Christopher Anjili

• Kenya Medical Research Institute

The study was designed to investigate on selected practices among rural population, and their likely contribution to the spread of amoebiasis (E. histolytica) and giardiasis (G. lamblia). A cross sectional study was carried out in three villages, namely Kikapu, Piave and Belbar in Njoro District, Kenya. Questionnaire, interviews and personal observ...

There are potential overlapping distributions of the protozoan parasite Leishmania and the parasitic helminth Schistosoma mansoni in eastern Africa most notably in endemic regions in the Sudan and Kenya. In murine model studies, the Th1-Th2 model of CD4+ T helper cell differentiation is a well-established paradigm for understanding the basis of pro...

Background: Leishmaniasis is an endemic tropical disease caused by Leishmania parasites, transmitted mainly by phlebotomine sandflies, impacting both health and socioeconomic wellbeing. Currently there are inadequate therapeutic measures to manage the disease thus indicating the need for the development of affordable and effective therapeutic inter...

Leishmania parasites (Kinetoplastida: Trypanosomatidae) are obligate intracellular parasites of macrophages that causes visceral and cutaneous leishmaniases. Currently, there is inadequate therapeutic interventions to manage this endemic tropical disease, transmitted mainly by phlebotomine sandflies hence there is need to develop affordable and eff...

This study determined the spatial-temporal distribution, natural infection and risk factors associated with phlebotomine sand flies (diptera: psychodidae) in Mt. Elgon Region, Kenya. Collections of sand flies were carried out for five nights of each month at two sites each in Bungoma and Trans Nzoia using the Center for Disease Control (CDC) light...

Abstract Background Conventional targeted leishmanicidal chemotherapy has persistently remained prohibitive for most economically deprived communities due to costs, associated time to accessing health services and duration for successful treatment programme. Alternatives are bound to be incorporated in rational management of leishmaniasis by choice...

p>The effi cacy of allopatric Tephrosia vogelii in killing eggs and larvae of the sand fl y Phlebotomus duboscqi was tested in the laboratory. In this study effects of both water and crude powder extracs of Tephrosia vogelii were tested against against pre-emerginal stages of P. duboscqi in the laboratory. Three groups of eggs were wetted with T. v...

Fruit and vegetables provides most of the carotenoids in the human diet, and their consumption is always an essential requirement for human nutrition due to the presence of bioactive compounds. The study investigated the presence of carotenoids in different parts (pulp, peel and seeds) of the underutilized, exotic fruits Annonaceae family species (...

Background: Leishmania major causes cutaneous leishmaniasis which leads to painful skin sores in humans. In the current study, efficacy of combination therapy of A. secundiflora and C. citrinus against L. major infected mice treated intra-peritoneally and orally was studied. Pentostam administered intra-peritoneally and phosphate buffered saline in...

Background: Medicinal plants have been of great importance to many traditional communities for many generations. However, there is need to carry out scientific studies in order to confirm the medicinal properties of many plants used traditionally. Carissa edulis Forskk. (Gentiales: Apocynaceae) used by local communities for the treatment of various...

Approximately 198 million cases of malaria manifested worldwide in 2013, causing 584,000 deaths, further solidifying malaria's status as a serious global health predicament. A vast array of immunopotentiating molecules like unmethylated CpG motif oligodeoxynucleotides (ODNs) operate in concert with cytokines in rendering hosts resistant to parasiti...

Leishmaniasis is one of the neglected tropical diseases that pose a threat to people in the endemic regions. In Africa, transmission is through the bite of an infected female phlebotomine sand fly. Disease control with chemotherapy is logistically difficult, toxic and expensive. Entomopathogenic fungi (EPF) hold great potential as alternative agent...

Despite advances to targeted leishmanicidal chemotherapy, defies around severe toxicity, recent emergence of resistant variants and absence of rational vaccine still persist. This necessitates search and/or progressive validation of accessible medicinal remedies including plant based. The study examined both in vivo and in vitro response of L. majo...

