Qualitative study of patient experiences of mental distress during TB investigation and treatment in Zambia.

BACKGROUND: The mental health and TB syndemic is a topic that remains under-researched with a significant gap in acknowledging and recognizing patient experiences, particularly in the sub-Saharan African region. In this qualitative study conducted in Zambia, we aimed to explore the lived mental health experiences of TB patients focusing on their multi-layered drivers of distress, and by so doing highlighting contextual factors that influence mental distress in TB patients in this setting. METHODS: The study draws on qualitative data collected in 2018 as part of the Tuberculosis Reduction through Expanded Antiretroviral Treatment and Screening for active TB trial (TREATS) being conducted in Zambia. The data was collected through in-depth interviews with former TB patients (n = 80) from 8 urban communities participating in the TREATS trial. Thematic analysis was conducted. Additional quantitative exploratory analysis mapping mental distress symptoms on demographic, social, economic and TB characteristics of participants was conducted. RESULTS: Most participants (76%) shared that they had experienced some form of mental distress during their TB investigation and treatment period. The reported symptoms ranged in severity. Some participants reported mild distress that did not disrupt their daily lives or ability to adhere to their TB medication, while other participants reported more severe symptoms of distress, for example, 15% of participants shared that they had suicidal ideation and thoughts of self-harm during their time on treatment. Mental distress was driven by unique interactions between individual, social and health level factors most of which were inextricably linked to poverty. Mental distress caused by individual level drivers such as TB morbidity often abated once participants started feeling better, however social, economic and health system level drivers of distress persisted during and beyond TB treatment. CONCLUSION: The findings illustrate that mental distress during TB is driven by multi-layered and intersecting stresses, with the economic stress of poverty often being the most powerful driver. Measures are urgently needed to support TB patients during the investigation and treatment phase, including increased availability of mental health services, better social security safety nets during TB treatment, and interventions targeting TB, HIV and mental health stigma. Trial registration ClinicalTrials.gov NCT03739736 . Trial registration date: November 14, 2018.

Conceptualization, detection, and management of psychological distress and mental health conditions among people with tuberculosis in Zambia: a qualitative study with stakeholders' and TB health workers.

BACKGROUND: In recent years, there has been increased recognition of the need to integrate mental health services into routine tuberculosis (TB) care. For successful integration, policymakers need to first understand the practices of TB health workers in the management of mental health conditions, including depression, anxiety, and psychological distress, and use this to decide how best mental health services could be delivered in tandem with TB services. In this qualitative study we aimed to understand how TB health workers and other stakeholders viewed mental health conditions linked to TB and how they screened and treated these in their patients. METHODS: The study draws on qualitative data collected in 2018 as part of the Tuberculosis Reduction through Expanded Antiretroviral Treatment and Screening for active TB trial (TREATS), conducted in eight urban communities in Zambia. Data were collected through 17 focus group discussions with local health committee members (n = 96) and TB stakeholders (n = 57) present in the communities. Further in-depth interviews were held with key TB health workers (n = 9). Thematic analysis was conducted. RESULTS: TB stakeholders and health workers had an inadequate understanding of mental health and commonly described mental health conditions among TB patients by using stigmatizing terminology and overtones, for example "madness", which often implied a characterological flaw rather an actual illness. Psychological distress was also described as "overthinking", which participants attributed to psychosocial stressors, and was not perceived as a condition that would benefit from mental health intervention. There were no standard screening and treatment options for mental health conditions in TB patients and most TB health workers had no mental health training. TB Stakeholders and health workers understood the negative implications of mental health conditions on TB treatment adherence and overall wellbeing for TB patients. CONCLUSIONS: TB stakeholders and health workers in Zambia have a complex conceptualisation of mental health and illness, that does not support the mental health needs of TB patients. The integration of mental health training in TB services could be beneficial and shift negative attitudes about mental health. Further, TB patients should be screened for mental health conditions and offered treatment. Trial registration number NCT03739736-Registered on the 14th of November 2018- Retrospectively registered- https://clinicaltrials.gov/ct2/results?cond=&term=NCT03739736&cntry=&state=&city=&dist.

Methane flux measurements along a floodplain soil moisture gradient in the Okavango Delta, Botswana.

