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The gastro-intestinal helminth parasites of goliath frog (Conraua goliath) from the Littoral Region of Cameroon in the Localities of Loum, Yabassi and Nkondjock were surveyed. Out of the 30 goliath frogs examined (13 males and 17 females) between April and May 2013, 26 (85%) contained at least one helminth parasite and yielded a total of nine hundred and seventy three (973) helminths comprising: Nematodes (90.5%), Trematodes (9.4%) and Pentastomids (0.1%). Nematodes included: Africana taylori (60%), Oswaldocruzia perreti (0.2%), Aplectana sp. (21%), Gendria sp. (7.1%), Amphibiophilus sp. (0.2%), Strongyluris sp. (0.1%), Physalopteroides sp. (1.6%), and Oxyuridae gen. sp. (0.3%). Trematodes comprised: Mesocoelium sp. (7.3%) and Diplodiscus subclavatus (2.1%). Pentastomids were represented by Sebekia sp. (0.1%). The mean species richness and diversity were 1.97±2.12 and 0.41±0.04 respectively. The intensity of parasite infection was correlated with host body weight, positively for Africana taylori, Aplectana sp., Diplodiscus subclavatus, and Mesocoeliumsp. Infection rates were influenced by land-use pattern. Thus higher prevalences were observed in Loum (intensive agricultural area).

Growing resistance is reported to carbamate insecticides in malaria vectors in Cameroon. However, the contribution of acetylcholinesterase (Ace-1) to this resistance remains uncharacterised. Here, we established that the G119S mutation is driving resistance to carbamates in Anopheles gambiae populations from Cameroon. Insecticide bioassay on field-collected mosquitoes from Bankeng, a locality in southern Cameroon, showed high resistance to the carbamates bendiocarb (64.8% ± 3.5% mortality) and propoxur (55.71% ± 2.9%) but a full susceptibility to the organophosphate fenitrothion. The TaqMan genotyping of the G119S mutation in field-collected adults revealed the presence of this resistance allele (39%). A significant correlation was observed between the Ace-1R and carbamate resistance at allelic ((bendiocarb; odds ratio (OR) = 75.9; p < 0.0001) and (propoxur; OR = 1514; p < 0.0001)) and genotypic (homozygote resistant vs. homozygote susceptible (bendiocarb; OR = 120.8; p < 0.0001) and (propoxur; OR = 3277; p < 0.0001)) levels. Furthermore, the presence of the mutation was confirmed by sequencing an Ace-1 portion flanking codon 119. The cloning of this fragment revealed a likely duplication of Ace-1 in Cameroon as mosquitoes exhibited at least three distinct haplotypes. Phylogenetic analyses showed that the predominant Ace-1R allele is identical to that from West Africa suggesting a recent introduction of this allele in Central Africa from the West. The spread of this Ace-1R represents a serious challenge to future implementation of indoor residual spraying (IRS)-based interventions using carbamates or organophosphates in Cameroon. [ABSTRACT FROM AUTHOR]

Our current knowledge of the clinical burden, biology, and transmission of Plasmodium malariae is extremely scarce. To start addressing some of those questions, we experimentally infected Anopheles gambiae mosquitoes with fresh P. malariae isolates obtained from asymptomatic individuals in Lambaréné, Gabon. The proportion of mosquitoes infected via direct membrane feeding assay with either P. malariae monoinfections (16% [19 of 121]) or coinfections (28% [31 of 112]) was higher after serum replacement than in parallel groups without serum replacement (4% [4 of 102] and 4% [2 of 45], respectively; P < .01). Our results show that isolates from asymptomatic carriers can be used for experimental studies of P. malariae transmission., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)