TB in US kids continues decline, but some groups carry big burdens

A 10-year analysis of US tuberculosis (TB) data shows that, for children and adolescents, incidence is low and steadily dropping, but rates are disproportionately high in some groups. Researchers from the Centers for Disease Control and Prevention (CDC) reported their findings yesterday in The Lancet Public Health.

The data they used were TB cases in children younger than 15 and adolescents ages 15 to 17 reported to the National Tuberculosis Surveillance System from 2007 to 2017. The incidence rate was low, at 1.0 per 100,000 person years during that period, with the rate declining 47.8%.

Levels were disproportionately high, however, in children and adolescents of all nonwhite ethnic and racial groups, in those living on US-affiliated islands, and those born in or with parents from TB-endemic countries. Of kids born outside the United States, TB levels varied by country, with the incidence highest in those from the Marshall Islands, Somalia, Myanmar, Malaysia, and Ethiopia.

TB incidence in kids also varied based on parents' birth country, and, of those with TB, 21% had at least one parent born outside the United States. Mortality was disproportionately high in young people with TB on US-affiliated islands compared with their peers on the mainland.

"Our findings suggest that tuberculosis care and prevention strategies in the USA are succeeding in reducing overall tuberculosis burden among children and adolescents, but that more attention and possibly new approaches are needed to address the disparities in tuberculosis incidence and mortality in these age groups," the team wrote.

In a commentary in the same issue, two experts from the Southeastern National TB Center at the University of Florida wrote that the report is generally good news and encouraging for those working on TB elimination. They said, however, that an outsized impact on some groups overshadow the findings. For example, they note that in the Marshall Islands and Micronesia, TB rates in kids exceed 150 per 100,000 person-years, accounting for 11% of all TB cases and 50% of deaths among kids with TB in the United States.

Still, the findings support the effectiveness of TB control efforts, though more work is needed to address the disparities, they wrote.
Aug 21 Lancet Public Health abstract
Aug 21 Lancet Public Health commentary

CDC: Teen uptake of HPV, meningitis vaccines rising

According to a study today in Morbidity and Mortality Weekly Reports (MMWR), adolescent rates of vaccination in 2018 continued to improve for meningococcal and human papillomavirus (HPV) vaccines, but the improvement was mostly seen in boys.

The data come from CDC researchers and the National Immunization Survey-Teen (NIS-Teen), a phone-based interview that estimates uptake and attitudes surrounding vaccine use among children 13 to 17 years old.

From 2017 to 2018, coverage with more than one dose of HPV vaccine increased from 65.5% to 68.1%, and the percentage of adolescents who were up to date with the HPV vaccine series increased from 48.6% to 51.1%, the study authors said. But the increases were observed almost exclusively among teenage boys (an increase of 4.4 percentage points in boys and 0.6 in girls).

"HPV vaccination coverage was higher among adolescents whose parent reported receiving a provider recommendation," the authors wrote. "However, even when a provider recommendation was given, only 75% accepted the vaccine, suggesting that there are other reasons adolescents are not being vaccinated."

Increases were also seen for one dose of quadrivalent meningococcal conjugate vaccine (MenACWY), from 85.1% to 86.6%, and in booster doses of MenACWY—from 44.3% to 50.8%. Coverage with tetanus and reduced diphtheria toxoids and acellular pertussis vaccine (Tdap) remained stable, at 89%.
Aug 23 MMWR report

Study details unreported 2017 Zika outbreak in Cuba

A study published today in Cell shows that Cuba experienced a previously unreported Zika outbreak in 2017, a full year after virus transmission peaked in neighboring countries.

When the Zika virus epidemic first became apparent in Brazil in 2015, scientists estimated it had already been circulating for up to 18 months, because so many Zika cases result in subclinical infections, and the symptoms of the disease can mimic dengue and chikungunya.

The study authors used a combination of travel surveillance, local case reporting, and clinical sequencing of Zika virus from infected travelers to detect the virus, and discovered a Cuban outbreak that was not reported to the Pan American Health Organization and occurred as the epidemic was waning in all other Latin American countries.

The authors used models to estimate the size of the outbreak. 

"Taking the population size of Cuba into account, we estimated that 5,707 Zika cases (interquartile range: 1,071 to 22,611) likely went unreported in this country, with the majority of these cases (>99%) having occurred in 2017," they wrote. That case count makes Cuba's 2017 outbreak comparable to those in Haiti, Jamaica, and the Dominican Republic in 2016.

The authors said genetic sequencing suggests the virus was brought to Cuba by infected travelers, and then established in local Aedes aegypti mosquito populations.
Aug 22 Cell study