Geospatial cluster analyses of pneumonia-associated hospitalisations among adults in New York City, 2010-2014.

Pneumonia is a leading cause of death in New York City (NYC). We identified spatial clusters of pneumonia-associated hospitalisation for persons residing in NYC, aged ⩾18 years during 2010-2014. We detected pneumonia-associated hospitalisations using an all-payer inpatient dataset. Using geostatistical semivariogram modelling, local Moran's I cluster analyses and χ2 tests, we characterised differences between 'hot spots' and 'cold spots' for pneumonia-associated hospitalisations. During 2010-2014, there were 141 730 pneumonia-associated hospitalisations across 188 NYC neighbourhoods, of which 43.5% (N = 61 712) were sub-classified as severe. Hot spots of pneumonia-associated hospitalisation spanned 26 neighbourhoods in the Bronx, Manhattan and Staten Island, whereas cold spots were found in lower Manhattan and northeastern Queens. We identified hot spots of severe pneumonia-associated hospitalisation in the northern Bronx and the northern tip of Staten Island. For severe pneumonia-associated hospitalisations, hot-spot patients were of lower mean age and a greater proportion identified as non-Hispanic Black compared with cold spot patients; additionally, hot-spot patients had a longer hospital stay and a greater proportion experienced in-hospital death compared with cold-spot patients. Pneumonia prevention efforts within NYC should consider examining the reasons for higher rates in hot-spot neighbourhoods, and focus interventions towards the Bronx, northern Manhattan and Staten Island.

The utility of stool cultures for diagnosing tuberculosis in people living with the human immunodeficiency virus.

BACKGROUND: Delayed diagnosis of tuberculosis (TB) increases mortality. OBJECTIVE: To evaluate whether stool culture improves the diagnosis of TB in people living with the human immunodeficiency virus (PLHIV). DESIGN: We analysed cross-sectional data of TB diagnosis in PLHIV in Cambodia, Thailand and Viet Nam. Logistic regression was used to assess the association between positive stool culture and TB, and to calculate the incremental yield of stool culture. RESULTS: A total of 1693 PLHIV were enrolled with a stool culture result. Of 228 PLHIV with culture-confirmed TB from any site, 101 (44%) had a positive stool culture; of these, 91 (90%) had pulmonary TB (PTB). After adjusting for confounding factors, a positive stool culture was associated with smear-negative (odds ratio [OR] 26, 95% confidence interval [CI] 12-58), moderately smear-positive (OR 60, 95%CI 23-159) and highly smear-positive (OR 179, 95%CI 59-546) PTB compared with no PTB. No statistically significant association existed with extra-pulmonary TB compared with no extra-pulmonary TB (OR 2, 95%CI 1-5). The incremental yield of one stool culture above two sputum cultures (5%, 95%CI 3-8) was comparable to an additional sputum culture (7%, 95%CI 4-11). CONCLUSION: Nearly half of the PLHIV with TB had a positive stool culture that was strongly associated with PTB. Stool cultures may be used to diagnose TB in PLHIV.

Risk factors associated with tuberculosis infection among health care workers in Inner Mongolia, China.

SETTING: Health care workers (HCWs) are at increased risk for tuberculosis (TB) infection. In China, surveys examining TB infection among HCWs have not studied general health care facilities, compared tuberculin tests conducted using local protocols against an internationally accepted test or characterised risk factors. OBJECTIVE: To measure the prevalence of and risk factors for TB infection among HCWs in Inner Mongolia, China. DESIGN: Between April and August 2010, we administered QuantiFERON®-TB Gold In-Tube (QFT-GIT) tests, skin tests using Chinese tuberculin (TST) and surveys among HCWs at an infectious diseases hospital and a general medical hospital. We assessed whether demographic characteristics, personal exposure and work exposure were associated with QFT-GIT and TST positivity, and assessed agreement between test results. RESULTS: Of 999 HCWs, 683 (68%) were QFT-GIT-positive, which was associated with greater age, longer HCW career, TB disease in a co-worker and greater daily patient exposure using multivariable analysis. TST reactions ≥ 5 mm occurred in 69% of the HCWs; agreement between test results was low ( 0.22). CONCLUSIONS: The prevalence of TB infection among HCWs in Inner Mongolia is high; infection was associated with occupational exposure. Results from locally conducted TST are difficult to interpret. In China, TB infection control in health care facilities should be strengthened.

