Trypanosomiasis Research Research Articles

Barriers and Facilitators to Career Advancement of Women in Infectious Diseases of Poverty Research in Nigeria

Women scientists are commonly under-represented in all stages of their research career, thus resulting in fewer women in leadership and decision-making positions. The dearth of women scientists in infectious diseases of poverty research often results in a lack of diverse perspectives necessary for addressing gender dimensions and the burden of the diseases. This study, therefore, aimed to look at barriers and facilitators to the career growth of women scientists in infectious diseases of poverty research in Nigeria. It also aimed at highlighting the importance of positive actions such as research mentorship and adequate funding to ensure that women achieve their full potential in their research careers. This was a cross-sectional quantitative study conducted in six higher institutions in the South-West, North-Central, and North-West geopolitical zones of Nigeria. The institutions were the Nigerian Institute of Medical Research, Lagos, and its Kainji out station in Niger State; University Teaching Hospital, Lagos; Nigerian Institute for Trypanosomiasis and Onchocerciasis Research, Kaduna, University of Lagos; and the University of Ibadan. The study population was made up of 134 participants, which included fifty-six (56) women scientists in infectious diseases of poverty research within the age range of 20 to 50 years. They held a minimum of master’s degrees in biomedical, socio-behavioral, and life sciences. Other participants were seventy-eight (78) graduate students and postdoctoral fellows in biomedical and life sciences, aged between 20 and 40 years. Family issues, which included balancing life and career and raising children, and gender stereotyping, such as having full responsibility for caregiving within the family, were some barriers to their career growth. Suggested facilitators to their career growth were adequate funding opportunities, including career re-entry grants, continuous and periodic participation in training, short courses, seminars, and webinars to enable them to stay up-to-date with the latest developments and techniques in their various research fields.

Isolation and Characterization of Bacteria Present in the Gut of Dead Females Glossina morsitan Submorsitans Using Culture Dependent and Independent Methods

This study aimed to isolate and characterize bacteria present in the gut of death female Glossina morsitan submorsitans using culture dependent and independent methods. Thirty-four fresh dead female flies were obtained from the insectary of Nigerian Institute for Trypanosomiasis Research (NITR), Kaduna. The flies were surface sterilized and the mid-guts were dissected under aseptic conditions. The gut bacterial cultures were done for pregnant and non-pregnant dead female flies (6weeks- 15weeks old) a total of 20 isolates. The culture dependent methods identified six bacterial genera namely, Serratia species, Staphylococcus species, Escherichia species, Myroides species, Providencia species and Alkaligenes species. Molecular analysis only identified four (4) out of the six (6) isolates; as 4(50%) Serratia mercesens, 1(12.5%) Alcaligenes faecalis, 2(25%) Myroides odoratimus and 1(12.5%) Providencia. This is not surprising because the microorganisms were not included in the targeted spectrum of the Polymerase Chain Reaction. Our study recorded for the first time the presence of Myroides odoratimus in the gut of G. M. submorsitans in Nigeria. Some of these bacteria are pathogenic to the flies and may be the cause of mortality of laboratory reared flies. We recommend intensive research on tse tse gut bacterial flora to give insight into their use as potential vector bio-control tool.

Retrospective mortality assessment of Glossina palpalis palpalis collections from Ijah-Gwari field station, Niger state Nigeria

Handling and transportation of tsetse flies are fundamental for mortality assessment during fly collections. Previous works have indicated that tsetse fly mortalities increase with the rise in ambient temperatures. A seasonal mortality assessment of Glossina palpalis palpalis population collected from Ijah-Gwari field station was carried out based on the record as kept in the insectary of the Nigerian Institute for Trypanosomiasis Research, during the period between 2011- 2018; in order to determined fly mortality rates associated with handling and transportation of flies. Results indicated that whereas high percentage mortalities were recorded between 2016 (44%) and 2017 (57%); moderate mortalities were recorded in 2011 (36%), 2014 (29%), 2015 (19%) and 2018 (30%); while low mortalities of 10% were recorded in 2012 and 2013. Hot months of May (51%) and July (25%) gross mortalities contributed significantly to the increase in mortalities recorded in these years. The findings of this study show that extreme temperatures and relative humidity might be contributing factor of fly mortality. The handling and transport conditions might have sustained the high temperatures and humidity during transportation. Mean percentage mortality was observed to be higher in male (44%) than the female (33%) flies from Ijah-Gwari. The implication of this study as pertains salivary gland hypertrophy virus transmission is discussed.

