Nipah virus infection of pigs in peninsular Malaysia

Between late 1998 and 1999, the spread of a new disease of pigs, characterized by a pronounced respiratory and neurological syndrome, sometimes accompanied by the sudden death of sows and boars, was recorded in pig farms in peninsular Malaysia. The disease appeared to have a close association with an epidemic of viral encephalitis among workers on pig farms. A previously unrecognised paramyxovirus was later identified from this outbreak; this virus was related to, but distinct from, the Hendra virus discovered in Australia in 1994. The new virus was named 'Nipah' and was confirmed by molecular characterization to be the agent responsible for the disease in both humans and pigs. The name proposed for the new pig disease was 'porcine respiratory and neurological syndrome' (also known as 'porcine respiratory and encephalitis syndrome'), or, in peninsular Malaysia, 'barking pig syndrome'. The authors describe the new disease and provide the epidemiological findings recorded among infected pigs. In addition, the control programmes which were instituted to contain the virus in the national swine herd are outlined.     

Nipah Virus Infection in Dogs, Malaysia, 1999

The 1999 outbreak of Nipah virus encephalitis in humans and pigs in Peninsular Malaysia ended with the evacuation of humans and culling of pigs in the epidemic area. Serologic screening showed that, in the absence of infected pigs, dogs were not a secondary reservoir for Nipah virus.     

Nipah virus infection in bats (order Chiroptera) in peninsular Malaysia

Nipah virus, family Paramyxoviridae, caused disease in pigs and humans in peninsular Malaysia in 1998-99. Because Nipah virus appears closely related to Hendra virus, wildlife surveillance focused primarily on pteropid bats (suborder Megachiroptera), a natural host of Hendra virus in Australia. We collected 324 bats from 14 species on peninsular Malaysia. Neutralizing antibodies to Nipah virus were demonstrated in five species, suggesting widespread infection in bat populations in peninsular Malaysia.     

Probable dengue virus infection among Italian troops,East Timor, 1999-2000

To investigate the attack rate and risk factors for probable dengue fever, a cross-sectional study was conducted of an Italian military unit after its deployment to East Timor. Probable dengue was contracted by 16 (6.6%) of 241 army troops and caused half of all medical evacuations (12/24); no cases were detected among navy and air force personnel.     

A survey of Nipah virus infection among various risk groups in Singapore

Following the Nipah virus (NV) outbreak in March 1999 in Singapore, a serological survey was undertaken to screen individuals potentially exposed to NV. Blood samples were tested for NV IgM, IgG and neutralizing antibodies. Twenty-two (1.5%) of 1469 people tested had antibodies suggesting NV infection. Although 12 of the 22 infected people (54.6%) were symptomatic, the remaining 10 (45.4%) were clinically well and had no past history of compatible pulmonary or neurological disease. Clinical and serological findings suggested three people had been infected with NV before the outbreak was recognized. All those who were infected were male abattoir workers. None of the people who had contact with horses, and no healthcare workers exposed to infected patients and their specimens had detectable antibodies. This study provides evidence that NV causes asymptomatic infection. All of the antibody positive individuals had direct contact with pigs and there was no evidence of human to human transmission.     

A cluster of leptospirosis among abattoir workers

In early December 1998, the Northern Rivers Public Health Unit (north-eastern New South Wales) was alerted to a possible cluster of leptospirosis cases by the supervising scientist of the Western Pacific Region World Health Organization/Food and Agricultural Organization Collaborating Centre for Reference and Research on Leptospirosis. Investigation revealed a cluster of eight leptospirosis cases diagnosed during October and November 1998. All were employees of a local meat works. Leptospira serovars isolated included pomona and hardjo. Symptoms included headache, fever, muscle pain, sore eyes, abdominal pain, vomiting, jaundice, and rash. Five of the eight cases were hospitalised. The infection could not be traced to any particular source. Unfortunately, records of stock killed during the exposure periods were not available. All cases reported exposure to large volumes of animal urine during the course of their work. Protective clothing provided included an apron, gloves, and rubber boots. All of the patients said they wore rubber boots and seven of the eight wore the apron provided. Only two patients reported wearing gloves, the remainder thought these were too difficult to work in.     

