1
|
Omondi P, Burugu M, Matoke-Muhia D, Too E, Nambati EA, Chege W, Musyoka KB, Thiongo K, Otinga M, Muregi F, Kimani F. Gametocyte clearance in children, from western Kenya, with uncomplicated Plasmodium falciparum malaria after artemether-lumefantrine or dihydroartemisinin-piperaquine treatment. Malar J 2019; 18:398. [PMID: 31801562 PMCID: PMC6891957 DOI: 10.1186/s12936-019-3032-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 11/24/2019] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND The efficacy and safety of artemether-lumefantrine (AL) and dihydroartemisinin-piperaquine (DP) against asexual parasites population has been documented. However, the effect of these anti-malarials on sexual parasites is still less clear. Gametocyte clearance following treatment is essential for malaria control and elimination efforts; therefore, the study sought to determine trends in gametocyte clearance after AL or DP treatment in children from a malaria-endemic site in Kenya. METHODS Children aged between 0.5 and 12 years from Busia, western Kenya with uncomplicated Plasmodium falciparum malaria were assigned randomly to AL or DP treatment. A total of 334 children were enrolled, and dried blood spot samples were collected for up to 6 weeks after treatment during the peak malaria transmission season in 2016 and preserved. Plasmodium falciparum gametocytes were detected by qRT-PCR and gametocyte prevalence, density and mean duration of gametocyte carriage were determined. RESULTS At baseline, all the 334 children had positive asexual parasites by microscopy, 12% (40/334) had detectable gametocyte by microscopy, and 83.7% (253/302) children had gametocytes by RT-qPCR. Gametocyte prevalence by RT-qPCR decreased from 85.1% (126/148) at day 0 to 7.04% (5/71) at day 42 in AL group and from 82.4% (127/154) at day 0 to 14.5% (11/74) at day 42 in DP group. The average duration of gametocyte carriage as estimated by qRT-PCR was slightly shorter in the AL group (4.5 days) than in the DP group (5.1 days) but not significantly different (p = 0.301). CONCLUSION The study identifies no significant difference between AL and DP in gametocyte clearance. Gametocytes persisted up to 42 days post treatment in minority of individuals in both treatment arms. A gametocytocidal drug, in combination with artemisinin-based combination therapy, will be useful in blocking malaria transmission more efficiently.
Collapse
Affiliation(s)
- Protus Omondi
- Department of Biochemistry, Microbiology, and Biotechnology, Kenyatta University, P.O Box 43884-00100, Nairobi, Kenya.,Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O Box 54840-00200, Nairobi, Kenya
| | - Marion Burugu
- Department of Biochemistry, Microbiology, and Biotechnology, Kenyatta University, P.O Box 43884-00100, Nairobi, Kenya
| | - Damaris Matoke-Muhia
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O Box 54840-00200, Nairobi, Kenya
| | - Edwin Too
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O Box 54840-00200, Nairobi, Kenya
| | - Eva A Nambati
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O Box 54840-00200, Nairobi, Kenya
| | - William Chege
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O Box 54840-00200, Nairobi, Kenya
| | - Kelvin B Musyoka
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, P.O Box 62000-00200, Nairobi, Kenya
| | - Kelvin Thiongo
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O Box 54840-00200, Nairobi, Kenya
| | - Maureen Otinga
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O Box 54840-00200, Nairobi, Kenya
| | - Francis Muregi
- Department of Biological Sciences, Mount Kenya University, P.O Box 342-00100, Nairobi, Kenya
| | - Francis Kimani
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O Box 54840-00200, Nairobi, Kenya.
| |
Collapse
|
2
|
Nderu D, Kimani F, Karanja E, Thiong'o K, Akinyi M, Too E, Chege W, Nambati E, Wangai LN, Meyer CG, Velavan TP. Genetic diversity and population structure of Plasmodium falciparum in Kenyan-Ugandan border areas. Trop Med Int Health 2019; 24:647-656. [PMID: 30816614 DOI: 10.1111/tmi.13223] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Kenya has, in the last decade, made tremendous progress in the fight against malaria. Nevertheless, continued surveillance of the genetic diversity and population structure of Plasmodium falciparum is required to refine malaria control and to adapt and improve elimination strategies. Twelve neutral microsatellite loci were genotyped in 201 P. falciparum isolates obtained from the Kenyan-Ugandan border (Busia) and from two inland malaria-endemic sites situated in western (Nyando) and coastal (Msambweni) Kenya. Analyses were done to assess the genetic diversity (allelic richness and expected heterozygosity, [He ]), multilocus linkage disequilibrium ( I S A ) and population structure. A similarly high degree of genetic diversity was observed among the three parasite populations surveyed (mean He = 0.76; P > 0.05). Except in Msambweni, random association of microsatellite loci was observed, indicating high parasite out-breeding. Low to moderate genetic structure (FST = 0.022-0.076; P < 0.0001) was observed with only 5% variance in allele frequencies observed among the populations. This study shows that the genetic diversity of P. falciparum populations at the Kenyan-Ugandan border is comparable to the parasite populations from inland Kenya. In addition, high genetic diversity, panmixia and weak population structure in this study highlight the fitness of Kenyan P. falciparum populations to successfully withstand malaria control interventions.
