Yes, homeopaths are incredibly fond of the notion that homeopathy has been proven to work in numerous population studies of outbreaks of infectious diseases. The argument is bound to come up in any discussion with a ‘well-informed’ homeopathy fan. Therefore, it might be worth addressing it once and for all.
This website offers a fairly good summary of what homeopaths consider to be convincing evidence. It also provides links to the original articles which is valuable for all who want to study them in full detail. I will therefore present the crucial passage here unchanged.
START OF QUOTE
By the end of year 2014, there have been 19 papers published on Epidemiological studies on 7 epidemic diseases (scarlet fever, typhus fever, Cholera, Dengue, meningococcal, influenza and Leptospirosis) in 11 peer-reviewed (beyond year 1893) journals in evidence of Homeopathy including 2 Randomised Controlled Trials.
1. Samuel Hahnemann, “The Cure and prevention of scarlet fever”, Zeitschrift für Praktischen Medizin (Journal of Practical Medicine), 1801, Republished in Lesser Writings. B.Jain Publishing, New Delhi
Preventive use of homeopathy was first applied in 1799 during an epidemic of scarlet fever in Königslütter, Germany, when Dr. Hahnemann prescribed a single dose of Belladonna, as the remedy of the genus epidemicus to susceptible children in the town with more than 95% success rate. In this paper, he also specified how the Belladonna has to be potentised to 1/24,000,000 dilution. His recommended dose of Belladonna was 0.0416 nanograms to be repeated every 72 hrs. This is the first recorded nano dose of medicine used in treatment of any disease . It was another 125 years before Gladys Henry and George Frederick developed a vaccine for scarlet fever in 1924.
2. Samuel Hahnemann, “Scarlet fever and Purpura miliaris, two different diseases”, Zeitschrift für Praktischen Medizin, vol. 24, part. 1, 1806
3. Samuel Hahnemann, “Observations on scarlet fever”, Allgemeine Reichanzeiger (General Reich Gazette), No. 160, Germany, 1808
4. Samuel Hahnemann, “Reply to a question about the prophylactic for scarlet fever”, Zeitschrift für Praktischen Medizin, vol. 27, part. 4, p. 152-156, 1808
5. Samuel Hahnemann, “Treatment of typhus & fever at present prevailing”, Allgemeine Reichanzeiger, No. 6, Jan. 1814.
6. Hufeland, Prophylactic powers of Belladonna against Scarlet Fever , The Lancet, 1829
The proper use of belladonna has, in most cases, prevented infection. Numerous observations have shown that, by the general use of belladonna, epidemics of scarlet fever have actually been arrested. In those few instances where the use of belladonna was insufficient to prevent infection, the disease has been invariably slight. The Prussian (German Empire) Government ordered the use of the prophylactic during all scarlet fever epidemics
7. Samuel Hahnemann, “Cure and prevention of Asiatic cholera”, Archiv für die homöopathische Heilkunst (Archives for the Homoeopathic Healing Art), Vol. 11, part 1, 1831.
Cuprum 30c once every week as preventive medicine
8. Samuel Hahnemann, “On the contagiousness of cholera”. British Homoeopathic Journal, Vol. 7, 1849
9. Samuel Hahnemann, “Appeal to Thinking Philanthropists Respecting the Mode of Propagation of the Asiatic Cholera”, 20 pages, 1831. Republished in British Homoeopathic Journal, Oct 1849.
He said, “On board ships – in those confined spaces, filled with mouldy watery vapours, the cholera-miasm finds a favourable element for its multiplication, and grows into an enormously increased brood of those excessively minute, invisible, living creatures, so inimical to human life, of which the contagious matter of the cholera most probably consists millions of those miasmatic animated beings, which, at first developed on the broad marshy banks or the tepid Ganges– on board these ships, I say, this concentrated aggravated miasm kills several of the crew …” .