Fatal occupational injuries among workers in Kocaeli, Turkey, 1990-1999

The authors evaluated occupational accidents in Kocaeli, Turkey, using epidemiologic criteria. Data were derived from the registries of the service on Occupational Injuries and Diseases of the Social Insurance Institution's District Authority in Kocaeli. The analysis was based on data from 387 deaths. The rates of occupational injuries and mortality and fatalities from them were 5.1%, 30.6 per 100,000 workers, and 6.0%, respectively, compared with 2.8%, 35.2 per 100.000 workers, and 12.7% in Turkey. Sectors with the highest rates of fatal occupational injuries were construction (30.2%), transportation (13.2%), basic metal industry (9.0%), manufacturing of metal products (5.9%), and heating with electricity, gas, and steam (5.9%). 38.2% of these workers were 25-34 years old. Nearly all were male, most were married, and three fourths had children. Of all deaths due to occupational injuries, 121 (31.3%) were caused by traffic injuries, 93 (24.1%) by falling from high places, and 43 (11.1%) by electrocution; 89% occurred at workplaces, 42% of the workplaces were small, and 45.9% of the deceased workers had been working there for less than three months. Although the situation was better than that in the rest of Turkey in terms of epidemiologic criteria, the death rates, as in other developing countries, are higher than those in the world in general.     

Characterization of Nipah virus from naturally infected Pteropus vampyrus bats, Malaysia

We isolated and characterized Nipah virus (NiV) from Pteropus vampyrus bats, the putative reservoir for the 1998 outbreak in Malaysia, and provide evidence of viral recrudescence. This isolate is monophyletic with previous NiVs in combined analysis, and the nucleocapsid gene phylogeny species.     

Update: respiratory syncytial virus activity--United States, 1998-1999 season

Respiratory syncytial virus (RSV) is the most common cause of lower respiratory tract disease in infants and young children worldwide. In temperate climates, RSV infections occur primarily during annual outbreaks, which peak during winter months . In the United States, RSV activity is monitored by the National Respiratory and Enteric Virus Surveillance System (NREVSS), a voluntary, laboratory-based system. This report summarizes trends in RSV activity reported to NREVSS during July 1998 June 1999 and presents preliminary surveillance data during July 1-November 12, 1999, which show that RSV community outbreaks are becoming widespread.     

Prevalence of measles antibody among young adult healthcare workers in a cancer hospital: 1980s versus 1998-1999.

Despite the 1989 Advisory Committee on Immunization Practices recommendation of a second dose of vaccine, measles seropositivity rates had declined for adult healthcare workers in their 20s hired at a cancer hospital between 1998 and 1999 compared with those of the same age hired between 1983 and 1988. Continued monitoring will be important as individuals born after 1989 enter the workforce.     

Outbreak of varicella-zoster virus infection among Thai healthcare workers.