Epidemiological and molecular analysis of a waterborne outbreak of norovirus GII.4.

Contaminated water is one of the main sources of norovirus (NoV) gastroenteritis outbreaks globally. Waterborne NoV outbreaks are infrequently attributed to GII.4 NoV. In September 2009, a NoV outbreak affected a small school in Guangdong Province, China. Epidemiological investigations indicated that household use water, supplied by a well, was the probable source (relative risk 1·9). NoV nucleic acid material in concentrated well-water samples was detected using real-time RT-PCR. Nucleotide sequences of NoV extracted from diarrhoea and well-water specimens were identical and had the greatest sequence identity to corresponding sequences from the epidemic strain GII.4-2006b. Our report documents the first laboratory-confirmed waterborne outbreak caused by GII.4 NoV genotype in China. Our investigations indicate that well water, intended exclusively for household use but not for consumption, caused this outbreak. The results of this report serve as a reminder that private well water intended for household use should be tested for NoV.

Barriers to human immunodeficiency virus testing of tuberculosis patients in Thailand, 2004-2007.

SETTING: Tuberculosis (TB) clinics in five provinces and one national referral hospital in Thailand. OBJECTIVE: To identify risk factors for TB patients not receiving human immunodeficiency virus (HIV) pre-test counseling and testing in Thailand. DESIGN: We collected data on TB patients treated at participating facilities from 2004 to 2007. Patients with known HIV status at the time of TB diagnosis were excluded from the analysis. We performed multivariate logistic regression to determine patient and facility characteristics associated with HIV counseling and testing. RESULTS: Of 15 903 TB patients, HIV pre-test counseling was provided to 13 604 (86%). HIV testing was provided to 11 702 (86%) of those counseled. Of 6141 patients with unknown HIV status, 2323 (38%) were treated in facilities that provide HIV testing in TB clinics compared with 6412 (58%) of 11 003 non-HIV-infected and 3814 (62%) of 6121 HIV-infected patients (P < 0.05). In multivariate analysis, patients treated in facilities in which HIV testing of TB patients was performed somewhere other than the TB clinic were significantly less likely to undergo HIV pre-test counseling (adjusted OR 1.55, 95%CI 1.28-1.86). CONCLUSION: In Thailand, providing HIV testing directly in TB clinics, rather than in other settings, may increase the proportion of TB patients with known HIV status.

Tuberculosis services and treatment outcomes in private and public health care facilities in Thailand, 2004-2006.

BACKGROUND: The World Health Organization recommends that national tuberculosis (TB) programs encourage public and private providers to follow the 'International standards for tuberculosis care'. We assessed services and treatment outcomes in TB patients in public and private facilities to inform public-private mix scale-up in Thailand. METHODS: We prospectively collected data on TB patients in four provinces and the national infectious diseases hospital during 2004-2006. We analyzed services and outcomes among new pulmonary TB patients according to facility type. RESULTS: Of 7526 patients, 4539 (60%) were treated in small public facilities, 2275 (30%) in large public facilities and 712 (10%) in private facilities. Compared with the private sector, more public sector patients had at least two sputum smears examined, were prescribed a standard anti-tuberculosis regimen and received directly observed therapy; however, public sector facilities also performed suboptimally. Treatment outcomes were unsuccessful for 237 (33%) patients in private facilities, and for respectively 1018 (23%) and 655 (29%) patients in small and large public facilities. CONCLUSIONS: TB diagnostic and treatment services and outcomes should be enhanced in both public and private facilities in Thailand. Initiatives are needed to improve treatment outcomes and increase the use of microscopy, standardized TB regimens, and directly observed therapy in the public and private sectors.