It was another 59 years (1890) before Koch saw these organisms, and later on orthodox medicine gave them the name ‘germs’
10. Charles Woodhull Eaton, The Facts about Variolinum, Transactions of the American Institute of Homoeopathy, 1907
2806 patients were treated prophylactically with Variolinum 30 (a nosode) for prevention of smallpox in Iowa. Of the 547 patients definitely exposed, only 14 developed the disease. Efficacy rate of 97.5%
11. Taylor Smith A, Poliomyelitis and prophylaxis British Homoeopathic Journal, 1950
In 1950 during an epidemic of poliomyelitis, Dr Taylor Smith of Johannesburg, South Africa protected 82 people with homoeopathic Lathyrus sativus. Of the 82 so immunised, 12 came into direct contact with disease. None were infected.
12. Oscillococcinum 200c in the treatment of influenza during epidemic in France from 1984-1987, British Journal of Clinical Pharmacology (1989)
A DBRPCT, Oscillococcinum 200c taken twice daily for 5 days significantly increased the rate of cure within two days (n=487, 237 treated and 241 on placebo), absence of symptoms at 48 hours, relative risk estimate significantly favour homeopathy (p=0.048), no pain and no fever (p=0.048), recovery rate (headache, stiffness, articular pain, shivering reduction) at 48 hours better in homeopathy group (p=0.032)
13. Bernard Leary, Cholera 1854 Update, British Homoeopathic Journal, 1994
Sir William Wilde, the well-known allopathic doctor of Dublin, which in his work entitled “Austria and its Institutions”, wrote: “Upon comparing the report of the treatment of Cholera in the Homeopathic hospital testified to by two allopathic medical inspectors appointed by Government with that of the treatment of the same disease in the other hospitals of Vienna during the same period the epidemic of 1836, it appeared that while two-thirds of the cases treated by Dr. Fleischmann the physician of the Homeopathic hospital, recovered, two-thirds of those treated by the ordinary methods in the other hospitals died.”
14. Meningococcinum – its protective effect against meningococcal disease, Homeopathy Links, 2001 (2001)
A total of 65,826 people between the ages of 0–20 were immunised homeopathically to protect against meningococcal disease while 23,532 were not. Over a year period, 4 out of 65,826 protected homeopathically developed meningococcal infection. 20 out of 23,532 not protected developed meningococcal infection. Based on the infection rate in the unprotected group, 58 cases of infection could have been expected in the homeopathically protected group. Instead, there were only four cases of meningococcal infection. Statistical analysis showed that homeopathic immunisation offered 95% protection in the first six months and 91% protection over the year against meningococcal disease. 
15. Contribution of homeopathy to the control of an outbreak of dengue epidemic in Macaé, Rio de Janeiro, Brazil in 2007-8 , International Journal of High Dilution Research, 2008
In a campaign ‘Homeopathy campaign against dengue’ by Brazilian Govt, “156,000 doses of homeopathic remedy were freely distributed in April and May 2007 to asymptomatic patients and 129 doses to symptomatic patients treated in outpatient clinics, according to the notion of genus epidemicus . The remedy used was a homeopathic complex against dengue containing Phosphorus 30c, Crotalus horridus 30c and Eupatorium perfoliatum 30c. The incidence of the disease in the first three months of 2008 fell 93% by comparison to the corresponding period in 2007, whereas in the rest of the State of Rio de Janeiro there was an increase of 128%.”
16. Marino R. Eupatorium perfoliatum 30c for the Dengue Epidemics in Brazil in 2007. International Journal of High Dilution Research, 2008
In May 2001, prophylactic use of Eupatorium perfoliatum 30c single dose was given during a dengue outbreak to 40% of residents in the most highly affected neighbourhood which resulted in significant decrease in dengue incidence by 81.5% (p<0.0001) when compared with those neighbourhoods that did not receive homeopathic prophylaxis.
