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Zhang EY, Kalmath P, Abernathy HA, Giandomenico DA, Nolan MS, Reiskind MH, Boyce RM. Rickettsia africae infections in sub-Saharan Africa: A systematic literature review of epidemiological studies and summary of case reports. Trop Med Int Health 2024. [PMID: 38813598 DOI: 10.1111/tmi.14002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
Rickettsia africae is a tick-borne bacteria known to cause African tick bite fever (ATBF). While the disease was first described more than 100 years ago, knowledge of transmission risk factors and disease burden remain poorly described. To better understand the burden of R. africae, this article reviewed and summarized the published literature related to ATBF epidemiology and clinical management. Using a systematic approach, consistent with the PRISMA guidelines, we identified more than 100 eligible articles, including 65 epidemiological studies and 41 case reports. Most reports described R. africae in ticks and livestock, while human studies were less common. Human disease case reports were exclusively among returning travellers from non-endemic areas, which limits our disease knowledge among at-risk populations: people living in endemic regions. Substantial efforts to elucidate the ATBF risk factors and clinical manifestations among local populations are needed to develop effective preventative strategies and facilitate appropriate and timely diagnosis.
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Affiliation(s)
- Elizabeth Y Zhang
- College of Arts and Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Prarthana Kalmath
- College of Arts and Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Haley A Abernathy
- Institute for Global Health and Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Dana A Giandomenico
- Institute for Global Health and Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Melissa S Nolan
- Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, South Carolina, USA
| | - Michael H Reiskind
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, North Carolina, USA
| | - Ross M Boyce
- Institute for Global Health and Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Carolina Population Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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Poungou N, Sevidzem SL, Koumba AA, Koumba CRZ, Mbehang P, Onanga R, Zahouli JZB, Maganga GD, Djogbénou LS, Borrmann S, Adegnika AA, Becker SC, Mavoungou JF, Nguéma RM. Mosquito-Borne Arboviruses Occurrence and Distribution in the Last Three Decades in Central Africa: A Systematic Literature Review. Microorganisms 2023; 12:4. [PMID: 38276174 PMCID: PMC10819313 DOI: 10.3390/microorganisms12010004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 10/13/2023] [Accepted: 10/19/2023] [Indexed: 01/27/2024] Open
Abstract
Arboviruses represent a real public health problem globally and in the Central African subregion in particular, which represents a high-risk zone for the emergence and re-emergence of arbovirus outbreaks. Furthermore, an updated review on the current arbovirus burden and associated mosquito vectors is lacking for this region. To contribute to filling this knowledge gap, the current study was designed with the following objectives: (i) to systematically review data on the occurrence and distribution of arboviruses and mosquito fauna; and (ii) to identify potential spillover mosquito species in the Central African region in the last 30 years. A web search enabled the documentation of 2454 articles from different online databases. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) and the quality of reporting of meta-analyses (QUORUM) steps for a systematic review enabled the selection of 164 articles that fulfilled our selection criteria. Of the six arboviruses (dengue virus (DENV), chikungunya virus (CHIKV), yellow fever virus (YFV), Zika virus (ZIKV), Rift Valley fever virus (RVFV), and West Nile virus (WNV)) of public health concern studied, the most frequently reported were chikungunya and dengue. The entomological records showed >248 species of mosquitoes regrouped under 15 genera, with Anopheles (n = 100 species), Culex (n = 56 species), and Aedes (n = 52 species) having high species diversity. Three genera were rarely represented, with only one species included, namely, Orthopodomyia, Lutzia, and Verrallina, but individuals of the genera Toxorhinchites and Finlayas were not identified at the species level. We found that two Aedes species (Ae. aegypti and Ae. albopictus) colonised the same microhabitat and were involved in major epidemics of the six medically important arboviruses, and other less-frequently identified mosquito genera consisted of competent species and were associated with outbreaks of medical and zoonotic arboviruses. The present study reveals a high species richness of competent mosquito vectors that could lead to the spillover of medically important arboviruses in the region. Although epidemiological studies were found, they were not regularly documented, and this also applies to vector competence and transmission studies. Future studies will consider unpublished information in dissertations and technical reports from different countries to allow their information to be more consistent. A regional project, entitled "Ecology of Arboviruses" (EcoVir), is underway in three countries (Gabon, Benin, and Cote d'Ivoire) to generate a more comprehensive epidemiological and entomological data on this topic.
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Affiliation(s)
- Natacha Poungou
- Ecole Doctorale Regionale en Infectiologie Tropical de Franceville (EDR), University of Science and Technique of Masuku (USTM), Franceville P.O. Box 943, Gabon;
- Laboratoire d’Ecologie des Maladies Transmissibles (LEMAT), Université Libreville Nord (ULN), Libreville P.O. Box 1177, Gabon
| | - Silas Lendzele Sevidzem
- Laboratoire d’Ecologie des Maladies Transmissibles (LEMAT), Université Libreville Nord (ULN), Libreville P.O. Box 1177, Gabon
| | - Aubin Armel Koumba
- Département de Biologie et Ecologie Animale, Institut de Recherche en Ecologie Tropicale (IRET-CENAREST), Libreville P.O. Box 13354, Gabon
| | - Christophe Roland Zinga Koumba
- Département de Biologie et Ecologie Animale, Institut de Recherche en Ecologie Tropicale (IRET-CENAREST), Libreville P.O. Box 13354, Gabon
| | - Phillipe Mbehang
- Département de Biologie et Ecologie Animale, Institut de Recherche en Ecologie Tropicale (IRET-CENAREST), Libreville P.O. Box 13354, Gabon
| | - Richard Onanga
- Center of Interdisciplinary Medical Analysis of Franceville (CIRMF), Franceville P.O. Box 769, Gabon
| | - Julien Zahouli Bi Zahouli
- Centre d’Entomologie Médicale et Vétérinaire, Université Alassane Ouattara, Bouaké 01 BPV 18, Côte d’Ivoire
| | - Gael Darren Maganga
- Center of Interdisciplinary Medical Analysis of Franceville (CIRMF), Franceville P.O. Box 769, Gabon
| | - Luc Salako Djogbénou
- Université d’Abomey-Calavi, Institut Régional de Santé Publique, Ouidah P.O. Box 384, Benin
| | - Steffen Borrmann
- Institute for Tropical Medicine (ITM), University of Tübingen, 72074 Tübingen, Germany
| | - Ayola Akim Adegnika
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné P.O. Box 242, Gabon
| | - Stefanie C. Becker
- Institute for Parasitology, University of Veterinary Medicine Hannover, 30559 Hannover, Germany;
| | - Jacques François Mavoungou
- Département de Biologie et Ecologie Animale, Institut de Recherche en Ecologie Tropicale (IRET-CENAREST), Libreville P.O. Box 13354, Gabon
| | - Rodrigue Mintsa Nguéma
- Laboratoire d’Ecologie des Maladies Transmissibles (LEMAT), Université Libreville Nord (ULN), Libreville P.O. Box 1177, Gabon
- Département de Biologie et Ecologie Animale, Institut de Recherche en Ecologie Tropicale (IRET-CENAREST), Libreville P.O. Box 13354, Gabon
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Palacios-Santana R, Wei L, Fernandez-Santos NA, Rodriguez-Perez MA, Uriegas-Camargo S, Mendell NL, Bouyer DH, Estrada-Franco JG. Spotted Fever and Typhus Group Rickettsiae in Dogs and Humans, Mexico, 2022. Emerg Infect Dis 2023; 29:1443-1446. [PMID: 37347822 PMCID: PMC10310375 DOI: 10.3201/eid2907.230333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/24/2023] Open
Abstract
We found serologic evidence of spotted fever group Rickettsia in humans and dogs and typhus group Rickettsia in dogs in Reynosa, Mexico. Our investigation revealed serologic samples reactive to spotted fever group Rickettsia in 5 community members, which highlights a potential rickettsial transmission scenario in this region.
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Skalinski LM, Santos AES, Paixão E, Itaparica M, Barreto F, da Conceição Nascimento Costa M, Teixeira MG. Chikungunya seroprevalence in population-based studies: a systematic review and meta-analysis. Arch Public Health 2023; 81:80. [PMID: 37127721 PMCID: PMC10150504 DOI: 10.1186/s13690-023-01081-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Accepted: 04/06/2023] [Indexed: 05/03/2023] Open
Abstract
BACKGROUND Seroprevalence studies about chikungunya infection are usually conducted after epidemics to estimate the magnitude of the attack. This study aimed to estimate the seroprevalence of CHIKV by WHO region, considering the periods of introduction of the virus in these regions and its potential to lead to epidemics. METHODS We systematically reviewed Medline/Pubmed, Embase, Lilacs, Scopus and Web of Science for original articles published up to 2020. Cohort, case-control and cross-sectional studies were eligible for inclusion, based on the results of laboratory diagnosis of previous or previous and recent infection. Those conducted with symptomatic individuals were excluded. RESULTS 596 articles were identified, 197 full-text were reviewed and 64 were included, resulting in 71 seroprevalences. Most were cross-sectional studies (92%), between 2001 and 2020 (92%), with population of all ages (55%), conducted in Kenya (10.9%), Brazil (9.4%) and French Polynesia (7.8%). The pooled estimates were 24% (95%CI 19-29; I2 = 99.7%; p < 0.00), being 21% (95%CI 13-30; I2 = 99.5%; p < 0.00) for adults, 7% (95%CI 0-23; I2 = 99.7%; p < 0.00) for children and 30% (95%CI 23-38; I2 = 99.7%; p < 0.00) for all ages. The higher seroprevalences were found in African, the Americas and South-East Asian Regions. CONCLUSIONS The great heterogeneity of seroprevalences points to the persistence of viral circulation. Even where the seroprevalence is high, the population replacement and the absence of vaccines mean that the risk of virus spread and epidemics remains. REGISTRATION PROSPERO CRD42020166227.
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Affiliation(s)
- Lacita Menezes Skalinski
- Universidade Estadual de Santa Cruz, Rodovia Jorge Amado, km 16, s/n, Salobrinho, Ilhéus, CEP 45662-900, BA, Brasil.
- Instituto de Saúde Coletiva/ Universidade Federal da Bahia, Rua Basílio da Gama, s/n, Campus Canela, Salvador, CEP 40110-040, BA, Brazil.
| | - Aline Elena Sacramento Santos
- Instituto de Saúde Coletiva/ Universidade Federal da Bahia, Rua Basílio da Gama, s/n, Campus Canela, Salvador, CEP 40110-040, BA, Brazil
| | - Enny Paixão
- London School of Hygiene and Tropical Medicine, Keppel St, London, WC1E 7HT, UK
| | - Martha Itaparica
- Instituto de Saúde Coletiva/ Universidade Federal da Bahia, Rua Basílio da Gama, s/n, Campus Canela, Salvador, CEP 40110-040, BA, Brazil
| | - Florisneide Barreto
- Instituto de Saúde Coletiva/ Universidade Federal da Bahia, Rua Basílio da Gama, s/n, Campus Canela, Salvador, CEP 40110-040, BA, Brazil
| | | | - Maria Glória Teixeira
- Instituto de Saúde Coletiva/ Universidade Federal da Bahia, Rua Basílio da Gama, s/n, Campus Canela, Salvador, CEP 40110-040, BA, Brazil
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Alenou LD, Nwane P, Mbakop LR, Piameu M, Ekoko W, Mandeng S, Bikoy EN, Toto JC, Onguina H, Etang J. Burden of mosquito-borne diseases across rural versus urban areas in Cameroon between 2002 and 2021: prospective for community-oriented vector management approaches. Parasit Vectors 2023; 16:136. [PMID: 37076896 PMCID: PMC10114431 DOI: 10.1186/s13071-023-05737-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 03/12/2023] [Indexed: 04/21/2023] Open
Abstract
BACKGROUND Over the past two decades, Cameroon has recorded one of the highest rates of urban population growth in sub-Saharan Africa. It is estimated that more than 67% of Cameroon's urban population lives in slums, and the situation is far from improving as these neighbourhoods are growing at an annual rate of 5.5%. However, it is not known how this rapid and uncontrolled urbanization affects vector populations and disease transmission in urban versus rural areas. In this study, we analyse data from studies conducted on mosquito-borne diseases in Cameroon between 2002 and 2021 to determine the distribution of mosquito species and the prevalence of diseases they transmit with regards to urban areas versus rural areas. METHODS A search of various online databases, such as PubMed, Hinari, Google and Google Scholar, was conducted for relevant articles. A total of 85 publications/reports were identified and reviewed for entomological and epidemiological data from the ten regions of Cameroon. RESULTS Analysis of the findings from the reviewed articles revealed 10 diseases transmitted by mosquitoes to humans across the study regions. Most of these diseases were recorded in the Northwest Region, followed by the North, Far North and Eastern Regions. Data were collected from 37 urban and 28 rural sites. In the urban areas, dengue prevalence increased from 14.55% (95% confidence interval [CI] 5.2-23.9%) in 2002-2011 to 29.84% (95% CI 21-38.7%) in 2012-2021. In rural areas, diseases such as Lymphatic filariasis and Rift valley fever, which were not present in 2002-2011, appeared in 2012-2021, with a prevalence of 0.4% (95% CI 0.0- 2.4%) and 10% (95% CI 0.6-19.4%), respectively. Malaria prevalence remained the same in urban areas (67%; 95% CI 55.6-78.4%) between the two periods, while it significantly decreased in rural areas from 45.87% (95% CI 31.1-60.6%) in 2002-2011 to 39% (95% CI 23.7-54.3%) in the 2012-2021 period (*P = 0.04). Seventeen species of mosquitoes were identified as involved in the transmission of these diseases, of which 11 were involved in the transmission of malaria, five in the transmission of arboviruses and one in the transmission of malaria and lymphatic filariasis. The diversity of mosquito species was greater in rural areas than in urban areas during both periods. Of the articles reviewed for the 2012-2021 period, 56% reported the presence of Anopheles gambiae sensu lato in urban areas compared to 42% reported in 2002-2011. The presence of Aedes aegypti increased in urban areas in 2012-2021 but this species was absent in rural areas. Ownership of long-lasting insecticidal nets varied greatly from one setting to another. CONCLUSIONS The current findings suggest that, in addition to malaria control strategies, vector-borne disease control approaches in Cameroon should include strategies against lymphatic filariasis and Rift Valley fever in rural areas, and against dengue and Zika viruses in urban areas.
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Affiliation(s)
- Leo Dilane Alenou
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, P.O. Box 2701, Douala, Cameroon.
