Feasibility of direct venous inoculation of the radiation-attenuated Plasmodium falciparum whole sporozoite vaccine in children and infants in Siaya, western Kenya

PfSPZ Vaccine, composed of radiation-attenuated, aseptic, purified, cryopreserved Plasmodium falciparum sporozoites, is administered by direct venous inoculation (DVI) for maximal efficacy against malaria. A critical issue for advancing vaccines that are administered intravenously is the ability to efficiently administer them across multiple age groups. As part of a pediatric safety, immunogenicity, and efficacy trial in western Kenya, we evaluated the feasibility and tolerability of DVI, including ease of venous access, injection time, and crying during the procedure across age groups. Part 1 was an age de-escalation, dose escalation trial in children aged 13 months-5 years and infants aged 5-12 months; part 2 was a vaccine efficacy trial including only infants, using the most skilled injectors from part 1. Injectors could use a vein viewer, if needed. A total of 1222 injections (target 0.5 mL) were initiated by DVI in 511 participants (36 were 5-9-year-olds, 65 were 13-59-month-olds, and 410 infants). The complete volume was injected in 1185/1222 (97.0%) vaccinations, 1083/1185 (91.4%) achieved with the first DVI. 474/511 (92.8%) participants received only complete injections, 27/511 (5.3%) received at least one partial injection (<0.5 mL), and in 10/511 (2.0%) venous access was not obtained. The rate of complete injections by single DVI for infants improved from 77.1% in part 1 to 92.8% in part 2. No crying occurred in 51/59 (86.4%) vaccinations in 5-9-year-olds, 25/86 (29.1%) vaccinations in 13-59-month-olds and 172/1067 (16.1%) vaccinations in infants. Mean administration time ranged from 2.6 to 4.6 minutes and was longer for younger age groups. These data show that vaccination by DVI was feasible and well tolerated in infants and children in this rural hospital in western Kenya, when performed by skilled injectors. We also report that shipping and storage in liquid nitrogen vapor phase was simple and efficient. (Clinicaltrials.gov NCT02687373).

In vivo and in vitro hypotensive effect of aqueous extract of Moringa stenopetala

BACKGROUND

Moringa stenopetala, Baker f. (Moringaceae) is used for food and medicine in Southern Ethiopia.

OBJECTIVE

To substantiate the hypotensive effect of M. stenopetala in vivo and in vitro.

METHODS

An in vivo experiment was carried out on male guinea pigs anaesthetized with pentobarbital. The arterial blood pressure was recorded from a carotid artery filled with heparinized saline via an arterial cannula connected to a pressure transducer. For the in vitro experiment the descending thoracic aorta was removed and kept moistened in Krebs-Henseleit solution and then mounted in a 20ml tissue bath maintained at 37°C and bubbled with a mixture of 95% oxygen and 5% carbon dioxide.

RESULTS

Crude aqueous leaf extract of M. stenopetala caused significant fall in systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial blood pressure (MABP) at doses of 10, 20, 30 and 40 mg/kg in normotensive anaesthetized guinea pigs (n = 12). The effect might have been mediated by non-autonomic nervous system as the effect is not altered by atropine and propranolol. The extract also caused significant dose and time dependent inhibition of K(+) induced contraction on guinea pig aorta.

CONCLUSION

M.stenopetala has blood pressure lowering effect substantiating the use of the plant in traditional medicine.

Zinc status and cognitive function of pregnant women in Southern Ethiopia

The relation between zinc status and cognitive function was examined in a cross-sectional study in the Sidama area of Southern Ethiopia. Pregnant women >24 weeks of gestation from three adjacent rural villages volunteered to participate. Mean (s.d.) plasma zinc of 99 women was 6.97 (1.07) mumol/l (below the cutoff of 7.6 mumol/l indicative of zinc deficiency at this stage of gestation). The Raven's Coloured Progressive Matrices (CPM) test was administered individually. Scores for the Raven's scale A, which is the simplest scale, ranged from 4 to 10 of a possible 12. Women with plasma zinc <7.6 mumol/l had significantly lower Raven's CPM scale A scores than women with plasma zinc concentrations >7.6 mumol/l. Plasma zinc and maternal age and education predicted 17% of the variation in Raven's CPM scale A scores. We conclude that zinc deficiency is a major factor affecting cognition in these pregnant women.

