Prevalence of Sarcoptes scabiei infestation and its associated factors among primary school children: A school-based cross-sectional survey in the Rufiji district, Tanzania.

Objectives: This study aimed to investigate the prevalence of Sarcoptes scabiei infestation and its associated factors among primary school children (PSC) in the Rufiji district. Methods: A quantitative school-based cross-sectional study was conducted among 447 PSC in the Rufiji district. The prevalence of scabies among PSC was determined by clinical examination and by microscopic examination of skin samples for the presence of S. scabiei. A structured questionnaire was used to gather data on factors associated with S. scabiei infestation. Descriptive analysis, Fisher's exact, chi-square tests, and logistic regression analysis were used to analyze the data. Results: The prevalence of scabies was 2.0%. Of the assessed factors, only physical contact with a person having itchy skin lesions (Adjusted Odds Ratio [AOR]=4.04, 95%CI 4.39-12.50) and infrequency of changing clothes before laundry (AOR=2.99, 95%CI 1.35-4.94) were significantly associated with scabies. The majority of participants demonstrated low levels of knowledge, with half exhibiting poor attitudes and inappropriate healthcare-seeking behaviors. Conclusions: There was an ongoing transmission of scabies among PSC in the Rufiji district, with the factors associated with the transmission being physical contact with a person who had an itchy skin lesion and the infrequency of changing clothes before laundry. Therefore, there is a need for regular clinical screening and treatment of positive cases with preventive measures on contact and provision of health education.

Prevalence and factors associated with ongoing transmission of Schistosoma haematobium after 12 rounds of Praziquantel Mass Drug Administration among school age children in Southern Tanzania.

Background: World Health Organization (WHO) recommends periodic praziquantel Mass Drug Administration (MDA) to vulnerable populations, especially school-aged children, to reduce the risk of transmission. In the S. haematobium endemic Lindi region, on the southeastern coast of Tanzania, praziquantel has been distributed for more than a decade (12 rounds) in schools. However, there is a paucity of data on the current burden and factors perpetuating ongoing urogenital schistosomiasis among SAC. The study investigated the prevalence and factors associated with the ongoing transmission of S. haematobium among school-age children (SAC) after 12 rounds of praziquantel in Nachingwea, Southern Tanzania. Material and methods: A quantitative cross-sectional study was conducted between May and June 2022 among 483 SAC in the Nachingwea district. Macrohematuria, microhaematuria, and S. haematobium eggs were assessed in the collected urine sample for each participant, using macroscopic observation, urine dipstick, and urine filtration techniques, respectively. Infection intensity was quantified for positive S. haematobium urine samples. Knowledge and attitudes towards schistosomiasis were assessed among participants through an interview-administered questionnaire, and water contact practices were registered through an observation checklist. Data were summarized using descriptive statistics, the Chi-square test, and logistic regression. Results: The prevalence of S. haematobium infection was 10.6%, with 0.6% (3/51) prevalence of heavy infection. The factors associated with S. haematobium persistence transmission were a habit of visiting the water bodies (AOR = 1.62, 95% CI: 0.40-1.96), swimming in the visited water bodies (AOR = 4.58, 95% CI: 1.72-12.19), using water from the river source (AOR = 3.79, 95% CI: 1.51-9.51) and attending Mkumba Primary School (17.4%; AOR = 6.12, 95% CI: 1.64-22.85). Conclusions: Findings suggest ongoing transmission of urogenital schistosomiasis in the Nachingwea District despite 12 rounds of praziquantel treatment, with a low prevalence of heavy infection (0.6%). Praziquantel distribution should be complemented with health education, especially on the cause and transmission of urogenital schistosomiasis to increase knowledge that will improve a good attitude towards schistosomiasis prevention. An adequate water supply is to be considered to reduce infections due to the visit to water sources for daily use.

The quality of malaria case management in different transmission settings in Tanzania mainland, 2017-2018.

