Human Louse and Disease

Brill-Zinsser disease is a form of recrudescent epidemic typhus that occurs years or decades after primary typhus infection [1–4]. However, in the United States, improved sanitation and hygiene measures have largely eliminated the human body louse vector and epidemic typhus as public health concerns [1]. In addition, the availability of tetracycline-class antibiotics to effectively treat rickettsial infections has reduced the severity and duration of infections [1, 4].Although the classic louseborne cycle of Rickettsia prowazekii is not common in the United States, R. prowazekii infections are still sporadically reported. There have been at least 47 cases documented in humans since 1976 (Centers for Disease Control and Prevention, unpublished data) [5, 6]. Most of these cases had reported …

Brill-Zinsser Disease in a Patient Following Infection with Sylvatic Epidemic Typhus Associated with Flying SquirrelsRead More

As an obligatory parasite of humans, the body louse (Pediculus humanus humanus) is an important vector for human diseases, including epidemic typhus, relapsing fever, and trench fever. Here, we present genome sequences of the body louse and its primary bacterial endosymbiont Candidatus Riesia pediculicola. The body louse has the smallest known insect genome, spanning 108 Mb. Despite its status as an obligate parasite, it retains a remarkably complete basal insect repertoire of 10,773 protein-coding genes and 57 microRNAs. Representing hemimetabolous insects, the genome of the body louse thus provides a reference for studies of holometabolous insects. Compared with other insect genomes, the body louse genome contains significantly fewer genes associated with environmental sensing and …

Genome sequences of the human body louse and its primary endosymbiont provide insights into the permanent parasitic lifestyleRead More

Genetic analyses of human lice have shown that the current taxonomic classification of head lice (Pediculus humanus capitis) and body lice (Pediculus humanus humanus) does not reflect their phylogenetic organization. Three phylotypes of head lice A, B and C exist but body lice have been observed only in phylotype A. Head and body lice have different behaviours and only the latter have been involved in outbreaks of infectious diseases including epidemic typhus, trench fever and louse borne recurrent fever. Recent studies suggest that body lice arose several times from head louse populations...We propose a hypothesis for the emergence of body lice, and suggest that humans with both low hygiene and head louse infestations provide an opportunity for head louse variants, able to ingest a larger …

Genotyping of Human Lice Suggests Multiple Emergences of Body Lice from Local Head Louse PopulationsRead More

In February 2006, a diagnosis of sylvatic epidemic typhus in a counselor at a wilderness camp in Pennsylvania prompted a retrospective investigation. From January 2004 through January 2006, 3 more cases were identified. All had been counselors at the camp and had experienced febrile illness with myalgia, chills, and sweats; 2 had been hospitalized. All patients had slept in the same cabin and reported having seen and heard flying squirrels inside the wall adjacent to their bed. Serum from each patient had evidence of infection with Rickettsia prowazekii. Analysis of blood and tissue from 14 southern flying squirrels trapped in the woodlands around the cabin indicated that 71% were infected with R. prowazekii. Education and control measures to exclude flying squirrels from housing are …

Cluster of Sylvatic Epidemic Typhus Cases Associated with Flying Squirrels, 2004–2006Read More

Department of Microbiology, Harvard School of Public Health, Boston, Mass.; Doboj, Grac'anica, Tuzla, and Sarajevo, Yugoslavia; and Department of Microbiology, Harvard School of Public Health. IN 1934 Zinsser defined Brill's disease as sporadic typhus occurring in the absence of lice among immigrants to the United States from the typhus-ridden areas of southeastern Europe.1 Subsequently, physicians in Switzerland,2 France,3' 4 England,5 and Portugal6 reported occasional cases of Brill's disease among immigrants and displaced persons from the typhus regions of Europe. There are no reports, however, that Brill's disease has been recognized as such in any area where typhus fever actually occurs in epidemics among the local population. If Brill's disease is indeed a recrudescence of typhus …

Brill’s Disease. IV. Study of 26 Cases in YugoslaviaRead More