The performance of health laboratories and the quality of malaria diagnosis in six districts of Tanzania.

Early laboratory diagnosis is critical for the optimal management of human malaria, particularly following the introduction of relatively expensive, artemisinin-combination therapies (ACT). The performance of the laboratories and the quality of malaria diagnosis have recently been assessed in 36 healthcare facilities in six districts of Tanzania. Questionnaires, checklists and observations were used to collect information on the availability and functional status of equipment as well as on laboratory personnel and their performance in malaria diagnosis. Together, the surveyed facilities had 112 laboratory staff [almost half (41.1%) of whom were laboratory assistants] and 57 microscopes. Twenty-seven (75.0%) of the healthcare facilities included in the survey had only one functional microscope each. Only seven (12.3%) of the assessed microscopes had been serviced in the previous 2 years. Of the 38 microscopists who were assessed, 24 (63.2%) were re-using microscope slides, 29 (73.5%) were producing bloodsmears of low quality, and 30 (79.0%) were using Field's stain. Although the facility microscopists gave similar results to experienced research microscopists when reading bloodsmears prepared by the survey team, using high-quality reagents (kappa=0.769), they appeared far less competent when reading smears stained using the reagents from the study laboratories (kappa=0.265-0.489). The quality of malaria diagnosis at healthcare facilities in Tanzania, which is generally poor (largely because of inadequate supplies of consumables and the limited skills of laboratory staff in the preparation of bloodsmears), urgently needs to be improved if the utilization of ACT is to be sustainable.

Biological and haematological safety profile of oral amodiaquine and chloroquine in healthy volunteers with or without Plasmodium falciparum infection in northeast Tanzania.

Amodiaquine (AQ), an effective antimalarial drug for uncomplicated malaria, has been greatly restricted after cases of life-threatening agranulocytosis and hepatic toxicity during prophylactic use. We conducted a hospital based open-label randomised clinical trial in 40 indigenous semi-immune healthy adult male volunteers with and without malaria parasites. The objective was to collect data on biological and haematological safety, tolerability, and parasitological efficacy to serve as baseline in the evaluation of the effectiveness of AQ preventive intermittent treatment against malaria morbidity in infants. Volunteers were stratified according to parasitaemia status and randomly assigned 20 participants each arm to three days treatment with either AQ or chloroquine (CQ). The level of difference of selected haematological and hepatological values pre-and post-trial were marginal and within the normal limits. Clinical adverse effects mostly mild and transient were noticed in 33.3% CQ treated-aparasitaemic, 23.8% of CQ treated-parasitaemic, 28.6% ofAQ-treated parasitaemic and 14.3% of aparasitaemic receiving AQ. Amodiaquine attained 100% parasitological clearance rate versus 70% in CQ-treated volunteers. The findings indicate that there was no agranulocytosis or hepatic toxicity suggesting that AQ may pose no public health risk in its wide therapeutic dosage uses. Larger studies are needed to exclude rare adverse effects.

Biological and Haematological Safety Profile of Oral Amodiaquine and Chloroquine in Healthy Volunteers with or without Plasmodium falciparum Infection in Northeast Tanzania

Amodiaquine (AQ); an effective antimalarial drug for uncomplicated malaria; has been greatly restricted after cases of life-threatening agranulocytosis and hepatic toxicity during prophylactic use. We conducted a hospital based open-label randomised clinical trial in 40 indigenous semi-immune healthy adult male volunteers with and without malaria parasites. The objective was to collect data on biological and haematological safety; tolerability; and parasitological efficacy to serve as baseline in the evaluation of the effectiveness of AQ preventive intermittent treatment against malaria morbidity in infants. Volunteers were stratified according to parasitaemia status and randomly assigned 20 participants each arm to three days treatment with either AQ or chloroquine (CQ). The level of difference of selected haematological and hepatological values pre-and post-trial were marginal and within the normal limits. Clinical adverse effects mostly mild and transient were noticed in 33.3CQ treated-aparasitaemic; 23.8of CQ treated-parasitaemic; 28.6of AQ-treated parasitaemic and 14.3of aparasitaemic receiving AQ. Amodiaquine attained 100parasitological clearance rate versus 70in CQ-treated volunteers. The findings indicate that there was no agranulocytosis or hepatic toxicity suggesting that AQ may pose no public health risk in its wide therapeutic dosage uses. Larger studies are needed to exclude rare adverse effects

Pattern and spatial distribution of plague in Lushoto, north-eastern Tanzania.