Tanzania is undergoing an epidemiological transition for malaria transmission with some areas of the country having <10% (hypoendemic) and other areas 10% - 50% malaria prevalence (mesoendemic). It is not known whether there is a difference in the quality of malaria case management based on endemicity in Tanzania mainland. We examined the influence of endemicity on the quality of malaria case management at health facilities. We conducted a cross-sectional analysis of 1713 health facilities in Tanzania mainland, using data collected by the National Malaria Control Program through an assessment tool to evaluate quality of malaria case management. The data was gathered from September 2017 to December 2018. Using standard quality factors, mean scores from facilities in the different endemicity regions were compared by a Student's t-test. Simple and multiple linear regression analyses were performed to determine the association between facility performance (score) and endemicity (mesoendemic vs. hypoendemic). Facilities in mesoendemic regions scored higher than those in hypoendemic regions on the overall quality of services [difference in mean scores ([Formula: see text]) = 2.52; (95% Confidence Interval (CI) 1.12, 3.91)], site readiness [[Formula: see text] = 2.97; (95% CI 1.30, 4.61)], availability of malaria reference materials [[Formula: see text] = 4.91; (95% CI 2.05, 7.76)], availability of Health Management Information System tools [[Formula: see text] = 5.86; (95% CI 3.80, 7.92)] and patient satisfaction [[Formula: see text] = 6.61; (95% CI 3.75, 9.48)]. Predictors associated with lower facility scores included; being located in a hypoendemic region [ß: -2.49; (95% CI -3.83, -1.15)] and urban area [ß: -3.84; (95% CI -5.60, -2.08)]. These findings highlight the differences in quality of malaria case management based on endemicity, but there is still a need to target improvement efforts in underperforming facilities, regardless of endemicity.

Burden and factors associated with onchocerciasis transmission among school-aged children after more than 20 years of Community Directed Treatment with Ivermectin in Ulanga district, Tanzania: A school-based cross-sectional study.

Onchocerciasis transmission in the Ulanga District of Morogoro-Tanzania is still ongoing despite more than 20 years of Community Directed Treatment with Ivermectin (CDTI) in the area. Even though surveys conducted over the years in the area have revealed a decrease in the prevalence of onchocerciasis, the prevalence of comorbidities suggested to be associated with this filarial infection, as epilepsy, is rising in endemic regions. This fact suggests continued transmission of Onchocerca volvulus and emphasizes the need for the evaluation of factors associated with it among school aged children. Therefore, this study determined the current burden of onchocerciasis in children aged 6 to 12 years and factors associated with continued transmission despite more than 20 years of CDTI in Ulanga District, Morogoro Region-Tanzania. A school-based cross-sectional study was conducted among 270 children aged 6 to 12 years in Ulanga District. Participants were tested using the OV-16 IgG4 Rapid Test. An interview-administered questionnaire was used to assess disease-associated symptoms, knowledge of onchocerciasis, and factors associated with continued transmission of the disease among participants. Descriptive statistics, chi-square test, and logistic regression were performed during data analysis. The prevalence of onchocerciasis was 19.6% (53/270), with boys being more infected; prevalence increased with increasing age groups and was higher in rural areas. Sex (AOR = 2.2, 95% CI: 1.13-4.28), age group of 11-12 years (AOR = 31.45, 95% CI: 2.73-362.27), and not taking ivermectin (AOR = 3.17, 95% CI: 1.53-6.58) were the only significant factors identified to be associated with the transmission of onchocerciasis in this study. The high prevalence of onchocerciasis among school age children in Ulanga district suggests continued transmission in the area. Therefore, a need to integrate CDTI with health education on the importance of ivermectin uptake.

Tungiasis infection among primary school children in Northeastern Tanzania: prevalence, intensity, clinical aspects and associated factors.

Objective: To investigate the prevalence, intensity, clinical aspects and factors associated with tungiasis infection among primary school children in Northeastern Tanzania. Methods: A quantitative school-based cross-sectional study was conducted among 401 primary school children. Participants were assessed through clinical examination to look for embedded Tunga penetrans in their hands, feet, arms and legs. A structured questionnaire was used to enquire about factors associated with tungiasis infection. The data were analysed using descriptive statistics, Chi-squared test and logistic regression, with p<0.05 taken to indicate significance. Results: The overall prevalence of tungiasis infection was 21.2%. Of the 85 tungiasis-infested children, 54 [63.5%, 95% confidence interval (CI) 53.1-74.1] had mild infection, 25 (29.4%, 95% CI 19.0-39.6) had moderate infection, and six (7.1%, 95% CI 1.2-12.9) had heavy infection. A moderate level of knowledge was significantly associated with high odds of tungiasis infection [adjusted odds ratio (AOR) 3.16, 95% CI 1.50-6.67], while not keeping a dog/cat at home was a protective factor (AOR 0.47, 95% CI 0.25-0.89). Conclusions: Moderate prevalence of tungiasis infection was observed among primary school children favoured by factors related to the host, parasitic agent and environment. There is a need for a health education programme in schools encouraging use of appropriate footwear (closed shoes), use of locally accessible repellents (coconut oil), fumigation of households, and washing dogs/cats with insecticides.

Intestinal schistosomiasis among secondary school students in Northern Tanzania: prevalence, infection intensity and associated risk factors.

