As US flu cases continue to slow, influenza B picks up
The rate of outpatient visits for influenza-like illnesses (ILI) dropped again this week to 2.5%, down from 2.7% in the previous week, and influenza B continues to cause an increasing percentage of flu cases, according to the latest influenza surveillance data reported today by the Centers for Disease Control and Prevention (CDC).
This is the 18th week ILI has been at or above the national baseline, which is 2.2%.
Only 4 states reported high ILI activity, while 16 states and Puerto Rico reported widespread flu activity, a clear sign that these are the last weeks of a severe flu season. Last week 6 states had high ILI activity, and 17 reported widespread flu.
The CDC confirmed 4 additional pediatric deaths, bringing the season's total to 137.
Overall hospitalization rates were 96.1 per 100,000 persons—up from 93.5 last week—with adults over the age of 65 representing the highest proportion of hospitalizations, at 412.6 per 100,000 population, followed by adults aged 50 to 64 (104.2 per 100,000 population) and children aged 0 to 4 years (68.7 per 100,000 population). A strong majority of hospitalizations (76.6%) were associated with influenza A virus.
Influenza B was the most commonly detected strain among all cases last week, seen in 57.8% of clinical lab specimens and 64.4% of public health lab specimens sent to the CDC. Influenza B tends to be the dominant strain at the end of a flu season.
Mar 30 CDC FluView
Study offers reassurance for newer drugs against repeat malaria
A 2-year study of two newer artemisinin combination therapies (ACTs) in three African nations that carry a high malaria disease burden found that, when compared with current first-line ACTs, the drugs are highly effective and tolerable for repeated treatment. Researchers published their findings yesterday in The Lancet.
The two newer ACTs are pyronaridine-artesunate and dihydroartemisinin-piperaquine. Diverse treatment options are needed in the battle against the disease and to address worries about resistance, but the introduction of the new ACTs to sub-Saharan Africa, where the global malaria problem is the worst, has been slow.
Also, experts have raised questions about possibility of hepatoxicity of pyronaridine-artesunate and cardiotoxicity of dihydroartemisinin-piperaquine. For both drugs, data are lacking on their use in people who have repeated malaria infections, a common problem in African nations.
The phase 3b/4 study took place in Burkina Faso, Guinea, and Mali, enrolling 4,710 patients age 6 months and older who had uncomplicated malaria infections. Patients were randomized to four treatment groups, two that received one of the newer ACTs and two that received one of the current frontline ACTs: artesunate-amodiaquine or artemether-lumefantrine. Researchers focused on incidence rates of all microscopically confirmed malaria cases and the safety of the drugs. Malaria incidence was high in the study area, and most patients had at least two malaria infections during the study.
All treatment regimens were highly effective and well tolerated in repeated treatment over 2 years. Pyronaridine-artesunate caused mild transient increases in liver transaminases, but there was no increased risk of liver injury. The incidence of QT prolongation (a heart rhythm condition) was higher after dihydroartemisinin-piperaquine treatment, but no clinical symptoms were seen.
The researchers concluded that the findings support the push for diversified ACT options in Africa, especially given the fragile current situation of only one available ACT in many countries.
In a related editorial in the same Lancet issue, two experts who are members of the World Health Organization (WHO) malaria treatment guidelines group said the study's safety and efficacy findings are reassuring. They added that the results are consistent with the opinions of a WHO expert group that looked at the cardiotoxicity of antimalarial drugs. The new study supports scaling up the use of the two newer ACTs in sub-Saharan Africa "so that they can contribute even more effectively to the global fight against malaria," they wrote.
Mar 29 Lancet abstract
Mar 29 Lancet commentary
Another polio case recorded in Afghanistan
Afghanistan confirmed the detection of a new case of wild poliovirus type 1 (WPV1), according to the latest update from the Global Polio Eradication Initiative (GPEI) today. This is the sixth case detected in Afghanistan this year.
GPEI said the case, detected in Kandahar province, involved an onset of paralysis on Feb 25. On Apr 9, Afghanistan will begin its next round of supplementary immunization with bivalent oral polio vaccine in 24 provinces. According to GPEI, the campaign is synchronized with a campaign in Pakistan, in an effort to interrupt transmission of the virus across the shared border.
In 2017, the GPEI noted 14 WPV1 cases in Afghanistan and 8 in Pakistan.
Mar 30 GPEI report