Field and laboratory investigation of highly pathogenic avian influenza H5N6 and H5N8 in Quang Ninh province, Vietnam, 2020 to 2021

BACKGROUND

Avian influenza (AI) is a contagious disease that causes illness and death in poultry and humans. High pathogenicity AI (HPAI) H5N6 outbreaks commonly occur in Quang Ninh province bordering China. In June 2021, the first HPAI H5N8 outbreak occurred at a Quang Ninh chicken farm.

OBJECTIVES

This study examined the risk factors associated with HPAI H5N6 and H5N8 outbreaks in Quang Ninh.

METHODS

A retrospective case-control study was conducted in Quang Ninh from Nov 2021 to Jan 2022. The cases were households with susceptible poultry with two or more clinical signs and tested positive by real-time reverse transcription polymerase chain reaction. The controls were households in the same village as the cases but did not show clinical symptoms of the disease. Logistic regression models were constructed to assess the risk factors associated with HPAI outbreaks at the household level.

RESULTS

There were 38 cases with H5N6 clade 2.3.4.4h viruses (n = 35) and H5N8 clade 2.3.4.4b viruses (n = 3). Compared to the 112 controls, raising poultry in uncovered or partially covered ponds (odds ratio [OR], 7.52; 95% confidence interval [CI], 1.44-39.27), poultry traders visiting the farm (OR, 8.66; 95% CI, 2.7-27.69), farms with 50-2,000 birds (OR, 3.00; 95% CI, 1.06-8-51), and farms with ≥ 2,000 birds (OR, 11.35; 95% CI, 3.07-41.94) were significantly associated with HPAI outbreaks.

CONCLUSIONS

Combining biosecurity measures, such as restricting visitor entry and vaccination in farms with more than 50 birds, can enhance the control and prevention of HPAI in Quang Ninh and its spread across borders.

Measuring levels of comorbidity in drug user* emergency patients treated in Ontario hospitals

We examined the nature and extent of health problems in drug user patients initially treated in emergency departments and who were subsequently admitted to all hospitals in Ontario, using data from the Hospital Medical Records Institute (HMRI). The modified standardized morbidity ratio (modified SMR) is introduced to improve the measurement and visual display of reduced morbidity as well as excess morbidity. During 1985-86, about 75% of drug user patients entered hospital through the emergency department. There were 5077 emergency patients with primary drug use-related diagnoses and 9827 with secondary drug use-related diagnoses. Cases with poisoning diagnosis made up over 80% of all drug use cases treated in emergency departments. Cases with non-dependent abuse of drugs accounted for 8-12% of emergency drug user patients, whereas those with drug dependence accounted for about 3% of emergency drug user patients. These patients had more than three times the comorbidity experience of all hospital patients. They had excess comorbidity due to mental disorders, infectious and parasitic disorders, and injury and poisoning diagnoses. However, they had reduced comorbidity due to complications of pregnancy, childbirth, and the puerperium and from congenital anomalies and conditions originating in the perinatal period. Cocaine patients were more likely to have infectious parasitic diseases and diseases of the skin and subcutaneous tissue, while amphetamine patients were more likely to have diseases of the digestive system and of the musculo-skeletal system and connective tissue.

The relative risks and etiologic fractions of different causes of death and disease attributable to alcohol, tobacco and illicit drug use in Canada

BACKGROUND

In 1996 the number of deaths and admissions to hospital in Canada that could be attributed to the use of alcohol, tobacco and illicit drugs were estimated from 1992 data. In this paper we update these estimates to the year 1995.

METHODS

On the basis of pooled estimates of relative risk, etiologic fractions were calculated by age, sex and province for 90 causes of disease or death attributable to alcohol, tobacco or illicit drugs; the etiologic fractions were then applied to national mortality and morbidity data for 1995 to estimate the number of deaths and admissions to hospital attributable to substance abuse.

RESULTS

In 1995, 6507 deaths and 82,014 admissions to hospital were attributed to alcohol, 34,728 deaths and 194,072 admissions to hospital were attributed to tobacco, and 805 deaths and 6940 admissions to hospital were due to illicit drugs.

INTERPRETATION

The use and misuse of alcohol, tobacco and illicit drugs accounted for 20.0% of deaths, 22.2% of years of potential life lost and 9.4% of admissions to hospital in Canada in 1995.