A 2015 outbreak of flea-borne rickettsiosis in San Gabriel Valley, Los Angeles County, California

Nelson, Kimberly; Maina, Alice N.; Brisco, Angela; Foo, Chelsea; Croker, Curtis; Ngo, Van; Civen, Rachel; Richards, Allen L.; Fujioka, Kenn K.; Wekesa, J. W.

doi:10.1371/journal.pntd.0006385

Cited by 22 publications

(10 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Stray dog populations are another potential reservoir for rickettsias. These factors are evident in the outbreaks of murine typhus in homeless populations of cities such as Los Angeles [ 17 ] or clusters of Rocky Mountain spotted fever in rural populations in Mexico [ 18 ]. Agricultural workers are at particular risk of rickettsial infection because of time spent outdoors and proximity to potentially infested animal and vector populations.…”

Section: The Public Health Burden Of Rickettsial Infectionsmentioning

confidence: 99%

Rickettsial infections: A blind spot in our view of neglected tropical diseases

et al. 2021

View full text Add to dashboard Cite

Rickettsial diseases are a group of vector-borne bacterial infections that cause acute febrile illness with potentially severe or fatal complications. These vector-borne diseases are prevalent in tropical and subtropical regions worldwide and disproportionately affect poorer communities but are scientifically underrecognized. Despite this, they are not included in the World Health Organization’s list of neglected tropical diseases nor were they mentioned in Peter Hotez’s recent reflections on “What constitutes a neglected tropical disease?” in PLOS Neglected Tropical Diseases [1]. Here we present the case that rickettsial infections, as an overlooked cause of morbidity, mortality, and economic losses in marginalized populations, should be recognized as neglected tropical diseases. We describe how this oversight is the result of a number of factors and how it negatively impacts patient outcomes. We then propose measures to address the neglect of rickettsial infections in both scientific research and public health interventions.

show abstract

Section: The Public Health Burden Of Rickettsial Infectionsmentioning

confidence: 99%

Rickettsial infections: A blind spot in our view of neglected tropical diseases

et al. 2021

View full text Add to dashboard Cite

show abstract

“…In the present work, we did not collect blood samples from the hosts for Rickettsia detection, since this mammal species exhibits short bacteraemia and the opportunities to detect this agent in blood are very scarce; for this reason, they are not considered reservoirs of R. typhi (Nelson et al., 2018). Nevertheless, a serological surveillance programme is imperative to identify the degree of exposure of this population of opossums to R. typhi in the remaining patch of this urban reserve.…”

Section: Discussionmentioning

confidence: 99%

“…In the present work, we did not collect blood samples from the hosts for Rickettsia detection, since this mammal species exhibits short bacteraemia and the opportunities to detect this agent in blood are very scarce; for this reason, they are not considered reservoirs of R. typhi (Nelson et al, 2018). It has been proven that increased anthropic pressures, in particular those related to deforestation and reduction of wild areas, cause animals to leave their natural distributions either by displacement of exotic species or related to the search for resources (Xu et al, 2019).…”

Section: F I G U R Ementioning

confidence: 99%

Urban foci of murine typhus involving cat fleas (Ctenocephalides felis felis) collected from opossums in Mexico City

Santoyo-Colín¹,

Sánchez‐Montes

Salceda-Sánchez

et al. 2020

Zoonoses and Public Health

View full text Add to dashboard Cite

Murine typhus, a neglected rickettsiosis caused by Rickettsia typhi, is a common disease in several Latin-American countries. The sylvatic life cycle of R. typhi encompasses the presence of several wild mammals, particularly opossums of the genus Didelphis and their associated fleas. Due to the colonization of wild environments by human populations, the increase in contact with opossum fleas has generated the presence of urban outbreaks of typhus. For this reason, the aim of our study was to identify the presence and diversity of Rickettsia sp. in fleas collected from opossums of an urban reserve in Mexico City. Opossums were captured from February to September 2017. For the detection of Rickettsia DNA, fragments of 800 bp of the citrate synthase (gltA) and the outer membrane protein B (ompB) were amplified. A total of 141 fleas (111 ♀, 30 ♂) of a single species (Ctenocephalides felis felis) were recovered from 31 Didelphis virginiana. Rickettsia DNA was detected in 17.7% (25/141) of the analysed fleas, recovered from seven infested opossums. The Maximum likelihood of sequences exhibited an identity of 99%-100% with sequences of R. typhi from southern United States. This work represents the first record of R. typhi in fleas from opossums in Mexico.

