First isolation of a new species of Leishmania responsible for human cutaneous leishmaniasis in Ghana and classification in the Leishmania enriettii complex

An active case detection approach with PCR diagnosis was used in the Ho District of the Volta Region, Ghana that identified individuals with active cutaneous leishmaniasis. Three isolates were successfully cultured and DNA sequences from these were analysed (ribosomal RNA internal transcribed spacer 1; ribosomal protein L23a intergenic spacer; RNA polymerase II large subunit), showing them to be Leishmania, identical to each other but different from all other known Leishmania spp. Phylogenetic analysis showed the parasites to be new members of the Leishmania enriettii complex, which is emerging as a possible new subgenus of Leishmania parasites containing human pathogens

An outbreak of suspected cutaneous leishmaniasis in Ghana: lessons learnt and preparation for future outbreaks

Human cutaneous leishmaniasis (CL) has previously been reported in West Africa, but more recently, sporadic reports of CL have increased. Leishmania major has been identified from Mauritania, Senegal, Mali, and Burkina Faso. Three zymodemes (MON-26, MON-117, and MON-74, the most frequent) have been found. The geographic range of leishmaniasis is limited by the sand fly vector, its feeding preferences, and its capacity to support internal development of specific species of Leishmania. The risk of acquiring CL has been reported to increase considerably with human activity and epidemics of CL have been associated with deforestation, road construction, wars, or other activities where humans intrude the habitat of the vector. In the Ho Municipality in the Volta Region of Ghana, a localised outbreak of skin ulcers, possibly CL, was noted in 2003 without any such documented activity. This outbreak was consistent with CL as evidenced using various methods including parasite identification, albeit, in a small number of patients with ulcers

Indoor residual spraying with a non-pyrethroid insecticide reduces the reservoir of <i>Plasmodium falciparum</i> in a high-transmission area in northern Ghana

High-malaria burden countries in sub-Saharan Africa are shifting from malaria control towards elimination. Hence, there is need to gain a contemporary understanding of how indoor residual spraying (IRS) with non-pyrethroid insecticides when combined with long-lasting insecticidal nets (LLINs) impregnated with pyrethroid insecticides, contribute to the efforts of National Malaria Control Programmes to interrupt transmission and reduce the reservoir of Plasmodium falciparum infections across all ages. Using an interrupted time-series study design, four age-stratified malariometric surveys, each of ~2,000 participants, were undertaken pre- and post-IRS in Bongo District, Ghana. Following the application of three-rounds of IRS, P. falciparum transmission intensity declined, as measured by a >90% reduction in the monthly entomological inoculation rate. This decline was accompanied by reductions in parasitological parameters, with participants of all ages being significantly less likely to harbor P. falciparum infections at the end of the wet season post-IRS (aOR = 0.22 [95% CI: 0.19–0.26], p-value < 0.001). In addition, multiplicity of infection (MOIvar) was measured using a parasite fingerprinting tool, designed to capture within-host genome diversity. At the end of the wet season post-IRS, the prevalence of multi-genome infections declined from 75.6% to 54.1%. This study demonstrates that in areas characterized by high seasonal malaria transmission, IRS in combination with LLINs can significantly reduce the reservoir of P. falciparum infection. Nonetheless despite this success, 41.6% of the population, especially older children and adolescents, still harboured multi-genome infections. Given the persistence of this diverse reservoir across all ages, these data highlight the importance of sustaining vector control in combination with targeted chemotherapy to move high-transmission settings towards pre-elimination. This study also points to the benefits of molecular surveillance to ensure that incremental achievements are not lost and that the goals advocated for in the WHO’s High Burden to High Impact strategy are realized

Susceptibility of Anopheles Mosquito to Agricultural Insecticides in the Adansi North District, Ghana

This study determined the susceptibility of Anopheles mosquitoes to some agricultural insecticides used in the Adansi North District of the Ashanti Region, and the efficacy of Actellic (pirimiphos-methyl) 50 EC as an alternative insecticide for the control of mosquitoes in the district. Anopheleslarvae were collected from mosquito breeding sites near farms. Five insecticides were assayed, pirimiphos-methyl (0.9%), DDT (4%), propoxur (0.1%), deltamethrin (0.05%), and lambda-cyhalothrin (0.05%). The residual efficacy of pirimiphos-methyl 50 EC sprayed on two surfaces (mud and cement) were determined by cone bioassay test at two-weekly intervals for 15 weeks after spraying. The susceptibility test showed the levels of phenotypic resistance of Anopheles spp. to the agricultural insecticides. Anopheles gambiae s.l. (96.50%) was the most dominant Anopheles species. The principal malaria vector in the district was resistant to DDT, Propoxur, Deltamethrin, and Lambda-cyhalothrin. Pirimiphos-methyl an organophosphate remained effective against the malaria vector. Student t-test analysis of bioassay test results showed that statistically the average mortality of Anopheles mosquitoes on cement surface was higher than the average mortality on mud surface. In conclusion, agricultural insecticides used in the district were negatively affecting malaria vector control activities. The use of pirimiphos-methyl (Actellic 50 EC) as an alternative insecticide against the malaria vector was more effective on cemented wall surface than on mud surface wall

First detection of Leishmania tropica DNA and Trypanosoma species in Sergentomyia sand flies (Diptera: Psychodidae) from an outbreak area of cutaneous leishmaniasis in Ghana.