- Malaria Research Laboratory, Yaoundé Research Institute (IRY), Organization for the Coordination of Endemic Diseases' Control in Central Africa (OCEAC), P.O. Box 288, Yaoundé, Cameroon.
| | - Philippe Nwane
- Malaria Research Laboratory, Yaoundé Research Institute (IRY), Organization for the Coordination of Endemic Diseases' Control in Central Africa (OCEAC), P.O. Box 288, Yaoundé, Cameroon
- Department of Animal Biology and Physiology, Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - Lili Ranaise Mbakop
- Malaria Research Laboratory, Yaoundé Research Institute (IRY), Organization for the Coordination of Endemic Diseases' Control in Central Africa (OCEAC), P.O. Box 288, Yaoundé, Cameroon
| | - Michael Piameu
- Malaria Research Laboratory, Yaoundé Research Institute (IRY), Organization for the Coordination of Endemic Diseases' Control in Central Africa (OCEAC), P.O. Box 288, Yaoundé, Cameroon
- School of Health Sciences, Catholic University of Central Africa, P.O. Box 1110, Yaounde, Cameroon
| | - Wolfgang Ekoko
- Malaria Research Laboratory, Yaoundé Research Institute (IRY), Organization for the Coordination of Endemic Diseases' Control in Central Africa (OCEAC), P.O. Box 288, Yaoundé, Cameroon
- Department of Animal Biology and Physiology, University of Bamenda, Bambili, P.O. Box 39, Douala, Cameroon
| | - Stanislas Mandeng
- Malaria Research Laboratory, Yaoundé Research Institute (IRY), Organization for the Coordination of Endemic Diseases' Control in Central Africa (OCEAC), P.O. Box 288, Yaoundé, Cameroon
- Department of Animal Biology and Physiology, Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - Elisabeth Ngo Bikoy
- Department of Animal Biology and Physiology, Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - Jean Claude Toto
- Malaria Research Laboratory, Yaoundé Research Institute (IRY), Organization for the Coordination of Endemic Diseases' Control in Central Africa (OCEAC), P.O. Box 288, Yaoundé, Cameroon
| | - Hugues Onguina
- Malaria Research Laboratory, Yaoundé Research Institute (IRY), Organization for the Coordination of Endemic Diseases' Control in Central Africa (OCEAC), P.O. Box 288, Yaoundé, Cameroon
| | - Josiane Etang
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, P.O. Box 2701, Douala, Cameroon.
- Malaria Research Laboratory, Yaoundé Research Institute (IRY), Organization for the Coordination of Endemic Diseases' Control in Central Africa (OCEAC), P.O. Box 288, Yaoundé, Cameroon.
- Department of Insect Biotechnology in Plant Protection, Institute for Insect Biotechnology, Faculty 09-Agricultural Sciences, Nutritional Sciences and Environmental Management, Justus-Liebig-University Gießen, Winchester Str. 2, 35394, Giessen, Germany.
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Nana-Ndjangwo SM, Djiappi-Tchamen B, Mony R, Demanou M, Keumezeu-Tsafack J, Bamou R, Awono-Ambene P, Bilong Bilong CF, Antonio-Nkondjio C. Assessment of Dengue and Chikungunya Infections among Febrile Patients Visiting Four Healthcare Centres in Yaoundé and Dizangué, Cameroon. Viruses 2022; 14:v14102127. [PMID: 36298682 PMCID: PMC9612120 DOI: 10.3390/v14102127] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 09/09/2022] [Accepted: 09/17/2022] [Indexed: 11/16/2022] Open
Abstract
Dengue and chikungunya are now widely distributed in Cameroon, but there is still not enough information on their prevalence in different epidemiological settings. This study was undertaken to assess the prevalence of dengue and chikungunya in both urban and rural settings in Cameroon using three diagnostic tools. From December 2019 to September 2021, willing febrile (temperature >38 °C) outpatients visiting four healthcare facilities in the cities of Yaoundé and Dizangué were screened for dengue, and chikungunya. Clinical features of patient were recorded in a form, and their blood samples were analysed using real-time reverse transcriptase-polymerase chain reaction (rtRT-PCR), rapid diagnostic tests (RDTs) and enzyme-linked immuno-sorbent assays (ELISA). Odds ratios were used to determine the level of association between socio-demographic factors, clinical features, and infection status. The Kappa coefficient permitted to assess the level of agreement between RDTs and ELISA. Overall, 301 febrile patients were recruited in the study: 198 in Yaoundé and 103 in Dizangué. The prevalence of infection varied with the diagnostic tool used. For dengue diagnostics, 110 patients were positive to rtRT-PCR: 90 (45.45%) in Yaoundé, and 20 (19.42%) in Dizangué. The prevalence of dengue IgM using ELISA varied from 22.3% in Dizangué to 30.8% in Yaoundé. Dengue IgM rate using RDTs was 7.6% in Yaoundé and 3.9% in Dizangué. For chikungunya, one (0.5%) patient (Yaoundé, suburb) was positive to rtRT-PCR. The prevalence of chikungunya IgM according to ELISA varied from 18.4% in Dizangué to 21.7% in Yaoundé, while it was 4.5% in Yaoundé and 12.6% in Dizangué with RDTs. Only abdominal and retro-orbital pains were significantly associated with acute dengue infection. All four dengue serotypes were recorded, with a predominance of DENV-3 (35.45%) and DENV-4 (25.45%). Rapid Diagnostic Tests for either chikungunya or dengue displayed very poor sensitivity. This study further confirms the high endemicity of both dengue and chikungunya in Yaoundé and Dizangué. These data stress the need for active surveillance and the implementation of vector control measures to prevent the occurrence of outbreaks across the country.
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Affiliation(s)
- Stella Mariette Nana-Ndjangwo
- Laboratory of Parasitology and Ecology, Department of Animal Physiology and Ecology, Faculty of Science, University of Yaoundé I, Yaoundé P.O. Box 337, Cameroon
- Institut de Recherche de Yaoundé (IRY), Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), Yaoundé P.O. Box 288, Cameroon
- Correspondence: (S.M.N.-N.); (C.A.-N.)
| | - Borel Djiappi-Tchamen
- Institut de Recherche de Yaoundé (IRY), Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), Yaoundé P.O. Box 288, Cameroon
- Vector Borne Diseases Laboratory of the Applied Biology and Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Science, University of Dschang, Dschang P.O. Box 067, Cameroon
| | - Ruth Mony
- Laboratory of Parasitology and Ecology, Department of Animal Physiology and Ecology, Faculty of Science, University of Yaoundé I, Yaoundé P.O. Box 337, Cameroon
| | - Maurice Demanou
- World Health Organization, IST West Africa, Ouagadougou P.O. Box 7019, Burkina Faso
| | - Joyce Keumezeu-Tsafack
- Institut de Recherche de Yaoundé (IRY), Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), Yaoundé P.O. Box 288, Cameroon
- Department of Biological Sciences, University of Douala, Douala P.O. Box 24157, Cameroon
| | - Roland Bamou
- Institut de Recherche de Yaoundé (IRY), Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), Yaoundé P.O. Box 288, Cameroon
- Vector Borne Diseases Laboratory of the Applied Biology and Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Science, University of Dschang, Dschang P.O. Box 067, Cameroon
| | - Parfait Awono-Ambene
- Institut de Recherche de Yaoundé (IRY), Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), Yaoundé P.O. Box 288, Cameroon
| | - Charles Félix Bilong Bilong
- Laboratory of Parasitology and Ecology, Department of Animal Physiology and Ecology, Faculty of Science, University of Yaoundé I, Yaoundé P.O. Box 337, Cameroon
| | - Christophe Antonio-Nkondjio
- Institut de Recherche de Yaoundé (IRY), Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), Yaoundé P.O. Box 288, Cameroon
- Vector Biology Liverpool School of Tropical Medicine Pembroke Place, Liverpool L3 5QA, UK
- Correspondence: (S.M.N.-N.); (C.A.-N.)
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Chiuya T, Villinger J, Falzon LC, Alumasa L, Amanya F, Bastos ADS, Fèvre EM, Masiga DK. Molecular screening reveals non-uniform malaria transmission in western Kenya and absence of Rickettsia africae and selected arboviruses in hospital patients. Malar J 2022; 21:268. [PMID: 36115978 PMCID: PMC9482282 DOI: 10.1186/s12936-022-04287-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 09/07/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
In sub-Saharan Africa, malaria is the common diagnosis for febrile illness and related clinical features, resulting in the under-diagnosis of other aetiologies, such as arboviruses and Rickettsia. While these may not be significant causes of mortality in malaria-endemic areas, they affect the daily life and performance of affected individuals. It is, therefore, important to have a clear picture of these other aetiologies to institute correct diagnoses at hospitals and improve patient outcomes.
Methods
Blood samples were collected from patients with fever and other clinical features associated with febrile illness at selected hospitals in the malaria-endemic counties of Busia, Bungoma, and Kakamega, and screened for Crimean-Congo haemorrhagic fever, Sindbis, dengue and chikungunya viruses, Rickettsia africae, and Plasmodium spp. using high-throughput real-time PCR techniques. A logistic regression was performed on the results to explore the effect of demographic and socio-economic independent variables on malaria infection.
Results
A total of 336 blood samples collected from hospital patients between January 2018 and February 2019 were screened, of which 17.6% (59/336) were positive for Plasmodium falciparum and 1.5% (5/336) for Plasmodium malariae. Two patients had dual P. falciparum/P. malariae infections. The most common clinical features reported by the patients who tested positive for malaria were fever and headache. None of the patients were positive for the arboviruses of interest or R. africae. Patients living in Busia (OR 5.2; 95% CI 2.46–11.79; p < 0.001) and Bungoma counties (OR 2.7; 95% CI 1.27–6.16; p = 0.013) had higher odds of being infected with malaria, compared to those living in Kakamega County.
Conclusions
The reported malaria prevalence is in line with previous studies. The absence of arboviral and R. africae cases in this study may have been due to the limited number of samples screened, low-level circulation of arboviruses during inter-epidemic periods, and/or the use of PCR alone as a detection method. Other sero-surveys confirming their circulation in the area indicate that further investigations are warranted.
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Abstract
Ticks are hematophagous ectoparasites capable of transmitting multiple human pathogens. Environmental changes have supported the expansion of ticks into new geographical areas that have become the epicenters of tick-borne diseases (TBDs). The spotted fever group (SFG) of Rickettsia frequently infects ticks and causes tick-transmitted rickettsioses in areas of endemicity where ixodid ticks support host transmission during blood feeding. Ticks also serve as a reservoir for SFG Rickettsia. Among the members of SFG Rickettsia, R. rickettsii causes Rocky Mountain spotted fever (RMSF), the most lethal TBD in the United States. Cases of RMSF have been reported for over a century in association with several species of ticks in the United States. However, the isolation of R. rickettsii from ticks has decreased, and recent serological and epidemiological studies suggest that novel species of SFG Rickettsia are responsible for the increased number of cases of RMSF-like rickettsioses in the United States. Recent analyses of rickettsial genomes and advances in genetic and molecular studies of Rickettsia provided insights into the biology of Rickettsia with the identification of conserved and unique putative virulence genes involved in the rickettsial life cycle. Thus, understanding Rickettsia-host-tick interactions mediating successful disease transmission and pathogenesis for SFG rickettsiae remains an active area of research. This review summarizes recent advances in understanding how SFG Rickettsia species coopt and manipulate ticks and mammalian hosts to cause rickettsioses, with a particular emphasis on newly described or emerging SFG Rickettsia species.
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Entomological risk of African tick-bite fever (Rickettsia africae infection) in Eswatini. PLoS Negl Trop Dis 2022; 16:e0010437. [PMID: 35576190 PMCID: PMC9135330 DOI: 10.1371/journal.pntd.0010437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 05/26/2022] [Accepted: 04/20/2022] [Indexed: 11/19/2022] Open
Abstract
Background
Rickettsia africae is a tick-borne bacterium that causes African tick-bite fever (ATBF) in humans. In southern Africa, the tick Amblyomma hebraeum serves as the primary vector and reservoir for R. africae and transmits the bacterium during any life stage. Previous research has shown that even when malaria has been dramatically reduced, unexplained acute febrile illnesses persist and may be explained by the serological evidence of rickettsiae in humans.
Methodology/Principal findings
We collected 12,711 questing Amblyomma larvae across multiple land use types in a savanna landscape in Eswatini. Our results show that host-seeking Amblyomma larvae are abundant across both space and time, with no significant difference in density by land use or season. We investigated the entomological risk (density of infected larvae) of ATBF from A. hebraeum larvae by testing over 1,600 individual larvae for the presence of R. africae using a novel multiplex qPCR assay. We found an infection prevalence of 64.9% (95% CI: 62.1–67.6%) with no land use type significantly impacting prevalence during the dry season of 2018. The mean density of infected larvae was 57.3 individuals per 100m2 (95% CI: 49–65 individuals per 100m2).
Conclusions
Collectively, our results demonstrate R. africae infected A. hebraeum larvae, the most common tick species and life stage to bite humans in southern Africa, are ubiquitous in the savanna landscape of this region. Increased awareness of rickettsial diseases is warranted for policymakers, scientists, clinicians, and patients. Early detection of disease via increased clinician awareness and rapid diagnostics will improve patient outcomes for travelers and residents of this region.
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Nemg FBS, Abanda NN, Yonga MG, Ouapi D, Samme IE, Djoumetio MD, Endegue-Zanga MC, Demanou M, Njouom R. Sustained circulation of yellow fever virus in Cameroon: an analysis of laboratory surveillance data, 2010-2020. BMC Infect Dis 2022; 22:418. [PMID: 35488234 PMCID: PMC9055699 DOI: 10.1186/s12879-022-07407-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 04/20/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The re-emergence of yellow fever poses a serious public health risk to unimmunized communities in the tropical regions of Africa and South America and unvaccinated travelers visiting these regions. This risk is further accentuated by the likely spread of the virus to areas with potential for yellow fever transmission such as in Asia, Europe, and North America. To mitigate this risk, surveillance of yellow fever is pivotal. We performed an analysis of laboratory-based surveillance of yellow fever suspected cases in Cameroon during 2010-2020 to characterize the epidemiology of yellow fever cases and define health districts at high risk. METHOD We reviewed IgM capture ELISA and plaque reduction neutralization test (PRNT) test results of all suspected yellow fever patients analyzed at Centre Pasteur of Cameroon, the national yellow fever testing laboratory, during 2010-2020. RESULTS Of the 20,261 yellow fever suspected patient's samples that were tested, yellow fever IgM antibodies were detected in 360 patients representing an annual average of 33 cases/year. A major increase in YF IgM positive cases was observed in 2015 and in 2016 followed by a decrease in cases to below pre-2015 levels. The majority of the 2015 cases occurred during the latter part of the year while those in 2016, occurred between February and May. This trend may be due to an increase in transmission that began in late 2015 and continued to early 2016 or due to two separate transmission events. In 2016, where the highest number of cases were detected, 60 health districts in the 10 regions of Cameroon were affected with the Littoral, Northwest and, Far North regions being the most affected. After 2016, the number of detected yellow fever IgM positive cases dropped. CONCLUSION Our study shows that yellow fever transmission continues to persist and seems to be occurring all over Cameroon with all 10 regions under surveillance reporting a case. Preventive measures such as mass vaccination campaigns and routine childhood immunizations are urgently needed to increase population immunity. The diagnostic limitations in our analysis highlight the need to strengthen laboratory capacity and improve case investigations.
