West Nile virus

Public domain image/National Atlas of the United States
Public domain image/National Atlas of the United States

California became the first state in the US to reach 200 human West Nile virus (WNV) this week after the California Department of Public Health (CDPH) saw 44 new cases during the pat seven days.

Of the total of 201 cases, the following counties have seen the most WNV–Butte (43), Los Angeles (24), Riverside (23) and Orange (20). Human cases have been reported from 27 counties with Fresno and Ventura counties being the latest.

WNV-related fatalities doubled in the past week to 10. They have been reported from the following counties: Butte (1), Los Angeles (2), Nevada (1), Orange (1), Riverside (2), San Bernardino (2), and San Diego(1).

Last year, California reported 801 human WNV cases, leading the country.

As of September 22, 2015, a total of 47 states and the District of Columbia have reported West Nile virus infections in people, birds, or mosquitoes in 2015. Overall, 877 cases of West Nile virus disease in people have been reported to CDC.


The number of pertussis, or whooping cough cases has increased by slightly more than 500 cases since last update about 6 weeks ago. The current pertussis case count now stands at 3,914, up from 3,404 cases in early August.

CDPH officials say pertussis incidence remains high in California and excluding the epidemic years of 2010 (9,159) and 2014 (11,203), more cases of pertussis have already been reported in 2015 than any year since the 1950’s.

The Los Angeles area has reported the most with 947 so far this year.

During 2014, 32,971 cases of pertussis were reported to CDC. This represented a 15% increase compared 28,639 cases reported during 2013.

Robert Herriman is a microbiologist and the Editor-in-Chief of Outbreak News Today and the Executive Editor of The Global Dispatch

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