Solanum acueastrum Dunal. has been shown to have some chemotherapeutic value. Leaf and berry water and methanol compounds of S. acueastrum were evaluated for possible antileishmanial activity In vivo on BALB/c mice and in vitro against Leishmania major promastigotes, amastigotes and vero cells. Dry S. aculeastrum berry and leaf material were extrac...

Cutaneous leishmaniasis (CL) treatment involves pentavalent antimonials, amphotericin B, pentamidine, miltefosine among others. These drugs are toxic, costly, and require prolonged use. CL is a protozoan skin infection which may lead to disfiguring and stigmatization. In Kenya, CL is common in Baringo County where it is caused by Leishmania major a...

Leishmania major is a protozoan parasite responsible for cutaneous leishmaniasis (CL) in humans. CL is transmitted via a bite by infected female phlebotomine sand fly. Research on herbal therapy for leishmaniases is increasing globally because conventional drugs are costly, toxic and require a prolonged administration. In vitro and in vivo antileis...

Leishmania major is a protozoan parasite that causes cutaneous leishmaniasis and the standard drugs are expensive and toxic. Cheaper and safer natural drugs are therefore needed. In this study, the in vitro efficacy of crude extracts of Callistemon citrinus were tested against L. major. Controls were anti leishmanial drugs pentostam and liposomal a...

Background: The sand fly, Phlebotomus duboscqi is the vector for zoonotic cutaneous leishmaniasis caused by Leishmania major. No definite control method for P. duboscqi is known. Of the plants known for entomocidal properties, Mundulea sericea is one, with the toxic principle being rotenone. Dried crude M. sericea powder extract mixed with water is...

Our current understanding of the host immune response during leishmaniases largely derives from studies performed in mice due to the intrusive techniques required to study infected human patients. Swiss mice are highly resistance to Leishmania infections in concordance with observed response in humans while BALB/c mice indicate a high susceptibilit...

Leishmaniases are endemic in over 88 countries in the world, and 350 million people are considered at risk. Antimonial drugs for leishmaniases are toxic, faced with increasing drug resistance and require protracted administration. Currently, there is no vaccine. This necessitates the search for alternative cheaper and easily accessible drugs. The m...

Most natural host populations are exposed to a diversity of parasite communities and co-infection of hosts by multiple parasites is commonplace across a diverse range of systems. Co-infection with Leishmania major and Schistosoma mansoni may have important consequences for disease development, severity and transmission dynamics. Pentavalent antimon...

Leishmania major caused cutaneous leishmaniasis leads to painful skin sores in humans and usual drugs are expensive, toxic and require prolonged use. The in vitro and in vivo efficacy of aqueous crude extracts from Callistemon citrinus flowers (B), Allium sativum bulbs (C) and Moringa stenopetala leaves (A) against L. major was studied. Controls we...

Human leishmaniases are a spectrum of diseases caused by protozoan parasites of the genus Leishmania. In this study antileishmanial activity of the methanolic and water leaf extracts from Aloe secundiflora plant were analysed by determining the minimum inhibition concentration (MIC), nitric oxide (NO) production stimulation, infection rates (IR) an...

Background & objectives: Leishmaniasis is a growing health problem in many parts of the world. Efforts to find new chemotherapeutics for leishmaniasis remain a priority. This study was carried out to determine the effect of combination and monotherapies using plant extracts and herbicides on Leishmania major infection in BALB/c mice. Methods: Th...

The study was designed to investigate on selected practices among rural population, and their likely contribution to the spread of amoebiasis (E. histolytica) and giardiasis (G. lamblia). A cross sectional study was carried out in three villages, namely Kikapu, Piave and Belbar in Njoro District, Kenya. Questionnaire, interviews and personal observ...

