Continuous treatment with newer agent protects infants against malaria
Long-term treatment with a newer artemisinin-based combination drug for malaria, dihydroartemisinin-piperaquine (DP), substantially and safely reduces the risk of malaria in young children, according to a study funded by the National Institutes of Health (NIH) and published online yesterday in PLoS Medicine.
Children under 3 years of age are at greater risk from malaria than other age-groups in that the disease is more likely to affect the brain and more likely to cause brain damage or be fatal, notes an NIH news release.
The researchers randomly assigned 393 young children from Tororo, Uganda, to one of four groups: DP once monthly, sulfadoxine-pyrethamine (SP) once monthly, trimethoprim-sulfamethoxozole (TS) once daily, or no treatment. Treatment began at 6 months of age and continued through 24 months of age, and the children were followed for an additional year.
Malaria episodes per person-year were 3.02 for the DP group, 5.21 for the TS group, 6.73 for the SP group, and 6.95 for the controls, translating to a protective efficacy (PE) of 58% for DP (95% confidence interval [CI], 45%-67%) and 28% for TS (95% CI, 1%-44%), compared with no treatment. The PE for SP was not statistically significant.
There were no differences between groups in rates of anemia or other adverse events. In addition, there were no differences in malaria rates between groups in the follow-up period, which was notable in that past studies have raised concern that early treatment might interfere with naturally acquired immunity, rendering children more susceptible to malaria after stopping prophylaxis.
SP and TS have been in use longer than DP, and resistance to them has developed in some areas with high malaria transmission, note the authors.
Aug 5 PLoS Med study
Aug 5 NIH news release
Study traces long-term decline in US pneumococcal meningitis
The US incidence of pneumococcal meningitis cases and deaths fell significantly between 1997 and 2010, with much of the drop following the introduction of conjugate vaccines in the early 2000s and the recommendation for use of adjunctive dexamethasone in 2005, according to a new report in The Lancet Infectious Diseases.
Using the HealthCare Cost Utilization Project (HCUP) network database, researchers from the University of Texas Health Science Center in Houston gathered hospital-discharge data on incidence and inpatient mortality for the most important causes of community and nosocomial bacterial meningitis between 1997 and 2010.
They defined three periods for assessing mortality: 1997-2001, baseline; 2002-04, transition years; and 2005-08, after dexamethasone recommendations were available.
Overall, the team found that the incidence of Streptococcus penumoniae infections dropped from 0.8 per 100,000 people in 1997 to 0.3 per 100,000 in 2010 (risk ratio, 0.3737; 95% confidence interval [CI], 0.1825-0.76560.1825-0.7656).
In the 2002-04 period, mortality due to pneumococcal meningitis dropped from 0.73 to 0.63 per 100,000. Between 2005 and 2008, mortality declined from 0.49 to 0.24 per 100,000.
The authors also found that the incidence of Neisseria meningitidis infection decreased from 0.721 per 100,000 in 1997 to 0.123 per 100,000 in 2010 (risk ratio, 0.1386; 95% CI, 0.048-0.4284), which places this pathogen "close to common bacterial causes of nosocomial meningitis such as staphylococcus and Gram-negative bacteria and to Haemophilus influenzae."
The researchers conclude that S pneumoniae "continues to be the leading identifiable cause of bacterial meningitis in the USA, but with a significant decrease in incidence and mortality associated with the introduction of conjugated vaccines and a mortality decrease that is associated with the introduction of recommendations for use of adjunctive dexamethasone for pneumococcal meningitis."
Aug 5 Lancet Infect Dis study
Related Aug 5 Lancet Infect Dis editorial (introduction)