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Affiliation(s)
| | - Ngu Njei Abanda
- Virology Unit, Virology Service, Centre Pasteur of Cameroon, 451 Rue 2005, BP 1274, Yaounde, Cameroon.
| | - Martial Gide Yonga
- Virology Unit, Virology Service, Centre Pasteur of Cameroon, 451 Rue 2005, BP 1274, Yaounde, Cameroon
| | - Diane Ouapi
- Virology Unit, Virology Service, Centre Pasteur of Cameroon, 451 Rue 2005, BP 1274, Yaounde, Cameroon
| | - Ivis Ewang Samme
- Expanded Programme on Immunization, Ministry of Public Health, Yaoundé, Cameroon
| | | | | | - Maurice Demanou
- World Health Organization, Inter-Country Support Team West Africa, 03 BP 7019, Ouagadougou, Burkina Faso
| | - Richard Njouom
- Virology Unit, Virology Service, Centre Pasteur of Cameroon, 451 Rue 2005, BP 1274, Yaounde, Cameroon
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11
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Silva-Ramos CR, Faccini-Martínez ÁA. Clinical, epidemiological, and laboratory features of Rickettsia africae infection, African tick-bite fever: A systematic review. LE INFEZIONI IN MEDICINA 2022; 29:366-377. [PMID: 35146341 DOI: 10.53854/liim-2903-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 07/27/2021] [Indexed: 11/03/2022]
Abstract
African tick-bite fever (ATBF), caused by Rickettsia africae, is the main tick-borne rickettsiosis and the second most frequent cause of fever after malaria in travelers returning from sub-Saharan Africa. General descriptions on ATBF were made in the first two decades after recognized as a new infectious entity, and since then, many authors have contributed to the knowledge of the disease by reporting clinical cases in scientific literature. We developed a systematic review that evaluated all available evidence in the literature regarding clinical, epidemiological, and laboratory features of confirmed R. africae rickettsiosis cases. We followed the recommendations made by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guide. A total of 48 scientific publications (108 confirmed cases) were analyzed in order to extract data for developing this review. Overall, our results show that R. africae rickettsiosis is more frequent in males in the age group of 18-64 years, more than 80% of the cases occurred in European travelers, South Africa was the country where most infections were acquired, and almost 40% of cases occurred in clusters. Clinically, more than 80% of the cases had fever and eschar (55% developed multiple eschars), rash was present in less than the half of cases, and lymphangitis was not a common sign (11%). Headache, myalgia and regional lymphadenopathy were predominant nonspecific clinical manifestation (mean of 60%, 49% and 51%, respectively). Our results show that at least 70% of R. africae cases had altered laboratory parameters, most often showing an increase in transaminases and C-reactive protein. Tetracycline-class antibiotics, as monotherapy, were used in most (>90%) of the patients. Overall, only 4% of cases had complications, 12% required hospitalization, and there was a 100% rate of clinical recovery.
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Affiliation(s)
- Carlos Ramiro Silva-Ramos
- Grupo de Enfermedades Infecciosas, Departamento de Microbiología, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Álvaro A Faccini-Martínez
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA.,Committee of Tropical Medicine, Zoonoses and Travel Medicine, Asociación Colombiana de Infectología, Bogotá, Colombia
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12
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Chiuya T, Villinger J, Masiga DK, Ondifu DO, Murungi MK, Wambua L, Bastos ADS, Fèvre EM, Falzon LC. Molecular prevalence and risk factors associated with tick-borne pathogens in cattle in western Kenya. BMC Vet Res 2021; 17:363. [PMID: 34838023 PMCID: PMC8627057 DOI: 10.1186/s12917-021-03074-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 11/05/2021] [Indexed: 11/29/2022] Open
Abstract
Background Tick-borne pathogens (TBPs) are of global importance, especially in sub-Saharan Africa where they represent a major constraint to livestock production. Their association with human disease is also increasingly recognized, signalling their zoonotic importance. It is therefore crucial to investigate TBPs prevalence in livestock populations and the factors associated with their presence. We set out to identify TBPs present in cattle and to determine associated risk factors in western Kenya, where smallholder livestock production is important for subsistence and market-driven income. Results Tick-borne pathogen infections in blood samples collected from cattle at livestock markets and slaughterhouses between May 2017 and January 2019 were identified by high-resolution melting analysis and sequencing of PCR products of genus-specific primers. Of the 422 cattle sampled, 30.1% (127/422) were infected with at least one TBP, while 8.8% (37/422) had dual infections. Anaplasma spp. (19.7%) were the most prevalent, followed by Theileria (12.3%), Ehrlichia (6.6%), and Babesia (0.2%) spp. Sequence analysis of the TBPs revealed them to be Anaplasma platys-like organisms (13.5%), Theileria velifera (7.4%), Anaplasma marginale (4.9%), Theileria mutans (3.1%), Theileria parva (1.6%), and Babesia bigemina (0.2%). Ehrlichia ruminantium, Rickettsia spp., and arboviruses were not detected. Exotic breeds of cattle were more likely to be infected with A. marginale compared to local breeds (OR: 7.99, 95% CI: 3.04–22.02, p < 0.001). Presence of ticks was a significant predictor for Anaplasma spp. (OR: 2.18, 95% CI: 1.32–3.69, p = 0.003) and Ehrlichia spp. (OR: 2.79, 95% CI: 1.22–7.23, p = 0.022) infection. Cattle sampled at slaughterhouses were more likely to be positive for Anaplasma spp. (OR: 1.64, 95% CI: 1.01–2.70, p = 0.048) and A. marginale (OR: 3.84, 95% CI: 1.43–12.21, p = 0.012), compared to those sampled at livestock markets. Conclusion This study reports TBP prevalence and associated risk factors in western Kenya, factors which are key to informing surveillance and control measures.
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Affiliation(s)
- Tatenda Chiuya
- International Centre of Insect Physiology and Ecology (icipe), P.O Box 30772-00100, Nairobi, Kenya. .,Department of Zoology and Entomology, University of Pretoria, Private Bag 20, Pretoria, 0028, South Africa.
| | - Jandouwe Villinger
- International Centre of Insect Physiology and Ecology (icipe), P.O Box 30772-00100, Nairobi, Kenya
| | - Daniel K Masiga
- International Centre of Insect Physiology and Ecology (icipe), P.O Box 30772-00100, Nairobi, Kenya
| | - Dickens O Ondifu
- International Centre of Insect Physiology and Ecology (icipe), P.O Box 30772-00100, Nairobi, Kenya
| | - Maurice K Murungi
- International Livestock Research Institute, Old Naivasha Road, P.O Box 30709, Nairobi, 00100, Kenya
| | - Lillian Wambua
- International Livestock Research Institute, Old Naivasha Road, P.O Box 30709, Nairobi, 00100, Kenya
| | - Armanda D S Bastos
- Department of Zoology and Entomology, University of Pretoria, Private Bag 20, Pretoria, 0028, South Africa
| | - Eric M Fèvre
- International Livestock Research Institute, Old Naivasha Road, P.O Box 30709, Nairobi, 00100, Kenya.,Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Leahurst Campus, Chester High Road, Neston, CH64 7TE, UK
| | - Laura C Falzon
- International Livestock Research Institute, Old Naivasha Road, P.O Box 30709, Nairobi, 00100, Kenya. .,Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Leahurst Campus, Chester High Road, Neston, CH64 7TE, UK.
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13
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Bamou R, Mayi MPA, Djiappi-Tchamen B, Nana-Ndjangwo SM, Nchoutpouen E, Cornel AJ, Awono-Ambene P, Parola P, Tchuinkam T, Antonio-Nkondjio C. An update on the mosquito fauna and mosquito-borne diseases distribution in Cameroon. Parasit Vectors 2021; 14:527. [PMID: 34635176 PMCID: PMC8507310 DOI: 10.1186/s13071-021-04950-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 08/12/2021] [Indexed: 11/10/2022] Open
Abstract
The expansion of mosquito-borne diseases such as dengue, yellow fever, and chikungunya in the past 15 years has ignited the need for active surveillance of common and neglected mosquito-borne infectious diseases. The surveillance should be designed to detect diseases and to provide relevant field-based data for developing and implementing effective control measures to prevent outbreaks before significant public health consequences can occur. Mosquitoes are important vectors of human and animal pathogens, and knowledge on their biodiversity and distribution in the Afrotropical region is needed for the development of evidence-based vector control strategies. Following a comprehensive literature search, an inventory of the diversity and distribution of mosquitoes as well as the different mosquito-borne diseases found in Cameroon was made. A total of 290 publications/reports and the mosquito catalogue website were consulted for the review. To date, about 307 species, four subspecies and one putative new species of Culicidae, comprising 60 species and one putative new species of Anopheles, 67 species and two subspecies of Culex, 77 species and one subspecies of Aedes, 31 species and one subspecies of Eretmapodites, two Mansonia, eight Coquillettidia, and 62 species with unknown medical and veterinary importance (Toxorhynchites, Uranotaenia, Mimomyia, Malaya, Hodgesia, Ficalbia, Orthopodomyia, Aedeomyia, and Culiseta and Lutzia) have been collected in Cameroon. Multiple mosquito species implicated in the transmission of pathogens within Anopheles, Culex, Aedes, Eretmapodites, Mansonia, and Coquillettidia have been reported in Cameroon. Furthermore, the presence of 26 human and zoonotic arboviral diseases, one helminthic disease, and two protozoal diseases has been reported. Information on the bionomics, taxonomy, and distribution of mosquito species will be useful for the development of integrated vector management programmes for the surveillance and elimination of mosquito-borne diseases in Cameroon. ![]()
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Affiliation(s)
- Roland Bamou
- Vector Borne Diseases Laboratory of the Biology and Applied Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Science of the University of Dschang, Dschang, Cameroon. .,Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroon. .,Aix Marseille Univ, IRD, SSA, AP-HM, UMR Vecteurs-Infections Tropicales et Méditerranéennes (VITROME), Marseille, France. .,IHU Méditerranée Infection, Marseille, France.
| | - Marie Paul Audrey Mayi
- Vector Borne Diseases Laboratory of the Biology and Applied Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Science of the University of Dschang, Dschang, Cameroon
| | - Borel Djiappi-Tchamen
- Vector Borne Diseases Laboratory of the Biology and Applied Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Science of the University of Dschang, Dschang, Cameroon.,Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroon
| | - Stella Mariette Nana-Ndjangwo
- Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroon.,Laboratoire de Parasitologie et d'écologie, Université de Yaoundé 1, Yaoundé, Cameroun
| | - Elysée Nchoutpouen
- Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroon
| | - Antony John Cornel
- Department of Entomology and Nematology, Mosquito Control Research Laboratory, University of California, Davis, California, USA
| | - Parfait Awono-Ambene
- Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroon
| | - Phillipe Parola
- Aix Marseille Univ, IRD, SSA, AP-HM, UMR Vecteurs-Infections Tropicales et Méditerranéennes (VITROME), Marseille, France.,IHU Méditerranée Infection, Marseille, France
| | - Timoléon Tchuinkam
- Vector Borne Diseases Laboratory of the Biology and Applied Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Science of the University of Dschang, Dschang, Cameroon
| | - Christophe Antonio-Nkondjio
- Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroon.,Vector Biology Liverpool School of Tropical Medicine, Liverpool, UK
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14
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Nkenfou CN, Fainguem N, Dongmo-Nguefack F, Yatchou LG, Kameni JJK, Elong EL, Samie A, Estrin W, Koki PN, Ndjolo A. Enhanced passive surveillance dengue infection among febrile children: Prevalence, co-infections and associated factors in Cameroon. PLoS Negl Trop Dis 2021; 15:e0009316. [PMID: 33861747 PMCID: PMC8051767 DOI: 10.1371/journal.pntd.0009316] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 03/16/2021] [Indexed: 11/18/2022] Open
Abstract
Dengue virus (DENV) causes a spectrum of diseases ranging from asymptomatic, mild febrile to a life-threatening illness: dengue hemorrhagic fever. The main clinical symptom of dengue is fever, similar to that of malaria. The prevalence of dengue virus infection, alone or in association with other endemic infectious diseases in children in Cameroon is unknown. The aim of this study was to determine the prevalence of dengue, malaria and HIV in children presenting with fever and associated risk factors. Dengue overall prevalence was 20.2%, Malaria cases were 52.7% and HIV cases represented 12.6%. The prevalence of dengue-HIV co-infection was 6.0% and that of Malaria-dengue co-infection was 19.5%. Triple infection prevalence was 4.3%. Dengue virus infection is present in children and HIV-Dengue or Dengue- Malaria co-infections are common. Dengue peak prevalence was between August and October. Sex and age were not associated with dengue and dengue co-infections. However, malaria as well as HIV were significantly associated with dengue (P = 0.001 and 0.028 respectively). The diagnosis of dengue and Malaria should be carried out routinely for better management of fever. Fever is a symptom common to several infectious diseases such as malaria, yellow fever, dengue fever and typhoid which are all present in Cameroon. In most cases, fever in Cameroon is assumed to be due to malaria and treated as such. This study present the prevalence of dengue fever among febrile children. Dengue fever as well as malaria is common among Cameroonian children. Since Cameroon is endemic for malaria, fever may indicate either malaria or dengue. Clinicians should be aware of the presence of dengue in Cameroon. Knowing the risk factors, parents are encouraged to use the bed net to protect their children and clean stagnant water from their environment. Children could be co-infected by dengue, malaria as well as HIV. Management of patients with dengue fever and HIV infection should be studied, especially in infants where both viral diseases are more severe. Close monitoring may prevent complications among HIV-infected individuals who contract dengue fever.
