Onchocerciasis situation in the Tukuyu focus of southwest Tanzania after ten years of ivermectin mass treatment.

A purposive cross-sectional epidemiological study was conducted in the Tukuyu Onchocerciasis focus in south-western Tanzania in 2004, ten years after launching the ivermectin mass treatment programme, and 23 years after establishing focal parasite prevalence. The objective was to assess contemporary Onchocerciasis clinical and parasitological situation and assess community knowledge about the disease and its control. From historical data, five villages with high parasite prevalence were selected, two each on the Lufilyo and Kiwira Rivers and one on lower Lumbira River. Skin biopsies were taken from the iliac crest on the left and right buttocks, for examination of Onchocerca volvulus microfilariae. Onchocercal skin lesions were checked using natural light, while nodules were palpated from head to ankles and scored. A structured questionnaire was administered to participants. A total of 438 persons (age=16-99 years) were examined. No skin microfilariae (mf) were detected. Onchocercal skin symptoms were found in 170 (38.8%), of which 30 (6.9%) had nodules, 48 (11.0%) chronic onchodermatitis and 92 (21%) itching. One-third (34.5%) had correct knowledge that black flies ("tusunya") are vectors of onchocerciasis. Half of the respondents (n=217) confirmed taking ivermectin for onchocerciasis treatment, and 428 (97.7%) were willing to continue for any duration. It is concluded that the undetectable skin microfilariae in the study sample was partly attributable to the consequences of ongoing ivermectin mass treatment. It is recommended that the control efforts, as well as monitoring and evaluation be sustained to determine its long term impact, and that a more sensitive technique be used to check O. volvulus skin mf prevalence.

Impact of ivermectin mass distribution for onchocerciasis control on Ascaris lumbricoides among schoolchildren in Rungwe and Kyela Districts; southwest Tanzania

Across-sectional survey on the impact of ivermectin treatment for onchocerciasis control; on Ascaris lumbricoides infections was conducted in 1994; before the first treatment cycle was implemented in the Tukuyu focus in Tanzania. A total of 560 pupils were randomly selected for stool samples before; 7 days and 3 months after treatment. Modified Kato Katz technique was used to prepare slides; and a dissection microscope for examination. Results showed pre-treatment A. lumbricoides prevalence ranging from 4.2(Lutete) to 34.0(Lufilyo). At day seven post-treatment; samples were devoid of Ascaris eggs; except at Lufilyo with 2.9prevalence. Three months post treatment showed 34 (8.2) out of 213 pupils had patent infections and 24 (5.8) re-infections. Mean infection intensities were significantly higher at pretreatment than three months post-treatment. A. lumbricoides adult worm expulsion was self-reported in the first week of treatment; especially 2-3 days after; by 21.9participants. Ivermectin treatment was effective against adult A. lumbricoides and cleared egg excretion by day seven; but re-infection occurred within three months. Visible worm excretion wasappreciated as potency of treatment. Long term mass treatment with ivermectin proposed for onchocerciasis control can be used to reduce A. lumbircoides infections. To benefit optimally from this programme; additional inputs should be availed to reduce re-infection between consecutive annual cycles. Appreciation of visible worm expulsion enhanced acceptance and compliance of onchocerciasis control campaign using ivermectin. Follow-up surveys are recommended

Malaria in the southern highlands of Tanzania: a review of hospital records.

Outpatient attendance and inpatient admission records were examined to assess malaria situation in ten hospitals in Mbeya and Iringa Regions in southern highlands of Tanzania for a period of fifteen years from 1986-2000. Generally, records were deficient, some hospitals with entire annual records missing for one or several years. However, malaria maintained a high profile as the leading cause of admissions and deaths among hospital attendees. Of the ten hospitals, seven recorded malaria as the leading cause of admissions for at least ten years; in three of these, it was also the top ranking cause of child death. Although the respective magnitude of malaria morbidity and mortality burdens was not directly correlated with altitude (P>0.5), three hospitals (Uwemba, Bulongwa and Ikonda) at above 2,000m, had relatively lower malaria morbidity and mortality burden compared to three worst affected facilities (Ilembula, Chimala and Mbozi) in the lower range of altitude, located in the flat plains. In conclusion, malaria is the major public health problem in the highlands districts of Mbeya and Iringa Regions in Tanzania that need the attention of health authorities and immediate intervention. However, more research is required to establish the true picture of the problem among the communities.