Association between distance to HIV testing site and uptake of HIV testing for tuberculosis patients in Cambodia.

SETTING: Banteay Meanchey Province, Cambodia. OBJECTIVE: Cambodia has the highest incidence of tuberculosis (TB) in Asia. Not all TB patients are tested for human immunodeficiency virus (HIV). We assessed the association between distance to HIV testing facility and HIV testing rates. METHODS: We analyzed data on TB patients from 11 clinics to determine the proportion tested for HIV infection. We categorized each TB clinic as having a voluntary confidential counseling and testing (VCCT) center onsite, or being at <15 min, 15-30 min or >30 min driving distance to the nearest VCCT. RESULTS: Of 1017 TB patients not previously tested for HIV, 708 (70%) were tested. Of 481 TB patients without onsite VCCT, 297 (62%) were tested, compared to 410 (77%) of 535 TB patients with onsite VCCT (RR 0.6, 95%CI 0.5-0.7). When the VCCT site was >15 min from the TB clinic, HIV testing occurred only half as frequently as when onsite VCCT was available. CONCLUSION: TB patients treated at clinics without onsite or nearby HIV testing are less commonly tested for HIV infection. Making HIV testing available to TB patients without the necessity of traveling to a distant HIV testing site is likely to increase HIV testing rates.

Directly observed treatment is associated with reduced default among foreign tuberculosis patients in Thailand.

SETTING: Thailand's Tuberculosis (TB) Active Surveillance Network in four provinces in Thailand. OBJECTIVE: As treatment default is common in mobile and foreign populations, we evaluated risk factors for default among non-Thai TB patients in Thailand. DESIGN: Observational cohort study using TB program data. Analysis was restricted to patients with an outcome categorized as cured, completed, failure or default. We used multivariate analysis to identify factors associated with default, including propensity score analysis, to adjust for factors associated with receiving directly observed treatment (DOT). RESULTS: During October 2004-September 2006, we recorded data for 14359 TB patients, of whom 995 (7%) were non-Thais. Of the 791 patients analyzed, 313 (40%) defaulted. In multivariate analysis, age>or=45 years (RR 1.47, 95%CI 1.25-1.74), mobility (RR 2.36, 95%CI 1.77-3.14) and lack of DOT (RR 2.29, 95%CI 1.45-3.61) were found to be significantly associated with default among non-Thais. When controlling for propensity to be assigned DOT, the risk of default remained increased in those not assigned DOT (RR 1.99, 95%CI 1.03-3.85). CONCLUSION: In non-Thai TB patients, DOT was the only modifiable factor associated with default. Using DOT may help improve TB treatment outcomes in non-Thai TB patients.

Validation of the line-probe assay for rapid detection of rifampicin-resistant Mycobacterium tuberculosis in Vietnam.

BACKGROUND: Delays in identifying multidrug-resistant tuberculosis (MDR-TB) contribute to higher TB morbidity and mortality, and ongoing transmission. The line-probe assay (LiPA) is a rapid, commercially available polymerase chain reaction based assay that detects most mutations in the rpoB gene for rifampicin (RMP) resistance. We validated and compared this assay with conventional drug susceptibility testing (DST). METHODS: We re-cultured a random sample of stored isolates known to be either RMP-resistant or RMP-susceptible according to DST (proportion method). We performed a blinded comparison between LiPA and conventional DST. Genetic sequencing of the rpoB gene was performed on RMP-resistant isolates and discordant results. RESULTS: We tested 79 RMP-resistant and 64 RMP-susceptible strains. Concordance of LiPA with DST was 94%. For detecting RMP resistance, LiPA sensitivity was 90% and specificity was 100%. Molecular analysis of possible false-negative isolates by LiPA revealed an absence of mutations in the rpoB gene. RMP resistance was a good proxy for MDR-TB, as 66 (93%) of 71 RMP-resistant isolates were also isoniazid-resistant. CONCLUSION: The LiPA provided rapid results that were highly predictive of RMP resistance and MDR-TB. False-negatives occurred, but only among isolates with mutations in regions not assessed by LiPA. Performance and cost-effectiveness should be evaluated in patients during routine program conditions.

