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Provocation of poliomyelitis by multiple injections
Insights
Multiple childhood injections, particularly in the tropics, may provoke paralytic poliomyelitis. This study links historical epidemics to injections, suggesting a significant causal role for multiple inoculations in polio cases.
Area of Science:
- Epidemiology
- Infectious Diseases
- Public Health
Background:
- Injections, including vaccines, have been linked to provoking paralytic poliomyelitis in children.
- The impact of multiple injections on polio risk, especially in tropical regions with high inoculation rates, has been underrecognized.
- Historical epidemics of poliomyelitis (1914-1962) in children treated for congenital syphilis or yaws with arsenicals or penicillin suggest a potential link.
Purpose of the Study:
- To investigate the potential causal relationship between injections and paralytic poliomyelitis.
- To highlight the previously unrecognized risk associated with multiple injections in polio provocation.
- To examine historical polio epidemics for evidence of injection-provoked cases, particularly in tropical contexts.
Main Methods:
- Review of historical poliomyelitis epidemics (1914-1962).
- Analysis of case data linking polio paralysis to prior treatments involving injections (arsenicals, penicillin).
- Epidemiological assessment of paralysis rates in relation to injection frequency and historical disease outbreaks.
Main Results:
- Injections were observed to provoke paralytic poliomyelitis in children.
- During epidemics, paralysis rates reached up to 25% in affected children.
- In non-epidemic periods, susceptibility to polio paralysis increased approximately 25-fold following injections.
- A strong correlation was found between multiple injections and high rates of polio paralysis, particularly in tropical settings.
Conclusions:
- Multiple injections represent a significant, previously unrecognized factor in provoking paralytic poliomyelitis.
- The high incidence of paralysis following multiple injections provides strong evidence for a causal link, especially in tropical regions.
- While difficult to definitively prove causality in all tropical cases due to potential coincidence, the evidence strongly suggests injections are often causal.
Abstract:
Injections of vaccines provoked paralytic poliomyelitis in children in the UK and elsewhere. The effect of multiple injections has not been recognized previously but could be important in the tropics where children receive many injections. A number of epidemics of poliomyelitis between 1914 and 1962 are related to children with congenital syphilis or yaws under treatment with arsenicals or penicillin. Rates of 25% of children with paralysis occurred in epidemics while in non-epidemic periods the increase in susceptibility was about 25 fold. Other possible cases of provocation are discussed. Although in the tropics injections before paralysis may be causal, it will be difficult to prove that they are not coincident. The very high rate of paralysis following multiple injections is powerful evidence that injections in the tropics are often causal.