Collapse
Affiliation(s)
- David Nderu
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany.,School of Health Sciences, Kirinyaga University, Kerugoya, Kenya
| | - Francis Kimani
- Center for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya
| | - Evaline Karanja
- Department of Biochemistry and Biotechnology, School of Biological and Life Sciences, Technical University of Kenya, Nairobi, Kenya
| | - Kelvin Thiong'o
- Center for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya
| | - Maureen Akinyi
- Center for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya
| | - Edwin Too
- Center for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya
| | - William Chege
- Center for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya
| | - Eva Nambati
- Center for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya
| | - Laura N Wangai
- School of Health Sciences, Kirinyaga University, Kerugoya, Kenya
| | - Christian G Meyer
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany.,Vietnamese-German Centre for Medical Research, Hanoi, Vietnam.,Faculty of Medicine, Duy Tan University, Da Nang, Vietnam
| | - Thirumalaisamy P Velavan
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany.,Vietnamese-German Centre for Medical Research, Hanoi, Vietnam.,Faculty of Medicine, Duy Tan University, Da Nang, Vietnam.,Fondation Congolaise pour la Recherche Médicale, Brazzaville, Republic of Congo
| |
Collapse
|
3
|
Nambati EA, Kiarie WC, Kimani F, Kimotho JH, Otinga MS, Too E, Kaniaru S, Limson J, Bulimo W. Unclear association between levels of Plasmodium falciparum lactate dehydrogenase (PfLDH) in saliva of malaria patients and blood parasitaemia: diagnostic implications? Malar J 2018; 17:9. [PMID: 29304786 PMCID: PMC5756406 DOI: 10.1186/s12936-017-2151-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 12/23/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The use of saliva in diagnosis of infectious diseases is an attractive alternative to procedures that involve blood drawing. It promises to reduce risks associated with accidental needle pricks and improve patient compliance particularly in malaria survey and drug efficacy studies. Quantification of parasitaemia is useful in establishing severity of disease and in assessing individual patient response to treatment. In current practice, microscopy is the recommended technique, despite its limitations. This study measured the levels of Plasmodium falciparum lactate dehydrogenase (PfLDH) in saliva of malaria patients and investigated the relationship with blood parasitaemia. METHODS Matched pre-treatment blood and saliva samples were collected from patients at Msambweni District Hospital, Kenya. Parasitaemia was determined and only those confirmed to be Plasmodium falciparum mono-infected were recruited. PfLDH was quantified in saliva using a commercial ELISA kit. A total of 175 samples were collected. Relationship between blood parasitaemia and concentration of PfLDH in saliva was determined using Pearson correlation statistics. F test was used to determine whether there is a significant difference between levels of PfLDH in saliva of patients with moderate to high parasitaemia and those with low parasitaemia. RESULTS One-hundred and seventy-five patient samples were positive for malaria by microscopy. Of these, 62 (35%) tested positive for PfLDH in saliva, 113 (65%) were false negatives. For those that tested positive, (53) 85% were from patients with moderate to high parasitaemia while 9 (15%) were from patients with low parasitaemia. A correlation co-efficient of 0.18 indicated a weak positive relationship between the concentration of PfLDH in saliva and blood parasitaemia. There was a marginal difference between levels of PfLDH in saliva of patients with moderate to high parasitaemia and those with low parasitaemia [F (1, 59) = 1.83, p = 0.1807]. CONCLUSION The results indicate that there is a weak correlation between levels of PfLDH in saliva and blood parasitaemia. This is weak association could be as a result of low sensitivity of the assay used as well as presence of inhibitors and proteases in saliva. Further studies should be focused towards reducing the number of false negatives and developing a customised assay that is specific for detection of PfLDH in saliva.
Collapse
Affiliation(s)
- Eva A Nambati
- KEMRI Centre for Biotechnology Research and Development, Nairobi, Kenya.
| | - William C Kiarie
- KEMRI Centre for Biotechnology Research and Development, Nairobi, Kenya
| | - Francis Kimani
- KEMRI Centre for Biotechnology Research and Development, Nairobi, Kenya
| | - James H Kimotho
- KEMRI Centre for Biotechnology Research and Development, Nairobi, Kenya
| | - Maureen S Otinga
- KEMRI Centre for Biotechnology Research and Development, Nairobi, Kenya
| | - Edwin Too
- KEMRI Centre for Biotechnology Research and Development, Nairobi, Kenya
| | - Stephen Kaniaru
- KEMRI Centre for Biotechnology Research and Development, Nairobi, Kenya
| | - Janice Limson
- Rhodes University Biotechnology Innovation Centre (RUBIC), Grahams Town, South Africa
| | - Wallace Bulimo
- Department of Biochemistry, University of Nairobi, Nairobi, Kenya
| |
Collapse
|