Last data update: May 13, 2024. (Total: 46773 publications since 2009)
Records 1-8 (of 8 Records) |
Query Trace: Kalemba L[original query] |
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Activity patterns and burrowing ecology of the giant pouched rat (Cricetomys emini) in Tshuapa Province, D. R. Congo
Kalemba LN , Morgan CN , Nakazawa YJ , Mauldin MR , Malekani JM , Doty JB . Mammalia 2022 86 (6) 562-569 Rodents of the genus Cricetomys have been reported to be nocturnal with a bimodal activity pattern and to frequently change burrows. However, no studies to date have examined these ecological aspects with the use of radio-telemetry. Five C. emini were captured and radio-collared to study their activity patterns and burrowing ecology from 9 March to 15 April 2016. Nocturnal activity ranged between the hours of 18:00 and 05:00 with a probable reduction of activities between 20:00-23:00 and around 04:00 with diurnal activity between 06:00 and 17:00 h with a reduction of activity between 11:00 and 14:00. While the present study does confirm nocturnal activity and a bimodal pattern, this study also suggests greater diurnal activity as compared to previous studies. Additionally, data presented here also suggest that C. emini may not change burrows as frequently as previously reported. 2022 Walter de Gruyter GmbH, Berlin/Boston 2022. |
The effect of a mass distribution of insecticide-treated nets on insecticide resistance and entomological inoculation rates of Anopheles gambiae s.l. in Bandundu City, Democratic Repub`lic of Congo.
Metelo-Matubi E , Zanga J , Binene G , Mvuama N , Ngamukie S , Nkey J , Schopp P , Bamba M , Irish S , Nguya-Kalemba-maniania J , Fasine S , Nagahuedi J , Muyembe JJ , Mansiangi P . Pan Afr Med J 2021 40 118 Introduction: insecticide-treated nets (ITNs) remain the mainstay of malaria vector control in the Democratic Republic of Congo. However, insecticide resistance of malaria vectors threatens their effectiveness. Entomological inoculation rates and insecticide susceptibility in Anopheles gambiae s.l. were evaluated before and after mass distribution of ITNs in Bandundu City for possible occurrence of resistance. Methods: a cross-sectional study was conducted from 15th July 2015 to 15th June 2016. Adult mosquitoes were collected using pyrethrum spray catches and human landing catches and identified to species level and tested for the presence of sporozoites. Bioassays were carried out before and after distribution of ITNs to assess the susceptibility of adult mosquitoes to insecticides. Synergist bioassays were also conducted and target site mutations assessed using Polymerase chain reaction (PCR). Results: a total of 1754 female An. gambiae s.l. were collected before and after deployment of ITNs. Fewer mosquitoes were collected after the distribution of ITNs. However, there was no significant difference in sporozoite rates or the overall entomological inoculation rate before and after the distribution of ITNs. Test-mosquitoes were resistant to deltamethrin, permethrin, and Dichlorodiphenyltrichloroethane but susceptible to bendiocarb. Pre-exposure of mosquitoes to Piperonyl butoxide increased their mortality after exposure to permethrin and deltamethrin. The frequency of the Kinase insert domain receptor (kdr)-West gene increased from 92 to 99% before and after the distribution of nets, respectively. Conclusion: seasonal impacts could be a limiting factor in the analysis of these data; however, the lack of decrease in transmission after the distribution of new nets could be explained by the high-level of resistance to pyrethroid. © Emery Metelo-Matubi et al. |
Epidemiologic and ecologic investigations of monkeypox, Likouala Department, Republic of the Congo, 2017