Effect of Pre and Post Infection Administration of Zinc and Selenium on some Biochemical indices in Wistar Rats infected with Trypanosoma brucei

Aims: The effect of pre and post-infection administration of zinc and selenium on Trypanosoma brucei brucei infection in wistar rats on some biochemical parameters were investigated.
 Study Design: The study was designed to evaluate the effect of pre and post infection administration of zinc and selenium on Trypanosoma brucei brucei infection in wistar rats.
 Place and Duration of Study: The study was conducted at the Nigerian Institute for Trypanosomiasis Research (NITR), Kaduna and Department of Biochemistry, Ahmadu Bello University (ABU), Zaria, between January 2014 to March 2014.
 Methodology: Fifty four (54) wistar rats were divided into nine groups of six (6) rats each. Groups III-IX were infected intraperitoneally with 1x103parasite load. Animals in group III were infected but untreated while the infected/treated groups received prophylactic (IV, V and VI) and therapeutic (VII, VIII and IX) treatment with zinc and selenium 50mg/kg and 10mg/kg body weight respectively.
 Results: Results obtained showed that serum alkaline phosphatase (ALP), alanine amino transferase (ALT) and aspartate amino transferase (AST) activities in the infected-untreated control group were significantly different (P<0.05) and higher as compared to infected treated and normal control. Similarly, the two minerals significantly decreased (P<0.05) the levels of Urea and Creatinine in the infected treated when compared to the infected untreated rats, with the exception of creatinine value of the post-infected treated with selenium where there was no significant (P>0.05) decrease. On the other hand, a significant (P<0.05) increase in serum levels of total Protein, albumin and total bilirubin and no significant (P>0.05) difference in direct bilirubin was recorded in infected treated group compared to infected untreated and normal control.
 Conclusion: It was concluded that administration of zinc and selenium ameliorate the infection-induced biochemical changes in tissues and organs associated with Trypanosoma brucei brucei infection in Wistar rats.

Scientometric analysis of global trypanosomiasis research: 1988–2017

Background and objectivesThis study provides a longitudinal scientometric analysis of global trypanosomiasis research between 1988 and 2017 as indexed in Clarivate Analytics’ Web of Science (WoS). Contributions by researchers from different countries and continents are outlined based on publication productivity, international collaborations, citation analysis, and keyword analysis. MethodsBibliographic records of research publications indexed by WoS were downloaded based on a broad search of related terms. The authors compared the growth of literature by continent using 5-year increments, conducted a citation and co-authorship analysis by country, and a keyword analysis by publication using the scientometric visualization software VOSviewer. ResultsThe trypanosomiasis research literature has seen more than a fourfold annual increase in production over the study period. Contributions by authors affiliated with European and South American countries proportionately account for the most research literature. The United States and Brazil, however, occupy central roles for citations and as national contributors to the literature. The terms ‘trypanosomiasis cruzi’ and ‘chagas disease’ have become more prominent, reflecting the regional growth of research from South America. Interpretation and conclusionRelative contributions from regions where the disease is prevalent show mixed developments. Contributions by African authors have declined proportionately to other areas of the world. However, South American contributions have increased during the study period. The contributing countries to the literature do not necessarily represent regions in which the diseases are prevalent. The same is true of the citation relationships, where European and North American contributions are more frequently cited.