show abstract

“…None of the opossums were seropositive for Rickettsia , whereas 46% of cats were seropositive. Public health authorities removed the feral cats and opossums, provided flea-collars for pets, and outdoor feeding sources were removed; no additional cases of FBT occurred during a post-intervention surveillance period [ 237 ].…”

Section: Flea-borne Typhus In California 1915–2019mentioning

confidence: 99%

History, Rats, Fleas, and Opossums. II. The Decline and Resurgence of Flea-Borne Typhus in the United States, 1945–2019

Anstead

2020

TropicalMed

View full text Add to dashboard Cite

Flea-borne typhus, due to Rickettsia typhi and R. felis, is an infection causing fever, headache, rash, and diverse organ manifestations that can result in critical illness or death. This is the second part of a two-part series describing the rise, decline, and resurgence of flea-borne typhus (FBT) in the United States over the last century. These studies illustrate the influence of historical events, social conditions, technology, and public health interventions on the prevalence of a vector-borne disease. Flea-borne typhus was an emerging disease, primarily in the Southern USA and California, from 1910 to 1945. The primary reservoirs in this period were the rats Rattus norvegicus and Ra. rattus and the main vector was the Oriental rat flea (Xenopsylla cheopis). The period 1930 to 1945 saw a dramatic rise in the number of reported cases. This was due to conditions favorable to the proliferation of rodents and their fleas during the Depression and World War II years, including: dilapidated, overcrowded housing; poor environmental sanitation; and the difficulty of importing insecticides and rodenticides during wartime. About 42,000 cases were reported between 1931–1946, and the actual number of cases may have been three-fold higher. The number of annual cases of FBT peaked in 1944 at 5401 cases. American involvement in World War II, in the short term, further perpetuated the epidemic of FBT by the increased production of food crops in the American South and by promoting crowded and unsanitary conditions in the Southern cities. However, ultimately, World War II proved to be a powerful catalyst in the control of FBT by improving standards of living and providing the tools for typhus control, such as synthetic insecticides and novel rodenticides. A vigorous program for the control of FBT was conducted by the US Public Health Service from 1945 to 1952, using insecticides, rodenticides, and environmental sanitation and remediation. Government programs and relative economic prosperity in the South also resulted in slum clearance and improved housing, which reduced rodent harborage. By 1956, the number of cases of FBT in the United States had dropped dramatically to only 98. Federally funded projects for rat control continued until the mid-1980s. Effective antibiotics for FBT, such as the tetracyclines, came into clinical practice in the late 1940s. The first diagnostic test for FBT, the Weil-Felix test, was found to have inadequate sensitivity and specificity and was replaced by complement fixation in the 1940s and the indirect fluorescent antibody test in the 1980s. A second organism causing FBT, R. felis, was discovered in 1990. Flea-borne typhus persists in the United States, primarily in South and Central Texas, the Los Angeles area, and Hawaii. In the former two areas, the opossum (Didelphis virginiana) and cats have replaced rats as the primary reservoirs, with the cat flea (Ctenocephalides felis) now as the most important vector. In Hawaii, 73% of cases occur in Maui County because it has lower rainfall than other areas. Despite great successes against FBT in the post-World War II era, it has proved difficult to eliminate because it is now associated with our companion animals, stray pets, opossums, and the cat flea, an abundant and non-selective vector. In the new millennium, cases of FBT are increasing in Texas and California. In 2018–2019, Los Angeles County experienced a resurgence of FBT, with rats as the reservoir.

show abstract

A 2015 outbreak of flea-borne rickettsiosis in San Gabriel Valley, Los Angeles County, California

Cited by 22 publications

References 30 publications

Rickettsial infections: A blind spot in our view of neglected tropical diseases

Rickettsial infections: A blind spot in our view of neglected tropical diseases

Urban foci of murine typhus involving cat fleas (Ctenocephalides felis felis) collected from opossums in Mexico City

History, Rats, Fleas, and Opossums. II. The Decline and Resurgence of Flea-Borne Typhus in the United States, 1945–2019

Contact Info

Product

Resources

About