Electrocardiographic findings in Ethiopians on pentavalent antimony therapy for visceral leishmaniasis

BACKGROUND

The old short course regimens of pentavalent antimonial (sb(v)) therapy of visceral leishmaniasis (VL) have largely been abandoned worldwide as they are associated with increasing problems of relapse and unresponsiveness. In Ethiopia, some hospitals still use the old interrupted and short course regimen partly because of fear of drug toxicity.

OBJECTIVE

To evaluate the safety of the WHO recommended uninterrupted therapy at a dose of 20 mg sb(v)/kg for up to thirty days.

DESIGN

A prospective study.

SETTING

Patients were recruited from Addis Ababa hospitals and from Konso VL endemic area in southern Ethiopia.

SUBJECTS

Forty nine patients who included, ten HIV-positive and 39 HIV-negative, were enrolled for the study.

RESULTS

Twenty three HIV-negative patients got treatment for 20 days and the rest, 16 HIV-negative and 10 HIV-positive, were treated for 28 to 30 days. Among HIV-seronegatives, the mean QT interval corrected for heart rate (QTc) at the end of therapy in patients treated for 20 days and 28-30 days was comparable (0.419 +/- 0.031 seconds versus 0.424 +/- 0.027 seconds, respectively). Among patients treated for 28-30 days, the mean QTc in HIV co-infected patients was comparable to that of HIV-negatives (0.416 +/- 0.018 seconds versus 0.424 +/- 0.027). Comparable rates of new ECG changes involving the T waves were observed in two HIV-positive (20%) and two HIV-negative (12.5%) patients treated for 28-30 days, and in seven (30.4%) HIV-negative patients treated for 20 days. Overall, only two (4.1%) patients (all HIV-negative males) had QTc interval > or = 0.50 seconds at the end of therapy. In one patient, the prolonged QTc was noted on the twentieth day with bradycardia of 44/minute.

CONCLUSIONS

In Ethiopian VL patients with normal renal function, sb(v) therapy at a daily dose of 20 mg/kg for up to 30 days is safe and only rarely associated with clinically significant bradycardia which resolves after temporary cessation of therapy. Furthermore, in areas with limited facilities, monitoring the pulse rate during antimonial therapy may help detect impending cardiotoxicity.

Inter-current and nosocomial infections among visceral leishmaniasis patients in Ethiopia: an observational study

From July 1989 up to September 1997, a total of 247 non-HIV associated visceral leishmaniasis (VL) patients were treated on outpatient basis in rural clinics (195 patients) and hospitalised in the Northern-Omo Regional Hospital (18 patients) and in Addis Ababa referral hospitals (34 patients). Patients treated in the rural clinics and in the Regional hospital originated from the same endemic area and had comparable baseline characteristics. Overall rates of complications (inter-current/concurrent infectious or non-infectious diseases or deaths) in the three categories were 10.7, 38.9 and 61.6%, while case fatality rates were 2.5, 5.6 and 11.7%, respectively. Nosocomial bacterial infections occurred in 16.6% of patients treated in the Regional hospital and 32.3% of patients treated in Addis Ababa referral hospitals, and these infections accounted for 42.8 and 52.4% of the complications seen in the respective categories. Among VL patients originating from the same endemic place and with comparable baseline clinical data, patients treated hospitalised had significantly higher rates of complications than patients treated on outpatient basis (P<0.001). Patients who had complications during the course of VL therapy had significantly lower pre-treatment haemoglobin levels. Considering the extra cost of hospitalisation and risk of nosocomial infections and petavalent antimonial therapy being fairly safe, we recommend that VL patients, unless with serious complications, should preferably be treated on ambulatory basis with follow-up to monitor response and inter-current infections if any.