NITR’s contributions towards the elimination of Trypanosomiasis and onchocerciasis in Nigeria

This is a report on the contributions of the Nigerian Institute for Trypanosomiasis (and Onchocerciasis) Research (NITR) towards the elimination of the two Neglected Tropical Diseases. The socio-economic importance of African trypanosomiasis (sleeping sickness in man, SammorA in domestic animals) and onchocerciasis (River blindness) cannot be overemphasized. The sleeping sickness epidemics in the twentieth century resulted in loss of huge numbers of human lives and desertion of the affected localities and farm lands by survivors. To provide short and long term strategies towards the elimination of the burden of African Trypanosomiasis, the then British Colonial Government established the West African Institute for Trypanosomiasis Research (WAITR) in 1951 to serve the needs of Nigeria, Gold Coast (Ghana), Sierra Leone and The Gambia. WAITR metamorphosed to NITR in 1964 following the nation’s independence in 1960. And in 1975, mandate for onchocerciasis research was given to NITR. From its inception to date, NITR had pioneered research works that curbed the outbreaks of Sleeping Sickness, enhanced recognition of the public health importance of onchocerciasis and emphasizing poor funding of research as a great challenge militating against the elimination of endemic parasitic diseases such as trypanosomiasis and onchocerciasis. This paper presents most of the directions and contents of research (diagnostics, therapeutic approaches, etc.) including collaborations NITR had to forge in its efforts to drive the elimination of the two diseases from Nigeria. Future research works are indicated. Keywords: Trypanosomiasis; onchocerciasis; elimination; Nigeria.

Impact of Transactional and Transformational Leadership Styles on Employees’ Performance in Nigerian Institute for Trypanosomiasis Research (NITR), Kaduna State

The aim of this study is to determine the impact of transactional and transformational leadership styles on employee performance in Nigeria Institute for Trypanosomiasis Research, Kaduna State. A structured questionnaire was used to sample respondents using simple random sampling technique. Multifactor Leadership Questionnaire (MLQ-5X) was used to measure leadership styles and employee performance was measured using salary, job experience and job satisfaction. A total of 230 questionnaires were distributed to the respondents. Structural equation model was used to analyze data using partial least squares method SmartPLS2. The result showed that transformational and transactional leadership styles has a significant and positive impact on employee performance. Therefore, it saw recommended that Nigeria Institute for Trypanosomiasis Research should practice transformational leadership styles to improve employee performance in the organization in Kaduna State.

Impact of Transactional and Transformational Leadership Styles on Employees’ Performance in Nigerian Institute for Trypanosomiasis Research (NITR), Kaduna State

The aim of this study is to determine the impact of transactional and transformational leadership styles on employee performance in Nigeria Institute for Trypanosomiasis Research, Kaduna State. A structured questionnaire was used to sample respondents using simple random sampling technique. Multifactor Leadership Questionnaire (MLQ-5X) was used to measure leadership styles and employee performance was measured using salary, job experience and job satisfaction. A total of 230 questionnaires were distributed to the respondents. Structural equation model was used to analyze data using partial least squares method SmartPLS2. The result showed that transformational and transactional leadership styles has a significant and positive impact on employee performance. Therefore, it saw recommended that Nigeria Institute for Trypanosomiasis Research should practice transformational leadership styles to improve employee performance in the organization in Kaduna State.

The effect of heavy metal air pollution arising from local metallurgical activities on albino rat

Introduction: The ecological equilibrium of the earth is endangered by the chemical process industries as most industries continue to spew chemical toxicants into the environment. Since local metallurgical activity is inevitable in Nigeria Aim:This research is aimed at assessing the effect of local metallurgical activity on the quality of air. Methods: Particular matter samples were collected for 24h at four different sites twice a month using a high volume air sampler. Point A is Bakin Dogo Market, Point B is Old Panteka market, Point C is new Panteka market and Point D is U/Ma’azu. All the collected samples were analyzed for heavy metals using standard laboratory procedures. Six hundred newly born male albino rats were collected from National Institution for Trypanosomiasis Research (NITR) and were exposed to the sampling points twenty four hours daily via out the experimental period. Mortality, haematological and histological parameters were investigated. The rat tissues were also digested for the determination of Bioconcentration factor (BCF). Result: The result obtained shows high Concentration of heavy metals (Pb, Cd, Cu and Ni) above the recommended limit by European commission (EC), World health organization (WHO) and NEPM (National Environmental Protection Measures). Higher BCF was obtained for all the heavy metals (Pb, Ni, Cu and Cd) which was attributed to the higher changes in Mortality, haematological and histological parameters if compare to the control. Conclusion: The studies shows how heavy metal air pollution could cause Mortality and also bring about changes in haematological and histological parameters, which resulted due to high BCF. It is thereby recommended that local metallurgical activities should be closely monitored by environmental agencies such as Kaduna state environmental protection agencies (KEPA) and Federal environmental protection agencies (FEPA). The government should also make regulations that will mandate the paying of environmental degradation tax owing to the daily multiplication of vehicles and other automobile materials.