17. Bracho et. al. Application of 200C potency of bacteria for Leptospirosis epidemic control in Cuba 2007-8 (2010)
Conducted by the Finlay Institute, a vaccines producer in Cuba gave 2.308562 million (70% of the target population above the age of 1 year) people in Cuba given two doses (1 dose=5 drops) of 200C potency of a nosode prepared from Leptospirosis bacteria, each (7-9 days apart), for protection against Leptospirosis (fever+jaundice+ inflammation in kidney+enlargement of spleen) with 84% decrease in disease incidence and only 10 reported cases. Dramatic decrease in morbidity within two weeks and zero morbidity of hospitalised patients, non-treated (8.8 millions) area saw an increase in number of cases from 309 cases in 2007 to 376 in 2008 representing a 21% increase. The cost of homeopathic immunization =1/15th of conventional vaccine.
18. Effect of individualized homoeopathic treatment in influenza like illness, Indian Journal of Research in Homeopathy (2013)
A multicenter, single blind, randomized, placebo controlled study to evaluate the effect of homoeopathic medicines in the treatment of Influenza like illness and to compare the efficacy of LM (50 millisimal) potency vis-à-vis centesimal (C) potency. In LM group (n=152), C group (n=147) or placebo (n=148) group. The study revealed the significant effect of individualized homoeopathic treatment in the patients suffering from ILI with no marked difference between LM and Centesimal groups. The medicines which were commonly prescribed were: Arsenic album, Bryonia alba, Rhus tox., Belladonna, Nux vomica, Sepia, Phosphorus, Gelsemium, Sulphur, Natrum mur. and Aconitum napellus. 
19. Reevaluation of the Effectiveness of Homoeoprophylaxis Against Leptospirosis in Cuba in 2007-8, Journal of Evidence-based Complementary & Alternative Medicine (2014)
The results support the previous conclusions that homoeoprophylaxis can be used to effectively immunize people against targeted infectious diseases such as leptospirosis.
 Iman Navab, Lives saved by Homeopathy in Epidemics and Pandemics, https://drnancymalik.wordpress.com/2013/01/23/epidemics-and-pandemics/
 Reshu Agarwal, Natural History of Disease and Homeopathy at different levels of Intervention, http://www.homeorizon.com/homeopathic-articles/homeopathic-philosophy/disease-history
 Homoeopathy- Science of Gentle Healing, Deptt. of AYUSH, Ministry of Health & Family Welfare, Govt, of India, 2013, http://www.ccrhindia.org/Dossier/content/page22.html
 Conversation with David Little, http://hpathy.com/homeopathy-papers/conversations-with-david-little/
 Nancy Malik, Principles of Homeopathy Explained, 2015, https://drnancymalik.wordpress.com/article/homeopathy-explained/
 Nancy Malik, Recent Advances in Nanoparticle Research in Homeopathy, Homeopathy 4 Everyone, Vol.12, Issue 6, 18 June 2015, http://hpathy.com/scientific-research/recent-advances-in-nanoparticle-research-in-homeopathy/
 Samuel Hahnemann, “Appeal to Thinking Philanthropists Respecting the Mode of Propagation of the Asiatic Cholera”, 20 pages, 1831, Translated by R E Dudgeon, M.D. in The Lesser Writings of Samuel Hahnemann, 1851, B Jain Publishers, reproduced edition, 2002, p. 758
 Fran Sheffield, Homeoprophylaxis: Human Records, Studies and Trials, 2014, http://homeopathyplus.com/Homeoprophylaxis-Human-Records-Studies-Trials.pdf
 Homoeopathy in Flu-like Illness- Factsheet, Central Council for Research in Homoeopathy, Deptt. of AYUSH, Ministry of Health & Family Welfare, Govt, of India, 2015, http://ccrhindia.org/pdf/swineflu.pdf
END OF QUOTE
Whenever I read articles of this nature, I get a little embarrassed. It seems obvious to me that the authors of such reviews have done some ‘research’ and believe strongly in the correctness in what they write. It embarrasses me to see how such people, full of good will, can be so naïve, ignorant and wrong. They clearly fail to understand several crucial issues. To me. this seems like someone such as me lecturing others about car mechanics, quantum physics or kite flying. I have no idea about these subjects, and therefore it would be idiotic to lecture others about them. But homeopaths tend to be different! And this is when my embarrassment quickly turns into anger: articles like the above spread nonsense and misguide people about important issues. THEY ARE DANGEROUS! There is little room for embarrassment and plenty of room for criticism. So, let’s criticise the notions advanced above.