Fluorescence microscopy is less expensive than Ziehl-Neelsen microscopy in Thailand.

Ziehl-Neelsen (ZN) microscopy is the primary method for acid-fast bacilli examination in resource-limited settings, including Thailand. Despite its considerably improved diagnostic performance, conventional fluorescent microscopy (FM) is rarely used due to its perceived high cost. An evaluation in Thailand found that the total cost of FM operated in the National Tuberculosis Reference Laboratory (NTRL) in Bangkok, Thailand, is similar to that of ZN performed in the NTRL and in four regional Thai laboratories. FM is therefore a cost-effective alternative to ZN in resource-limited settings.

Monitoring the performance of mycobacteriology laboratories: a proposal for standardized indicators.

SETTING: Thailand Tuberculosis (TB) Active Surveillance Network: Bangkok, Chiang Rai, Phuket, Tak and Ubon-Ratchathani, Thailand. BACKGROUND: Mycobacteriology laboratories in resource-limited, high TB burden settings are expanding to perform conventional solid media culture and broth-based mycobacteriology culture. Indicators that measure how well a laboratory performs sputum microscopy have been developed and broadly implemented. Routine monitoring of sputum culture performance, however, is not as common. DESIGN: We implemented indicators for monitoring the quality of laboratory services in five province-level mycobacteriology culture facilities in Thailand. These indicators were derived from literature review, consultation with subject matter experts and our program experience. CONCLUSIONS: We believe that an international consensus document providing monitoring guidelines for mycobacteriology laboratories is urgently needed.

Provider-initiated diagnostic HIV counselling and testing in tuberculosis clinics in Thailand.

SETTINGS: Twelve large public hospitals geographically distributed in Thailand. OBJECTIVES: To assess the uptake of diagnostic human immunodeficiency virus (HIV) counselling and testing (DCT), HIV prevalence in tuberculosis (TB) patients and HIV services provided to newly diagnosed HIV-infected TB patients. METHOD: We provided DCT in TB clinics to newly registered TB patients. Post-test counselling was provided at TB clinics for non-HIV-infected patients and at HIV voluntary counselling and testing centres for HIV-infected patients. HIV-infected patients were referred for HIV-related care during TB treatment. RESULTS: From July to October 2006, 8% of 1086 new TB patients were known to be HIV-infected at the time of TB diagnosis. Of 1000 patients with unknown HIV status, 93% were tested: HIV infection was diagnosed in 11%. Including patients with previously diagnosed HIV infection, 17% of all TB patients were HIV-infected. Of 99 newly diagnosed HIV patients, 36% received cotrimoxazole prophylaxis. Of 41 with CD4 < 200 cells/microl, 42% began antiretroviral treatment during TB treatment. CONCLUSION: The acceptance of DCT was high, but the provision of HIV services was disappointingly low. Increased staff capacity building, stronger coordination with the acquired immune-deficiency syndrome programme and better field supervision are needed to achieve universal access to care for HIV-infected TB patients.

Using program evaluation to improve the performance of a TB-HIV project in Banteay Meanchey, Cambodia.