Kenya Trypanosomiasis Research Institute cryobank for human and animal trypanosome isolates to support research: opportunities and challenges.

Human African trypanosomiasis (HAT) is classified in the category of the most neglected tropical diseases. In man, the disease is caused by two tsetse (Glossina spp.)-transmitted trypanosome subspecies: Trypanosoma brucei gambiense, which is responsible for the chronic form of HAT in West and Central Africa, and T. b. rhodesiense, which causes acute disease in eastern and southern Africa. African animal trypanosomiasis (AAT) is caused by various trypanosome species, the major ones being T. vivax, T. congolense, and T. evansi [1]. Current diagnostic tools are inadequate and diagnosis is complicated, whereas the drugs for treatment are highly toxic and not very effective; patients die if untreated [2]. In 2005, an annual prevalence of 50,000–70,000 cases per year and incidence rates of 15,000–17,000 cases per year were reported [3]. Although recent data from the World Health Organization (WHO) shows that the number of reported cases of HAT declined to less than 10,000 in 2009, leading to speculation that the disease could be eliminated [4], [5], there is great need to maintain vigilance. The East African Trypanosomiasis Research Organization (EATRO) was established to carry out research and develop technologies for effective control of trypanosomiasis. In view of this, a trypanosome cryobank was established in Tororo, Uganda, in the mid-1950s to provide materials for research. At that time, dry ice was used as a refrigerant, but in 1977 it was replaced with liquid nitrogen. Following the collapse of the East African Community in 1977, the Kenya Trypanosomiasis Research Institute (KETRI) was established to take over the functions of tsetse and trypanosomiasis research in Kenya. The cryobank was therefore transferred to KETRI during this period. In 2003, following a reorganization of research institutions by the Government of Kenya, KETRI was merged with the Kenya Agricultural Research Institute (KARI) and renamed the Trypanosomiasis Research Centre (KARI-TRC). KARI-TRC continued with all the research programmes and activities that were being carried out under KETRI, including collection and preservation of trypanosome stabilates. The institution developed a policy on stabilate collection by scientists and clinicians for cryopreservation. We describe the establishment of the cryobank and procedures used in cryopreservation of stabilates and summarize the data (numbers and types) on trypanosome species stored in the cryobank, which are available for use in research by the scientific community. The cryobank contains 2,347 stabilates, including 1,747 primary isolates, out of which there are 42 mixed infections and one miscellaneous Herpetomonas muscorum, and 600 derivatives, including six mixed infections. Primary isolates were collected mainly from countries in the eastern Africa region, including Kenya, Uganda, Tanzania, Sudan, and Ethiopia. However, collections or donations from countries outside the region, including Nigeria, Mozambique, Botswana, Germany, and South America, have been added as part of collaborations between KARI-TRC and other institutions around the world. The stabilates were isolated between 1934 and 2010. The majority of the stabilates were recovered between 1960 and 1970 (Figure 1), the same period when some of the worst epidemics occurred, after which the numbers added have been on the decline. The period from 1940 to 1949 coincided with World War II, when the work on trypanosomiasis research and control stalled: the laboratories in eastern Africa that were the source of isolates were closed, only to resume after 1945 when the war came to an end. Open in a separate window Figure 1 Number of primary trypanosome stabilates collected, preserved, and stored at the Kenya Trypanosomiasis Research Institute cryobank. Trypanosomes Trypanosomes are extracellular protozoan parasites which cause disease in humans and animals. Isolation and cryopreservation of new trypanosome strains from patients in different HAT foci ensures availability of these stabilates for use in parasitological, biochemical, molecular, serological, and pharmacological studies many years after their isolation from the host. Brun et al. [1] observed that one of the major obstacles in the elucidation of the factors responsible for relapses after melarsopol treatment was lack of recent T. b. gambiense isolates from patients from various endemic areas where the problem had been reported. The WHO steering committee on human African trypanosomiasis treatment and the East African Network for Tsetse and Trypanosomiasis (EANETT) have therefore recommended that collection of stabilates be a continuous activity in order to monitor the occurrence and spatial distribution of treatment failure [6]. Since its inception, KETRI has established an institutional policy of encouraging collection of stabilates by scientists and clinicians for cryopreservation. In this paper, we describe the establishment of the cryobank and summarize the data (numbers and types) on trypanosome species stored in the cryobank, which are available for research by the wider scientific community.

