 years old (1.8% vs 6.1%, respectively; p < 0.01) and persons 45 to 64 years old (22.9% vs 27.9%, respectively; p < 0.01). Pleural TB patients (63.4%) were born slightly more often in the United States than were pulmonary TB patients (60.9%; p < 0.01). Drug-resistance patterns of pleural TB broadly reflected those of pulmonary TB. However, isolates from pleural TB patients were less often resistant to at least isoniazid (6.0% vs 7.8%, respectively; p < 0.01) and to at least one first-line TB drug (9.9% vs 11.9%, respectively; p < 0.01) compared with pulmonary TB patients. CONCLUSIONS: Knowledge of pleural TB demographic, clinical, and drug-resistance patterns may assist clinicians in making diagnostic and therapeutic decisions.     

Clinical characteristics of <Emphasis Type="Italic">Mycobacterium tuberculosis</Emphasis> infection among rheumatoid arthritis patients

To evaluate the clinical characteristics of Mycobacterium tuberculosis infection in rheumatoid arthritis (RA) patients, we examined the clinical manifestations and radiography/computed tomography (CT) findings in RA patients with tuberculosis (RA+/TB+). A total of 1121 tuberculosis patients were admitted to our hospital from 1995 to 2003, with the RA patients among them comprising 1.8% (20 cases; 9 men and 11 women). This is approximately three times as high as the prevalence of RA in the entire population in Japan. In addition, the RA+/TB+ patients were older and had a longer history of RA than the 140 outpatients in our RA clinic who did not have tuberculosis (RA+/TB–). Half of the RA+/TB+ patients had no symptoms (e.g., cough, sputum, pyrexia), and their tuber-culosis was detected accidentally by radiography/CT. The positive rates of the bacilli in the smear and culture of the sputum from the RA+/TB+ patients were lower than those from 143 patients randomly selected from among 1091 tuberculosis patients without any collagen disease including RA (RA–/TB+). The RA+/TB+ patients had a higher incidence of extrapulmonary tuberculosis (30%), including four cases (20%) of miliary tuberculosis, an incidence seven times higher than among the general population of tuberculosis patients. Among 14 cases of pulmonary tuberculosis patients with RA, bilateral lesions and noncavitary lesions were found in 71.4% and 64.3%, respectively, which tended to be a higher incidence than in the RA–/TB+ patients. The mortality rate and sputum conversion time of the RA+/TB+ patients were no different from those of the RA–/TB+ patients. The prevalence of tuberculosis in RA patients is expected to increase after introduction of anticytokine therapy in Japan, and careful observation should be done to avoid this complication in RA patients.     

Immune responses in bovine tuberculosis.

Knowledge of the immune responses which develop in cattle following infection with Mycobacterium bovis is essential both to the understanding of disease pathogenesis and to the logical development of immune-dependent tools, such as diagnostic tests and vaccines, which can be used to combat the disease. Studies of field cases of bovine tuberculosis (TB) and of experimental bovine models of M. bovis infection have indicated that cell-mediated immune responses (CMI) predominate within a spectrum of immunity which exists. This paper reviews aspects of recent research and indicates how knowledge of T-cell antigenic targets in bovine TB along with increasing knowledge of T-cell subpopulations and their interactions with M. bovis -infected macrophages provides opportunities for the development of better methods for disease control.