Objective: Our study investigated the prevalence, infection intensity and associated risk factors of intestinal schistosomiasis among secondary school students in Shinyanga Municipal Council, Northern Tanzania. Methods: A quantitative school-based cross-sectional study was conducted from June to August 2022 among 620 secondary students. One stool specimen per participant was collected and screened for Schistosoma mansoni ova by microscopy using the Kato-Katz technique. Ova were counted to estimate infection intensity in all positive stool samples. Participants' socio-demographic characteristics and risk factors for intestinal schistosomiasis were gathered using a structured questionnaire. Data analysis consisted of descriptive statistics, Chi-square test and logistic regression. Results: Overall prevalence of S. mansoni was 1.9%. All infected participants had light infection intensity. Overall prevalence of other intestinal parasites was 2.7%, with Hookworm spp (17.6%) and Entamoeba coli (52.9%) the most observed intestinal helminth and protozoa, respectively. Among assessed factors, being in form II or III, visiting water sources and doing activities in water sources were statistically significantly associated with increased risk of S. mansoni transmission. Conclusions: There is ongoing transmission of intestinal schistosomiasis among secondary students. Hence, the need for extending praziquantel administration in this group, health education provision, and improvement of water supply, sanitation and hygienic practices.

Burden and risk factors for Schistosoma mansoni infection among primary school children: A quantitative school-based cross-sectional survey in Busega district, Northern Tanzania.

BACKGROUND: Intestinal schistosomiasis is one of the most common neglected tropical diseases in Tanzania. Despite massive praziquantel administration, data from Northern Tanzania have reported a prevalence of up to 93.2%. Because the disease is focal, depending on host, environmental and intermediate host factors, there is a need to acquire data in specific settings to better tailor interventions. Therefore, the study assessed the prevalence and factors associated with persistent transmission of intestinal schistosomiasis among school-age children in Busega district, Northern Tanzania. METHODS: A school-based cross-sectional study was conducted among 363 primary school children, randomly selected from school clusters in the Busega district. A single stool sample was collected from each child for S. mansoni ova and infection intensity examination using Kato-Katz. Factors related to intestinal schistosomiasis transmission were acquired through a questionnaire. A malacological survey was carried out to determine the Biomphalaria infectivity rate. Descriptive statistics and logistic regression analysis were conducted to analyse the association between schistosoma infection and factors related to transmission in this setting. RESULTS: The prevalence of S. mansoni infection was 41.3% (95% CI: 36.3-46.5), statistically significantly higher among the younger group aged less than 11 years (46.4% vs 35.3%, p = 0.032). The intensity of infection was heavy in 1.6% of participants, moderate in 9.6%, and light in 30.9%. Studying at Mwamayombo Primary School (AOR = 2.50, 95% CI: 1.12-5.60) was the only factor significantly associated with S. mansoni infestations. The snail intermediate host belonged to Biomphalaria sudanica species, whose infectivity rate was quantified as 0.97%, thus confirming ongoing transmission in the area. CONCLUSIONS: There was a high prevalence of S. mansoni infection among school-age children in the Busega district. The presence of the infected Biomphalaria sudanica in the area documents the persistent transmission of the disease, favored by low knowledge and negative attitudes among school-aged children. Hence, the need for multi-approach intervention for schistosomiasis prevention and elimination.

Prevalence and factors associated with persistent transmission of Schistosoma haematobium among primary school children after five rounds of mass drug administration using praziquantel: A cross sectional study in Mkuranga district, Tanzania.

Despite a human schistosomiasis control programme through praziquantel mass drug administration (MDA) between 2011 and 2015,there was still persistent transmission among primary schoolchildren (PSC) in Mkuranga district, Tanzania. Our cross-sectional study was conducted among 396 PSC who provided urine for diagnosis of Schistosoma haematobium infection. Observations were conducted to determine PSC water contact activities. Logistic regression was used to test association between dependent and independent variables. We found MDA uptake among PSC as 72.5%, and the prevalence of Schistosoma haematobium infection 5.8%. The risk of infection increased among PSC engaged in fetching water and adjusted odds ratio (AOR) for swimming, bathing, fishing, crossing ponds and paddy fields were 0.123, 0.166, 0.232, 0.202 and 0.093 respectively. Thus we conclude that multiple water contact activities and low participation in MDA is responsible for persistent Schistosoma transmission.

Adolescents and young adults excluded from preventive chemotherapy for schistosomiasis control in Northern Tanzania: are they at risk and reservoirs of infection? Prevalence and determinants of transmission in Northern Tanzania.