The fatal sleep: Africa’s killer disease that went undiscovered for centuries

In the realm of tropical diseases, African trypanosomiasis has always offered researchers glamor, drama, and mystery. Numerous physicians have written accounts of their adventures amid the jungles, savannas, and coasts of equatorial Africa in their quest for a cure for sleeping sickness. Symptoms — caused by the African trypanosome, a single-celled parasite, and its transmission vector, the tsetse fly — arise mysteriously, and epidemics can start without warning. More than a century of research on trypanosomiasis has shown that the parasite is one of the most sophisticated pathogens ever to have evolved. In The fatal sleep: Africa’s killer disease that went undiscovered for centuries, Peter Kennedy presents a memoir about his fascination with this illness. His goal, he says in the preface, is “to tell the nonscientist about the history and profound importance of human African trypanosomiasis.” To achieve this goal, he relates his career experiences, first as a medical student in London, later as a clinical neurologist, and most importantly, as a researcher who, at the time of writing, had made 18 trips to Africa to study this disease. Many of his anecdotes, while not always specific to his disease-related research, offer portraits of his training as a physician-scientist and his experiences in Africa — the best of which relate his adventures in Zambia, Uganda, and Kenya. The reader will appreciate the author’s difficulty in rendering scientific ideas, particularly experimental results, into nonscientific language, which sometimes results in an uneven voice. As Kennedy tells it, a thousand years ago a physician in Sudan reported a human disease characterized by fatal lethargy that seemed to be linked to the deaths of camels and horses. In 1771, naval surgeon John Atkins described a similar illness among natives of Guinea, where patients lingered unto death with “sleepy distemper.” In 1803, physician Thomas Winterbottom noted in Sierra Leone that slaves with swollen posterior cervical lymph nodes — now known as Winterbottom’s sign — could not be traded. The inveterate physician-explorer David Livingston, who tested in horses a cure for animal trypanosomiasis, published a letter in the British Medical Journal in May 1858 titled “Arsenic as a remedy for the tsetse fly bite.” The disease first received international attention when an epidemic broke out at the end of the nineteenth century near Lake Victoria in present-day Uganda. Physician-scientists rushed to find preventions and cures that would protect both European colonists and their African workers. Kirk Arden Hoppe, in his book Lords of the fly (1), describes a “circus” of professional interest in sleeping sickness at the beginning of the twentieth century that eventually led to mass relocation of Africans out of tsetse fly–infested areas. Large areas of vegetation were burned in hopes of eliminating the tsetse fly, vast numbers of game were killed to extinguish the reservoir, and humans were forbidden to occupy emptied territories. Today, epidemic trypanosomiasis occurs primarily where populations are disrupted by war, famine, and unrest. Two subspecies of African trypanosomes present slightly different courses of disease. Trypanosoma brucei gambiense in west and central Africa leads to a more indolent, but equally fatal, disease lasting months to years, whereas T. b. rhodesiense in east Africa is fatal within 3–4 months. The disease begins with itching, fever, skin chancre and/or rash, and malaise. Diagnosis is made by identifying parasites in the blood or spinal fluid or by the card agglutination trypanosomiasis test (CATT). Progressive disease leads to disturbances in personality, visual problems, and a variety of CNS symptoms (including sleep abnormalities and profound lethargy), followed by death. DNA analysis suggests that African trypanosomes have evolved over 100 million years, including 3 million years in tandem with humans. The parasite evades the host immune system by changing its protein coat in a process known as antigenic variation. Such a change occurs as often as every 2 weeks and seems to preclude development of a vaccine. The disease is said to kill at least 50,000 people every year. More than 60 million people in sub-Saharan Africa are currently at risk for trypanosomiasis, with severe pockets of illness in the Central African Republic, Uganda, Angola, Congo-Kinshasa, and Sudan. As Kennedy points out, treatment options are few. A toxic arsenical administered intravenously is still used to treat late-stage disease; however, the treatment itself proves fatal in 1 of 20 patients. A concise review article by Peter Kennedy on human sleeping sickness appeared in the JCI in 2004 (2). His book, as a memoir of a life in trypanosomiasis research, calls much-needed attention to a widespread disease of poor and isolated Africans, for whom pharmaceutical companies should spend more time developing therapeutic drugs. Notably, 50% of the author’s royalties from sales of this book will be donated to charities devoted to sleeping sickness research and human health in Africa.