SETTING: Cambodia has the highest human immunodeficiency virus (HIV) prevalence (1.9%) and tuberculosis (TB) incidence (508/100000) in Asia. Banteay Meanchey, a province with high HIV prevalence of 1.9%, established a pilot project in 2003 to enhance TB-HIV activities. We evaluated this project to improve performance. METHODS: In March 2005, we analyzed 17 months of data on all persons diagnosed with HIV or TB at 11 participating clinics. We determined barriers to HIV testing and TB screening, modified the program to reduce these barriers and assessed whether our interventions improved testing and screening rates. RESULTS: Among 952 patients newly diagnosed with TB disease, 138 (14%) had known HIV infection at the time of TB diagnosis. Of the 814 TB patients with unknown HIV status, 432 (53%) were HIV tested. Of 1228 persons newly diagnosed with HIV infection, 450 (37%) were screened for TB disease. We found and addressed barriers to HIV testing and TB screening. In the 9 months after the interventions, 240/322 (71%) TB patients were HIV tested, an increase of 34% (P < 0.01); 426/751 (57%) HIV-infected patients were screened for TB, an increase of 54% (P < 0.01). CONCLUSION: Evaluations of TB-HIV collaborative activities can lead to increased TB screening and HIV testing rates.

Population-based chest X-ray screening for pulmonary tuberculosis in people living with HIV/AIDS, An Giang, Vietnam.

SETTING: Human immunodeficiency virus/acquired immune-deficiency syndrome (HIV/AIDS) program, An Giang Province, Vietnam. OBJECTIVE: To evaluate the coverage and yield of a chest radiography (CXR) screening program for tuberculosis (TB) among people living with HIV/AIDS (PLHA), risk factors for a TB CXR, inter-rater reliability of CXR readings and direct costs. DESIGN: Retrospective review of routine public health program records and CXRs. RESULTS: An increasing proportion of PLHAs received a screening CXR each year of the program (range 21% in 2001 to 61% in 2004, P<0.001). Of 876 screening CXRs performed, 191 (22%) were classified as suspicious for active TB ('TB CXR'). Compared to PLHAs with a CXR not suspicious for active TB, PLHAs with a TB CXR were more likely to be aged between 24 and 64 years, male and previously treated for TB (P<0.01 for each comparison). Agreement between the expert and local program CXR readings was 81% (kappa 0.50). Direct costs were approximately US$40 per TB suspect identified. Among TB suspects, <10% were followed up with sputum smear examination and enrolled for treatment. CONCLUSION: In An Giang Province, a large proportion of PLHAs are screened for TB annually, and one in five persons screened is classified as a TB suspect based on CXR. Annual CXRs may be a high-yield, inexpensive method for TB screening in PLHAs, but the follow-up of TB suspects to confirm diagnosis and initiate treatment is crucial.

The epidemiology of HIV-associated tuberculosis in rural Cambodia.

SETTING: Banteay Meanchey Province, Cambodia. OBJECTIVE: The World Health Organization recommends human immunodeficiency virus (HIV) testing for all tuberculosis (TB) patients and TB screening for all HIV-infected persons in countries with a TB-HIV syndemic. We sought to determine whether evidence supports implementing these recommendations in South-East Asia. DESIGN: We conducted a cross-sectional survey and retrospective cohort study of patients newly diagnosed with HIV or TB from October 2003 to February 2005 to identify risk factors for HIV infection and TB, and for death during TB treatment. RESULTS: HIV infection was diagnosed in 216/574 (38%) TB patients. TB disease was found in 124/450 (24%) HIV-infected persons. No sub-groups of patients had a low risk of HIV infection or TB. Of 180 TB patients with HIV infection and a recorded treatment outcome, 49 (27%) died compared to 17/357 (5%) without HIV infection (relative risk [RR] 5.2, 95% confidence interval [CI] 3.1-8.7). HIV-infected TB patients with smear-negative pulmonary disease died less frequently than those with smear-positive pulmonary disease (RR 0.39, 95%CI 0.16-0.93). CONCLUSIONS: No sub-groups of patients had low risk for HIV infection or TB, and mortality among HIV-infected TB patients was high. These data justify using the WHO global TB-HIV recommendations in South-East Asia. Urgent interventions are needed to reduce the high mortality rate in HIV-infected TB patients.

Re-assessment of risk factors for sporadic Salmonella serotype Enteritidis infections: a case-control study in five FoodNet Sites, 2002-2003.

