LETTERS tional Center for Biotechnology Infor- DOI: 10.3201/eid1603.091431 africae, mation basic local alignment sequence tool, BLAST (www.ncbi.nlm.nih.gov/ References Western Africa blast/Blast.cgi). 1. Matthewman L, Kelly P, Hayter D, Down- To the Editor: Rickettsia africae, To determine whether R. felis oc- ie S, Wray K, Bryson N, et al. Domestic the causative agent of African tick- curs on another Caribbean island, we cats as indicators of the presence of spot- bite fever, is transmitted by Ambly- tested 32 C. felis fl eas from Dominica ted fever and group rickettsiae. omma hebraeum and A. variegatum and found 1 (3%) to be positive by PCR Eur J Epidemiol. 1997;13:109–11. DOI: 10.1023/A:1007375718204 ticks (1,2). These ticks are common when primers targeting ompA were 2. Garris GI. Control of ticks. Vet Clin in western, central, and southern Af- used. The sequence obtained was also North Am Small Anim Pract.Review. rica. Adults rarely feed on humans, al- identical to that of R. felis URRxCal2. 1991;21:173–83. though nymphs attach more frequently Our study provides further evi- 3. Wedincamp J Jr, Foil LD. Infection and seroconversion of cats exposed to cat and larvae are sometimes serious pests dence that cats can be sentinels for the fl eas (Ctenocephalides felis Bouche) in- (abundant and aggressive) (3). presence of rickettsiae (1). However, fected with . J Vector Ecol. African tick-bite fever is a ne- although rickettsemia can develop 2000;25:123–6. glected disease that has been mainly in cats experimentally infected with 4. Pérez-Osorio CE, Zavala-Velázquez JE, Zavala-Velázquez JE. Rickettsia felis detected in tourists who were bitten R. felis (3), no compelling evidence as emergent global threat for humans. by a tick while traveling in disease- shows that cats help maintain the or- Emerg Infect Dis. 2008;14:1019–23 endemic areas (2). A recent worldwide ganism or transmit it to humans (8,9). 10.3201/eid1407.071656. DOI: 10.3201/ report showed rickettsial infection in- Rather, it appears that C. felis fl eas, eid1407.071656 5. Kelly PJ, Meads N, Theobald A, Fournier cidence to be 5.6% in a group of trav- which are also commonly found on P-E, Raoult D. Rickettsia felis, elers in whom acute febrile infection dogs and to a lesser extent other mam- henselae, and B. clarridgeiae, New Zea- developed after they returned from mals, are the major reservoir hosts land. Emerg Infect Dis. 2004;10:967–8. sub-Saharan Africa. African tick-bite and vectors of infection, although the 6. Bitam I, Parola P, De La Cruz KD, Mat- sumoto K, Baziz B, Rolain JM, et al. First fever is the second most frequently exact mechanisms are unknown (10). molecular detection of Rickettsia felis in identifi ed cause for systemic febrile Our study also expands the known fl eas from Algeria. Am J Trop Med Hyg. illness among travelers, following ma- distribution of R. felis and should alert 2006;74:532–5. laria (4). Seroprevalence for spotted healthcare workers who see residents 7. Karpathy SE, Hayes EK, Williams AM, Hu R, Krueger L, Bennett S, et al. Detec- fever group rickettsiae is high in the of or vacationers from the Caribbean tion of Rickettsia felis and Sahel regions of Africa (5), although islands of the possibility of fl ea-borne in an area of California endemic for mu- there may be different emergent and in their patients. rine typhus. Clin Microbiol Infect. 