The Trypanosomiases (ed. Maudlin, I., Holmes, P. H. & Miles, M. A.), pp. 624. International CABI Publishing, UK, 2004. ISBN 0 85199 475 X. £99.50 (US$185.00).

Back in the early 1960s, when the curtain was falling on British colonial administration in Africa, the newly-created Ministry of Overseas Development decided to gather together for posterity the expertise and experience of authorities on tsetse and trypanosomiasis control. Weighing in at three and a half pounds, the resulting publication, ‘The African Trypanosomiases’ edited by Colonel Hugh Mulligan and published in 1969, has since been a baseline not only for investigators in the field but also for pure scientists working on related problems at the laboratory bench. The editors of the present volume were inspired by the enormous progress made in trypanosomiasis research over the last thirty years to produce ‘an update of Mulligan’ – so, how do the two books compare? Well, amazingly, their weights are exactly the same – but content and coverage are, as might be expected, very different.

Effectiveness of a 10‐Day Melarsoprol Schedule for the Treatment of Late‐Stage Human African Trypanosomiasis: Confirmation from a Multinational Study (ImpamelII)

Treatment of late-stage human African trypanosomiasis (HAT) with melarsoprol can be improved by shortening the regimen. A previous trial demonstrated the safety and efficacy of a 10-day treatment schedule. We demonstrate the effectiveness of this schedule in a noncontrolled, multinational drug-utilization study. A total of 2020 patients with late-stage HAT were treated with the 10-day melarsoprol schedule in 16 centers in 7 African countries. We assessed outcome on the basis of major adverse events and the cure rate after treatment and during 2 years of follow-up. The cure rate 24 h after treatment was 93.9%; 2 years later, it was 86.2%. However, 49.3% of patients were lost to follow-up. The overall fatality rate was 5.9%. Of treated patients, 8.7% had an encephalopathic syndrome that was fatal 45.5% of the time. The rate of severe bullous and maculopapular eruptions was 0.8% and 6.8%, respectively. The 10-day treatment schedule was well implemented in the field and was effective. It reduces treatment duration, drug amount, and hospitalization costs per patient, and it increases treatment-center capacity. The shorter protocol has been recommended by the International Scientific Council for Trypanosomiasis Research and Control for the treatment of late-stage HAT caused by Trypanosoma brucei gambiense.

Robert S Desowitz, Federal bodysnatchers and the New Guinea virus: tales of parasites, people and politics, New York and London, W W Norton, 2002, pp. x, 262, £19.95 (hardback 0-393-05185-4).

Robert S Desowitz, Federal bodysnatchers and the New Guinea virus: tales of parasites, people and politics, New York and London, W W Norton, 2002, pp. x, 262, £19.95 (hardback 0-393-05185-4).