A review of plague records from 1986 to 2002 and household interviews were carried out in the plague endemic villages to establish a pattern and spatial distribution of the disease in Lushoto district, Tanzania. Spatial data of households and village centres were collected and mapped using a hand held Global Positioning System and Geographical Information System. During the 16-year period, there were 6249 cases of plague of which 5302 (84.8%) were bubonic, 391 (6.3%) septicaemic, and 438 (7.0%) pneumonic forms. A total of 118 (1.9%) cases were not categorized. Females and individuals aged 7-18 years old were the most affected groups accounting for 54.4% (95% CI: 52.4-56.0) and 47.0% (95% CI: 45-49) of all reported cases, respectively. Most cases were found in villages at high altitudes (1700-1900m); and there was a decline in case fatality rate (CFR) in areas that experienced frequent outbreaks. Overall, there was a reduction in mean reporting time (from symptoms onset to admission) to an average of 1.35 days (95% CI: 1.30-1.40) over the years, although this remained high among adult patients (>18 years). Despite the decrease in the number of cases and CFR over the years, our findings indicate that Lushoto district experiences human plague epidemic every year; with areas at high altitudes being more prone to outbreaks. The continued presence of plague in this focus warrants further studies. Nonetheless, our findings provide a platform for development of an epidemic preparedness plan to contain future outbreaks.

Malaria specific mortality in lowlands and highlands of Muheza district, north-eastern Tanzania.

Vital registration of causes of death in Tanzania is incomplete and many deaths occur outside health care settings. Verbal autopsies (VA) are used to determine the underlying cause of death, and the probable diagnosis helps to estimate reasonably cause-specific mortality. In this paper, we report findings of a verbal autopsy survey which involved eight villages in both low and highlands of Muheza district, north-eastern Tanzania. The survey was conducted following a rapid census, which was done to identify households that had lost one or more members within a period of two years from the date of census. Trained research assistants administered VA questionnaires to parents/close relatives. Two physicians reviewed each report independently and a third opinion was sought where there was discordant report between the two. A total of 9,872 households were surveyed and 134 deaths were recorded. A total of 96 (71.6%) deaths were from lowland villages representing high malaria transmission. Majority (72.4%) of the reported deaths occurred at home whilst 32.1% occurred at heath facility settings. Overall, severe malaria was the leading cause accounting for 34.3% of all deaths. Infants were most affected and accounted for 43.5% of the total deaths. Pulmonary tuberculosis ranked second (8.2%) cause of deaths and was exclusively confined to individuals > or = 15 years. Probable cause of death could not be determined in 13.4% of deaths. In conclusion, majority of deaths in rural north-eastern Tanzania occur at home and the immediate causes are usually unknown or not documented. These findings indicate that the verbal autopsy is a useful tool for detecting leading causes of death at community level in the absence of health facility-based data.

Malaria specific mortality in lowlands and highlands of Muheza district; north-eastern Tanzania

Vital registration of causes of death in Tanzania is incomplete and many deaths occur outside health care settings. Verbal autopsies (VA) are used to determine the underlying cause of death, and the probable diagnosis helps to estimate reasonably cause-specific mortality. In this paper, we report findings of a verbal autopsy survey which involved eight villages in both low and highlands of Muheza district, north-eastern Tanzania. The survey was conducted following.a rapid census, which was done to identify households that had lost one or more members within a period of two years from the date of census. Trained research assistants administered VA questionnaires to parents/close relatives. Two physicians reviewed each report independently and a third opinion was sought where there was discordant report between the two. A total of 9,872 households were surveyed and 134 deaths were recorded. A total of 96 (71.6%) deaths were from lowland villages representing high malaria transmission. Majority (72.4%) of the reported deaths occurred at home whilst 32.1% occurred at heath facility settings. Overall, severe malaria was the leading cause accounting for 34.3% of all deaths. Infants were most affected and accounted for 43.5% of the total deaths. Pulmonary tuberculosis ranked second (8.2%) cause of deaths and was exclusively confined to individuals ≥15 years. Probable cause of death could not be determined in 13.4% of deaths. In conclusion, majority of deaths in rural north-eastern Tanzania occur at home and the immediate causes are usually unknown or not documented. These findings indicate that the verbal autopsy is a useful tool for detecting leading causes of death at community level in the absence of health facility-based data

Pattern and spatial distribution of plague in Lushoto; north-eastern Tanzania

A review of plague records from 1986 to 2002 and household interviews were carried out in the plague endemic villages to establish a pattern and spatial distribution of the disease in Lushoto district; Tanzania. Spatial data of households and village centres were collected and mapped using a hand held Global Positioning System and Geographical Information System. During the 16-year period; there were 6249 cases of plague of which 5302 (84.8) were bubonic; 391 (6.3)septicaemic; and 438 (7.0) pneumonic forms. A total of 118 (1.9) cases were not categorized. Females and individuals aged 7-18 years old were the most affected groups accounting for 54.4(95CI: 52.4-56.0) and 47.0(95CI: 45- 49) of all reported cases; respectively. Most cases were found in villages at high altitudes (1700-1900m); and there was a decline in case fatality rate (CFR) in areas that experienced frequent outbreaks. Overall; there was a reduction in mean reporting time (from symptoms onset to admission) to an average of 1.35 days (95CI: 1.30-1.40) over the years; although this remained high among adult patients (18 years). Despite the decrease in the number of cases and CFR over the years; our findings indicate that Lushoto district experiences human plague epidemic every year; with areas at high altitudes being more prone to outbreaks. The continued presence of plague in this focus warrants further studies. Nonetheless; our findings provide a platform for development of an epidemic preparedness plan to contain future outbreaks