Data-poor tropical wetlands constitute an important source of atmospheric CH4 in the world. We studied CH4 fluxes using closed chambers along a soil moisture gradient in a tropical seasonal swamp in the Okavango Delta, Botswana, the sixth largest tropical wetland in the world. The objective of the study was to assess net CH4 fluxes and controlling environmental factors in the Delta's seasonal floodplains. Net CH4 emissions from seasonal floodplains in the wetland were estimated at 0.072 ± 0.016 Tg a-1. Microbial CH4 oxidation of approximately 2.817 × 10-3 ± 0.307 × 10-3 Tg a-1 in adjacent dry soils of the occasional floodplains accounted for the sink of 4% of the total soil CH4 emissions from seasonal floodplains. The observed microbial CH4 sink in the Delta's dry soils is, therefore, comparable to the global average sink of 4-6%. Soil water content (SWC) and soil organic matter were the main environmental factors controlling CH4 fluxes in both the seasonal and occasional floodplains. The optimum SWC for soil CH4 emissions and oxidation in the Delta were estimated at 50% and 15%, respectively. Electrical conductivity and pH were poorly correlated (r2 ≤ 0.11, p < 0.05) with CH4 fluxes in the seasonal floodplain at Nxaraga. This article is part of a discussion meeting issue 'Rising methane: is warming feeding warming? (part1)'.

Water use practices, water quality, and households' diarrheal encounters in communities along the Boro-Thamalakane-Boteti river system, Northern Botswana.

BACKGROUND: Some rural African communities residing along rivers use the untreated river water for domestic purposes, making them vulnerable to waterborne diseases such as diarrhea. METHODS: We determined water use practices and water quality, relating them to prevalence of diarrhea in communities along the Boro-Thamalakane-Boteti river system, northern Botswana. A total of 452 households were interviewed and 196 water samples collected show during February, May, September, and December 2012 in settlements of Boro, Maun, Xobe, Samedupi, Chanoga, and Motopi. Information was sought on water use practices (collection, storage, and handling) and diarrheal experience using questionnaires. Water quality was assessed for physicochemical and microbiological parameters using portable field meters and laboratory analysis, respectively. RESULTS: All (100%) of the river water samples collected were fecally contaminated and unsuitable for domestic use without prior treatment. Samples had Escherichia coli (E.coli) and fecal streptococci levels reaching up to 186 and 140 CFU/100 ml, respectively. Study revealed high dependence on the fecally contaminated river water with low uptake of water treatment techniques. Up to 48% of households indicated that they experience diarrhea, with most cases occurring during the early flooding season (May). Nonetheless, there was no significant relationship between river water quality and households' diarrheal experience across studied settlements (p > 0.05). Failure to treat river water before use was a significant predictor of diarrhea (p = 0.028). CONCLUSIONS: Even though the river water was unsafe for domestic use, results imply further recontamination of water at household level highlighting the need for simple and affordable household water treatment techniques.

Sclerocarya birrea [(A. Rich.) Hochst.] [Anacardiaceae] stem-bark ethanolic extract (SBE) modulates blood glucose, glomerular filtration rate (GFR) and mean arterial blood pressure (MAP) of STZ-induced diabetic rats.

Studies in our laboratories suggest that Sclerocarya birrea stem-bark ethanolic extract (SBE) has hypoglycemic properties. Accordingly, we investigated the effects of SBE on major complications of diabetes mellitus; blood glucose, renal function and mean arterial blood pressure (MAP) in non-diabetic and STZ-induced diabetic rats. Oral glucose tolerance test responses to various SBE doses (60, 120 and 240 mg kg(-1)) were studied in fasted rats following glucose load (0.86 g kg(-1), p.o.). Rats treated with deionized water (3 ml kg(-1) p.o.), or standard hypoglycemic drugs (insulin, 100 microg kg(-1), s.c.; metformin, 500 mg kg(-1), p.o. or glibenclamide, 500 microg kg(-1), p.o) acted as untreated and treated positive controls, respectively. Blood was collected in non-diabetic rats after 45 min of SBE, metformin or glibenclamide for plasma insulin determination. Acute SBE effects on renal function and MAP were studied in anesthetized rats challenged with hypotonic saline after 3.5h equilibration for 4h of 1h control, 1.5h treatment and 1.5h recovery periods. SBE was added to the infusate during the treatment period. Chronic effects were monitored for 5 weeks in animals daily treated with SBE (120 mg kg(-1) p.o.) while hepatic glycogen concentration was measured at the end of the experimental period. SBE exhibited dose-dependent reduction in blood glucose concentration. SBE and metformin did not affect plasma insulin secretion in non-diabetic rats, while glibenclamide increased plasma insulin concentration. The hypoglycemic effect of SBE treatment was associated with increased hepatic glycogen synthesis. Acute SBE administration did not significantly alter kidney function, but chronic SBE treatment for decreased plasma urea and creatinine concentrations of STZ-diabetic rats with concomitant increase in GFR by comparison with control rats at the corresponding period (0.7+/-0.2 vs. 1.4+/-0.3 ml min(-1)). SBE treatment reduced blood pressure in all groups of animals. The observations suggest that SBE has reno- and cardio-protective effects in diabetes mellitus. The current results indicate the basis for SBE use as complementary remedy in diabetes.