Visceral and cutaneous leishmaniases are endemic in some parts of Kenya, where they are transmitted by phlebobotomine sandflies of genus Phlebotomus. This review is a compilation of the currently known distribution of phlebotomine sandflies in the parts of Kenya that have been studied, from the time sandflies were first reported in the country. So...

A laboratory based study was designed to characterize 43 cryo-preserved Leishmania-like flagellates. These Leishmania-like flagellates were originally obtained from non-human hosts that included spiny mice (Acomys subspinosus), plated lizards (Gerrosaurus major) and sand flies of the Genus Sergentomyia caught at Masinga location, Machakos District...

Several plant products have been tested and found to possess antileishmanial activity. The present study was undertaken to establish whether methanolic extract of Allium sativum Linn has antileishmanial activity in comparison to standard drugs. Methanolic extract of A. sativum bulbs was screened for in vitro and in vivo antileishmanial activity aga...

Phlebotomine sandflies are vectors of leishmaniases and other diseases. Long-lasting insecticidal nets (LLINs) as possible tools for control have not been widely tested against them. The objective of this study was to determine the efficacy of Olyset Net and PermaNet LLINs alongside a local brand, K-O Tab treated net (Supanet) against Phlebotomus d...

In order to understand sandfly bionomics, vector species identification, and to develop methods for sandfly control, there is a need to sample sandflies in any particular habitat. This survey was aimed at determining the best method of sampling Phlebotomus (Phlebotomus) duboscqi (Diptera: Psychodidae) in the field. Different animal baits and CO2-ba...

Leishmaniasis is a vector-borne disease in which Leishmania parasites are transmitted by the bite of phlebotomine sand flies. Amastigotes are ingested by the sand fly vector with a blood meal taken from an infected host. This is followed by their differentiation into metacyclic promastigotes which are selectively released and permitted to migrate i...

Research in our laboratory has previously shown that immune-mediated transmission blocking may be applied to Leishmania infections and that the LPG molecule and anti-LPG monoclonal antibodies was found to be an excellent candidate against L. major infections. To test the effect of monoclonal antibodies (MABs) raised against different species of Lei...

Currently there is no vaccine available in use against any form of leishmaniases worldwide. To assess potential of a live-attenuated Leishmania major promastigates, for protection against a challenge infection with L. major in BALB/c mice. A laboratory based study. Study was carried out at Centre for Biotechnology Research and Development, Kenya Me...

This is the first report on the nocturnal flight activity of the phlebotomine sandflies in the field by trap collection in Mukusu, Masinga, the kala-azar (visceral leishmaniasis in humans) area in Kenya. A total of 514 sandflies were collected with three different types of traps (sticky traps, CDC light traps and a goat-baited trap), and seven spec...

New strategies for control of leishmaniasis is needed as chemotherapy using antimonial drugs is prolonged, expensive, associated with side effects and relapses. Vector control has limitations and a vaccine which may be the best approach is not available. To assess the level of inhibition of promastigote development and gut morphology in infected Ph...

Safe, effective and inexpensive vaccines may be the most practical tool for control of any form of leishmaniasis. Leishmaniasis produces a state of pre-immunition which is the underlying mechanism for prolonged immunity to re-infection. Low doses of parasites has been shown to be able to induce protection in mice. It is not known, however, how immu...

Leishmania major is a protozoan parasite that causes chronic cutaneous lesions that often leave disfiguring scars. Infections in mice have demonstrated that leishmanial vaccines that include interleukin-12 (IL-12) as an adjuvant are able to induce protective immunity. In this study, we assessed the safety, immunopotency, and adjuvant potential of t...

Background: Safe, effective and inexpensive vaccines may be the most practical tool for control of any form of leishmaniasis. Leishmaniasis produces a state of pre-immunition which is the underlying mechanism for prolonged immunity to re-infection. Low doses of parasites has been shown to beable to induce protection in mice. It is not known, howeve...