Clinical and parasitological aspects of itching caused by onchocerciasis in Morogoro, Tanzania.

A clinical and parasitological assessment of onchodermatitis was conducted in a rural area of Morogoro district, Tanzania. The study population consisted of 1,005 individuals aged > or = 5 years: 749 from a hyper-endemic community and 256 from a hypo-endemic. The prevalence of troublesome itching was 67.0% in the hyper-endemic community but only 5% (13/256) in the hypo-endemic. The corresponding prevalences of nodules among the adult male subjects were 77.7% (171/220) and 2.3% (2/86). The most common onchocercal skin lesion in the hyper-endemic community was chronic papular onchodermatitis (CPOD) manifested by itching, which was often very severe. There was a strong association between skin itching and endemicity (r = 0.75; P < 0.001). The prevalence of CPOD in the hyper-endemic community was significantly higher in males than females (P< 0.001). CPOD was only observed in subjects aged > or = 7 years. Many of the subjects were checked for microfilaridermia, by skin-snipping. The prevalence of microfilaridermia [58.2% (393/675) v. 6.2% (3/48)] and its geometric mean intensity (8.9 v. 1.0 microfilariae/mg skin snip) were both higher in the hyper-endemic community than the hypo-endemic. Itching appears to be related to reactive onchodermatitis.

Clinical and parasitological aspects of Bancroftian filariasis in Hale, northeast Tanzania.

OBJECTIVES: To document the endemicity characteristic of Bancroftian filariasis and to validate the effect of blood sampling time adjustment method on microfilarial intensity in relation to sex and age. DESIGN: Community based cross sectional survey. SETTING: Four rural communities in Hale area, Muheza district, northeast Tanzania. SUBJECTS: A sample of 1,025 inhabitants aged one year and above. MAIN OUTCOME MEASURES: Chronic clinical manifestations (elephantiasis and hydrocele), microfilarial prevalence as well as crude and time adjusted microfilarial geometric mean intensity (GMI). RESULTS: Clinically, 6.9% of examined individuals had elephantiasis and 28.5% males aged 15 years and above had hydrocele. Prevalence of Wuchereria bancrofti infection was 31.8%, with females and males showing a microfilarial rate of 32.1% and 31.5% respectively. Both the clinical manifestations and microfilarial prevalence increased with age. The GMI among microfilarial positive individuals for the crude microfilaraemia was 1,122 or 1,175 mf/ml of blood after adjustment of the sample to the expected level if it had been collected at peak hour. In different age and sex groups, the adjusted microfilarial GMI was slightly higher but exhibited a similar pattern to crude microfilaraemia count suggesting that time of blood sampling has similar effect on each age and sex group.

Malaria presumptive treatment in Tanzania: is it rational approach for malaria management in rural health units?

Against imperfect performance of presumptive treatment strategy in malaria management in most endemic areas with perennial and seasonal transmission, its potential benefits have not been adequately evaluated in areas with low malaria transmission. We assessed the rationality of presumptive treatment in 688 Tanzanian children attended at the Amani government rural dispensary, northeast Tanzania, an area with low malaria transmission form April to December 1993. A total of 549 (80%)) children were clinically diagnosed by the attending clinical officer and managed as malaria cases. Among these, 216 (39%) children were misdiagnosed based on the diagnosis criteria 1(DC1) of reported or history of fever plus asexual Plasmodium falciparum density at any level. At cut-off point of reported or history of fever, axillary temperature of 37.5 degrees Centigrade or above plus asexual P. falciparum density of either >/=40 per microL (DC2) or >/=5000 per microL (DC3) of blood, 380 (67%) and 484 (88%) children were respectively erroneously diagnosed. The level of misdiagnosis increased with age and was significantly higher during the dry season. These findings suggests that in Amani an area with low malaria transmission, presumptive treatment based on reported or history fever was less effective resulting into a substantial proportion of children being inappropriately managed. However, in the absence of sensitive, simple and affordable diagnostic devices in rural health units, we consider that effective use of thermometers and consideration of alternative diagnosis among feverish children might minimise the magnitude of unwarranted malaria treatment.