DRC sees no let-up in Ebola cases in Katwa
Over the weekend and through today the Democratic Republic of the Congo (DRC) health ministry reported 16 more lab-confirmed Ebola cases, 13 of them from Katwa, the outbreak's current hot spot. Also, in a Feb 9 update, health officials reported 7 more probable cases, all from Katwa involving people who became ill in November and December and died between November and January.
Two of the latest lab-confirmed cases are from Butembo and one is from Vuhovi. The latest developments bring the overall outbreak total to 816 cases, which includes 755 confirmed and 61 probable infections. Outbreak responders are also investigating 178 suspected Ebola cases.
Eleven more people died from their infections. Seven occurred in the community, including six from Katwa and one from Vuhovi. Four people died in Ebola treatment centers, including three from Butembo and one from the Katwa facility. The latest deaths lift the outbreak's fatality total to 513.
In other outbreak developments, the ministry said in its Feb 9 update that immunization of primary care providers has started in Rwampara, a new health zone in Ituri province. It said it took the step, because the health zone is located on a road used by thousands of people from Beni, and that vaccinating health workers is part of plan to limit the spread of the virus to other provinces.
Rotavirus symptoms and costs in household contacts
Rotavirus-related acute gastroenteritis in children poses a significant burden on household contacts, especially children younger than 5 years old, according to a study from researchers with the New Vaccine Surveillance Network, which included scientists with the US Centers for Disease Control and Prevention (CDC).
To examine transmission and impact of rotavirus on families, the group enrolled children between the ages of 15 days through age 10 who were seen for acute gastroenteritis at emergency departments at seven different medical centers between December 2011 and June 2016. The team published their findings in the Feb 7 issue Journal of the Pediatric infectious Diseases Society.
Their analysis included 829 kids who were positive for rotavirus and 8,858 who tested negative. They found that households of confirmed rotavirus patients were more likely to report acute gastrointestinal illness and one or more household contact than kids who tested negative for the virus, 35% and 20%, respectively.
Overall, 466 (16%) of the household contacts of rotavirus patients reported illness symptoms. Of that group, 107 (23%) sought medical care, of which 6 (6%) resulted in hospitalization. Household contacts who were younger than 5 were more likely to report illness than those in other age groups (odds ratio, 2.2 [P=.004]). Also, 144 households reported out-of-pocket expenses that ranged from $2 to $640 (median, $20).
Researchers note that traditional cost burden studies haven't adequately direct[O1] and indirect costs for the household. "Prevention of pediatric rotavirus illness, especially though vaccination, can prevent additional illnesses in HHCs [household contacts]," they wrote.
Feb 7 J Pediatric Infect Dis Soc abstract
Study: Flu vaccination cut hospitalization in Israeli children
Flu vaccination helped prevent hospitalization in fully vaccinated children in Israel, according to new findings based on three flu seasons. A team from Clalit Health Services in Israel and the University of Michigan reported their findings today in Clinical Infectious Diseases.
The team compared flu-positive cases and test-negative controls; 326 and 2,821, respectively, from 2015-16, 36 and 1,069 from 2016-17, and 150 and 781 from 2017-18.
Over the three seasons, vaccine effectiveness (VE) for fully vaccinated children was 53.9% children (95% confidence interval [CI], 38.6% to 68.3%), compared with a statistically not significant 25.6% for partially vaccine kids (95% CI, -3% to 47%). The researchers noted that VE varied depending on the makeup of the seasonal strains that circulated.
For example, for the 2015-16 season, most viruses were 2009 H1N1 and there was a mismatched influenza B lineage, and VE for fully vaccinated kids was statistically significant for influenza A, but not influenza B. For the 2016-17 season when H3N2 was predominant, VE was 70.8% (95% CI, 17.4% to 92.4%). And for the following season when H3N2, 2009 H1N1, and a mismatched B lineage circulated, VE was statistically significant for influenza B but not influenza A.
The authors concluded that flu immunization was effective in preventing hospitalization in fully vaccinated Israeli kids, but not among their partially vaccinated peers. Also, the team observed signs of cross-lineage protection in a season when the vaccine contained B/Victoria and the circulating lineage was B/Yamagata, but not in a season in which the opposite occurred.
Feb 11 Clin Infect Dis abstract
Prior dengue may prime women for severe Zika in pregnancy
A new animal model study published in Immunity suggests that pregnancies in hosts with a prior dengue infection may be more likely to result in severe outcomes from Zika virus illness.
The study was conducted by researchers at Mount Sinai, who transferred dengue virus-specific antibodies into mice before infecting the mice with Zika during pregnancy. Priming the mice with dengue led to increased placental damage, fetal growth, and fetal resorption.
"Our data demonstrate that antibodies generated from a previous dengue virus infection can enhance the severity of Zika virus infection during pregnancy," said Jean Lim, PhD, lead study author and associate professor of microbiology at the Icahn School of Medicine at Mount Sinai in a press release. "Our research may explain the high rate of microcephaly and birth defects observed in the recent Zika virus outbreak in South America."
Both dengue and Zika are flaviviruses, vector-borne diseases that tend to co-circulate in communities. Dengue is antibody-dependent–enhancing, meaning that prior infections with the virus heighten the response to future infections instead of protect against them.
Feb 8 Mount Sinai press release
Feb 8 Immunity study