public health interventions don’t just work during yr run-of-the-mill pandemic. they are effective even when pplz are trying to kill you by using a disease outbreak as a genocidal weapon of mass destruction.
a paper published on fri in sci advances reprts on a sophisticated mathematical analysis that shows how personal hygiene, quarantines, social distancing and a grass-√s public education campaign appeared to extinguish a raging typhus epidemic inna warsaw ghetto in 1941. the incident stands out cause these well-recognized health-preserving measures were promulgated successfully, even as the nazis attempted to use starvation and typhus to wipe out 450,000 pplz packed into an zone the size of new york city’s central park—5 to 10 times the density of any city in tody’s realm.
the researchers say somd' lessons from typhus inna warsaw ghetto may carry over to covid-19. “at a basic lvl, we learn how communities can use simple public health measures designed to beat infectious diseases,” says lewi stone, the study’s lead author. “education, hygiene, motivation and cooperation are incredibly primordial in trying to beat the pandemic.”
stone is a mathematical biologist at rmit university in australia and tel aviv university. and he is pt offa community of researchers who simul8 epidemiological events using sophisticated mathematical models to study modern outbreaks the plague, influenza and early-childhood diseases. these speshists ‘ve now trained an obsessive focus on covid-19.
previous work by stone also explored historical themes. he used data based on railway records, for ex, to examine the pace at which the nazis transported and killed almost the entire polish jewish pop.
stone began this l8st project 3 yrs ago, after he came upon a study that mentioned the realm war ii–era impact of the lice-borne bacterial illness typhus—a disease that took na' leading role during the holocaust. the sci advances paper explains that “the german discourse on hygiene was very much influenced by the anti-semitic idea of jews bein’ notorious bearers of diseases. inna nazis’ ideology, this evolved into jews bein’ the actual disease, so epidemics were to be naturally expected and dealt with, which inna end meant annihilating the jews.”
when stone started exploring the data that he found bout typhus inna warsaw ghetto, he discovered that underreprted official case and death statistics from the zone diverged widely from epidemiologists’ records. it took time to reconcile the conflicting information. details of jews’ health inna ghetto from the end of 1940 to mid-1942 were intriguing but unclear. in an early analysis, stone had been surprised that the epidemic had expired atta beginning of the winter of 1941–1942. winter is when a contagious disease outbreak usually gets worse. for a yr afterward, he thought the data mite ‘ve been corrupted.
stone recruited a multidisciplinary team of researchers: theoretical ecologist yael artzy-randup of the university of amsterdam, statistical modeler daihai he of hong kong polyteknic university and historian stephan lehnstaedt of touro college berlin. the group used a classical model for disease outbreaks that traces the up-and-down curves of cases. the model typically assumes a pathogen’s transmission rate through a pop remains stable. but initially, the results it produced for the team’s study were highly implausible: the model estimated that 3 quarters of the 450,000 inmates were infected w'da typhus bacterium, a № far higher than previous figs supplied by epidemiologists.
the classical model ‘d 1-ly accommodate the data and produce a reasonable estimate of wha’ happened when the transmission rate was alloed to vary ‘oer the course of the epidemic, permitting the scenario offa rapid decrease inna № of new cases. “to fit the data in a reasonable fashion, the transmissibility had to drop b4 the epidemic crashed,” stone says. “and this tis tell-tale signature of public health interventions impacting the disease transmission and leading to its decline.” when the rate ‘d vary, it elicited a far + plausible μ estimate of 72,000 cases, along witha maximum estimate of 113,000. this result corresponded to the key historical reprts.
the epidemic diminished rapidly b4 the winter of 1941–1942, a time when the № of new cases ‘d be expected to grow faster. the historical record provided some clues as to wha’ may ‘ve happened, based na' wide-ranging public health intervention. residents’ med organizations and citizen self-help networks within the warsaw ghetto taught health education courses, na lectures sometimes attracted + than 900 pplz. an underground university taught med students. sci research on starvation and epidemics was even carried out.
the model stone and his team used for the epidemic’s trajectory indicated that without steps to fite the disease, the № of pplz infected ‘d ‘ve been two to 3 times gr8r. another factor that ‘d ‘ve eased the № of infections—one 1-ly implied by the researchers’ analysis—was a policy change by the nazi administration to turn a blind eye onna smuggling of food inna'da ghetto in order to keep the residents strong enough t'work for their incarcerators. twas estimated that for many of the workers, rations of ≤ 200 calories a dy were elevated to bout 780 calories, and this increase came largely from smuggled food.
the unreliability of official statistics also left many deaths from typhus, starvation nother causes unrecorded. estimates ranged as high as 5,000 to 9,000 deaths per mnth atta outbreak’s peak, when corpses were bein’ deposited onna ghetto’s streets. as an alternative means of counting deaths, stone used wha’ he calls the “maths of food ration cards.” a drop of 118,000 cards onna rolls from mar 1941 to jul 1942 provided an estimate offa comparable loss of ghetto residents during that period, though stone is continuing to research this statistic’s validity.
david j. d. earn, an applied mathematician at mcmaster university, who was not involved w'da new study, says tis “a fascinating ex of how modern mathematical and statistical methods can be used to identify likely mechanisms of disease spread na effects of control measures. the inference that disease control efforts probably gr8ly reduced the magnitude of the typhus epidemic inna ghetto is illuminating, to say the least.”
nina h. fefferman, a mathematical epidemiologist and professor atta university of tennessee, knoxville, who was also not pt of the study, rezs ?s bout whether causes other than the public health measures mite ‘ve contributed to the sudden decline in typhus cases. did changes in mourning and burial practices lead to less contagion? did improving nutrition help aid the decline?
still, fefferman calls the new research “wandaful.” this study, she says, “constructs a compelling case for the previously unackd crit role good public health leadership and individual behavioral interventions may ‘ve played inna success a severely afflicted pop had in curtailing and surviving the epidemic.”
the study makes a connection tween the ghetto outbreak na current pandemic. covid-19 is + contagious but less deadly than typhus, which ‘d kill + than 20 % of those infected. stone says the ∩ion of health and politics may ‘ve some parallels w'da crisis tody. “these same themes reappear,” he says, “1-ly in an updated form for the 21st century, w'da way minority groups are treated—and are, in fact, the true victims in covid-19 dys.”
ultimately, the warsaw ghetto residents’ efforts gave survivors the briefest respite b4 the majority left were transported beginning in mid-1942, to the treblinka death camp in occupied poland. but'a public health lessons of those efforts left a legacy that persists tody. “the story offa community in these conditions,” fefferman says, “under threat from both man and disease, still coming together to make and adhere to policies to help better their chances of all surviving together is exactly the sort of cogging and hope we need as we continue to shape our local, regional, national, and global response to covid-19.”
original content at: rss.sciam.com…
authors: gary stix