Doshi RH , Guagliardo SAJ , Doty JB , Babeaux AD , Matheny A , Burgado J , Townsend MB , Morgan CN , Satheshkumar PS , Ndakala N , Kanjingankolo T , Kitembo L , Malekani J , Kalemba L , Pukuta E , N'Kaya T , Kangoula F , Moses C , McCollum AM , Reynolds MG , Mombouli JV , Nakazawa Y , Petersen BW . Emerg Infect Dis 2019 25 (2) 281-289 Monkeypox, caused by a zoonotic orthopoxvirus, is endemic in Central and West Africa. Monkeypox has been sporadically reported in the Republic of the Congo. During March 22-April 5, 2017, we investigated 43 suspected human monkeypox cases. We interviewed suspected case-patients and collected dried blood strips and vesicular and crust specimens (active lesions), which we tested for orthopoxvirus antibodies by ELISA and monkeypox virus and varicella zoster virus DNA by PCR. An ecologic investigation was conducted around Manfouete, and specimens from 105 small mammals were tested for anti-orthopoxvirus antibodies or DNA. Among the suspected human cases, 22 met the confirmed, probable, and possible case definitions. Only 18 patients had available dried blood strips; 100% were IgG positive, and 88.9% (16/18) were IgM positive. Among animals, only specimens from Cricetomys giant pouched rats showed presence of orthopoxvirus antibodies, adding evidence to this species' involvement in the transmission and maintenance of monkeypox virus in nature. |
Assessing monkeypox virus prevalence in small mammals at the human-animal interface in the Democratic Republic of the Congo
Doty JB , Malekani JM , Kalemba LN , Stanley WT , Monroe BP , Nakazawa YU , Mauldin MR , Bakambana TL , Liyandja Dja Liyandja T , Braden ZH , Wallace RM , Malekani DV , McCollum AM , Gallardo-Romero N , Kondas A , Peterson AT , Osorio JE , Rocke TE , Karem KL , Emerson GL , Carroll DS . Viruses 2017 9 (10) During 2012, 2013 and 2015, we collected small mammals within 25 km of the town of Boende in Tshuapa Province, the Democratic Republic of the Congo. The prevalence of monkeypox virus (MPXV) in this area is unknown; however, cases of human infection were previously confirmed near these collection sites. Samples were collected from 353 mammals (rodents, shrews, pangolins, elephant shrews, a potamogale, and a hyrax). Some rodents and shrews were captured from houses where human monkeypox cases have recently been identified, but most were trapped in forests and agricultural areas near villages. Real-time PCR and ELISA were used to assess evidence of MPXV infection and other Orthopoxvirus (OPXV) infections in these small mammals. Seven (2.0%) of these animal samples were found to be anti-orthopoxvirus immunoglobulin G (IgG) antibody positive (six rodents: two Funisciurus spp.; one Graphiurus lorraineus; one Cricetomys emini; one Heliosciurus sp.; one Oenomys hypoxanthus, and one elephant shrew Petrodromus tetradactylus); no individuals were found positive in PCR-based assays. These results suggest that a variety of animals can be infected with OPXVs, and that epidemiology studies and educational campaigns should focus on animals that people are regularly contacting, including larger rodents used as protein sources. |
Characterization of monkeypox virus infection in African rope squirrels (Funisciurus sp.)
Falendysz EA , Lopera JG , Doty JB , Nakazawa Y , Crill C , Lorenzsonn F , Kalemba LN , Ronderos MD , Mejia A , Malekani JM , Karem K , Carroll DS , Osorio JE , Rocke TE . PLoS Negl Trop Dis 2017 11 (8) e0005809 Monkeypox (MPX) is a zoonotic disease endemic in Central and West Africa and is caused by Monkeypox virus (MPXV), the most virulent orthopoxvirus affecting humans since the eradication of Variola virus (VARV). Many aspects of the MPXV transmission cycle, including the natural host of the virus, remain unknown. African rope squirrels (Funisciurus spp.) are considered potential reservoirs of MPXV, as serosurveillance data in Central Africa has confirmed the circulation of the virus in these rodent species [1,2]. In order to understand the tissue tropism and clinical signs associated with infection with MPXV in these species, wild-caught rope squirrels were experimentally infected via intranasal and intradermal exposure with a recombinant MPXV strain from Central Africa engineered to express the luciferase gene. After infection, we monitored viral replication and shedding via in vivo bioluminescent imaging, viral culture and real time PCR. MPXV infection in African rope squirrels caused mortality and moderate to severe morbidity, with clinical signs including pox lesions in the skin, eyes, mouth and nose, dyspnea, and profuse nasal discharge. Both intranasal and intradermal exposures induced high levels of viremia, fast systemic spread, and long periods of viral shedding. Shedding and luminescence peaked at day 6 post infection and was still detectable after 15 days. Interestingly, one sentinel animal, housed in the same room but in a separate cage, also developed severe MPX disease and was euthanized. This study indicates that MPXV causes significant pathology in African rope squirrels and infected rope squirrels shed large quantities of virus, supporting their role as a potential source of MPXV transmission to humans and other animals in endemic MPX regions. |