Effects of Persea americana Mill (Lauraceae) ["Avocado"] ethanolic leaf extract on blood glucose and kidney function in streptozotocin-induced diabetic rats and on kidney cell lines of the proximal (LLCPK1) and distal tubules (MDBK).

Extracts of Persea americana Mill (Lauraceae) ("Avocado") have been traditionally used to treat hypertension and diabetes mellitus. Accordingly, we studied the hypoglycaemic and renal function effects of P. americana leaf ethanolic extracts (PAE) in STZ-induced diabetic rats. Oral glucose tolerance responses to various doses of PAE were monitored in fasted rats following a glucose load. Rats treated with deionized water or standard hypoglycaemic drugs acted as untreated and treated positive controls, respectively. Acute renal effects of PAE were investigated in anesthetized rats challenged with 0.077 M NaCl after a 3.5-h equilibration for 4 h comprising 1 h control, 1.5 h treatment and 1.5 h recovery periods. PAE was added to the infusate during the treatment period. Hepatic glycogen concentration was measured after 6 weeks of daily treatment with PAE. PAE induced dose-dependent hypoglycaemic responses in STZ-induced diabetic rats while subchronic PAE treatment additionally increased hepatic glycogen concentrations. Acute PAE infusion decreased urine flow and electrolyte excretion rates, whilst subchronic treatment reduced plasma creatinine and urea concentrations. These results indicate not only the basis of the ethnomedicinal use of P. americana leaf extract in diabetes management, but also of need for further studies to identify and evaluate the safety of PAE's bioactive compounds.

Cardiovascular Effects of Helichrysum ceres S Moore [Asteraceae] Ethanolic Leaf Extract in Some Experimental animal Paradigms : Cardiovascular Topic

The aim of this study was to examine some in vivo and in vitro cardiovascular effects of Helichrysum ceres leaf ethanolic extract (HCE) in experimental animal paradigms. The acute effects of HCE on blood pressure were studied in anaesthetised normotensive male Wistar rats challenged with intravenous hypotonic saline infusion after a 3.5-hour equilibration for four hours of one-hour control; 1.5-hour treatment and 1.5-hour recovery periods. HCE was added to the infusate during the treatment period. Sub-chronic hypotensive effects of HCE were examined in weanling Dahl Salt-sensitive (DSS) genetically hypertensive rats; which progressively develop hypertension with age; treated with HCE (80 mg / kg) every third consecutive day for seven weeks. isolated atrial muscle strips; portal veins and descending thoracic aortic rings of healthy normotensive Wistar rats were used to investigate the vascular effects of HCE. Acute HCE administration caused a significant (p 0.05) fall in blood pressure in the normotensive anaesthetised Wistar rats. DSS hypertensive rats treated with HCE displayed low arterial blood pressure and heart rate values from weeks five to seven. HCE produced concentration-dependent negative inotropic and chronotropic effects on rat isolated electrically driven left; and spontaneously beating right atrial muscle preparations; respectively. HCE also evoked concentration-dependent relaxation responses of endothelium-intact aortic rings and portal veins isolated from healthy normotensive Wistar rats. The vasorelaxant effects of HCE in intact aortic rings were significantly reduced; but not completely abolished by adding endothelial-derived factor (EDRF) inhibitor; L-NAME; suggesting that the vasorelaxant effect of the extract is mediated via EDRF-dependent and independent mechanisms. The results of the study suggest that the hypotensive action of HCE is elicited; in part; directly by decreasing myocardial contractile performance and total peripheral vascular resistance due to its negative inotropic and chronotropic effects on rat isolated atrial muscle strips; and vasorelaxant effects on isolated vascular smooth muscles. The observed cardiovascular effects of HCE partly support the basis for its use in the management of high blood pressure in folkloric medicine

Effects of Ficus thonningii (Blume) [Morarceae] stem-bark ethanolic extract on blood glucose, cardiovascular and kidney functions of rats, and on kidney cell lines of the proximal (LLC-PK1) and distal tubules (MDBK).