Evaluation of antigen and antibody rapid detection tests for Trypanosoma evansi infection in camels in Kenya

The card agglutination test for Trypanosoma evansi (CATT/ T. evansi) for the detection of antibodies, and Suratex ® for the detection of circulating antigens were compared in a cross-sectional study involving camels in eastern and central parts of Kenya. Of the 2227 camels screened, 2038 were owned by nomadic pastoralists in T. evansi endemic areas in eastern Kenya. A herd of 86 camels were from a ranch in Mugwoni. In Athi River area, 35 camels belonged to Kenya Trypanosomiasis Research Institute, and 68 were slaughter animals. Diagnostic sensitivity estimates were obtained by testing sera from 51 camels that had been found to be parasitologically positive by the haematocrit centrifugation technique, buffy-coat technique and mouse inoculation. Diagnostic specificity was estimated by testing sera from 35 camels known to be trypanosome-free. Positive and negative predictive values (NPVs) were calculated using a range of prevalence values. The sensitivity of CATT/ T. evansi (68.6%) was higher than that of Suratex ® (58.8%), but not significantly. Both tests had equally high specificity (100%). The overall prevalence was 2.3% (51 out of 2227) by parasite detection, 32.2% (327 out of 1017) by CATT/ T. evansi and 19.6% (188 out of 961) by Suratex ®. Overall, there was a positive association between CATT/ T. evansi and Suratex ® though the strength of association was low (McNemar’s test=46.12, P=0.001; kappa=0.26, CI: 0.20–0.33). Parasite prevalence ranged from 0% in several herds to 27.8% in a herd in Isiolo. Prevalence was highest in Isiolo with 2.5% (51 out of 2030) by parasitological detection, 38.8% (321 out of 828) by CATT/ T. evansi and 21.9% (169 out of 772) by Suratex ®. In Mugwoni prevalence was 7 and 18% by CATT/ T. evansi and Suratex ®, respectively, and no parasites were detected. In Athi River Suratex ® detected 2.9% (3 out of 103) positive while CATT/ T. evansi and parasitological methods gave negative results. At prevalence values between 10 and 100%, CATT/ T. evansi as well as Suratex ® had infinitely high positive predictive values, whereas Suratex ® had a lower NPV than CATT/ T. evansi. In conclusion, results of this study showed that CATT/ T. evansi and Suratex ® were able to detect aparasitaemic infections rapidly and were more sensitive than parasitological methods in revealing the true extent of trypanosomosis in a herd. The tests effectively complemented parasitological methods in the detection of T. evansi infections in camels.

The colony as laboratory: German sleeping sickness campaigns in German East Africa and in Togo, 1900-1914.

This paper is on dangerous human experimentations with drugs against trypanosimiasis carried out in the former German colonies of German East Africa and Togo. Victory over trypanosomiasis could not be achieved in Berlin because animals were thought to be unsuitable for therapeutic laboratory research in the field of trypanosomiasis. The colonies themselves were necessarily chosen as laboratories and the patients with sleeping sickness became the objects of therapeutical and pharmacological research. The paper first outlines Robert Koch's trypanosomiasis research in the large sleeping sickness laboratory of German East Africa and then focuses on the escalating human experiments on trypanosomiasis in the German Musterkolonie Togo, which must be interpreted as a reaction to the starting signal given by Robert Koch in East Africa.

Unravelling the phylogenetic relationships of African trypanosomes of suids.

African trypanosomes of the subgenera Nannomonas and Pycnomonas have been recorded from both wild and domestic suids. However, complete descriptions of some of these trypanosomes with regard to host range, pathogenicity, transmission and distribution are still lacking. Neither the recently described Trypanosoma (Nannomonas) godfreyi nor Trypanosoma (Nannomonas) congolense Tsavo have been isolated from mammalian hosts, while Trypanosoma (Pycnomonas) suis remains the rarest of the Salivarian trypanosomes. The only isolate presumed to be of the latter species is maintained at the Kenya Trypanosomiasis Research Institute, Nairobi. We present here the results of characterization of this isolate by morphology, tsetse transmission, the use of species-specific DNA probes and DNA sequence analysis. Morphology in stained blood smears revealed a small trypanosome with a free flagellum. Experimental transmission through Glossina morsitans morsitans showed a developmental cycle typical of subgenus Nannomonas A positive identification was obtained with species-specific PCR primers for T. congolense Tsavo; moreover, the sequence of the SSU rRNA gene was almost identical to that of T. congolense Tsavo on database. In phylogenetic analysis of the SSU rRNA genes of Salivarian trypanosomes, T. congolense Tsavo grouped with T. simiae rather than T. congolense, suggesting that the name T. simiae Tsavo is more appropriate.