Exposure to Lyssaviruses in bats of the Democratic Republic of the Congo
Kalemba LN , Niezgoda M , Gilbert AT , Doty JB , Wallace RM , Malekani JM , Carroll DS . J Wildl Dis 2017 53 (2) 408-410 Lyssavirus infections in the Democratic Republic of Congo are poorly documented. We examined 218 bats. No lyssavirus antigens were detected but Lagos bat virus (LBV) neutralizing antibodies (VNA) were detected in Eidolon helvum and Myonycteris torquata . Four samples with LBV VNA reacted against Shimoni bat virus. |
Introduction of monkeypox into a community and household: risk factors and zoonotic reservoirs in the Democratic Republic of the Congo
Nolen LD , Osadebe L , Katomba J , Likofata J , Mukadi D , Monroe B , Doty J , Kalemba L , Malekani J , Kabamba J , Bomponda PL , Lokota JI , Balilo MP , Likafi T , Lushima RS , Tamfum JJ , Okitolonda EW , McCollum AM , Reynolds MG . Am J Trop Med Hyg 2015 93 (2) 410-5 An increased incidence of monkeypox (MPX) infections in the Democratic Republic of the Congo was noted by the regional surveillance system in October 2013. Little information exists regarding how MPX is introduced into the community and the factors associated with transmission within the household. Sixty-eight wild animals were collected and tested for Orthopoxvirus. Two of three rope squirrels (Funisciurus sp.) were positive for antibodies to Orthopoxviruses; however, no increased risk was associated with the consumption or preparation of rope squirrels. A retrospective cohort investigation and a case-control investigation were performed to identify risk factors affecting the introduction of monkeypox virus (MPXV) into the community and transmission within the home. School-age males were the individuals most frequently identified as the first person infected in the household and were the group most frequently affected overall. Risk factors of acquiring MPXV in a household included sleeping in the same room or bed, or using the same plate or cup as the primary case. There was no significant risk associated with eating or processing of wild animals. Activities associated with an increased risk of MPXV transmission all have potential for virus exposure to the mucosa. |
Bats are a major natural reservoir for hepaciviruses and pegiviruses
Quan PL , Firth C , Conte JM , Williams SH , Zambrana-Torrelio CM , Anthony SJ , Ellison JA , Gilbert AT , Kuzmin IV , Niezgoda M , Osinubi MO , Recuenco S , Markotter W , Breiman RF , Kalemba L , Malekani J , Lindblade KA , Rostal MK , Ojeda-Flores R , Suzan G , Davis LB , Blau DM , Ogunkoya AB , Alvarez Castillo DA , Moran D , Ngam S , Akaibe D , Agwanda B , Briese T , Epstein JH , Daszak P , Rupprecht CE , Holmes EC , Lipkin WI . Proc Natl Acad Sci U S A 2013 110 (20) 8194-9 Although there are over 1,150 bat species worldwide, the diversity of viruses harbored by bats has only recently come into focus as a result of expanded wildlife surveillance. Such surveys are of importance in determining the potential for novel viruses to emerge in humans, and for optimal management of bats and their habitats. To enhance our knowledge of the viral diversity present in bats, we initially surveyed 415 sera from African and Central American bats. Unbiased high-throughput sequencing revealed the presence of a highly diverse group of bat-derived viruses related to hepaciviruses and pegiviruses within the family Flaviridae. Subsequent PCR screening of 1,258 bat specimens collected worldwide indicated the presence of these viruses also in North America and Asia. A total of 83 bat-derived viruses were identified, representing an infection rate of nearly 5%. Evolutionary analyses revealed that all known hepaciviruses and pegiviruses, including those previously documented in humans and other primates, fall within the phylogenetic diversity of the bat-derived viruses described here. The prevalence, unprecedented viral biodiversity, phylogenetic divergence, and worldwide distribution of the bat-derived viruses suggest that bats are a major and ancient natural reservoir for both hepaciviruses and pegiviruses and provide insights into the evolutionary history of hepatitis C virus and the human GB viruses. |
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