Previous observations indicate that Ficus thonningii (Blume) [Moraceae] stem-bark extracts may be useful in the control of diabetes mellitus. Accordingly, we investigated in some experimental animal paradigms the effects of F. thonningii stem-bark ethanolic extract (FTE) on renal and cardiovascular functions as complications of diabetes. Oral glucose tolerance tests were conducted in separate groups of non-diabetic and STZ-treated diabetic rats given glucose load (0.86 g x kg(-1), p.o.) after 18-h fast, followed by various FTE doses (60, 120, and 240 mg x kg(-1)). Rats treated with deionized water (3 mL x kg(-1) p.o.), or metformin (500 mg x kg(-1) p.o.) acted as untreated and treated positive controls, respectively. Blood glucose was monitored at 15-min intervals for the first hour, and hourly thereafter for 3 h. Acute effects of FTE on kidney function and mean arterial blood pressure (MAP) were investigated in anaesthetized rats challenged with hypotonic saline after a 3.5-h equilibration for 4 h of 1 h control, 1.5 h treatment, and 1.5 h recovery periods. FTE was added to the infusate during the treatment period. Chronic effects of FTE were studied in individually caged rats treated daily with FTE (120 mg x kg(-1), p.o.) for five weeks. Cytotoxicity of FTE was assessed by dye-reduction colorimetric (MTT) assay on MDBK and LLCPK1 kidney cell lines exposed for 24 h, 48 h, and 72 h to graded concentrations of the extract. Myocardial contractile performance was evaluated on rat isolated atrial muscle strips. FTE, like metformin, decreased blood glucose levels in non-diabetic and STZ-diabetic rats. Both acute and chronic FTE treatments did not affect renal function. In vitro studies demonstrated that FTE increased MDBK cell metabolic activity by an average of 15% (72 h), and LLCPK1 mirrored the controls. Acute intravenous infusion of FTE reduced the MAP from 119 +/- 1 mmHg to 98 +/- 4 mmHg. The MAP also was reduced throughout the five-week experimental study period. FTE also produced concentration-dependent, negative inotropic and chronotropic effects on rat isolated, electrically driven left-, and spontaneously beating right-, atrial muscle preparations. Our experimental findings suggest that FTE possesses reno- and cardio-protective effects in diabetes mellitus.

Cardiovascular effects of Persea americana Mill (Lauraceae) (avocado) aqueous leaf extract in experimental animals.

The cardiovascular effects of Persea americana Mill (Lauraceae) aqueous leaf extract (PAE) have been investigated in some experimental animal paradigms. The effects of PAE on myocardial contractile performance was evaluated on guinea pig isolated atrial muscle strips, while the vasodilatory effects of the plant extract were examined on isolated portal veins and thoracic aortic rings of healthy normal Wistar rats in vitro. The hypotensive (antihypertensive) effect of the plant extract was examined in healthy normotensive and hypertensive Dahl salt-sensitive rats in vivo. P americana aqueous leaf extract (25-800 mg/ml) produced concentration-dependent, significant (p < 0.05-0.001), negative inotropic and negative chronotropic effects on guinea pig isolated electrically driven left and spontaneously beating right atrial muscle preparations, respectively. Moreover, PAE reduced or abolished, in a concentration-dependent manner, the positive inotropic and chronotropic responses of guinea pig isolated atrial muscle strips induced by noradrenaline (NA, 10(-10)-10(-5) M), and calcium (Ca(2+), 5-40 mM). PAE (50-800 mg/ml) also significantly reduced (p < 0.05-0.001) or abolished, in a concentration-dependent manner, the rhythmic, spontaneous, myogenic contractions of portal veins isolated from healthy normal Wistar rats. Like acetylcholine (ACh, 10(-8)-10(-5) M), the plant extract (25- 800 mg/ml) produced concentration-related relaxations of isolated endothelium-containing thoracic aortic rings pre-contracted with noradrenaline. The vasorelaxant effects of PAE in the isolated, endothelium-intact aortic rings were markedly inhibited or annulled by N(G)-nitro-L-arginine methyl ester (L-NAME, 10(-5) M), a nitric oxide synthase inhibitor. Furthermore, PAE (25-400 mg/kg iv) caused dose-related, transient but significant reductions (p < 0.05-0.001) in the systemic arterial blood pressure and heart rates of the anaesthetised normotensive and hypertensive rats used. The results of this laboratory animal study indicate that PAE caused bradycardia, vasorelaxation and hypotension in the mammalian experimental models used. The vasorelaxant action of PAE was endothelium dependent, and was, therefore, possibly dependent on the synthesis and release of nitric oxide (NO). The vasorelaxant effects of PAE appeared to contribute significantly to the hypotensive (antihypertensive) effects of the plant extract. However, the findings of this study tend to suggest that P americana leaf could be used as a natural supplementary remedy in essential hypertension and certain cases of cardiac dysfunctions in some rural Africa communities.