2009 Apr 3; [Epub ahead of print] classic rickettsioses in Africa. R. africae has been detected by Patrick J. Kelly, Helene Lucas, 8. Bayliss DB, Morris AK, Horta MC, Labruna MB, Radecki SV, Hawley JR, et PCR in many African countries, in- Marina E. Eremeeva, al. Prevalence of Rickettsia species anti- cluding Niger, Mali, Burundi, and Kathryn G. Dirks, bodies and Rickettsia species DNA in the Sudan (6), and in most countries of Jean Marc Rolain, blood of cats with and without fever. J equatorial and southern Africa (Fig- Charles Yowell, Feline Med Surg. 2009;11:266–70. DOI: 10.1016/j.jfms.2008.06.007 ure). Most strains and cases have been Reginald Thomas, 9. Tabar MD, Altet L, Francino O, Sánchez A, found in South Africa (2). R. africae Trevrone Douglas, Ferrer L, Roura X. Vector-borne infections and African tick-bite fever have not Gregory A. Dasch, in cats: molecular study in Barcelona area previously been reported in Senegal, and Didier Raoult (Spain). Vet Parasitol. 2008;151:332–6. DOI: 10.1016/j.vetpar.2007.10.019 and few positive human serum sam- Author affi liations: Ross University School 10. Reif KE, Makaluso KR. Ecology ples have been documented in west- of Veterinary Medicine, St. Kitts, West In- of Rickettsia felis: a review. J Med ern Africa. A. variegatum, the main dies (P.J. Kelly, H. Lucas); Centers for Entomol. 2009;46:723–36. DOI: vector of R. africae, was introduced Disease Control and Prevention, Atlanta, 10.1603/033.046.0402 by cattle into Guadeloupe, West In- Georgia, USA (M.E. Eremeeva, K.G. Dirks, Address for correspondence: Patrick J. Kelly, dies, from Senegal in the early 1800s. G.A. Dasch); Unité de Recherche sur les Ross University School of Veterinary Medicine, Spotted fever caused by R. africae has Maladies Infectieuses et Tropicales Emer- PO Box 334, West Farm, St. Kitts, West Indies; become endemic there in the past 30 gentes, Marseille, France (J.M. Rolain, D. email: [email protected] years (7). In addition to R. africae, A. Raoult); University of Florida, Gainesville, variegatum ticks may transmit other Florida, USA (C. Yowell); and Division of human and animal pathogens, includ- Agriculture, Roseau, Dominica, West Indies ing Crimean-Congo hemorrhagic fe- (R. Thomas, T. Douglas) ver virus, Dugbe virus, Thogoto virus,

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Bhanja virus, Ehrlichia ruminantium, PCR by using primers designed for the deposited in GenBank, accession no. Theileria spp., Anaplasma spp., and gltA and ompA genes (6). Three rick- GU062743. Dermatophilus congolensis (3,6). ettsial spacers were chosen for typ- Adult ticks (n = 492) were col- From November through Decem- ing: dksA-xerC, rpmE-tRNAmet, and lected from domestic animals; 85 ber 2008, ticks were collected from mppA-purC (9). (17.3%) were A. variegatum, and 74 domestic animals (cattle, goats, sheep, Tick larvae were the only stage (87.1%) were positive for rickettsial dogs, horses, donkeys) in the Sine- collected by fl agging at ground level. genes according to real-time PCR. Saloum region of Senegal (villages Flagging for 30 minutes collected No associations between animal host, Dielmo, Ndiop, Medina, and Passi). 495 larvae near the village of Passi place of collection, and presence of R. Among the collected ticks, 8 fully and 325 in Dielmo. The larvae were africae were found (data not shown). engorged nymphs were kept alive in aggressive, and several attached onto During the subsequent amplifi cation fl asks at 90%–95% relative humidity. the collector’s ankles despite pre- and sequencing of the 632-bp frag- Other ticks were stored in 70% etha- ventive measures. All larvae were ment of the ompA gene, all amplicons nol. Flagging at ground level was used morphologically identifi ed as Am- were found to be 100% identical to to collect ticks from pastures. Species blyomma spp. Amplifi cation and se- the ompA sequence of R. africae pub- were identifi ed according to stan- quencing of the portion of mitochon- lished in GenBank (CP001612.1). dard taxonomic keys for adult ticks. drial cytochrome oxidase I gene of Molted nymphs were the source Nymphs were allowed to molt before 3 adult A. variegatum ticks, 2 indi- of 3 strains of R. africae. Although identifi cation and subsequent bacterial