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We read with interest the report by Makwana and Riordan on community needlestick injuries in children.1 We do not believe, however, that the authors have presented sufficient data to support their conclusion that routine follow up after community needlestick injury is unnecessary.
In their study only 25 children had complete serological follow up. Their literature review cites three additional papers in which children were followed up after needlestick injury. Adding all of these children gives a total of 138 children who had serological testing following needlestick injury. This is an insufficient number to allow one to conclude with confidence that the risk of transmission is low.
If all of these needles contained HIV positive blood, applying the rule of threes2 to the pooled data, we can say with 95% confidence that the risk of HIV transmission following community needlestick injury in children is less than 2%. The transmission rate in healthcare workers following HIV positive needlestick injury is around 0.35%. Their study, therefore, does not provide sufficient evidence to state that these children are at a lower risk of acquiring HIV following needlestick injury than healthcare workers in similar circumstances. Until such evidence becomes available, there seems to be no good reason to treat these children differently to healthcare workers following needlestick injury.
We were interested to read this letter. The authors feel that children with community needlestick injuries should be treated the same as healthcare workers. This seems to miss the point of our paper. Hospital needlestick injuries are very different to out-of-hospital needlestick injuries: the blood is generally dry, so therefore less likely to be infectious;1 the injuries are often superficial—again less likely to be infectious;1 and, although the HIV status of the needlestick user is often unknown, the incidence outside of London is very low.
The risk of HIV transmission is estimated to be less than 1:100 000.2 Our study was not designed to show the risk of transmission (which incidentally would need a study of more than 100 000 patients), but showed that only half those offered follow up returned for their appointment. Studies examining needlestick exposure and HIV seroconversion have shown that no children seroconverted despite not receiving HIV post-exposure prophylaxis.3–5 Within this population of children were included those who sustained injuries from areas with a high prevalence of injecting drug use. Zamora and colleagues6 evaluated HIV-1 proviral DNA from 28 discarded syringes of intravenous drug users and found no traces of the virus, concluding that the risk of HIV transmission in that setting was zero.
These children are therefore in a low risk group for transmission of infectious viruses, and together with the low rate of attendance for follow up, it is still reasonable, we feel, to offer follow up to those children who have high risk injuries or in whom parents have a high level of anxiety.