C-reactive protein in acute and delayed preconditioning of the rat heart.

UNLABELLED: The involvement of C-reactive protein (CRP) in early (acute) and delayed ischaemic (IPC) and pharmacological (chemical) (CPC) preconditioning in an in vivo model of rat myocardial infarction is presented. Acute IPC was produced by three 5-min occlusion (ischaemia) periods interspersed with 5 min reperfusion, followed by 30-min occlusion of the left coronary artery and 2 h reperfusion injury. Acute CPC was produced by a Kappa-opioid receptor agonist U50488H (5 mg/kg) applied i.v. 15 min before 30-min ischaemia/2-h reperfusion. Delayed preconditioning was produced by 30-min ischaemia/2-h reperfusion, induced 24 h after either ischaemic or pharmacological preconditioning. The myocardial ischaemia/reperfusion injury was evaluated on the basis of total and cardiac creatine kinase isoenzyme activity, functional recovery of the heart (ECG), infarct size (% IS/RA) and mortality at the end of the experiments. The results obtained showed that: . The Kappa-opioid receptor agonist U50488H mimics both the acute and delayed IPC in the above experimental protocol. .Both acute IPC and CPC produce effects by opening of the KATP channels (the effects were blocked by nonspecific ATP-sensitive K channel blocker glybenclamide), and via activation of protein kinase C (a selective protein kinase C inhibitor chelerythrine blocked the effects). .C-reactive protein was significantly elevated by 54% in non-preconditioned acute ischaemia/reperfusion injury. The elevation was more pronounced (82% increase) 24 h after non-preconditioned ischaemia/ reperfusion injury. It reflected very well the increase in cardiac isoenzymes, infarct size and mortality of the rats, and can be used as a marker of the severity of myocardial injury in this model. . The increase of CRP was prevented by both IPC and CPC in early, and especially in late preconditioning. This shows the involvement of CRP, not only as a marker, but as a causative factor in cardiac ischaemic/reperfusion injury. CONCLUSION: In addition to the established involvement of adenosine, bradykinin, opioid and other receptors, a suppression of myocardial CRP/complement production might be involved in the biological mechanism of preconditioning. This could be a promising perspective in clinical interventions against ischaemia/reperfusion injuries of the heart.

The role of C-reactive protein in ischemia/reperfusion injury and preconditioning in a rat model of myocardial infarction.

For the first time the involvement of C-Reactive protein (CRP) in early (acute) and delayed ischemic (IPC) and pharmacological (chemical) preconditioning (CPC) in an in vivo model of rat myocardial infarction was presented. Acute IPC was produced by three 5 minute occlusion (ischemia) periods interspersed with 5 minute reperfusion, followed by 30 minute occlusion of the left coronary artery and 2 hour reperfusion injury. Acute CPC was produced by a k-opioid receptor agonist U50488H (5 mg/kg) applied i.v. 15 minutes before 30 minute ischemia/ 2 hour reperfusion. Delayed preconditioning was produced by 30 minute ischemia/ 2 hour reperfusion, induced 24 hour after either ischemic or pharmacological preconditioning. The myocardial ischemia/reperfusion injury was evaluated on the basis of total and cardiac creatine kinase isoenzyme activity, functional recovery of the heart (ECG), infarct size (% IS/RA) and mortality at the end of the experiments. The results obtained showed that: k-opioid receptor agonist U50488H mimics both the acute and delayed IPC in the above experimental protocol; Both acute IPC and most probably CPC act by opening of K(ATP) channels (the effects were blocked by nonspecific ATP-sensitive K channel blocker glybenclamide), and via activation of protein kinase C (a selective protein kinase C inhibitor chelerythrine blocked the efects); C-reactive protein (CRP) was significantly elevated by 54% in non-preconditioned acute ischemia/reperfusion injury. The elevation was more pronounced (82% increase) 24 hour after non-preconditioned ischemia/reperfusion injury. It reflected very well the increase in cardiac isoenzymes, infarct size and mortality of the rats, and can be used as a marker of the severity of myocardial injury in this model; The increase of CRP was prevented by both IPC and CPC in early, and especially in late preconditioning. This confirms the involvement of CRP as a marker in cardiac ischemic/reperfusion injury. It was concluded that in addition to the established involvement of adenosine, bradykinin, opioid and other receptors, a suppression of myocardial CRP/complement production might be involved in the biological mechanism of preconditioning. This could be a promising perspective in clinical interventions against ischemia/reperfusion injuries of the heart.