The ability of antibodies in bloodmeals of mice and hamsters immunized with Leishmania major subcellular fractions and sandfly (Phlebotomus duboscqi) gut antigens to inhibit development of L. major in its vector P. duboscqi was examined. Antibodies from animals immunized with either L. major subcellular fractions alone or sandfly gut antigen alone...

Domestic sheep were intradermally inoculated with culture-derived stationary phase Leishmania donovani promastigotes. Sampling of site of inoculation, liver and spleen for 244 days showed that this parasite can stay alive in the skin for up to 28 days post-inoculation. Apart from pyrexia that was evident in all the animals for 42 days, no other sym...

The study was aimed at analyzing immunological cross-reactivity between Leishmania major and Leishmania donovani and possible cross-protection between the two parasite species in the vervet monkey model of the disease. Nine vervet monkeys (Cercopithecus aethiops) from the institute animal colony were sued in the study. Five of the animals had been...

The hypoxic model of pulmonary hypertension was used to examine temporal alterations in the deposition of the basement membrane (BM) and components of fibronectin, laminin, and Type IV collagen within vascular, airway, and gas exchange compartments of the lung. Because hypoxic pulmonary hypertension is a reversible model of hypertension, changes in...

The ability of hamsters (Mesocricetus auratus) to retain amastigotes of Leishmania donovani at cutaneous sites was examined. Following intradermal inoculation of L. donovani stationary phase culture promastigotes in fore and hind footpads, nasal area and belly skin, cultures of aspirates taken fortnightly from these sites showed that amastigotes ca...

Phlebotomus duboscqi were fed on hamsters previously immunized with different concentrations of homogenized crude sandfly gut antigen and supernatant obtained from whole body extract. The humoral response in the rodents was quantified at different times post-immunization by the enzyme-linked immunosorbent assay. Sandflies were fed on either immuniz...

A total of 1128 rodents belonging to seven genera were examined for leishmanial parasites over a period of sixteen months. Parasites were isolated from 36 (12.5%) Tatera robusta, 3 (0.5%) Arvicanthis niloticus, and 2 (0.8%) Mastomys natalensis. All isolates were characterised by isoenzyme analysis using nine enzymes. The enzymes examined were: mala...

Phlebotomus duboscqi were fed on hamsters previously immunized with different concentrations of homogenized crude sandfly gut antigen and supernatant obtained from whole body extract. The humoral response in the rodents was quantified at different times post-immunization by the enzyme-linked immunosorbent assay. Sandflies were fed on either immuniz...

Vervet monkeys (Cercopithicus aethiops) were shown to give a positive delayed-type hypersensitivity (DTH) reaction to gp63, a major surface glycoprotein of Leishmania parasites, and also produce antibodies to the molecule following a triple vaccination with a total dose of 150 micrograms of recombinant gp63 mixed with Bacille Calmette Guerin (BCG)....

A total of 728 animals comprising of 633 rodents and 95 canids were examined for leishmanial parasites. Flagellates were isolated from 67 out of 111 (60.4%) Acomys subspinosus (spiny mouse), 12 out of 143 (8.4% ) Mastomys natalensis (multimammate rat), 2 out of 50 (4.0%) Lemniscomys striatus (striped mouse), 2 out of 6 (33.3%) Herpestes sanguineus...

The possibility that salivary gland lysates of Phlebotomus duboscqi are able to attract vertebrate monocytes was investigated. In vitro studies showed that salivary gland lysates of P. duboscqi, the vector of Leishmania major in Kenya, are chemotactic to mouse peritoneal monocytes. This attraction of monocytes by vector salivary gland lysates may f...

Leishmania major-derived flagella and nuclear fractions, and a combination of flagella and sand fly gut antigens were assessed for protection against L. major infection in BALB/c mice. Mice immunized with flagella antigen developed a severe infection while nuclear fraction-immunized animals were partially protected at the onset of infection from we...