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Affiliation(s)
- Celine Nguefeu Nkenfou
- “Chantal Biya” International Reference Centre for Research on HIV and AIDS Prevention and Management (CIRCB), Yaoundé, Cameroon
- University of Yaoundé I, Higher Teachers’ Training College, Department of Biology, Yaoundé, Cameroon
- * E-mail:
| | - Nadine Fainguem
- “Chantal Biya” International Reference Centre for Research on HIV and AIDS Prevention and Management (CIRCB), Yaoundé, Cameroon
| | - Félicitée Dongmo-Nguefack
- Mother and Child Centre of the Chantal Biya Foundation, Pediatric Service, Yaoundé, Cameroon
- University of Yaoundé I, Faculty of Medicine and Biomedical Sciences, Yaoundé, Cameroon
| | - Laeticia Grace Yatchou
- “Chantal Biya” International Reference Centre for Research on HIV and AIDS Prevention and Management (CIRCB), Yaoundé, Cameroon
| | - Joel Josephine Kadji Kameni
- “Chantal Biya” International Reference Centre for Research on HIV and AIDS Prevention and Management (CIRCB), Yaoundé, Cameroon
| | - Elise Lobe Elong
- “Chantal Biya” International Reference Centre for Research on HIV and AIDS Prevention and Management (CIRCB), Yaoundé, Cameroon
| | - Amidou Samie
- Department of Microbiology, University of Venda, Venda, South Africa
| | - William Estrin
- California Pacific Medical Center, San Francisco, CA, United States of America
| | - Paul Ndombo Koki
- Mother and Child Centre of the Chantal Biya Foundation, Pediatric Service, Yaoundé, Cameroon
- University of Yaoundé I, Faculty of Medicine and Biomedical Sciences, Yaoundé, Cameroon
| | - Alexis Ndjolo
- “Chantal Biya” International Reference Centre for Research on HIV and AIDS Prevention and Management (CIRCB), Yaoundé, Cameroon
- University of Yaoundé I, Faculty of Medicine and Biomedical Sciences, Yaoundé, Cameroon
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15
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Chiuya T, Masiga DK, Falzon LC, Bastos ADS, Fèvre EM, Villinger J. Tick-borne pathogens, including Crimean-Congo haemorrhagic fever virus, at livestock markets and slaughterhouses in western Kenya. Transbound Emerg Dis 2020; 68:2429-2445. [PMID: 33142046 PMCID: PMC8359211 DOI: 10.1111/tbed.13911] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 10/26/2020] [Accepted: 10/31/2020] [Indexed: 12/14/2022]
Abstract
Vectors of emerging infectious diseases have expanded their distributional ranges in recent decades due to increased global travel, trade connectivity and climate change. Transboundary range shifts, arising from the continuous movement of humans and livestock across borders, are of particular disease control concern. Several tick-borne diseases are known to circulate between eastern Uganda and the western counties of Kenya, with one fatal case of Crimean-Congo haemorrhagic fever (CCHF) reported in 2000 in western Kenya. Recent reports of CCHF in Uganda have highlighted the risk of cross-border disease translocation and the importance of establishing inter-epidemic, early warning systems to detect possible outbreaks. We therefore carried out surveillance of tick-borne zoonotic pathogens at livestock markets and slaughterhouses in three counties of western Kenya that neighbour Uganda. Ticks and other ectoparasites were collected from livestock and identified using morphological keys. The two most frequently sampled tick species were Rhipicephalus decoloratus (35%) and Amblyomma variegatum (30%); Ctenocephalides felis fleas and Haematopinus suis lice were also present. In total, 486 ticks, lice and fleas were screened for pathogen presence using established molecular workflows incorporating high-resolution melting analysis and identified through sequencing of PCR products. We detected CCHF virus in Rh. decoloratus and Rhipicephalus sp. cattle ticks, and 82 of 96 pools of Am. variegatum were positive for Rickettsia africae. Apicomplexan protozoa and bacteria of veterinary importance, such as Theileria parva, Babesia bigemina and Anaplasma marginale, were primarily detected in rhipicephaline ticks. Our findings show the presence of several pathogens of public health and veterinary importance in ticks from livestock at livestock markets and slaughterhouses in western Kenya. Confirmation of CCHF virus, a Nairovirus that causes haemorrhagic fever with a high case fatality rate in humans, highlights the risk of under-diagnosed zoonotic diseases and calls for continuous surveillance and the development of preventative measures.
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Affiliation(s)
- Tatenda Chiuya
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya.,Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Daniel K Masiga
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Laura C Falzon
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Neston, UK.,International Livestock Research Institute, Nairobi, Kenya
| | - Armanda D S Bastos
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Eric M Fèvre
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Neston, UK.,International Livestock Research Institute, Nairobi, Kenya
| | - Jandouwe Villinger
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
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16
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Barradas PF, Mesquita JR, Ferreira P, Gärtner F, Carvalho M, Inácio E, Chivinda E, Katimba A, Amorim I. Molecular identification and characterization of Rickettsia spp. and other tick-borne pathogens in cattle and their ticks from Huambo, Angola. Ticks Tick Borne Dis 2020; 12:101583. [PMID: 33160189 DOI: 10.1016/j.ttbdis.2020.101583] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 08/23/2020] [Accepted: 09/11/2020] [Indexed: 10/23/2022]
Abstract
Ticks are one of the most common vectors of a broad variety of pathogenic agents that significantly affects cattle production causing reduced productivity and important economic losses, while simultaneously having an impact on human health due to the zoonotic risk. In much of the territory of Angola urban population has grown rapidly in recent decades, sharing today close contact with large farms that are generally owned by city residents, providing the ideal conditions for vector-borne pathogens (VBP) transmission between animals and humans. Here we studied the occurrence of Rickettsia, Anaplasma, Ehrlichia, Babesia and Theileria in domestic cattle (n = 98) from Huambo, Angola, and their ticks (n = 116) to obtain a more detailed knowledge into the spectrum of tick-borne agents circulating in this population. We morphologically identified Amblyomma variegatum, Rhipicephalus decoloratus and R. evertsi mimeticus ticks, further confirmed by molecular analysis of the 12S rDNA and 16S rDNA genes. Although none of the bovine blood showed to be positive for R. africae by the ompB, ompA and gltA assays, five ticks showed to be positive for R. africae by the ompB, ompA and the gltA PCRs. Two 18S rRNA sequences were retrieved from bovine blood and one sequence from A. variegatum tick, showing 100% identity with Theileria mutans. By using a PCR targeting the 16S rRNA gene of Anaplama spp. we have also obtained six bovine blood samples showing 99-100 % nucleotide sequence identity with A. capra, two showing 98 % nucleotide sequence identity with A. phagocytophilum and three showing 98-100 % nucleotide sequence identity with A. platys. None of the ticks were positive. The present study shows the presence of a wide range of vector-borne diseases in domestic cattle and their ticks in Huambo province, Angola. Given the lack of both animal and human health infrastructures in this rural region, swift diagnosis and treatment is hampered which could produce a more severe impact on health.
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Affiliation(s)
- Patrícia F Barradas
- Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal; Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Porto, Portugal
| | - João R Mesquita
- Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal; Epidemiology Research Unit (EPIUnit), Instituto de Saúde Pública da Universidade do Porto, Porto, Portugal
| | - Paula Ferreira
- Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal
| | - Fátima Gärtner
- Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal; Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Porto, Portugal; Institute for Research and Innovation in Health (i3S), University of Porto, Porto, Portugal
| | - Madalena Carvalho
- Faculty of Veterinary Medicine, University José Eduardo dos Santos, Huambo, Angola
| | - Esmeralda Inácio
- Faculty of Veterinary Medicine, University José Eduardo dos Santos, Huambo, Angola
| | - Eduardo Chivinda
- Faculty of Veterinary Medicine, University José Eduardo dos Santos, Huambo, Angola
| | - António Katimba
- Faculty of Veterinary Medicine, University José Eduardo dos Santos, Huambo, Angola
| | - Irina Amorim
- Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal; Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Porto, Portugal; Institute for Research and Innovation in Health (i3S), University of Porto, Porto, Portugal.
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Serological Evidence of Rickettsia Exposure among Patients with Unknown Fever Origin in Angola, 2016-2017. Interdiscip Perspect Infect Dis 2020; 2020:4905783. [PMID: 32908499 PMCID: PMC7463337 DOI: 10.1155/2020/4905783] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 06/04/2020] [Accepted: 07/09/2020] [Indexed: 11/18/2022] Open
Abstract
Spotted fever group Rickettsia (SFGR) is one among the aetiologies that cause fever of unknown origin in Angola. Despite their occurrence, there is little information about its magnitude in this country either because it is misdiagnosed or due to the lack of diagnostic resources. For this purpose, eighty-seven selected malaria- and yellow fever-negative serum specimens collected between February 2016 and March 2017 as part of the National Laboratory of Febrile Syndromes, from patients with fever (≥37.5°C) for at least 4 days and of unknown origin, were screened for Rickettsia antibodies through an immunofluorescence assay (IFA). Serological results were interpreted according to the 2017 guidelines for the detection of Rickettsia spp. Three seroreactive patients had detectable IgM antibodies to Rickettsia with an endpoint titre of 32 and IgG antibodies with endpoint titres of 128 and 256. These findings supported a diagnosis of Rickettsia exposure amongst these patients and highlight that rickettsioses may be among the cause of unknown febrile syndromes in Angola. Therefore, physicians must be aware of this reality and must include this vector-borne disease as part of aetiologies that should be considered and systematically tested in order to delineate appropriate strategies of diagnostic and control of Rickettsia in Angola.
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Habitat and Seasonality Affect Mosquito Community Composition in the West Region of Cameroon. INSECTS 2020; 11:insects11050312. [PMID: 32429075 PMCID: PMC7291174 DOI: 10.3390/insects11050312] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 05/09/2020] [Accepted: 05/12/2020] [Indexed: 12/20/2022]
Abstract
To identify potential sylvatic, urban and bridge-vectors that can be involved in current or future virus spillover from wild to more urbanised areas, entomological field surveys were conducted in rural, peri-urban and urban areas spanning the rainy and dry seasons in western Cameroon. A total of 2650 mosquitoes belonging to 37 species and eight genera were collected. Mosquito species richness was significantly influenced by the specific combination of the habitat type and the season. The highest species richness was found in the peri-urban area (S = 30, Chao1 = 121 ± 50.63, ACE = 51.97 ± 3.88) during the dry season (S = 28, Chao1 = 64 ± 25.7, ACE = 38.33 ± 3.1). Aedes (Ae.) africanus and Culex (Cx.) moucheti were only found in the rural and peri-urban areas, while Cx. pipiens s.l. and Ae. aegypti were only found in the urban area. Cx. (Culiciomyia) spp., Cx. duttoni and Ae. albopictus were caught in the three habitat types. Importantly, approximately 52% of the mosquito species collected in this study have been implicated in the transmission of diverse arboviruses. This entomological survey provides a catalogue of the different mosquito species that may be involved in the transmission of arboviruses. Further investigations are needed to study the vectorial capacity of each mosquito species in arbovirus transmission.
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Kamgang B, Vazeille M, Tedjou AN, Wilson-Bahun TA, Yougang AP, Mousson L, Wondji CS, Failloux AB. Risk of dengue in Central Africa: Vector competence studies with Aedes aegypti and Aedes albopictus (Diptera: Culicidae) populations and dengue 2 virus. PLoS Negl Trop Dis 2019; 13:e0007985. [PMID: 31887138 PMCID: PMC6953884 DOI: 10.1371/journal.pntd.0007985] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 01/10/2020] [Accepted: 12/10/2019] [Indexed: 02/02/2023] Open
Abstract
Introduction Dengue is the most important mosquito-borne diseases worldwide but was considered scarce in West-Central Africa. During the last decade, dengue outbreaks have increasingly been reported in urban foci in this region suggesting major epidemiological changes. However, in Central Africa where both vectors, Aedes aegypti and Aedes albopictus are well established, the role of each species in dengue transmission remains poorly investigated. Methodology/Principal findings Field-collected strains of Ae. aegypti and Ae. albopictus from different ecological settings in Central Africa were experimentally challenged with dengue 2 virus (DENV-2). Mosquitoes were analysed at 14- and 21-days post-infection. Analysis provide evidence that both Ae. aegypti and Ae. albopictus in Central Africa were able to transmit dengue virus with Ae. aegypti exhibiting a higher transmission rate. Unexpectedly, two Ae. aegypti populations from Bénoué and Maroua, in northern Cameroon, were not able to transmit DENV-2. Conclusions/Significance We conclude that both Ae. aegypti and Ae. albopictus are susceptible to DENV-2 and may intervene as active dengue vectors. These findings highlight the urgent need to plan a vector surveillance program and control methods against dengue vectors in Central Africa in order to prevent future outbreaks. Dengue virus (DENV) is a flavivirus mainly transmitted to humans through the bite of infected mosquitoes notably Aedes aegypti and Aedes albopictus. In Central Africa where both vectors, Ae. aegypti and Ae. albopictus are well established, the role of each species in dengue transmission remains poorly investigated. Here, we assessed the vector competence of Ae. aegypti and Ae. albopictus collected in different ecological settings in Central Africa to transmit dengue 2 virus (DENV-2). We provide evidence that both Ae. aegypti and Ae. albopictus in Central Africa were able to transmit dengue virus with Ae. aegypti exhibiting a higher transmission rate. These findings could increase the risk of dengue outbreak in the region and emphasize the need for a comprehensive vector surveillance program to prevent and preparedness for an intervention in case of outbreaks.
