NEWS SCAN: Record West Nile cases, rodent-borne illness outbreak

Aug 16, 2012

CDC reports record West Nile cases for this time of year
Through the first half of August, 693 West Nile virus (WNV) infections have been reported in the United States, the highest number for this point in the summer since the virus was first detected in the country on 1999, according to an Aug 14 update from the Centers for Disease Control and Prevention (CDC). Of that total, 406 (59%) were neuroinvasive infections, and 26 patients (4%) died. Though 43 states have reported WNV in people, birds, or mosquitoes, the CDC said more than 80% of cases have been reported from six states: Texas, Mississippi, Louisiana, Oklahoma, South Dakota, and California. Almost half of the cases have been from Texas. Many of the infections in Texas have been from the Dallas area, where county health officials declared a public health emergency because of record case numbers and recently approved the use of aerial spraying to control mosquitoes. Ten WNV deaths have been reported in the Dallas area.
Aug 14 CDC update
In other WNV developments, Michigan and Indiana recently reported their first WNV deaths of the season. The Michigan Department of Community Health (MDCH) said today that a previously healthy Washtenaw County woman between ages 75 and 85 has died from the disease. It said WNV activity is widespread in the southern half of the state's Lower Peninsula. Yesterday's report from the Indiana State Department of Health (ISDH) didn't include any details about its first case but said seven illnesses so far have been reported from six Indiana counties.
Aug 16 MDCH statement
Aug 15 ISDH report

Rodent-borne illness outbreak linked to Indiana breeder
Health officials are working to prevent and identify lymphocytic choriomeningitis virus (LCMV) infections linked to live mice distributed by an unnamed Indiana rodent breeder, according to a report today in Morbidity and Mortality Weekly Report (MMWR). The risk came to light in late April when LCMV, an arenavirus carried by the common house mouse, was diagnosed in an employee who worked at the facility, which produces live and frozen mice and rats for reptiles and birds of prey. After the illness was detected, health officials conducted a seroprevalence survey of 52 of the facility's former and current employees who agreed to be tested. Thirteen (25%) had evidence of infection, nine of whom reported clinical illness, ranging from severe flulike symptoms to meningeal illness that required hospital care. All patients recovered. Lab studies also showed that three other employees had evidence of previous LCMV infection. About 20% of a representative sample of mice tested positive for LCMV infection, but no evidence of the disease was found in a sampling of rats. Authorities destroyed all remaining live mice, along with animals that were in cold storage, and disinfected and cleaned the facility. Investigators are tracking live mice distributed from the facility before the LCMV illness was detected and is advising anyone who had contact with the animals to be aware of the risk and seek medical evaluation if they have been sick.
Aug 17 MMWR report

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