vidual larvae, and 1 pool of 10 larvae dogs are rarely reported to be hosts of culture. Rickettsial DNA in other ticks detected a 659-bp sequence 100% A. variegatum (3), a dog was the host was detected by semiquantitative PCR identical among all larvae and adults of the tick that carried the fi rst iso- with Rickettsia-specifi c primers (8). and corresponding to cytochrome ox- lated strain. A 1,290-bp fragment of All positive samples were subjected to idase I of other ticks. The sequence is the rickettsial gltA gene and a 632-bp fragment of the ompA gene from all 3 strains were identical to the published sequence of the R. africae genome (CP001612.1). Multispacer typing showed that all 3 R. africae strains exhibited a genotype identical to that of all previously genotyped R. africae strains (genotype 38). To the best of our knowledge, this is the northern- most reported isolation of this patho- gen in western Africa. Taking into consideration data described in previous studies and the results of our work, we conclude that A. variegatum is an aggressive and abundant species of tick. The reported Molecular detection in ticks transovarial transmission rate of 100% Cases of spotted fever documented by serologic examination for R. africae (10), the abundance of Human cases documented by PCR ticks, and the high percentage of ticks Isolates obtained from patients that are infected (3) increase the prob- Isolates obtained from ticks ability that humans will be bitten by infected ticks. R. africae is present in Senegal, and human infections (in tourists and indigenous populations) may be as common there as in south- ern Africa, but better availability of diagnostic assays is needed. Surveys of the distribution of vector ticks and Figure. Distribution of Rickettsia africae in the African continent and serologic evidence of rickettsiae should be performed, and spotted fevers in humans. Gray shading indicates location of Senegal. target groups should be screened.

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Oleg Mediannikov, 9. Fournier PE, Raoult D. Identifi cation of veterinary student during the autopsy Jean-François Trape, rickettsial isolates at the species level us- of a horse. The study was reviewed ing multi-spacer typing. BMC Microbiol. Georges Diatta, Philippe Parola, 2007;7:72. DOI: 10.1186/1471-2180-7-72 and approved by the Ethics Commit- Pierre-Edouard Fournier, 10. Socolovschi C, Huynh TP, Davoust B, tee of the University of Pretoria, and and Didier Raoult Gomez J, Raoult D, Parola P. Transovarial informed consent was provided by the and trans-stadial transmission of Rickett- Author affi liations: Unité de Recherche sur veterinary student. siae africae in Amblyomma variegatum les Maladies Infectieuses et Tropicales ticks. Clin Microbiol Infect. 2009 May 18; On April 9, 2008, a 4-month-old Emergentes, Marseille, France (O. Median- [Epub ahead of print]. Welsh pony from Gauteng in South nikov, P. Parola, P.-E. Fournier, D. Raoult); Africa had fever, Schiff-Sherrington and Unité de Recherche sur les Maladies Address for correspondence: Oleg Mediannikov, signs, and a leukocyte count of 32 × Infectieuses et Tropicales Emergentes, Da- Mediterranean University, CNRS-IRD UMR 109 cells/L. He was treated with dim- kar, Senegal (O. Mediannikov, J.F. Trape, 6236-198, 27 blvd Jean Moulin, Marseille ethyl sulfoxide, dexamethasone, and G. Diatta) 13385 CEDEX 5, France; email: olegusss1@ chloramphenicol and responded well. gmail.com He was able to stand with help, and DOI: 10.3201/eid1603.090346 did not show neurologic signs at this stage. On May 9, he was sent home References and was able to walk with support. 1. Kelly PJ. Rickettsia africae sp. nov., the On May 12, he had a relapse with etiological agent of . neurologic deterioration and rectal Int J Syst Bacteriol. 