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Affiliation(s)
- Basile Kamgang
- Centre for Research in Infectious Diseases, Department of Medical Entomology, Yaoundé, Cameroon
- * E-mail: ,
| | - Marie Vazeille
- Institut Pasteur, Department of Virology, Unit of Arboviruses and Insect Vectors, Paris, France
| | - Armel N. Tedjou
- Centre for Research in Infectious Diseases, Department of Medical Entomology, Yaoundé, Cameroon
- Department of Animal Biology, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon
| | - Theodel A. Wilson-Bahun
- Centre for Research in Infectious Diseases, Department of Medical Entomology, Yaoundé, Cameroon
- Faculty of Science and Technology, Marien Ngouabi University, Brazzaville, Congo
| | - Aurélie P. Yougang
- Centre for Research in Infectious Diseases, Department of Medical Entomology, Yaoundé, Cameroon
- Department of Animal Biology, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon
| | - Laurence Mousson
- Institut Pasteur, Department of Virology, Unit of Arboviruses and Insect Vectors, Paris, France
| | - Charles S. Wondji
- Centre for Research in Infectious Diseases, Department of Medical Entomology, Yaoundé, Cameroon
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Anna-Bella Failloux
- Institut Pasteur, Department of Virology, Unit of Arboviruses and Insect Vectors, Paris, France
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Nemg Simo FB, Sado Yousseu FB, Evouna Mbarga A, Bigna JJ, Melong A, Ntoude A, Kamgang B, Bouyne R, Moundipa Fewou P, Demanou M. Investigation of an Outbreak of Dengue Virus Serotype 1 in a Rural Area of Kribi, South Cameroon: A Cross-Sectional Study. Intervirology 2019; 61:265-271. [PMID: 31048588 DOI: 10.1159/000499465] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 03/08/2019] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND On May 2017, a case of dengue serotype 1 was detected and confirmed through routine surveillance in a traveler returning from Kribi, a seaside town of Southern Cameroon. This study aimed at confirming the circulation of dengue virus (DENV) in Southern Cameroon. METHODS A cross sectional study was carried out in Londji near Kribi from June 21-25, 2017, by a joint team of Centre Pasteur of Cameroon and the Department of Diseases, Epidemics and Pandemics Control. Blood samples of consented participants were collected and tested for anti-D ENV IgM using an IgM antibody capture enzyme-linked immunosorbent assay (MAC-ELISA), and for the detection of Zika, dengue, or chikungunya viruses using Trioplex real-time reverse transcription-polymerase chain reaction (RT-PCR). DENV RNA-positive samples were serotyped using an end-point nested RT-PCR. RESULTS Ninety-one participants were enrolled, 50.55% (46/91) of them males. The mean age of the population was 30.71 years (±18.89). In total, 14.28% (13/91) of the participants had DENV infection (3 anti-DENV IgM positive and 10 DENV serotype 1 RT-PCR positive). CONCLUSION The detection of DENV serotype 1 in an autochthonous population during this survey is a confirmation that the seaside city of Kribi is a risk area for contracting dengue infection in Cameroon.
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Affiliation(s)
- Fredy Brice Nemg Simo
- National Reference Laboratory for Chikungunya and Dengue, Department of Virology, Centre Pasteur of Cameroon, Yaoundé, Cameroon.,Department of Biochemistry, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
| | - Francine Berlange Sado Yousseu
- National Reference Laboratory for Chikungunya and Dengue, Department of Virology, Centre Pasteur of Cameroon, Yaoundé, Cameroon
| | - Armel Evouna Mbarga
- Cameroon Field Epidemiology Training Program, Ministry of Public Health, Yaoundé, Cameroon
| | - Jean Joel Bigna
- School of Public Health, Faculty of Medicine, University of Paris Sud, Kremlin Bicêtre, Paris, France
| | - Armel Melong
- Cameroon Field Epidemiology Training Program, Ministry of Public Health, Yaoundé, Cameroon
| | - Anicet Ntoude
- Délégation régionale de la santé publique du Sud Cameroun, Ebolowa, Cameroon
| | - Basile Kamgang
- Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroon
| | - Raphael Bouyne
- Centre Médico-Social de l'Ambassade de France, Yaoundé, Cameroon
| | - Paul Moundipa Fewou
- Department of Biochemistry, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
| | - Maurice Demanou
- National Reference Laboratory for Chikungunya and Dengue, Department of Virology, Centre Pasteur of Cameroon, Yaoundé, Cameroon,
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Tedjou AN, Kamgang B, Yougang AP, Njiokou F, Wondji CS. Update on the geographical distribution and prevalence of Aedes aegypti and Aedes albopictus (Diptera: Culicidae), two major arbovirus vectors in Cameroon. PLoS Negl Trop Dis 2019; 13:e0007137. [PMID: 30883552 PMCID: PMC6438584 DOI: 10.1371/journal.pntd.0007137] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 03/28/2019] [Accepted: 01/07/2019] [Indexed: 01/02/2023] Open
Abstract
Introduction Arboviral diseases including dengue are increasingly spreading in the tropical/subtropical world including Africa. Updated knowledge on the distribution and abundance of the major vectors Aedes aegypti and Aedes albopictus constitutes crucial surveillance action to prepare African countries such as Cameroon for potential arbovirus outbreaks. Here, we present a nationwide survey in Cameroon to assess the current geographical distribution and prevalence of both vectors including a genetic diversity profiling of Ae. albopictus (invasive species) using mitochondrial DNA. Methods Immature stages of Aedes were collected between March and August 2017 in 29 localities across Cameroon following north-south and east-west transects. Larvae and pupae were collected from several containers in each location, reared to adult and morphologically identified. Genetic diversity of Ae. albopictus from 16 locations were analysed using Cytochrome Oxidase I gene (COI). Results In total, 30,381 immature stages of Aedes with an average of 646.40±414.21 per location were identified across the country comprising 69.3% of Ae. albopictus and 30.7% of Ae. aegypti. Analysis revealed that Ae. aegypti is still distributed nation widely whereas Ae. albopictus is limited to the southern part, around 6°4’N. However, Ae. albopictus is the most prevalent species in all southern locations where both species are sympatric except in Douala where Ae. aegypti is predominant. This suggests that factors such as climate, vegetation, and building density impact the distribution of both species in Cameroon. Mitochondrial DNA analysis revealed a low genetic diversity in Ae. albopictus populations with a major common haplotype resulting in low haplotype diversity ranging from 0.13 to 0.65 and 0.35 for the total sample. Similarly, low nucleotide diversity was also reported varying from 0.0000 to 0.0017 with an overall index of 0.0008. This low genetic polymorphism is consistent with the recent introduction of Ae. albopictus in Cameroon. Conclusion This updated distribution of arbovirus vectors across Cameroon will help in planning vector control programme against possible outbreak of arbovirus related diseases in the country. Aedes albopictus and Ae. aegypti are the most important arbovirus vectors worldwide. Ae. albopictus, native of Asia, was recorded for the first time in early 2000s in Cameroon, central Africa. Previous studies performed a decade ago in Cameroon showed that Ae. albopictus has a geographical distribution limited to the south under 6°N. Whereas the native species Ae. aegypti was present across the country. To update our knowledge in this regards, a nationwide survey was performed in Cameroon to assess the current geographical distribution and prevalence of both vectors including a genetic diversity profiling of Ae. albopictus (invasive species) using mitochondrial DNA. Analysis revealed that Ae. aegypti is still distributed nation widely whereas Ae. albopictus is limited to the southern part, around 6°4’N. However, Ae. albopictus is the most prevalent species in all southern locations where both species are sympatric except in Douala where Ae. aegypti is predominant. This suggests that factors such as climate, vegetation and building density impact the distribution of both species in Cameroon. Mitochondrial DNA analysis revealed a low genetic diversity in Ae. albopictus populations with a major common haplotype detected in almost all locations. This study provides the relevant data that can be helpful to establish the vector surveillance of epidemic arbovirus vectors across the country.
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Affiliation(s)
- Armel N. Tedjou
- Centre for Research in Infectious Diseases, Yaoundé, Cameroon
- Department of Animal Biology, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon
| | - Basile Kamgang
- Centre for Research in Infectious Diseases, Yaoundé, Cameroon
- * E-mail:
| | - Aurélie P. Yougang
- Centre for Research in Infectious Diseases, Yaoundé, Cameroon
- Department of Animal Biology, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon
| | - Flobert Njiokou
- Centre for Research in Infectious Diseases, Yaoundé, Cameroon
- Department of Animal Biology, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon
| | - Charles S. Wondji
- Centre for Research in Infectious Diseases, Yaoundé, Cameroon
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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22
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Tchuandom SB, Tchouangueu TF, Antonio-Nkondjio C, Lissom A, Djang JON, Atabonkeng EP, Kechia A, Nchinda G, Kuiate JR. Seroprevalence of dengue virus among children presenting with febrile illness in some public health facilities in Cameroon. Pan Afr Med J 2018; 31:177. [PMID: 31086629 PMCID: PMC6488248 DOI: 10.11604/pamj.2018.31.177.16390] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 08/21/2018] [Indexed: 01/05/2023] Open
Abstract
Introduction A routine diagnosis of Dengue virus (DENV) infection is not usually conducted in hospitals. Because symptoms overlap, many potential febrile illnesses due to DENV may be confused for malaria, typhoid or paratyphoid (enteric) fever. The absence of data on DENV exposure rates among children attending health facilities could undermine management of this disease. This study aimed to investigate the seroprevalence of dengue virus infection in children presenting febrile illness in some public health facilities in Cameroon. Methods A cross-sectional study was performed in children ≤ 15 years attending seven urban and three semi-urban public hospitals of Cameroon. From each volunteer, 2ml of whole blood was collected and tested for dengue virus IgM, malaria (Pf/Pan antigens) and enteric fever (Typhoid IgM) using rapid diagnostic tests (RDT); in order to allow the healthcare workers to quickly put the positive cases under appropriate treatment. Positive cases of dengue virus infection were confirmed by indirect ELISA. Data analysis were performed using the statistical package for social sciences software, version 22.1. Results A total of 961 children were enrolled in the study and 492 (51.2%) were infected with at least one of the three pathogens. Overall, DENV IgM seroprevalence among febrile children was 14.4% (138/961). About 390 (40.6%) and 22 (2.3%) had malaria (Pf/Pan Ag) and enteric fever (Typhoid IgM) respectively. Co-infection with dengue virus was found in 51 (5.3%) participants. The dengue virus IgM seroprevalence was higher in Bankim (19.3%), Ntui (18.3%) and Douala (18.2%). Conclusion Dengue virus infection seroprevalence appears to be low in children presenting with febrile illness in the studied health centres in Cameroon but call for more attention and research to further characterise the circulating strains of the dengue virus.
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Affiliation(s)
- Salomon Bonsi Tchuandom
- Department of Biochemistry, University of Dschang, Cameroon.,Public School of medical Laboratory Technicians, Yaoundé, Cameroon
| | - Thibau Flaurant Tchouangueu
- Department of Biochemistry, University of Dschang, Cameroon.,Laboratory of Microbiology and Immunology, Chantal Biya International Reference Centre for Research and Prevention on HIV/AIDS Yaoundé
| | - Christophe Antonio-Nkondjio
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroun
| | - Abel Lissom
- Department of Animal Biology and Physiology, University of Yaoundé 1, Yaoundé
| | | | | | | | - Godwin Nchinda
- Laboratory of Microbiology and Immunology, Chantal Biya International Reference Centre for Research and Prevention on HIV/AIDS Yaoundé
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Yousseu FBS, Nemg FBS, Ngouanet SA, Mekanda FMO, Demanou M. Detection and serotyping of dengue viruses in febrile patients consulting at the New-Bell District Hospital in Douala, Cameroon. PLoS One 2018; 13:e0204143. [PMID: 30281633 PMCID: PMC6169880 DOI: 10.1371/journal.pone.0204143] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 09/03/2018] [Indexed: 11/29/2022] Open
Abstract
Arboviruses are a major public health problem worldwide and are predominantly present in intertropical areas. Chikungunya, dengue and zika viruses have been implicated in recent epidemics in Asia, America and Africa. In Cameroon, data on these viruses are fragmentary. The purpose of this study was to determine the frequency of detection of these three viruses in febrile patients in Douala, Cameroon. A cross-sectional and descriptive study was conducted from March to April 2017 at the New-Bell District Hospital in Douala. Blood samples were collected from febrile patients and tested for malaria infections using Rapid Diagnostic test. Plasma harvested was later analyzed for the presence of chikungunya, dengue and zika viruses by a Trioplex real-time RT-PCR at Centre Pasteur of Cameroon. A total of 114 participants were included, of which 63.2% were females, reflecting a sex ratio (female/male) of 1.7. The median age was 26 years, range [0.25–81]. Eight (7%) of the 114 participants were infected with Dengue virus (DENV) among which 5 were identified as serotype 1. No cases of infection by either Zika virus or Chikungunya virus were detected. Three cases of dengue-malaria co-infection (13%) were recorded. No association was found between socio-demographic factors and dengue infection. The phylogenetic analysis of the partial envelope E gene showed that all the five DENV serotype 1 samples belonged to subtype V, similarly to strains from West African countries, particularly those from Nigeria, Senegal and Côte d’Ivoire. This study showed the circulation of DENV serotype 1 in febrile patients and raises the alarm for the establishment of a sustained surveillance system to detect cases and prevent potential outbreaks in Cameroon. The existence of dengue-malaria co-infections suggests that surveillance of arboviruses should not be limited to febrile, non-malarial cases.
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Affiliation(s)
- Francine Berlange Sado Yousseu
- Department of Virology, National Reference Laboratory for Chikungunya and Dengue, Centre Pasteur of Cameroon (CPC), Yaoundé, Centre, Cameroon
- Department of Biomedical Sciences, University of Dschang, Dschang, West, Cameroon
| | - Fredy Brice Simo Nemg
- Department of Virology, National Reference Laboratory for Chikungunya and Dengue, Centre Pasteur of Cameroon (CPC), Yaoundé, Centre, Cameroon
| | | | - Franck Martin Obam Mekanda
- Department of Virology, National Reference Laboratory for Chikungunya and Dengue, Centre Pasteur of Cameroon (CPC), Yaoundé, Centre, Cameroon
| | - Maurice Demanou
- Department of Virology, National Reference Laboratory for Chikungunya and Dengue, Centre Pasteur of Cameroon (CPC), Yaoundé, Centre, Cameroon
- * E-mail:
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24
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Vanegas A, Keller C, Krüger A, Manchang TK, Hagen RM, Frickmann H, Veit A, Achukwi MD, Krücken J, Poppert S. Molecular detection of spotted fever group rickettsiae in ticks from Cameroon. Ticks Tick Borne Dis 2018; 9:1049-1056. [PMID: 29636236 DOI: 10.1016/j.ttbdis.2018.03.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 03/21/2018] [Accepted: 03/22/2018] [Indexed: 10/17/2022]
Abstract
In western and eastern Africa, rickettsioses are one cause of fever in humans. Little is known regarding the presence of Rickettsia sp. in northern Cameroon. The present work was conducted in order to identify potential tick-borne spotted fever group Rickettsia in the Adamawa region of northern Cameroon, which may contribute filling some of the knowledge gaps of these pathogens. Ticks were collected from cattle in the municipal slaughterhouse of Ngaoundere in the Adamawa region of northern Cameroon. After morphological identification of tick species, extracted DNA was analyzed by PCR targeting the rickettsial ompB gene and the intergenic spacers dksA-xerC, mppA-purC and rpmE-tRNAfMet. Of the 316 adult ticks collected, 149 (47.1%) were Amblyomma variegatum, 92 (29%) Rhipicephalus spp. and 75 (23.7%) Hyalomma spp. Through the use of conventional PCR assays for the rickettsial ompB gene, rickettsial DNA was detected in 104 (32.9%) samples (85 Amblyomma sp., 14 Hyalomma spp. and 5 Rhipicephalus spp.). The ompB gene and the three intergenic were sequenced for 10 ticks in order to determine the rickettsial species. Rickettsia africae was detected in Amblyomma variegatum, Rickettsia aeschlimannii in Hyalomma rufipes and Hyalomma truncatum, Rickettsia sibirica in H. truncatum, Rickettsia massiliae in Rhipicephalus lunulatus and Candidatus Rickettsia barbariae in R. lunulatus. To the best of the author's knowledge, this report represents the first molecular evidence of rickettsial infection in ticks in the Adamawa region of northern Cameroon, which suggests a possible exposure of the human population in this region.