Leishmania donovani-infected Syrian hamsters were treated intraperitoneally with 0.23 mmoles/kg/day of EDTA, EGTA, HEEDTA and 100 mg/kg/day of Pentostam R. The control group received 0.1 ml of phosphate buffered saline. After 30 days of treatment, the animals were sacrificed. Of the Pentostam-treated animals, 5 out 6 had negative spleen cultures, w...

Identical impression smears of spleen, liver and bone marrow biopsy materials from Leishmania donovani-infected hamsters were stained using either acridine orange or Giemsa. Spleen parasite-loads calculated from the two stains for identical biopsy material were significantly different from each other. However, liver and bone marrow parasite- loads...

The course of Leishmania infection in pristane-primed BALB/c mice infected with either Leishmania major or Leishmania donovani was examined. Pristane-primed L. donovani infected mice had spleen parasite-loads that were 13 times less than controls. Likewise pristane-primed L. major infected animals had significantly smaller footpad lesion areas than...

Exposure of Leishmania donovani culture promastigotes to ethyleneglycol-bis-((-aminoethyl ether) N,N,N(1),N(1),-tetraacetic acid (EGTA) concentrations of between 0.2 to 1.6 mg/ml significantly inhibited their growth, though the different concentrations did not significantly differ between themselves on their effect on promastigotes in cell free med...

Syrian hamsters and BALB/c mice were inoculated intraperitoneally with various doses of stationary phase Leishmania donovani promastigotes derived from primary, secondary and tertiary cultures. Axenic derived amastigotes from a tertiary culture and mass-culture derived promastigotes from primary, secondary, and tertiary cultures were also used. Ani...

Anjili, C.O., Olobo, J.O., Mbati, P.A., Robert, L. and Githure, J.I., 1994. Experimental infection of domestic goats with Leishmania major through bites of infected Phlebotomus duboscqi and needle inoculation of culture-derived promasfigotes. Veterinary Research Communications, 18 (4), 301-305

IFN-γ levels and delayed-type hypersensitivity (DIM) responses were evaluated in vervet monkeys, following secondary infection with leishmania major (L. major). The animals had previously been vaccinated with leishmanial antigen, exposed to a primary infection and allowed to self-cure. Supernatants of peripheral blood mononuclear cell (PBMC) cultur...

Sand flies were collected in light traps and on oiled papers at four active case sites of human cutaneous leishmaniasis due to Leishmania tropica at Muruku Sublocation, Laikipia District, Kenya. Nearly 5,200 females of five species, including Phlebotomus guggisbergi, were dissected and examined for flagellates. Of 3,867 P. guggisbergi females colle...

The extrinsic development of Leishmania major was observed in 2 man-biting sand flies, Phlebotomus duboscqi, a known vector, and Sergentomyia schwetzi, an assumed non-vector. Flies fed on a leishmanial lesion on the nose of a hamster were examined for infection at 0, 6, 12, 18, 24, 36, 48, and 60 hr and at approximately 24 hr intervals from day 3 t...

Experimental transmission of Leishmania major to vervet monkeys (Cercopithecus aethiops) was accomplished by bites of Phlebotomus duboscqi sandflies. Three-day-old, laboratory-reared P. duboscqi were fed on leishmanial lesions on hamsters infected with L. major. The flies were re-fed on monkeys 10 d after infection. Five adult male vervet monkeys w...

An 18-month sandfly survey was conducted at 4 locations in Baringo District, Rift Valley Province, Kenya. 3 collection techniques were used: aspiration, sticky paper trap, and light trap in sites selected because of their proximity to homes of visceral leishmaniasis patients diagnosed and treated within 6 months before the survey. Over 2000 female...

Amastigotes of a Kenyan strain of Leishmania donovani from a previously infected hamster were used to inoculate Rattus rattus and the laboratory white rat intracardially. The animals were sampled at 2, 4, 6, and 12 weeks post-inoculation to determine infectivity and total parasite burdens in the liver and spleen. Higher parasite burdens were observ...