1996;46:611–4. prolapse, and was treated with antiin- 2. Jensenius M, Fournier PE, Vene S, Hoel Transmission of T, Hasle G, Henriksen AZ, et al. Afri- fl ammatory agents. Symptoms wors- can tick bite fever in travelers to rural West Nile Virus ened and he was humanely killed sub-equatorial Africa. Clin Infect Dis. during Horse on May 15 by using ketamine and 2003;36:1411–7. DOI: 10.1086/375083 MgSO . The carcass was sent to the 3. Hoogstraal H. African Ixodoidea: I. Ticks Autopsy 4 of the Sudan (with special reference to Faculty of Veterinary Sciences, Uni- Equatoria Province and with preliminary To the Editor: West Nile virus versity of Pretoria, for autopsy be- reviews of the genera Boophilus, Marga- (WNV) circulates mainly in birds and cause of unusual neurologic signs in ropus, and Hyalomma). Washington: US ornithophilic mosquitoes. Humans and the pony. Autopsy was performed by Navy; 1956. 4. Freedman DO, Weld LH, Kozarsky PE, horses are considered incidental, dead- a veterinary pathologist and 2 stu- Fisk T, Robins R, von Sonnenburg F, et al. end hosts (1). Fever, rash, arthralgia, dents on May 16, 2008. Spectrum of disease and relation to place and myalgia develop in ≈20% of cases Macroscopic fi ndings included of exposure among ill returned travelers. in humans; severe neurologic disease moderate intermuscular, fascicular, N Engl J Med. 2006;354:119–30. DOI: 10.1056/NEJMoa051331 may develop in <1% (1). In horses, perineural edema, severe diffuse pul- 5. Dupont HT, Brouqui P, Faugere B, Raoult 20% of infections result in clinical monary edema, mild hydropericar- D. Prevalence of antibodies to Coxiella disease, of which ≈90% involve neu- dium, and rectal prolapse resulting in burnetii, , and Rickettsia rologic disease with ataxia, weakness, marked submucosal edema and mu- typhi in seven African countries. Clin In- fect Dis. 1995;21:1126–33. recumbency, muscle fasciculation, and cosal hyperamia, i.e., traumatic proc- 6. Parola P, Inokuma H, Camicas JL, Brouqui high death rates (30%) (2). titis. The spinal cord up to C1 showed P, Raoult D. Detection and identifi cation Genetic variants of WNV include marked Wallerian degeneration of the of spotted fever group Rickettsiae and lineage 1 found in the Northern Hemi- peripheral white matter from the me- Ehrlichiae in African ticks. Emerg In- fect Dis. 2001;7:1014–7. DOI: 10.3201/ sphere and Australia; lineage 2 found dian fi ssure, which extended along the eid0706.010616 mainly in southern Africa and Mada- ventral funiculus up to the most dorsal 7. Parola P, Jourdan J, Raoult D. Tick- gascar (3); lineages 3 and 4 found in section of the lateral funiculus. Chang- borne infection caused by Rickettsia central and eastern Europe (4); and lin- es were characterized by white matter africae in the West Indies. N Engl J Med. 1998;338:1391. DOI: 10.1056/ eage 5 found in India (5). Differences spongiosis with numerous digestion NEJM199805073381918 in neuroninvasiveness and pathogenic chambers containing phagocytosing 8. Rolain JM, Sthul L, Maurin M, Raoult potential are functions of individual myelinophages and scattered intersti- D. Evaluation of antibiotic susceptibili- genotypes, not lineage (3,6–8). tial gemistocytes. No infl ammatory re- ties of three rickettsial species including Rickettsia felis by a quantitative PCR We recently reported WNV lin- action was detected. We also observed DNA assay. Antimicrob Agents Chemoth- eage 2 in several cases of neurologic septal edema and moderate multifocal er. 2002;46:2747–51. DOI: 10.1128/ disease in horses in South Africa perivascular and peribronchiolar lym- AAC.46.9.2747-2751.2002 (most cases were fatal) (7). We report phocytic infi ltration with occasional a case of zoonotic transmission to a apoptosis in the lungs.

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