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Affiliation(s)
- Andrea Vanegas
- Department of Dermatology, Bundeswehr Hospital Hamburg, Lesserstr. 180, 22049 Hamburg, Germany; Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-Str. 74, 20359 Hamburg, Germany.
| | - Christian Keller
- Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-Str. 74, 20359 Hamburg, Germany.
| | - Andreas Krüger
- Department of Microbiology and Hospital Hygiene, Bundeswehr Hospital Hamburg, Bernhard-Nocht-Str. 74, 20359 Hamburg, Germany.
| | - Tanyi K Manchang
- Veterinary Research Laboratory, Institute of Agricultural Research for Development, Wakwa Regional Center, B.P. 65 Ngaoundere, Cameroon.
| | - Ralf M Hagen
- Department of Microbiology and Hospital Hygiene, Bundeswehr Hospital Hamburg, Bernhard-Nocht-Str. 74, 20359 Hamburg, Germany.
| | - Hagen Frickmann
- Department of Microbiology and Hospital Hygiene, Bundeswehr Hospital Hamburg, Bernhard-Nocht-Str. 74, 20359 Hamburg, Germany.
| | - Alexandra Veit
- Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-Str. 74, 20359 Hamburg, Germany.
| | - Mbunkah D Achukwi
- Veterinary Research Laboratory, Institute of Agricultural Research for Development, Wakwa Regional Center, B.P. 65 Ngaoundere, Cameroon.
| | - Jürgen Krücken
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Robert-von Ostertag-Str. 7-13, 14163 Berlin, Germany.
| | - Sven Poppert
- Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-Str. 74, 20359 Hamburg, Germany.
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Ehounoud C, Fenollar F, Dahmani M, N’Guessan J, Raoult D, Mediannikov O. Bacterial arthropod-borne diseases in West Africa. Acta Trop 2017; 171:124-137. [PMID: 28365316 DOI: 10.1016/j.actatropica.2017.03.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Indexed: 01/18/2023]
Abstract
Arthropods such as ticks, lice, fleas and mites are excellent vectors for many pathogenic agents including bacteria, protozoa and viruses to animals. Moreover, many of these pathogens can also be accidentally transmitted to humans throughout the world. Bacterial vector-borne diseases seem to be numerous and very important in human pathology, however, they are often ignored and are not well known. Yet they are in a phase of geographic expansion and play an important role in the etiology of febrile episodes in regions of Africa. Since the introduction of molecular techniques, the presence of these pathogens has been confirmed in various samples from arthropods and animals, and more rarely from human samples in West Africa. In this review, the aim is to summarize the latest information about vector-borne bacteria, focusing on West Africa from 2000 until today in order to better understand the epidemiological risks associated with these arthropods. This will allow health and veterinary authorities to develop a strategy for surveillance of arthropods and bacterial disease in order to protect people and animals.
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Achonduh-Atijegbe OA, Mfuh KO, Mbange AHE, Chedjou JP, Taylor DW, Nerurkar VR, Mbacham WF, Leke R. Prevalence of malaria, typhoid, toxoplasmosis and rubella among febrile children in Cameroon. BMC Infect Dis 2016; 16:658. [PMID: 27825318 PMCID: PMC5101675 DOI: 10.1186/s12879-016-1996-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 10/28/2016] [Indexed: 01/21/2023] Open
Abstract
Background The current roll-out of rapid diagnostic tests (RDTs) in many endemic countries has resulted in the reporting of fewer cases of malaria-attributed illnesses. However, lack of knowledge of the prevalence of other febrile illnesses and affordable diagnostic tests means that febrile patients are not managed optimally. This study assessed the prevalence of commonly treatable or preventable febrile illnesses in children between 6 months and 15 years using rapid diagnostic tests at the point-of-care. Methods Febrile children were enrolled between February-April 2014 at a health facility after obtaining informed consent from parent. Eligible participants were aged 6 months-15 years with a history of fever in the last 24 h or axillary temperature ≥38 °C at consultation. All participants were tested using RDTs for malaria, typhoid, toxoplasmosis and rubella. Malaria parasites were further identified by microscopy and PCR. Clinical and household characteristics were recorded and association with pathogens determined. Results Of the 315 children enrolled, the mean age was 5.8 ± 3.8 years. Stomach pain (41.2 %) was the most reported symptom. Prior to attending the health facility, 70.8 % had taken antipyretics, 27.9 % antimalarials, 11.4 % antibiotics and 13.3 % antifungal drugs. Among 315 children with fever, based on RDTs, 56.8 % were infected with malaria, 4.4 % with typhoid, 3.2 % with acute toxoplasmosis, and 1.3 % with rubella (all positive for rubella were in the same family and not vaccinated). All non-malarial infections were co-infections and approximately 30 % of the fever cases went un-diagnosed. Malaria prevalence by microscopy and PCR was 43.4 and 70.2 % respectively. The sensitivity and specificity of RDTs for the diagnosis of malaria were 75.98 and 100 % respectively, with 0.73 measurement agreement between RDTs and microscopy while that of RDT and PCR were 81 and 100 % respectively with a K value of 0.72. The use of Insecticide Treated Bednets was 44 %. There was a significant association between ITN non-usage and malaria (p = 0. 029) as well as drinking water and presence of typhoid (p = 0.047). No association was observed between type of housing and malaria, or toxoplasmosis and raising cats. Conclusion Though malaria still remains the major cause of fever in children, using RDTs for other treatable febrile illnesses like typhoid and toxoplasmosis could facilitate the optimal management of febrile illnesses in children especially when these occur as co-infections with malaria Electronic supplementary material The online version of this article (doi:10.1186/s12879-016-1996-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Olivia A Achonduh-Atijegbe
- The Biotechnology Centre, University of Yaoundé I, Yaoundé, Cameroon. .,North Pacific Global Health Program, University of Hawaii, Hawaii, USA.
| | - Kenji O Mfuh
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, University of Hawaii, Hawaii, USA
| | | | - Jean P Chedjou
- The Biotechnology Centre, University of Yaoundé I, Yaoundé, Cameroon
| | - Diane W Taylor
- North Pacific Global Health Program, University of Hawaii, Hawaii, USA.,Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, University of Hawaii, Hawaii, USA
| | - Vivek R Nerurkar
- North Pacific Global Health Program, University of Hawaii, Hawaii, USA.,Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, University of Hawaii, Hawaii, USA
| | - Wilfred F Mbacham
- The Biotechnology Centre, University of Yaoundé I, Yaoundé, Cameroon
| | - Rose Leke
- The Biotechnology Centre, University of Yaoundé I, Yaoundé, Cameroon.,North Pacific Global Health Program, University of Hawaii, Hawaii, USA
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Tomassone L, De Meneghi D, Adakal H, Rodighiero P, Pressi G, Grego E. Detection of Rickettsia aeschlimannii and Rickettsia africae in ixodid ticks from Burkina Faso and Somali Region of Ethiopia by new real-time PCR assays. Ticks Tick Borne Dis 2016; 7:1082-1088. [PMID: 27641952 DOI: 10.1016/j.ttbdis.2016.09.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 08/09/2016] [Accepted: 09/10/2016] [Indexed: 11/16/2022]
Abstract
In the framework of cooperation for development projects in Burkina Faso and Ethiopia, we collected ixodid ticks from cattle, small ruminants and camels. We optimized new TaqMan Probe real-time PCR assays to detect Rickettsia aeschlimannii and Rickettsia africae OmpA gene in the collected samples. Rickettsia africae was identified in 75.0% Amblyomma variegatum (95%CI: 56.6-88.5), while R. aeschlimannii in 24.0% Hyalomma truncatum (95%CI: 9.4-45.1) and 50.0% H. rufipes (95%CI: 29.9-70.0) collected from cattle in different provinces throughout Burkina Faso. Ticks from the Libaan zone, Somali Region of Ethiopia, were also infected by R. africae (28.5% prevalence in Amblyomma gemma, 95%CI: 14.7-46.0) and R. aeschlimannii (27.0% H. truncatum, 95%CI: 5.0-62.9; 88.3% H. rufipes, 95%CI: 60.5-99.3). All tested ticks were adults. The developed diagnostic tools were highly sensitive and enabled us to rapidly classify R. aeschlimannii and R. africae, which were identified in Burkina Faso and in the Somali Region of Ethiopia for the first time. Further studies are needed to assess the zoonotic risk and prevalence of infection in local human populations, who have high contact rates with ticks and their animal hosts.
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Affiliation(s)
- L Tomassone
- Dipartimento Scienze Veterinarie, Università degli Studi di Torino, Largo Braccini 2, 10095 Grugliasco, Torino, Italy.
| | - D De Meneghi
- Dipartimento Scienze Veterinarie, Università degli Studi di Torino, Largo Braccini 2, 10095 Grugliasco, Torino, Italy
| | - H Adakal
- Centre International de Recherche-Développement sur l'Elevage en zone Subhumide - CIRDES, Bobo Dioulasso, Burkina Faso; present affiliation: Département Sciences et Techniques de l'Elevage, Université Dan Dicko Dankoulodo de Maradi, Niger
| | - P Rodighiero
- Comitato di Collaborazione Medica, via Cirié 32/e, Torino, Italy; present affiliation: Associazione Veterinaria di Cooperazione con i Paesi in Via di Sviluppo - AVEC PVS, Via Laffait 13, Donnas, Aosta, Italy
| | - G Pressi
- Comitato di Collaborazione Medica, via Cirié 32/e, Torino, Italy; present affiliation: Associazione Veterinaria di Cooperazione con i Paesi in Via di Sviluppo - AVEC PVS, Via Laffait 13, Donnas, Aosta, Italy
| | - E Grego
- Dipartimento Scienze Veterinarie, Università degli Studi di Torino, Largo Braccini 2, 10095 Grugliasco, Torino, Italy
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Adjou Moumouni PF, Terkawi MA, Jirapattharasate C, Cao S, Liu M, Nakao R, Umemiya-Shirafuji R, Yokoyama N, Sugimoto C, Fujisaki K, Suzuki H, Xuan X. Molecular detection of spotted fever group rickettsiae in Amblyomma variegatum ticks from Benin. Ticks Tick Borne Dis 2016; 7:828-833. [PMID: 27150592 DOI: 10.1016/j.ttbdis.2016.03.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 01/31/2016] [Accepted: 03/30/2016] [Indexed: 11/28/2022]
Abstract
Spotted fever group (SFG) rickettsiae are obligate intracellular, Gram-negative bacteria transmitted by ticks and causing febrile illness in humans. Despite the presence of suitable tick vectors, the occurrence of SFG rickettsiae has never been investigated in the Republic of Benin (West Africa). In the present study, 910 Amblyomma variegatum ticks collected from 8 different locations in North Eastern Benin were tested for SFG rickettsiae. The samples were first screened for the presence of rickettsial bacteria using 16S rDNA PCR and positive samples were subsequently characterized by ompA PCR. Randomly selected samples among those positive for both assays were subjected to sequencing of 16S rDNA and ompA genes for species identification. The 16S rDNA gene was amplified in 63.4% of the samples (585/910) and the SFG rickettsia-specific ompA gene was detected in 29.4% of the samples (267/910). The prevalence of SFG rickettsiae varied according to the location, and tick gender. Sequence analyses demonstrated the presence of Rickettsia africae and/or closely related species in Benin. These findings extend the geographic distribution of R. africae and spotted fever rickettsioses in Africa. Clinicians in Benin and those treating travellers should be aware of the possibility of SFG rickettsiae infection when they are treating patients with febrile illness.
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Affiliation(s)
- Paul Franck Adjou Moumouni
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan; United Graduate School of Veterinary Sciences, Gifu University, Gifu, Gifu 501-1193, Japan
| | - Mohamad Alaa Terkawi
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan
| | - Charoonluk Jirapattharasate
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan
| | - Shinuo Cao
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan
| | - Mingming Liu
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan
| | - Ryo Nakao
- Research Center for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido 001-0020, Japan
| | - Rika Umemiya-Shirafuji
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan
| | - Naoaki Yokoyama
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan; United Graduate School of Veterinary Sciences, Gifu University, Gifu, Gifu 501-1193, Japan
| | - Chihiro Sugimoto
- Research Center for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido 001-0020, Japan
| | - Kozo Fujisaki
- Laboratory of Parasitic Diseases, National Institute of Animal Health, National Agricultural and Food Research Organization, Tsukuba, Ibaraki 305-0856, Japan
| | - Hiroshi Suzuki
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan; United Graduate School of Veterinary Sciences, Gifu University, Gifu, Gifu 501-1193, Japan
| | - Xuenan Xuan
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan.
