Apr 4, 2012
Lassa fever outbreak in Nigeria grows to 623 suspected cases, 70 deaths
A Lassa fever outbreak in Nigeria that was first reported in January has increased to 623 suspected cases, with 70 deaths, including deaths in three doctors and four nurses, the World Health Organization (WHO) announced today. Suspected cases have been reported in 19 of Nigeria's 36 states. Lab tests at the Irrua Specialist Teaching Hospital in Irrua Edo state have confirmed the disease in 108 patients, the WHO said. Nigeria's federal and state governments are responding to the outbreak by enhancing surveillance for early detection, reinforcing treatment of patients, and conducting awareness campaigns, the statement said. The governments face obstacles that include ongoing security risks that limit access to some areas and shortages of resources. The WHO is not recommending any travel restrictions, but it said travelers returning from affected areas should seek medical care if they experience such symptoms as fever, malaise, headache, sore throat, muscle pain, chest pain, nausea, vomiting, diarrhea, or abdominal pain. Lassa fever, one of the viral hemorrhagic fevers, is endemic in West Africa. People usually get infected through exposure to rodents in the Mastomys genus, the WHO said. Case-fatality rates for hospitalized Lassa fever patients can be as high as 15% to 25%.
Apr 4 WHO statement
CIDRAP overview of viral hemorrhagic fevers
Australian abattoir workers test positive for H10 avian flu
Low-pathogenicity H10N7 avian flu was confirmed in a 2010 outbreak at an Australian chicken farm, and H10 was subsequently confirmed in two abattoir workers who processed apparently healthy birds from the farm, according to a report in Emerging Infectious Diseases. Australian scientists detail a March 2010 outbreak on a "biosecure intensive" commercial farm in New South Wales, during which 10 to 25 chickens died per day, compared with a baseline of 2 to 6 deaths a day. Egg production fell 15%. All 10 dead and 10 live birds from an initial flock and 9 of 40 poultry in four other flocks tested positive for H10N7. Ten days after the outbreak was confirmed, three flocks from the farm that had tested negative for influenza and passed state inspection were sent to an abattoir. Within a week, seven abattoir workers showed signs of conjunctivitis; two of them had rhinorrhea, and one had a sore throat. H10 was confirmed in two of them. They had been exposed 4 to 7 days before symptom onset. No virus was cultured from these workers, but partial sequence analysis showed that the isolates were identical to the subtype H10 found in the farm's chickens. The authors say this is the first instance to their knowledge of H10 avian flu infection in humans.
Apr 2 Emerg Infect Dis report
Trial shows comparable immunogenicity for quadrivalent, trivalent flu vaccines
MedImmune's quadrivalent (four-strain) live attenuated influenza vaccine containing two type B strains was comparable in immunogenicity and safety to trivalent live attenuated vaccines in a recent trial in children, according to a study in The Pediatric Infectious Disease Journal. The US Food and Drug Administration approved the nasal-spray vaccine in February for ages 2 through 49. In the trial, children aged 2 through 17 were randomly assigned to receive either the quadrivalent vaccine or one of two trivalent vaccines. Children 9 to 17 years old received one dose, and 2- to 8-year-olds received two doses a month apart. Serum antibody responses were assessed 1 month after the single or second dose, depending on the age-group. The geometric mean titers (GMTs) of antibodies in the quadrivalent vaccine groups met the study's predefined noninferiority margin (upper limits of the 95% confidence intervals for the ratio of quadrivalent to trivalent vaccine GMTs were no greater than 1.5). In addition, the percentages of children who had at least a fourfold rise in antibody titers (seroresponse rates) were comparable among the groups. The safety profiles of the vaccines also were similar, except that in the younger children fever was more common after the first dose in the quadrivalent group than in the trivalent groups (5.1% versus 3.1%).
Mar 29 Ped Infect Dis J abstract
Mar 1 CIDRAP News story on FDA approval of quadrivalent vaccine