Occupational environment as perceived by workers at a textile mill in Bahir Dar, northwest Ethiopia

This cross sectional study was conducted among textile mill workers in Bahir Dar town in 1995/96. The main objective of the study was to investigate how workers perceive their work environment and explore their state of satisfaction with their work. A pretested questionnaire was administered by trained health workers to 394 production workers. The majority of the workers (53.6%) claimed the work environment to be hot. For 66.8%, the physical conditions around the working departments was worst during the hot season. The work place was perceived as dusty and noisy by 47.2% and 36.0% of the respondents respectively. The distribution of adverse environmental complaint by work department was not the same. A higher proportion of the workers in the spinning department complained of inadequate air movement (64.5%) and dusty work place (53.3%); whereas those in the weaving department complained the work place to be hot and noisy (60.5%, 53.5% respectively). Aprons were used by 95.7%, but other personal protectors such as ear protectors, gloves and goggles were used rarely. In general, 228 (57.9%) workers were satisfied but the rest were dissatisfied with their work environment. In order to improve the hygienic conditions in the work place, 71.2% suggested use of different kinds of personal protectors. In conclusion, personal protectors should always be used, environmental hygiene should be conducted and health education should be provided to workers.

Pulmonary response of mice to aqueous cotton dust extract

OBJECTIVE

To determine the pulmonary response of mice to acute exposure of aqueous cotton dust extract (CDE).

DESIGN

CDE was made from a standard cotton mill dust. Under mild anaesthesia, 0.05 ml of CDE was instilled intratracheally in balb/c mice. The same volume of sterile isotonic saline was instilled in controls. After 1, 5 and 10, days animals were given an overdose of pentobarbital by intraperitoneal injection, and the upper thorax was opened to expose the trachea. An incision was made and cannulae was inserted. Bronchoalveolar lavage (BAL) was done by instilling, phosphate buffer saline. Total and differential counts were done. The lavage supernatant was assayed for protein.

SETTING

The laboratory of Division of Pulmonary and Critical Care Medicine, Duke University Medical Center, USA.

ANIMALS

Balb/c mice.

MAIN OUTCOME MEASURES

Post-exposure acute effects at bronchoalveolar level.

RESULTS

Total and differential cell counts in BAL fluid were significantly higher in CDE exposed compared to controls (P < 0.01). The total mean values (expressed as cells x 10(4)) after exposure for days 1, 5 and 10 were 193.4 +/- 8.6, 177.8 +/- 7.7 and 113.5 +/- 6.4 respectively versus controls (41.6 +/- 3.4). Differential counts (cell no. x 10(4)) revealed 124.3 +/- 6.8, 94.2 +/- 7.9, 19.9 +/- 3.5 polymorph neutrophils (PNM) and 67.3 +/- 7.1, 81.6 +/- 9.4, 90.2 +/- 8.6 macrophages (AM) on days 1, 5 and 10 respectively compared to controls 2.8 +/- 2.3 (PMN) and 37.2 +/- 1.1 (AM). Analysis of protein (mg/ml BAL fluid) demonstrated a significant increase on exposure for days 5 and 10 (0.8 +/- 0.05 and 0.9 +/- 0.6 respectively versus controls, 0.09 + 0.01, p < 0.01).

CONCLUSION

Acute exposure to CDE causes influx into the air spaces of inflammatory leukocytes accompanied by an increase in lung permeability (evidenced by the presence of protein in BAL fluid). In cotton mill workers, the above factors may contribute to the development of chronic byssinosis by as yet undefined agent(s) in cotton dust.

Shift work and sleep disorder among textile mill workers in Bahir Dar, northwest Ethiopia

OBJECTIVE

To assess the length and quality of sleep among shift workers at Bahir Dar textile mill.

DESIGN

A cross sectional study using structured questionnaire that contained sociodemographic variables, duration of work, work schedule, number of sleeping hours, sleep disorders, and associated reasons for such disorders.

SETTING

A textile mill in Bahir Dar, northwest Ethiopia.

SUBJECTS

Three-hundred ninety four random sample of production workers of the mill.

OUTCOME MEASURES

Sleep disorders, and the impact of external and home environment on sleep.