Tuberculosis control in Malawian prisons: from research to policy and practice.

Following an operational research study in Zomba Central Prison, Malawi, in 1996, the National Tuberculosis Control Programme (NTP) and the Prison Medical Services worked together to improve the diagnosis and treatment of tuberculosis (TB) in prisoners. Prisoners are screened for TB on admission and during their prison sentences. A system was established of treating patients, according to NTP guidelines, while in prison and on discharge from prison. Monitoring and evaluation is undertaken using TB officers at district and regional level, and 6-monthly meetings are held with all stakeholders and the central unit to collate data and review prison TB control activities.

Use of a multiple choice questionnaire to stimulate TB officers to read the TB manual in Malawi.

Forty-four tuberculosis (TB) officers who attended the National TB Seminar were given a multiple choice questionnaire (MCQ), based on information in the TB manual. They were asked to complete the MCQ in their hospitals, using the manual, and return it within 6 weeks to the Central Unit. Thirty-one (70%) officers returned completed MCQs. There was negative marking for incorrect answers. The mean mark was 69%. Twelve (39%) officers scored 80% or higher and four (13%) scored below 50%. MCQ assessments may be a useful way of stimulating TB officers to read TB manuals and other guidelines.

Growth of urban school children in Malawi.

The objective of this cross-sectional study was to assess growth pattern of urban school children in Malawi from low socio-economic strata and to compare anthropometric measurements of the children to data from the region of South-Central Africa and to international standards. A total of 493 urban school children aged 6-17 years were selected randomly from two primary schools in semi-urban Blantyre, the largest city in Malawi. Anthropometric measurements included height, weight, mid-upper arm circumference, triceps skinfold thickness, mid-upper arm muscle circumference and maximal grip strength of the stronger hand. All parameters of Malawian children of both sexes were lower than medians of WHO/NCHS reference data. Expressed as percentage of WHO/NCHS references, the relative means of height, weight, mid-upper arm circumference and mid-upper arm muscle circumference of Malawian girls were considerably higher than those of boys, and older girls had better parameters than younger ones. Older pupils of both sexes had higher triceps skinfold thickness relative to the international references than the younger children. Mean maximal grip strength values of boys and girls were not significantly different. For girls, the relative values increased with age, while for boys they decreased. It is concluded that younger primary school pupils have similar body sizes to their counterparts from the region. Adolescents, particularly girls, have more favourable anthropometric parameters which approach WHO/NCHS reference data.

Ventilatory capacity indices in Malawian children.

OBJECTIVE: To compare ventilatory capacity indices in healthy Malawian school children with those of other ethnic Africans and Caucasians. DESIGN: Forced vital capacity (FVC), forced expiratory volume in one second (FEV1), peak expiratory flow rate (PEFR), FEV1 expressed as a percentage of FVC (FEV%), weight and height. SETTING: Two primary schools in urban Blantyre, Malawi. SUBJECTS: Five hundred and fourteen apparently healthy school children (230 boys and 284 girls) aged six to 17 years. RESULTS: Ventilatory capacity indices (FEV1, FVC and PEFR) strongly and significantly correlated to body size and age of children of both sexes. The mean value of FEV% was 88.3% and it did not change significantly with increasing body size and age of children. The mean values of FEV1 and FVC were 9.8% and 10.8% higher in boys than in girls, respectively. The 1.4% gender difference in PEFR values was statistically non-significant. For FEV1 and FVC values, the average differences between Malawian and European children were between 20.5% and 23% while for PEFR the ethnic difference was about 12%. The Malawian children have similar ventilatory capacity indices to those of Nigerian, Jamaican and Tanzanian children. CONCLUSION: Prediction equations calculated in this study should be used for interpretation of ventilatory capacity indices in Malawian children instead of reference values for Caucasians or ethnic scaling factors. Computation of regional reference values for ventilatory capacity indices shall be continued. It shall embrace additional factors contributing to variance in respiratory functions such as customary physical activity, local environmental conditions, altitude of residence, nutritional status and smoking.