Active surveillance for laboratory-confirmed Salmonella serotype Enteritidis (SE) infection revealed a decline in incidence in the 1990s, followed by an increase starting in 2000. We sought to determine if the fluctuation in SE incidence could be explained by changes in foodborne sources of infection. We conducted a population-based case-control study of sporadic SE infection in five of the Foodborne Diseases Active Surveillance Network (FoodNet) sites during a 12-month period in 2002-2003. A total of 218 cases and 742 controls were enrolled. Sixty-seven (31%) of the 218 case-patients and six (1%) of the 742 controls reported travel outside the United States during the 5 days before the case's illness onset (OR 53, 95% CI 23-125). Eighty-one percent of cases with SE phage type 4 travelled internationally. Among persons who did not travel internationally, eating chicken prepared outside the home and undercooked eggs inside the home were associated with SE infections. Contact with birds and reptiles was also associated with SE infections. This study supports the findings of previous case-control studies and identifies risk factors associated with specific phage types and molecular subtypes.

An outbreak of hospital-acquired hepatitis B virus infection among patients receiving chronic hemodialysis.

OBJECTIVE: To investigate a cluster of hepatitis B virus (HBV) infections between December 1995 and May 1996 among chronic hemodialysis patients in one county. SETTING: Two dialysis centers (A and B) and a hospital (C) in one county. PATIENTS: Six case-patients who were dialyzed in one of two centers, A and B, and had all been hospitalized between January and February 1996 at hospital C. METHODS: Patient 1, usually dialyzed in center A, sero-converted to hepatitis B surface antigen (HBsAg) in December 1995 and could have been the source of infection for the others, who seroconverted between March and April 1996. Two cohort studies were conducted: one among patients dialyzed in center A, to determine where transmission had occurred, and one among patients dialyzed at hospital C at the time patient 1 was hospitalized, to identify factors associated with infection. RESULTS: Four (15%) of the 26 susceptible patients dialyzed at center A became infected with HBV. Hospitalization at hospital C when patient 1 was hospitalized was associated with infection (P = .002). A cohort study of the 10 susceptible patients dialyzed at hospital C during the time patient 1 was hospitalized did not identify specific risk factors for infection. However, supplies and multidose vials were shared routinely among patients, providing opportunities for transmission. CONCLUSION: When chronic hemodialysis patients require dialysis while hospitalized, their HBsAg status should be reviewed, and no instrument, supplies, or medications should be shared among them.

Monitoring for mefloquine-resistant Plasmodium falciparum in Africa: implications for travelers' health.

The effectiveness of mefloquine to prevent malaria caused by Plasmodium falciparum is influenced by the sensitivity of the malaria parasites to this drug. Concern has been raised that resistance to mefloquine may develop in sub-Saharan Africa as has been observed in Southeast Asia. Case reports, along with blood smears to confirm the diagnosis and blood samples to determine the mefloquine concentration, were provided on any Peace Corps volunteer serving in sub-Saharan Africa who was diagnosed with malaria. We defined prophylaxis failures probably due to mefloquine resistance as patients with P. falciparum malaria confirmed at the Centers for Disease Control and Prevention, reported compliance with prophylaxis, no ingestion of mefloquine between date of illness onset and date of blood drawing, and a mefloquine level > or = 620 ng/ml in blood drawn within five days of onset of illness. Between January 1, 1991 and September 6, 1996, 44 (31%) of 140 volunteers with confirmed P. falciparum had blood drawn within five days of onset of illness. Twenty-nine (66%) had not fully complied with prophylaxis. Five of 15 prophylaxis failures in four countries had mefloquine levels > or = 620 ng/ml. Failure of mefloquine prophylaxis is primarily due to noncompliance. Evidence of probable resistance to mefloquine among strains of P. falciparum was found in five Peace Corps volunteers in sub-Saharan Africa. Clusters of well-documented prophylaxis failures need to be followed-up by therapeutic in vivo studies to document parasite resistance to mefloquine. Reduced sensitivity to mefloquine does not (yet) appear to be a significant problem in sub-Saharan Africa.