OBJECTIVE: To evaluate the correlation between self-report of a prior history of chickenpox and results of varicella-zoster virus (VZV) immunoglobulin (Ig) G serologic test results in an outbreak of VZV infection among Thai healthcare workers (HCWs) and to conduct a cost-benefit analysis of establishing routine VZV immunization as part of an occupational health program on the basis of the outbreak data. METHODS: All exposed patients received prophylaxis and the HCWs in our 3 intensive care units (ICUs) were prospectively evaluated. HCWs were assessed for disease history and serologic evidence of VZV IgG. A cost-benefit analysis was performed. RESULTS: After 140 HCWs and 18 ICU patients were exposed to VZV, 10 HCWs (7%) with active VZV infection were relieved from work until skin lesions were crusted. Acyclovir (ACV) was prescribed to all 10 HCWs with active disease, and all 18 exposed patients received prophylaxis with ACV. Of 140 HCWs, 100 consented to longitudinal follow-up. Twenty-three (100%) of the HCWs who reported a history of chickenpox also had serologic test results that were positive for VZV IgG, compared with 30 (39%) of 77 HCWs who reported no prior history of chickenpox, yet had test results that were positive for VZV IgG. Reported history of chickenpox had a sensitivity of 43%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 61% with respect to VZV infection immunity. The total cost estimate for this outbreak investigation was $23,087. CONCLUSIONS: An HCW's reported history of chickenpox was a reliable predictor of immunity; a report of no prior history of chickenpox was unreliable. Our cost-benefit analysis suggests that the costs of an occupational health program that included VZV surveillance and immunization for the next 323 HCWs would be approximately equal to the excess costs of $17,227 for the ACV therapy, HCW furloughs, and staff overtime associated with this outbreak.     

Mortality among Rocketdyne workers who tested rocket engines, 1948-1999

OBJECTIVE: The objective of this study was to evaluate potential health risks associated with testing rocket engines. METHODS: A retrospective cohort mortality study was conducted of 8372 Rocketdyne workers employed 1948 to 1999 at the Santa Susana Field Laboratory (SSFL). Standardized mortality ratios (SMRs) and 95% confidence intervals (CIs) were calculated for all workers, including those employed at specific test areas where particular fuels, solvents, and chemicals were used. Dose-response trends were evaluated using Cox proportional hazards models. RESULTS: SMRs for all cancers were close to population expectations among SSFL workers overall (SMR = 0.89; CI = 0.82-0.96) and test stand mechanics in particular (n = 1651; SMR = 1.00; CI = 0.86-1.16), including those likely exposed to hydrazines (n = 315; SMR = 1.09; CI = 0.75-1.52) or trichloroethylene (TCE) (n = 1111; SMR = 1.00; CI = 0.83-1.19). Nonsignificant associations were seen between kidney cancer and TCE, lung cancer and hydrazines, and stomach cancer and years worked as a test stand mechanic. No trends over exposure categories were statistically significant. CONCLUSION: Work at the SSFL rocket engine test facility or as a test stand mechanic was not associated with a significant increase in cancer mortality overall or for any specific cancer.     

Prevalence of hepatitis A virus infection among sewage workers in Singapore.

To determine whether or not occupational exposure to sewage is associated with a higher seroprevalence of hepatitis A virus (HAV) infection, 600 sewage workers in Singapore were tested for total (IgG and IgM) antibody to HAV by enzyme immunoassay. Using logistic regression with stepwise procedure, the adjusted seroprevalence of sewage workers was 2.2 times higher than that of another non-occupationally exposed population group. Seroprevalence was significantly correlated with age and educational levels, the association being independent of the occupational association. The epidemiological data in the study show that sewage workers have an increased occupational risk of acquiring HAV infection and should be protected by active immunization.     

丹阳市1998～2002年休闲娱乐业性工作者梅毒感染状况分析

梅毒由密螺旋体属中的苍白螺旋体引起，梅毒病人是其唯一的传染源，性接触是主要的传播途径。根据丹阳市1998～2002年浴室、美容美发厅、舞厅等休闲娱乐场所性工作者感染梅毒的检测资料，笔者对其感染情况及流行趋势进行分析如下。     

Prevalence of hepatitis B virus infection markers among factory workers in Beijing, China.

Nearly 1,000 serum samples were obtained from apparently healthy workers of both sexes in various factories in Beijing during 1988-1989 and were examined for hepatitis B virus infection markers by radioimmunoassay. The overall prevalence (all ages and both sexes combined) of cases positive for HBsAg, anti-HBs and anti-HBc were 3.7%, 36.6% and 37.7%, respectively and the rate of those negative to any of the three markers studied was 56.1%. The infection rate was lower than the values reported early in the 1980s for Beijing populations or the values for populations in other parts of China.