Zinc therapy decreases childhood pneumonia deaths
MedWire News: Treatment with zinc supplements significantly decreases mortality among children with severe pneumonia, study findings indicate.
Furthermore, the protective effect of zinc therapy was greater in children with HIV than in those without.
James Tumwine (Makerere University, Kampala, Uganda) and colleagues explain that pneumonia is a leading cause of childhood mortality in developing countries.
In the present study, they examined the impact of zinc therapy - which is known to boost immune response - on time to normalization of respiratory rate, temperature, and oxygen saturation in 352 children, aged 6-59 months, with severe pneumonia.
A normal respiratory rate was defined as being consistently (for more than 24 hours) below 50 breaths per minute in infants and 40 breaths per minute in children above 12 months of age. Temperature was normal if consistently below 37.5°C and oxygen saturation was normal if it was above 92% (breathing room air) for more than 15 minutes.
The team also investigated whether zinc adjunct therapy had any effect on case fatality.
The children were randomized to receive zinc (10 mg for children <12 months; 20 mg for those ≤12 months) or placebo once daily for 7 days, in addition to standard antibiotics for severe pneumonia.
At baseline, serum zinc concentration was 4.4 µmol/L in the children assigned to zinc therapy and 4.8 µmol/L in those assigned to placebo. These levels are "lower than those previously reported in Ugandan children," the researchers note.
They observed that there was no significant difference between the zinc and placebo groups in time to normalization of the respiratory rate (96 vs 86 hours), temperature (18 vs 18 hours), and oxygen saturation (24 vs 18 hours).
However, the children who received placebo were nearly three times more likely to die than those who received zinc supplementation, with respective mortality rates of 11.9% and 4.0%. This is equivalent to a 67% reduction in the relative risk for mortality among the children who received zinc, report Tumwine et al in BMC Medicine.
Subgroup analysis showed that the protective effect of zinc therapy was greater among HIV-infected children than among those without HIV. Indeed, none of the 28 children with HIV who received zinc died, compared with seven (25.9%) of 27 who received placebo.
Overall, HIV-positive children were 2.6 times more likely to die than HIV-negative children, but this increased risk was mostly attributable to the subgroup of HIV-positive children who received placebo. The relative risk (RR) for death in these children was 4.7 times higher than that in HIV-negative children who received placebo, whereas there was no difference in mortality between HIV-positive and HIV-negative children who received zinc (RR=0.9).
"Given these results, zinc could be considered for use as adjunct therapy for severe pneumonia, especially among HAART [highly-active antiretroviral therapy]-naive HIV-infected children in our environment," Tumwine and co-authors conclude.
Tumwine added in a press statement: "Zinc is known to bolster the immune system and zinc deficiency is rife all over the developed, and developing, world. In Uganda, where this study was performed, zinc deficiency in some areas can be as high as 70%. We would only need to give 13 of these children with pneumonia zinc on top of their antibiotics to save one life. This equates to about 4 US dollars - a small price to pay."
By Laura Cowen