Financial analysis of animal trypanosomiosis control using cypermethrin pour-on in Kenya

The financial impact of use of cypermethrin pour-on (Ectopor R) in control of animal trypanosomiosis was determined in a trial undertaken by the Kenya Trypanosomiasis Research Institute (KETRI). This trial started in December 1990 and ended in February 1992. It was undertaken in two adjacent ranches in the coast province of Kenya. The trial site was in an area of high apparent density (AD) of tsetse flies, and at the start of the trial no cattle were kept in this area. Cypermethrin was applied fortnightly to the 1100 steers which were kept in pour-on ranch ‘A’ while another 100 steers were kept in control ranch ‘B’ to act as control sentinels. From the main pour-on group, 100 animals were identified as the pour-on sentinels and compared to the control sentinels which received no pour-on. Pour-on application led to a significant decrease in the tsetse AD in the pour-on ranch A to 90% of the initial AD in some areas. The animals treated with pour-on had a significantly higher mean packed-cell volume (PCV). The weekly prevalence of trypanosome infections in animals treated with pour-on was <4% with only one exception when it was <10%. In the control animals, the prevalence ranged between 10 and 50% (with a few exceptions when it was <10%). The incidence of tick-borne diseases was lower in the pour-on animals. The mean monthly weights of the pour-on animals was significantly higher, and at the end of the trial the pour-on animals had a mean weight gain of 136.70±16.7 kg while the control animals had gained 97.16±22.6 kg. The financial net return of using cypermethrin pour-on was positive and the financial rate of return of 122.6% indicated that use of the pour-on was highly beneficial despite the high cost of the product.

An analysis of the growth of African trypanosomiasis research between 1900 and 1985

The purpose of this study is to elucidate the production dynamics, growth characteristics and trends of African trypanosomiasis research (ATREP) literature between 1900 and 1985 through graphical methods. The data analysed comprised 5139 articles from Tropical Diseases Bulletin and Tsetse and Trypanosomiasis Information Quarterly. Counting technique was employed in sorting the articles according to yearly production and respective subject disciplines. The bibliometric ranks of the disciplines were determined based on (1) the total output and (2) the average decennial relative changes (Rc) in publications between 1936 and 1985 using 1936/45 as the base decade. The results show that the growth is neither linear nor logistic but exponential with an average 39.5-year doubling time. A marked feature is the occurrence of high “epidemic” peaks between 1910–1914 and 1979–1985, a state in which publications were produced at relatively high level probably due to new discoveries or research orientation; and hence capable of quickly infecting a large number of scientists enhancing productivity. There was also a low level of activity from 1914 which lasted for about 22 years. The foundation disciplines for African Trypanosomiasis Research Programme (ATREP) are entomology and parasitology. Entomology had the highest bibliometric rank followed by parasitology. However, the Refactors indicate that greater attention, as depicted by publication outburst, was given to physiology, immunology, biochemistry, and epidemiology between 1976–1985 than had been before. In spite of its consistently higher output, entomology exhibited the greatest fluctuating growth trend than all the other components. A possible explanation for this behaviour was ventured.

Differential susceptibility to DL-alpha-difluoromethylornithine in clinical isolates of Trypanosoma brucei rhodesiense

DL-alpha-Difluoromethylornithine is an enzyme-activated inhibitor of ornithine decarboxylase and an antagonist of polyamine metabolism that has been successful in clinical trials against West African sleeping sickness caused by Trypanosoma brucei gambiense. Its potential for use against the more virulent East African form of the disease, caused by T. brucei rhodesiense, is not certain. We examined 14 East African clinical isolates from the Kenya Trypanosomiasis Research Institute strain bank plus 2 established isolates for susceptibility to DL-alpha-difluoromethylornithine and to standard trypanocides. Seven of 16 strains were partially or totally refractory to DL-alpha-difluoromethylornithine in our test system. Four strains were also refractory to arsenical drugs, and five were refractory to diamidines. The results indicate that other novel agents or combinations of established agents may be needed for chemotherapy of East African disease.