Leptospirosis is a potentially fatal infectious disease caused by contact with contaminated water. In a 2007 outbreak in Cuba, homeopathic medicines were provided to 2.3 million people at high risk, leaving the remaining 8.8 million untreated. In the study by Bracho et al., the largest study ever to evaluate a homeopathic medicine, homeopathic treatment « was strongly associated with a substantial reduction in disease incidence, thereby fully controlling the outbreak. »

Significant Effects of Homeopathic Prophylaxis (HP ) Interventions

After a three-week homeopathic prophylaxis (HP) intervention, the number of confirmed cases decreased significantly, from 38 cases per week (per 100,000 people) before the intervention to 4.4 cases per week (per 100,000 people) after the intervention. This decrease coincides with 70% of the target population receiving treatment for HP.

The total number of infections in treatment areas fell from 401 cases in 2007 to 64 cases in 2008 – an 84% decrease in incidence – while the number of infections in non-treatment areas increased from 309 cases in 2007 to 376 cases in 2008 – an increase of 21%.

Homeopathic prophylaxis was administered to 92% of the 2.3 million people at high risk, in addition to 15,000 routine vaccinations which reached 0.6% of those at high risk. Because leptospirosis incidence is typically highest during periods of high rainfall, infection rates were analysed in relation to rainfall. Although rainfall generally decreased in 2008, infection rates increased in untreated areas, while infection rates decreased significantly in treated areas.

Homeopathic immunotherapy (HP) deserves further study

While these results are very encouraging, it must be emphasised that this study was not a clinical trial – there was no placebo control and there were a number of confounding factors, such as the concurrent use of conventional vaccines in 0.6% of the treatment area. It is also possible that implementing a large-scale intervention will itself increased people’s awareness of taking action against the epidemic, e.g. using non-medical preventive measures.

That said, the authors included as many controls as possible in the context of such a large-scale and emergency intervention, e.g. comparison with untreated areas, mathematical modelling of incidence and comparison with rainfall). This study establishes a strong case that homeopathy has the potential to be a viable tool for epidemic control and deserves further study.