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Keller C, Krüger A, Schwarz NG, Rakotozandrindrainy R, Rakotondrainiarivelo JP, Razafindrabe T, Derschum H, Silaghi C, Pothmann D, Veit A, Hogan B, May J, Girmann M, Kramme S, Fleischer B, Poppert S. High detection rate of Rickettsia africae in Amblyomma variegatum but low prevalence of anti-rickettsial antibodies in healthy pregnant women in Madagascar. Ticks Tick Borne Dis 2015; 7:60-65. [PMID: 26318262 DOI: 10.1016/j.ttbdis.2015.08.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 05/22/2015] [Accepted: 08/10/2015] [Indexed: 11/29/2022]
Abstract
Tick-borne spotted fever group (SFG) rickettsioses are emerging infectious diseases in Sub-Saharan Africa. In Madagascar, the endemicity of tick-borne rickettsiae and their vectors has been incompletely studied. The first part of the present study was conducted in 2011 and 2012 to identify potential anthropophilic tick vectors for SFG rickettsiae on cattle from seven Malagasy regions, and to detect and characterize rickettsiae in these ticks. Amblyomma variegatum was the only anthropophilic tick species found on 262 cattle. Using a novel ompB-specific qPCR, screening for rickettsial DNA was performed on 111 A. variegatum ticks. Rickettsial DNA was detected in 96 of 111 ticks studied (86.5%). Rickettsia africae was identified as the only infecting rickettsia using phylogenetic analysis of ompA and ompB gene sequences and three variable intergenic spacers from 11 ticks. The second part of the study was a cross-sectional survey for antibodies against SFG rickettsiae in plasma samples taken from healthy, pregnant women at six locations in Madagascar, two at sea level and four between 450 and 1300m altitude. An indirect fluorescent antibody test with Rickettsia conorii as surrogate SFG rickettsial antigen was used. We found R. conorii-seropositives at all altitudes with prevalences between 0.5% and 3.1%. Our results suggest that A. variegatum ticks highly infected with R. africae are the most prevalent cattle-associated tick vectors for SFG rickettsiosis in Madagascar. Transmission of SFG rickettsiosis to humans occurs at different altitudes in Madagascar and should be considered as a relevant cause of febrile diseases.
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Affiliation(s)
- Christian Keller
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany; Institute for Virology, Philipps University, Marburg, Germany.
| | | | | | | | | | | | | | - Cornelia Silaghi
- Comparative Tropical Medicine and Parasitology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Daniela Pothmann
- Comparative Tropical Medicine and Parasitology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Alexandra Veit
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Benedikt Hogan
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Jürgen May
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Mirko Girmann
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Stefanie Kramme
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | | | - Sven Poppert
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany; Institute for Medical Microbiology, Justus Liebig University, Giessen, Germany
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Faburay B. The case for a 'one health' approach to combating vector-borne diseases. Infect Ecol Epidemiol 2015; 5:28132. [PMID: 26027713 PMCID: PMC4450247 DOI: 10.3402/iee.v5.28132] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 04/29/2015] [Accepted: 04/29/2015] [Indexed: 12/03/2022] Open
Affiliation(s)
- Bonto Faburay
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA;
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Affiliation(s)
- David H. Walker
- *Address correspondence to David H. Walker, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555-0609. E-mail:
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Klaasen M, Roest HJ, van der Hoek W, Goossens B, Secka A, Stegeman A. Coxiella burnetii seroprevalence in small ruminants in The Gambia. PLoS One 2014; 9:e85424. [PMID: 24454863 PMCID: PMC3893215 DOI: 10.1371/journal.pone.0085424] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Accepted: 11/26/2013] [Indexed: 11/30/2022] Open
Abstract
Background Q fever is a zoonosis caused by Coxiella burnetii, a Gram negative bacterium present worldwide. Small ruminants are considered the main reservoirs for infection of humans. This study aimed to estimate the extent of C. burnetii infection among sheep and goats in part of The Gambia. Methodology/Principal Findings This survey was carried out from March to May 2012 at two areas in The Gambia. The first area comprised a cluster of seven rural villages situated 5–15 km west of Farafenni as well as the local abattoir. A second sampling was done at the central abattoir in Abuko (30 km from the capital, Banjul) in the Western Region. Serum samples were obtained from 490 goats and 398 sheep. In addition, 67 milk samples were obtained from lactating dams. Sera were tested with a Q fever ELISA kit. C. burnetii DNA was extracted from milk samples and then detected using a specific quantitative multiplex PCR assay, targeting the IS1111a element. A multivariable mixed logistic regression model was used to examine the relationship between seropositivity and explanatory variables. An overall seroprevalence of 21.6% was found. Goats had a significantly higher seroprevalence than sheep, respectively 24.2% and 18.5%. Seropositive animals were significantly older than seronegative animals. Animals from the villages had a significantly lower seroprevalence than animals from the central abattoir (15.1% versus 29.1%). C. burnetii DNA was detected in 2 out of 67 milk samples, whereas 8 samples gave a doubtful result. Conclusion/Significance A substantial C. burnetii seroprevalence in sheep and goats in The Gambia was demonstrated. People living in close proximity to small ruminants are exposed to C. burnetii. Q fever should be considered as a possible cause of acute febrile illness in humans in The Gambia. Future studies should include a simultaneous assessment of veterinary and human serology, and include aetiology of febrile illness in local clinics.
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Affiliation(s)
- Marieke Klaasen
- Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Hendrik-Jan Roest
- Department Bacteriology and TSEs, Central Veterinary Institute, part of Wageningen University and Research Centre, Lelystad, The Netherlands
| | - Wim van der Hoek
- Epidemiology and Surveillance Unit, National Institute for Public Health and Environment, Bilthoven, The Netherlands
| | - Bart Goossens
- SOS Children’s Villages International, Bakau, The Gambia
| | - Arss Secka
- International Trypanotolerance Centre, Banjul, The Gambia
| | - Arjan Stegeman
- Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
- * E-mail:
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Kernif T, Djerbouh A, Mediannikov O, Ayach B, Rolain JM, Raoult D, Parola P, Bitam I. Rickettsia africae in Hyalomma dromedarii ticks from sub-Saharan Algeria. Ticks Tick Borne Dis 2012; 3:377-9. [DOI: 10.1016/j.ttbdis.2012.10.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Prabhu M, Nicholson WL, Roche AJ, Kersh GJ, Fitzpatrick KA, Oliver LD, Massung RF, Morrissey AB, Bartlett JA, Onyango JJ, Maro VP, Kinabo GD, Saganda W, Crump JA. Q fever, spotted fever group, and typhus group rickettsioses among hospitalized febrile patients in northern Tanzania. Clin Infect Dis 2012; 53:e8-15. [PMID: 21810740 DOI: 10.1093/cid/cir411] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The importance of Q fever, spotted fever group rickettsiosis (SFGR), and typhus group rickettsiosis (TGR) as causes of febrile illness in sub-Saharan Africa is unknown; the putative role of Q fever as a human immunodeficiency virus (HIV) coinfection is unclear. METHODS We identified febrile inpatients in Moshi, Tanzania, from September 2007 through August 2008 and collected acute- and convalescent-phase serum samples. A ≥4-fold increase in immunoglobulin (Ig) G immunfluorescence assay (IFA) titer to Coxiella burnetii phase II antigen defined acute Q fever. A ≥4-fold increase in IgG IFA titer to Rickettsia conorii or Rickettsia typhi antigen defined SFGR and TGR, respectively. RESULTS Among 870 patients, 483 (55.5%) were tested for acute Q fever, and 450 (51.7%) were tested for acute SFGR and TGR. Results suggested acute Q fever in 24 (5.0%) patients and SFGR and TGR in 36 (8.0%) and 2 (0.5%) patients, respectively. Acute Q fever was associated with hepato- or splenomegaly (odds ratio [OR], 3.1; P = .028), anemia (OR, 3.0; P = .009), leukopenia (OR, 3.9; P = .013), jaundice (OR, 7.1; P = .007), and onset during the dry season (OR, 2.7; P = .021). HIV infection was not associated with acute Q fever (OR, 1.7; P = .231). Acute SFGR was associated with leukopenia (OR, 4.1; P = .003) and with evidence of other zoonoses (OR, 2.2; P = .045). CONCLUSIONS Despite being common causes of febrile illness in northern Tanzania, Q fever and SFGR are not diagnosed or managed with targeted antimicrobials. C. burnetii does not appear to be an HIV-associated co-infection.
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Affiliation(s)
- Malavika Prabhu
- Department of Medicine, Division of Infectious Diseases and International Health, Duke University Medical Center, Duke University, Durham, North Carolina 27710, USA
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Ndip LM, Biswas HH, Nfonsam LE, LeBreton M, Ndip RN, Bissong MA, Mpoudi-Ngole E, Djoko C, Tamoufe U, Prosser AT, Burke DS, Wolfe ND. Risk factors for African tick-bite fever in rural central Africa. Am J Trop Med Hyg 2011; 84:608-13. [PMID: 21460018 PMCID: PMC3062457 DOI: 10.4269/ajtmh.2011.10-0191] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
African tick-bite fever is an emerging infectious disease caused by the spotted fever group Rickettsia, Rickettsia africae, and is transmitted by ticks of the genus Amblyomma. To determine the seroprevalence of exposure to R. africae and risk factors associated with infection, we conducted a cross-sectional study of persons in seven rural villages in distinct ecological habitats of Cameroon. We examined 903 plasma samples by using an indirect immunofluorescence assay for antibodies to R. africae and analyzed demographic and occupational data collected from questionnaires. Of the 903 persons tested, 243 (26.9%) had IgG/IgM/IgA reactive with R. africae. Persons from four of the seven village sites were significantly more likely to be seropositive (P < 0.05), and lowland forest sites tended to have higher seroprevalences. These results suggest that African tick-bite fever is common in adults in rural areas of Cameroon and that ecological factors may play a role in the acquisition of R. africae infection.
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Affiliation(s)
- Lucy M Ndip
- Department of Biochemistry and Microbiology, University of Buea, Buea, Cameroon
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Jentes ES, Robinson J, Johnson BW, Conde I, Sakouvougui Y, Iverson J, Beecher S, Bah MA, Diakite F, Coulibaly M, Bausch DG, Bryan J. Acute arboviral infections in Guinea, West Africa, 2006. Am J Trop Med Hyg 2010; 83:388-94. [PMID: 20682888 PMCID: PMC2911191 DOI: 10.4269/ajtmh.2010.09-0688] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Acute febrile illnesses comprise the majority of the human disease burden in sub-Saharan Africa. We hypothesized that arboviruses comprised a considerable proportion of undiagnosed febrile illnesses in Guinea and sought to determine the frequency of arboviral disease in two hospitals there. Using a standard case definition, 47 suspected cases were detected in approximately 4 months. Immunoglobulin M antibody capture enzyme-linked immunosorbent assays and plaque-reduction neutralization assays revealed that 63% (30/47) of patients were infected with arboviruses, including 11 West Nile, 2 yellow fever, 1 dengue, 8 chikungunya, and 5 Tahyna infections. Except for yellow fever, these are the first reported cases of human disease from these viruses in Guinea and the first reported cases of symptomatic Tahyna infection in Africa. These results strongly suggest that arboviruses circulate and are common causes of disease in Guinea. Improving surveillance and laboratory capacity for arbovirus diagnoses will be integral to understanding the burden posed by these agents in the region.
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Affiliation(s)
- Emily S Jentes
- Department of Tropical Medicine, Tulane School of Public Health and Tropical Medicine, New Orleans, LA, USA.
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Chikungunya outbreak in a rural area of Western Cameroon in 2006: A retrospective serological and entomological survey. BMC Res Notes 2010; 3:128. [PMID: 20444282 PMCID: PMC2883987 DOI: 10.1186/1756-0500-3-128] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2010] [Accepted: 05/05/2010] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Although arboviral infections including Chikungunya virus (CHIKV) are common in sub-Saharan Africa, data on their circulation and prevalence are poorly documented. In 2006, more than 400 cases of dengue-like fever were reported in Kumbo (Northwest Region of Cameroon). The aim of this study was to identify the aetiology of this fever and to define its extent in the area. METHODS We conducted a cross-sectional seroprevalence survey one year after clinical investigations to define the extent of the infection. An entomological survey consisted of the collection and identification of mosquito immature stages in water containers in or around human dwellings. RESULTS A total of 105 sera were obtained from volunteers and tested for CHIKV, O'Nyong-nyong virus (ONNV) and Dengue virus (DENV) specific IgM and IgG antibodies by enzyme-linked immunosorbent assays (ELISA). CHIKV infection was defined as the presence of IgM antibodies to CHIKV. There was serological evidence for recent Chikungunya infection, as 54 subjects (51.4%) had detectable IgM anti-CHIKV in their sera. Amongst these, 52 showed both anti-CHIKV IgM and IgG, and 2 (1.9%) had IgM anti-CHIKV in the absence of IgG. Isolated anti-CHIKV IgG positives were detected in 41 (39%) cases. No anti-ONNV and anti-DENV IgM antibodies were found amongst the sample tested. Out of 305 larvae collected in the different breeding sites, 87 developed to the adult stage; 56 (64.4%) were Aedes africanus and the remaining Culex spp. CONCLUSIONS These findings suggest that the outbreak of febrile illness reported in three villages of Western Cameroon was due to CHIKV. The issue of a possible persistence of anti-CHIKV IgM antibodies is discussed. Ae. africanus which was found to be relatively abundant among the raffia palm bushes probably plays a role in the transmission of CHIKV along the chain of sylvatic/domestic mosquito species in this rural area. Particular attention should therefore be given to arbovirus infections in the Central African sub-region where these infections are becoming an emerging public health threat.
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Ndip LM, Labruna M, Ndip RN, Walker DH, McBride JW. Molecular and clinical evidence of Ehrlichia chaffeensis infection in Cameroonian patients with undifferentiated febrile illness. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 2010; 103:719-25. [PMID: 20030996 DOI: 10.1179/000349809x12554106963753] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
In the U.S.A., human monocytotropic ehrlichiosis (HME) caused by Ehrlichia chaffeensis is an emerging tick-transmitted zoonosis. In Cameroon, where E. canis, E. chaffeensis and E. ewingii have recently been detected in dogs and/or ticks (Rhipicephalus sanguineus), the potential exists for human infections. Patients from the coastal region of Cameroon who had acute fevers of unknown aetiology were therefore checked for ehrlichial infection, using a real-time PCR that amplifies part of a genus-specific gene (dsb) that codes for a disulphide-bond formation protein. Ehrlichial blood was detected in the peripheral blood from 12 (10%) of the 118 patients investigated by PCR. When the 12 amplicons from the positive cases were sequenced, they were found to be identical to each other and to the corresponding dsb sequence of an Arkansas strain of E. chaffeensis. The 12 patients who were PCR-positive for E. chaffeensis suffered from fever (100%), headache (67%), myalgia (42%), arthralgia (58%), pulmonary involvement (17%) and/or a diffuse rash (17%).