In my recent book, I briefly touched upon epidemics in relation to homeopathy:
Epidemics are outbreaks of disease occurring at the same time in one geographical area and affecting large number of people. In homeopathy, epidemics are important because, in its early days, they seemed to provide evidence for the notion that homeopathy is effective. The results of homeopathic treatment seemed often better than those obtained by conventional means. Today we know that this was not necessarily due to the effects of homeopathy per se, but might have been a false impression caused by bias and confounding.
This tells us the main reason why the much-treasured epidemiological evidence of homeopaths is far from compelling. The review above does not mention these caveats at all. But it is lousy also for a whole host of other reasons, for instance:
- The text contains several errors (which I find too petty to correct here).
- The list of studies is the result of cherry-picking the evidence.
- It confuses what epidemiological studies are; RCTs are certainly not epidemiological studies, for instance.
- It also omits some of the most important epidemiological studies suggesting homeopathy works.
- It cites texts that are clearly not epidemiological studies.
- Several studies are on prevention of illness rather than on treatment.
- Some studies do not even employ homeopathy at all.
In the typical epidemiological case/control study, one large group of patients [A] is retrospectively compared to another group [B]. By large, I mean with a sample size of thousands of patients. In our case, group A has been treated homeopathically, while group B received the treatments available at the time. It is true that several of such reports seemed to suggest that homeopathy works. But this does by no means prove anything; the result might have been due to a range of circumstances, for instance:
- group A might have been less ill than group B,
- group A might have been richer and therefore better nourished,
- group A might have benefitted from better hygiene in the homeopathic hospital,
- group A might have received better care, e. g. hydration,
- group B might have received treatments that made the situation not better but worse.
Because these are RETROSPECTIVE studies, there is no way to account for these and many other factors that might have influenced the outcome. This means that epidemiological studies of this nature can generate interesting results which, in turn, need testing in properly controlled studies where these confounding factors are adequately controlled for. Without such tests, they are next to worthless for recommendations regarding clinical practice.
As it happens, the above author also included two RCT in the review (these are NOT epidemiological studies, as I already mentioned). Let’s have a quick look at them.
The first RCT is flawed for a range of reasons and has been criticised many times before. Even its authors state that “the result cannot be explained given our present state of knowledge, but it calls for further rigorously designed clinical studies.” More importantly, the current Cochrane review of Oscillococcinum, the remedy used in this study, concluded: “There is insufficient good evidence to enable robust conclusions to be made about Oscillococcinum® in the prevention or treatment of influenza and influenza-like illness.”
The second RCT is equally flawed; for instance, its results could be due to the concomitant use of paracetamol, and it seems as though the study was not double blind. The findings of this RCT have so far not been confirmed by an independent replication.
What puzzles me most with these regularly voiced notions about the ‘epidemiological evidence’ for homeopathy is not the deplorable ineptitude of those who promote them, but it is this: do homeopaths really believe that conventional medics and scientists would ignore such evidence, if it were sound or even just encouraging? This assumes that all healthcare professionals (except homeopaths) are corrupt and cynical enough not to follow up leads with the potential to change medicine for ever. It assumes that we would supress knowledge that could save the lives of millions for the sole reason that we are against homeopathy or bribed by ‘BIG PHARMA’.
Surely, this shows more clearly than anything else how deluded homeopaths really are!!!