RESULTS

The mean duration of work in the factory was 25.4 +/- 7.1 years. Ninety-seven per cent of the study population work in a rotating eight hourly shift system. The mean number of hours a worker sleeps after a worked shift was 5.1 +/- 2.3. Two hundred thirty (58.4%) claimed to experience a sleep disorder. Sleep disturbance was significantly associated with rotating shift work, external environmental noise, and working in the spinning department.

CONCLUSION

The majority of the workers in Bahir Dar textile mill experienced sleep disturbances as detailed in the study methodology.

Byssinosis and other respiratory disorders among textile mill workers in Bahr Dar northwest Ethiopia

The prevalence of byssinosis and other respiratory symptoms were studied among 433 workers who were occupationally exposed to cotton dust in Bahr Dar Textile Mill. One-hundred-one nonexposed workers living in the same geographical area were included as controls. All of the subjects completed the British Medical Research Council Questionnaire. Pulmonary function tests were administered on a vitalograph spirometer before starting the shift for all subjects, and after at least four hours of exposure for exposed subjects. Among the cotton dust exposed workers, byssinotics behaved distinctly and showed the maximum acute and chronic changes in pulmonary functions. The overall prevalence of byssinosis was 45.5%. The highest prevalence was found in carding (57.9%) and in ring frame (57.1%) operatives and the lowest in weaving preparatory section (32.1%). Unlike bronchial asthma, chronic cough and chronic bronchitis were significantly higher (p < 0.01) in cotton dust exposed subjects compared with controls. The mean measured values of ventilatory capacity (FEV1 and FVC) are to a significant extent reduced in the exposed groups compared with controls (p < 0.01). In view of the above findings, preventive measures are of paramount importance in minimizing the prevalence of byssinosis and other respiratory disorders.

Byssinosis and tuberculosis among textile mill workers in Bahar Dar, Ethiopia

A cross-sectional study was conducted in 1991 on 433 workers of a cotton mill in Bahar Dar, northern Ethiopia. The study consisted of symptom evaluation using a standardized questionnaire, lung function tests, chest x-ray, and measurement of dust concentration in the various work areas. A hundred non-exposed hospital workers were included as control group. The overall prevalence of byssinosis among the exposed subjects was 45.5%, being highest among carding (57.9%) and ring frame workers (57.1%). Lower prevalences were found in weavers (36.7%) and those working in the preparatory unit (32.1%). Chronic bronchitis occurred in 48.8% of workers in the carding section, and in none of the control group. Bronchial asthma occurred in 11.5% of workers in the carding and ring frame sections, and in 28.6% of the workers in the waste section. Twelve per cent of the control group had bronchial asthma. Tuberculosis was prevalent in 5.3% of the mill workers and in 2.1% of the control group. Ventilatory capacity (FEV1 and FVC) was significantly reduced in the exposed workers (p < 0.05). The study revealed that the prevalence of byssinosis and other respiratory disorders was extremely high among the cotton mill workers. In view of the above findings preventive measures deserve a high priority.

Plasma level distribution, effect and toxicity of antiepileptic drugs among Ethiopian epileptics

Plasma phenytoin and phenobarbitone levels were estimated in 123 adult Ethiopian epileptics by gas-liquid chromatography. Thirty four (38.2%) of the patients on phenytoin, and 52 (52%) of those on phenobarbitone, had plasma levels in the conventional therapeutic ranges of 10-20 micrograms/ml and 10-30 micrograms/ml respectively. Of the 89 patients who were taking phenytoin either singly or combined with phenobarbitone, motor disturbances (ataxia and nystagmus) were seen in 31 (34.8%) and dysmorphic and idiosyncratic side effects including gum hypertrophy, hirsutism, acne and skin rash in 37 (41.6%). Subnormal serum calcium levels were noted in 15 (30.6%) and high alkaline phosphatase was found in 13 (26.5%). Phenobarbitone was found to be an effective anticonvulsant (78.1% seizure control rate), with adverse effects of sedation and intellectual depression. Seizure control was achieved in 77.1% of patients on a single drug as opposed to 55.6% on combination of phenytoin and phenobarbitone (p less than 0.05). The overall seizure control rate was 66%.