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Affiliation(s)
- L M Ndip
- Department of Biochemistry and Microbiology, University of Buea, South West Region, Cameroon
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Stephany D, Buffet P, Rolain JM, Raoult D, Consigny PH. Rickettsia africae infection in man after travel to Ethiopia. Emerg Infect Dis 2010; 15:1867-9. [PMID: 19891894 PMCID: PMC2857237 DOI: 10.3201/eid1511.090521] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
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Hotez PJ, Kamath A. Neglected tropical diseases in sub-saharan Africa: review of their prevalence, distribution, and disease burden. PLoS Negl Trop Dis 2009; 3:e412. [PMID: 19707588 PMCID: PMC2727001 DOI: 10.1371/journal.pntd.0000412] [Citation(s) in RCA: 723] [Impact Index Per Article: 48.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The neglected tropical diseases (NTDs) are the most common conditions affecting the poorest 500 million people living in sub-Saharan Africa (SSA), and together produce a burden of disease that may be equivalent to up to one-half of SSA's malaria disease burden and more than double that caused by tuberculosis. Approximately 85% of the NTD disease burden results from helminth infections. Hookworm infection occurs in almost half of SSA's poorest people, including 40-50 million school-aged children and 7 million pregnant women in whom it is a leading cause of anemia. Schistosomiasis is the second most prevalent NTD after hookworm (192 million cases), accounting for 93% of the world's number of cases and possibly associated with increased horizontal transmission of HIV/AIDS. Lymphatic filariasis (46-51 million cases) and onchocerciasis (37 million cases) are also widespread in SSA, each disease representing a significant cause of disability and reduction in the region's agricultural productivity. There is a dearth of information on Africa's non-helminth NTDs. The protozoan infections, human African trypanosomiasis and visceral leishmaniasis, affect almost 100,000 people, primarily in areas of conflict in SSA where they cause high mortality, and where trachoma is the most prevalent bacterial NTD (30 million cases). However, there are little or no data on some very important protozoan infections, e.g., amebiasis and toxoplasmosis; bacterial infections, e.g., typhoid fever and non-typhoidal salmonellosis, the tick-borne bacterial zoonoses, and non-tuberculosis mycobaterial infections; and arboviral infections. Thus, the overall burden of Africa's NTDs may be severely underestimated. A full assessment is an important step for disease control priorities, particularly in Nigeria and the Democratic Republic of Congo, where the greatest number of NTDs may occur.
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Affiliation(s)
- Peter J. Hotez
- Department of Microbiology, Immunology, and Tropical Medicine, The George Washington University, Washington, D.C., United States of America
- Sabin Vaccine Institute, Washington, D.C., United States of America
- * E-mail: or (PJH)
| | - Aruna Kamath
- Department of Microbiology, Immunology, and Tropical Medicine, The George Washington University, Washington, D.C., United States of America
- Sabin Vaccine Institute, Washington, D.C., United States of America
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Cazorla C, Socolovschi C, Jensenius M, Parola P. Tick-borne Diseases: Tick-borne Spotted Fever Rickettsioses in Africa. Infect Dis Clin North Am 2008; 22:531-44, ix-x. [DOI: 10.1016/j.idc.2008.03.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Roch N, Epaulard O, Pelloux I, Pavese P, Brion JP, Raoult D, Maurin M. African tick bite fever in elderly patients: 8 cases in French tourists returning from South Africa. Clin Infect Dis 2008; 47:e28-35. [PMID: 18558881 DOI: 10.1086/589868] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND African tick-bite fever, a tickborne disease caused by Rickettsia africae, is endemic in rural areas of sub-Saharan Africa and in the French West Indies. Most cases reported in the literature occurred in middle-aged, otherwise-healthy persons and corresponded to benign diseases. The course of African tick bite fever in elderly people is less well documented. METHODS The medical records of 8 elderly patients infected with R. africae during a trip to South Africa in 2005 are presented to summarize the epidemiologic, clinical, microbiological, treatment, and disease course characteristics. RESULTS Eight patients, aged 63-75 years, developed African tick bite fever symptoms after a trip to South Africa. R. africae was grown from cutaneous eschar biopsy specimens obtained from 4 patients, confirming African tick bite fever. We observed unusual findings in this elderly population. Rash was frequent (present in 87.5% of patients), vesicular (in 100% of patients with rash), and often associated with an enanthema (in 50% of patients with rash). Severe clinical manifestations occurred: lymphangitis and myocarditis in 1 patient and suspected brain involvement in 2 patients. We observed severe and long-lasting general symptoms, including fever (in 75% of patients), chills (87.5%), asthenia (50%), anorexia (50%), and weight loss (12.5%). With doxycycline therapy, the outcome was favorable in all cases, but complete recovery was slow. CONCLUSION Ecotourism to sub-Saharan Africa is expanding, and people of advanced age, often with underlying chronic diseases, account for an increasing proportion of travelers. African tick bite fever appears to be more symptomatic in this population. Recommendations advising personal prophylactic measures to prevent tick bites in travelers to regions of endemicity may be particularly important for elderly individuals.
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Affiliation(s)
- Nathalie Roch
- Department of Infectious Diseases, Centre Hospitalier Universitaire de Grenoble, Grenoble, France.
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Molecular detection of spotted fever group rickettsiae in ticks from Ethiopia and Chad. Trans R Soc Trop Med Hyg 2008; 102:945-9. [PMID: 18440576 DOI: 10.1016/j.trstmh.2008.03.015] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2007] [Revised: 03/12/2008] [Accepted: 03/12/2008] [Indexed: 11/22/2022] Open
Abstract
DNA extracted from 363 ticks collected in Ethiopia and 9 ticks collected in Chad, Africa were screened by PCR to detect DNA from spotted fever group rickettsiae. Fifteen ticks (4.1%) collected in Ethiopia and one tick (11%) collected in Chad tested positive when PCR targeting the gltA and ompA rickettsial genes was performed. PCR-positive products of the gltA and ompA genes were used for DNA sequencing. Rickettsia africae was detected in 12/118 Amblyomma lepidum and in 1/2 A. variegatum. Also, 2/12 Hyalomma marginatum rufipes collected in Ethiopia and one H. marginatum rufipes collected in Chad were positive for R. aeschlimannii. Our results confirm the previously reported presence of R. africae in Ethiopia and also show the first evidence of R. aeschlimannii in ticks collected in Ethiopia and Chad.
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Peyrefitte CN, Rousset D, Pastorino BA, Pouillot R, Bessaud M, Tock F, Mansaray H, Merle OL, Pascual AM, Paupy C, Vessiere A, Imbert P, Tchendjou P, Durand JP, Tolou HJ, Grandadam M. Chikungunya virus, Cameroon, 2006. Emerg Infect Dis 2008; 13:768-71. [PMID: 17553262 PMCID: PMC2738435 DOI: 10.3201/eid1305.061500] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We report the isolation of chikungunya virus from a patient during an outbreak of a denguelike syndrome in Cameroon in 2006. The virus was phylogenetically grouped in the Democratic Republic of the Congo cluster, indicating a continuous circulation of a genetically similar chikungunya virus population during 6 years in Central Africa.
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Affiliation(s)
| | | | - Boris A.M. Pastorino
- Institut de Médecine Tropicale du Service de Santé des Armées, Marseille, France
| | | | - Maël Bessaud
- Institut de Médecine Tropicale du Service de Santé des Armées, Marseille, France
| | - Fabienne Tock
- Institut de Médecine Tropicale du Service de Santé des Armées, Marseille, France
| | | | - Olivier L. Merle
- Institut de Médecine Tropicale du Service de Santé des Armées, Marseille, France
| | - Aurelie M. Pascual
- Institut de Médecine Tropicale du Service de Santé des Armées, Marseille, France
| | | | | | - Patrice Imbert
- Institut de Recherche pour le Développement, Yaoundé, Cameroon
| | | | - Jean-Paul Durand
- Institut de Médecine Tropicale du Service de Santé des Armées, Marseille, France
| | - Hugues J. Tolou
- Institut de Médecine Tropicale du Service de Santé des Armées, Marseille, France
| | - Marc Grandadam
- Institut de Médecine Tropicale du Service de Santé des Armées, Marseille, France
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Walker DH. Rickettsiae and Rickettsial Infections: The Current State of Knowledge. Clin Infect Dis 2007; 45 Suppl 1:S39-44. [PMID: 17582568 DOI: 10.1086/518145] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
New human rickettsial pathogens have been discovered, and long-known rickettsiae of undetermined pathogenicity have been demonstrated to cause illness. Disease associated with Rickettsia slovaca has unique clinical manifestations, including prominent lymphadenopathy without fever and rash. Rickettsial genomes are highly conserved, with reductive evolution leading to a small genome that relies on the host cell for many biosynthetic functions. Advances in the evaluation of the pathogenesis of rickettsial disease include identification of rickettsial adhesins, a host cell receptor, signaling elements associated with entry of rickettsiae by induced phagocytosis, rickettsial enzymes mediating phagosomal escape, and host actin-based rickettsial cell-to-cell spread. Disruption of adherens junctions of infected endothelial cells likely plays a role in the critical pathophysiologic mechanism: increased microvascular permeability. Production of reactive oxygen species by infected endothelium injures these cells. However, disseminated intravascular coagulation rarely occurs. Immunity is mediated by reactive cytokine-activated rickettsicidal nitrogen and oxygen species and by clearance of rickettsiae by cytotoxic CD8 T cells.
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Affiliation(s)
- David H Walker
- Department of Pathology, Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, TX 77555-0609, USA.
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Kaabia N, Rolain JM, Khalifa M, Ben Jazia E, Bahri F, Raoult D, Letaïef A. Serologic study of rickettsioses among acute febrile patients in central Tunisia. Ann N Y Acad Sci 2007; 1078:176-9. [PMID: 17114704 DOI: 10.1196/annals.1374.126] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Although Mediterranean spotted or "boutonneuse" fever (MSF) has been documented in central Tunisia, other spotted fever group rickettsioses (SFGR) and typhus group rickettsioses (TGR) have received little attention in our region. We sought to determine the role of rickettsioses, Q fever, ehrlichioses, and bartonelloses among patients with acute fever. The results of this study of 47 persons with acute fever of undetermined origin are reported in this paper. We concluded that SFGR, murine typhus, and acute Q fever are common causes of acute isolate fever in summer in central Tunisia and should be investigated systematically in patients with acute fever of unknown origin.
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Affiliation(s)
- N Kaabia
- Service de Médecine Interne et Maladies Infectieuses, CHU F, Hached-Sousse 4000 Tunisia
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48
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Abstract
Although rickettsioses are among the oldest known vector-borne zoonoses, several species or subspecies of rickettsias have been identified in recent years as emerging pathogens throughout the world including in sub-Saharan Africa. To date, six tick-borne spotted fever group pathogenic rickettsias are known to occur in sub-Saharan Africa, including Rickettsia conorii conorii, the agent of Mediterranean spotted fever; R. conorii caspia, the agent of Astrakhan fever; R. africae, the agent of African tick-bite fever; R. aeschlimannii; R. sibirica mongolitimonae; and R. massiliae. On the other hand, fleas have long been known as vectors of the ubiquitous murine typhus, a typhus group rickettsiosis induced by R. typhi. However, a new spotted fever rickettsia, R. felis, has also been found to be associated with fleas, to be a human pathogen, and to be present in sub-Saharan Africa. Finally, R. prowazekii the agent of louse-borne epidemic typhus continues to strikes tens to hundreds of thousands of persons who live in Sub-Saharan with civil war, famine and poor conditions. We present an overview of these rickettsioses occurring in sub-Saharan Africa, focusing on the epidemiological aspects of emerging diseases.
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Affiliation(s)
- Philippe Parola
- Unité des Rickettsies, CNRS UMR 6020 IFR 48, WHO Collaborative Center for Rickettsial Reference and Research, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France.
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Parola P, Paddock CD, Raoult D. Tick-borne rickettsioses around the world: emerging diseases challenging old concepts. Clin Microbiol Rev 2005; 18:719-56. [PMID: 16223955 PMCID: PMC1265907 DOI: 10.1128/cmr.18.4.719-756.2005] [Citation(s) in RCA: 716] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
During most of the 20th century, the epidemiology of tick-borne rickettsioses could be summarized as the occurrence of a single pathogenic rickettsia on each continent. An element of this paradigm suggested that the many other characterized and noncharacterized rickettsiae isolated from ticks were not pathogenic to humans. In this context, it was considered that relatively few tick-borne rickettsiae caused human disease. This concept was modified extensively from 1984 through 2005 by the identification of at least 11 additional rickettsial species or subspecies that cause tick-borne rickettsioses around the world. Of these agents, seven were initially isolated from ticks, often years or decades before a definitive association with human disease was established. We present here the tick-borne rickettsioses described through 2005 and focus on the epidemiological circumstances that have played a role in the emergence of the newly recognized diseases.
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Affiliation(s)
- Philippe Parola
- Unité des Rickettsies, CNRS UMR 6020, IFR 48, Université de la Méditerranée, Faculté de Médecine, 13385 Marseille Cedex 5, France
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Jensenius M, Pretorius AM, Clarke F, Myrvang B. Repellent efficacy of four commercial DEET lotions against Amblyomma hebraeum (Acari: Ixodidae), the principal vector of Rickettsia africae in southern Africa. Trans R Soc Trop Med Hyg 2005; 99:708-11. [PMID: 15993907 DOI: 10.1016/j.trstmh.2005.01.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2004] [Revised: 12/28/2004] [Accepted: 01/07/2005] [Indexed: 11/24/2022] Open
Abstract
African tick bite fever, caused by Rickettsia africae, is an emerging zoonotic infection in rural sub-Saharan Africa and the French West Indies. We tested the repellent efficacy of four commercial diethyl-3-methylbenzamide (DEET) lotions against Amblyomma hebraeum Koch, the principal vector of R. africae in southern Africa, by using a human bioassay in which repellent-treated fingers were presented to questing tick nymphs hourly for 4h. Three lotions with 19.5, 31.6 and 80% DEET concentrations, respectively, had a repellent efficacy of > or =90% at 1h post-application, of > or =77% at 2h post-application and of <70% during the rest of the experiment. By contrast, a lotion with 2% DEET plus 1% citronella oil provided only a 59% repellency at 1h post-application, with a drop to <22% during the following hours. Hourly negative control trials repelled <5% of tick attacks. Our results suggest that commercial repellents containing > or =19.5% DEET provide a significant but short-lasting protection against questing A. hebraeum ticks.
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Affiliation(s)
- Mogens Jensenius
- Division of Infectious Diseases, Department of Internal Medicine, Aker University Hospital, N-0514 Oslo, Norway.
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