Potential number of human cases of H5N1 avian influenza in Egypt.

OBJECTIVES: H5N1 is one of the avian influenza virus subtypes that has the potential to evolve into a global pandemic that could cause millions of human deaths and great economic losses. Cases involving humans have occurred in 15 countries. Costly interventions have been used by governments and health organisations. Thus, a challenging question arises regarding how many cases of the disease may actually have been prevented as a result of such interventions. STUDY DESIGN: This paper answers such a question by applying a statistical model to the 2006-January 2009 outbreak in Egypt. Egypt was chosen as it had the highest number of human avian influenza cases outside Asia, and the second highest number in that period worldwide. METHODS: Brookmeyer and Blades' statistical model was applied. The sensitivities of the estimated number of human cases and exposure dates to the assumed incubation period, the delay in intervention and the coverage/effectiveness of the intervention were investigated. RESULTS: In the absence of intervention, it appears that the outbreak could have been approximately 1.5 times as large, but it is unlikely it would have exceeded 150 cases. CONCLUSIONS: The results underscore the importance of early detection of an outbreak and intervention, together with effective public health control measures.

A spatiotemporal statistical model of the risk factors of human cases of H5N1 avian influenza in South-east Asian countries and China.

OBJECTIVES: This article aims to quantify the risk factors associated with the human cases of H5N1 avian influenza in South-east Asian countries and China; a dangerous region for this disease that has the potential for a pandemic outbreak. STUDY DESIGN: A statistical model with time and spatial dimensions was built to capture the international spread patterns of this disease. METHODS: The grid search method was used to fit the model with 2004-2006 data. The grid search approach is a simple procedure that allows the fit of any function to data. RESULTS: This study found that: (1) when the number of domestic H5N1 human cases increases by one person in a certain time period, the chance that the country will have a human case in the next period increases by 22.10%; (2) when the number of human cases in a neighbouring country increases by one person in a certain time period, the chance that the country will have a human case in the next period increases by 1.62%; (3) when the number of avian cases in a neighbouring country increases by one, the chance that the country will have a human case increases by 0.02%; (4) as the human population increases by one unit, the chance that the country will have a human case increases by 0.10%; (5) when the quantity of imported poultry increases by 1000 metric tons, the chance that the country will have a human case increases by 0.03%; (6) when the outbreak of the disease among domestic birds increases by one, the chance that the country will have a human case increases by 0.19%; and finally (7) when the number of birds destroyed increases by 1000, the chance that the country will have a human case decreases by 0.30%. CONCLUSIONS: These findings shed new light on the spatiotemporal characteristics of the epidemic, and thus need to be taken into consideration in interdisciplinary and scientific discussion of the disease.

[The significance of the alerting tasks in the vestibular's caloric test].

OBJECTIVE: To evaluate the vestibular's sensitivity to the stimulus of the cold and hot water. METHOD: Forty volunteers are randomly divided into four groups, group one for maths calculation, group two for answering the questions (they are active alerting groups) and group three and four for listening to music and to stories respectively (they are passive alerting groups). Each group has ten volunteers, their left ears are separately stimulated with the cold and hot water, recording the nystagmus slow phase velocity for 20 s at the highest level with the nystagmography instrument of HB-3 ENG computer treatment system. RESULT: There are significant differences between the two active alerting groups and the two passive ones (P < 0.01). CONCLUSION: In performing the vestibular's caloric test, it's more reasonable for clinic to use active alerting tasks.