BackgroundLeishmania major and an uncharacterized species have been reported from human patients in a cutaneous leishmaniasis (CL) outbreak area in Ghana. Reports from the area indicate the presence of anthropophilic Sergentomyia species that were found with Leishmania DNA.Methodology/principal findingsIn this study, we analyzed the Leishmania DNA positive sand fly pools by PCR-RFLP and ITS1 gene sequencing. The trypanosome was determined using the SSU rRNA gene sequence. We observed DNA of L. major, L. tropica and Trypanosoma species to be associated with the sand fly infections. This study provides the first detection of L. tropica DNA and Trypanosoma species as well as the confirmation of L. major DNA within Sergentomyia sand flies in Ghana and suggests that S. ingrami and S. hamoni are possible vectors of CL in the study area.Conclusions/significanceThe detection of L. tropica DNA in this CL focus is a novel finding in Ghana as well as West Africa. In addition, the unexpected infection of Trypanosoma DNA within S. africana africana indicates that more attention is necessary when identifying parasitic organisms by PCR within sand fly vectors in Ghana and other areas where leishmaniasis is endemic

Phylogenetic tree of 18S rRNA gene sequences among sand fly species.

<p>The 18S rRNA (<i>S. ingrami</i> HLE-9, <i>S. ingrami</i> HLE-22, <i>S. ingrami</i> KLE-2, <i>S. ingrami</i> TAV-51, <i>S. hamoni</i> KLE-18 and S. <i>africana africana</i> HLE-82) gene was amplified from infected sand flies and sequenced. Analysis of the sequences together with those from <i>Sergentomyia</i> species, <i>Phlebotomus</i> species and <i>Lutzomyia</i> species registered in GeneBank were performed. The bar scale represents 0.005% divergences. Bootstrap values are shown above or below branches.</p

Phylogenetic tree of COI gene sequences among sand fly species.

<p>The COI (<i>S. ingrami</i> HLE-9, <i>S. ingrami</i> HLE-22, <i>S. ingrami</i> KLE-2, <i>S. ingrami</i> TAV-51, <i>S. hamoni</i> KLE-18 and S. <i>africana africana</i> HLE-82) gene was amplified from infected sand flies and sequenced. Analysis of the sequences together with those from <i>Sergentomyia</i> species, <i>Phlebotomus</i> species and <i>Lutzomyia</i> species registered in GeneBank were performed. The bar scale represents 0.02% divergences. Bootstrap values are shown above or below branches. HLE, Hlefi community; KLE, Klefe community; TAV, Taviefe community.</p

Phylogenetic tree of SSU rRNA gene sequences among species.

<p>The SSU rRNA (IAFR/GH/2007/HLE-82) gene was amplified within <i>S. africana africana</i> pool and sequenced. Phylogenetic analysis of the SSU rRNA gene sequences was performed by the neighbor-joining method on the sequence together with those from 25 <i>Trypanosoma</i> species. The sequences from the database are represented by the name of the species, isolates and GeneBank (accession number). The scale bar represents 0.02% divergence. Bootstrap values are reported at nodes.</p

Detection of <i>Leishmania</i> DNA in sand flies.

<p><b>A.</b> PCR of <i>Leishmania</i> internal transcribed spacer 1 (ITS1) region amplified within pools of female <i>Sergentomyia</i> sand flies captured indoors and <i>Leishmania</i> spp. controls. M: 100 bp size marker; Lanes 1 and 2 (<i>L. major</i> and <i>L. tropica</i> reference strains, respectively); Lanes 3 to 6, <i>S. ingrami</i> pools, Lane 7, <i>S. hamoni</i> pool; Lane 8, <i>S. africana africana</i> pool (∼500 bp) and Lane 9, negative control. <b>B. </b><i>Hae</i>III digestion of restriction fragment length polymorphisms of ITS1 PCR products shown in A. M: 100 bp size marker; Lane 1, <i>L. major</i> (IPAP/EG/1989/S1-177); Lane 2, <i>L. tropica</i> (MHOM/SU/1974/K27); Lanes 3 to 6, <i>S. ingrami</i> pools; Lane 7, <i>S. hamoni</i> pool and Lane 8, <i>S. africana africana</i> pool.</p