Objective: To investigate the magnitude of urogenital schistosomiasis and determinants of transmission among adolescents and young adults in Itilima district, Simiyu region, Northern Tanzania. Methods: A quantitative cross-sectional study was carried out using probability sampling strategies to select 433 secondary school students from five schools among the five wards of Itilima district, an area endemic for urogenital schistosomiasis. A self-administered structured questionnaire was used to gather data on determinants, and urine samples were examined for macrohaematuria and the presence of Schistosoma haematobium using the standard urine filtration technique. Data analysis was performed using descriptive statistics, Chi-squared test and logistic regression. Results: The overall prevalence rates of S. haematobium infection and macrohaematuria among adolescents and young adults were 15.9% and 3%, respectively, with the majority of individuals being lightly infected (85.5%). The determinants for urogenital schistosomiasis among the adolescents and young adults in Itilima district were: being in Form I [adjusted odds ratio (aOR) 2.42, 95% confidence interval (CI) 1.16-11.8; P=0.018]; being resident in Sasago ward (aOR 5.57, 95% CI 1.98-15.67; P=0.001) or Budalabujiga ward (aOR 2.99, 95% CI 1.04-8.56; P=0.042); having positive attitudes towards urogenital schistosomiasis (aOR 3.14, 95% CI 1.27-7.72; P=0.013); swimming in rivers (aOR 1.92, 95% CI 1.06-3.50; P=0.032); and urinating in water bodies (aOR 1.68, 95% CI 1.05-2.69; P=0.032). Conclusions: Urogenital schistosomiasis is prevalent among adolescents and young adults, and serves as a reservoir for transmission of S. haematobium. Preventive chemotherapy campaigns should be extended to adolescents and young adults, and integrated with regular screening, health education and an adequate water supply.

Prevalence and management of filarial lymphoedema and its associated factors in Lindi district, Tanzania: A community-based cross-sectional study.

OBJECTIVE: To determine the burden and management of filarial lymphoedema and its associated factors in Lindi district, Tanzania. METHODS: Cross-sectional study involving 954 community members who were screened for filarial lymphoedema by using a checklist. Moreover, lymphoedema patients were examined for the presence of entry lesions, staging of disease, and interviewed on acute dermatolymphangioadenitis (ADLA) attacks, and their current practices on lymphoedema management. Descriptive statistics and logistic regression analyses were performed. A p < 0.05 was considered statistically significant. RESULTS: The prevalence of filarial lymphoedema was 7.8%, with the majority in the early stage of lymphoedema (78.4%). The large majority (98.6%) of the patients had lower limb lymphoedema and 46% of lymphoedema patients had entry lesions. More than a half (60.8%) of those lymphoedema patients had experienced ADLA attacks; close to two-thirds (64.8%) had one or two attacks in the past 6 months. Generally, patients had inappropriate hygiene care practices for filarial lymphoedema management. Inappropriate hygiene care practice for lymphoedema management was associated with an increased risk for the development of advance stage of lymphoedema (adjusted odds ratio = 7.379, 95%, confidence interval: 3.535-16.018, p = 0.04). CONCLUSION: Though lymphatic filariasis transmission has drastically declined, chronic manifestations of lymphoedema persist in Lindi district. The recommended disease management practices are deficient, which calls for a programmatic approach for mapping the burden of lymphoedema and implementing its management.

Prevalence and risk factors of urogenital schistosomiasis among under-fives in Mtama District in the Lindi region of Tanzania.

INTRODUCTION: Despite the ongoing intervention for schistosomiasis control among school-age children in the Lindi region of Tanzania, urogenital schistosomiasis continues to be a public health problem, presumably because other at-risk populations are not covered in praziquantel deworming campaigns. Evidence shows that under-fives become infected in their early life hence the need to understand the disease profile and the risk factors for exposure to infection so as to plan effective control strategies in this group. This study examined the prevalence and risk factors of urogenital schistosomiasis among under-fives in the Mtama district, Lindi region of Tanzania. METHODOLOGY/PRINCIPAL FINDINGS: A quantitative community-based cross-sectional study was carried out among 770 participants (385 under-fives and their 385 parents/guardians) in the Mtama district to investigate the burden and the risk factors associated with S. haematobium infection. A single urine specimen was collected from the under-fives and tested for macro and microhaematuria, presence of S. haematobium ova, and intensity of infection. A structured questionnaire gathered on risk factors for S. haematobium exposure in under-fives from their parents/guardians. Data analysis was performed using descriptive statistics, chi-square test, and logistic regression. Prevalence of S. haematobium ova was 16.9%, and that of macro and microhaematuria was 6% and 17.9%, respectively. Of the 65 positive under-fives, 49 (75.4%) 95% CI 65.4-86.3 had a light infection intensity, and 16 (24.6%) 95% CI 13.7-35.5 had a heavy infection intensity. Among the assessed risk factors, the parents/guardians habit of visiting water bodies for domestic routines (AOR: 1.44, 95% CI: 1.13-1.74), especially the river (AOR: 6.00, 95% CI: 1.20-35.12), was found to be a significant risk factor for infection of S. haematobium in under-fives. CONCLUSION/SIGNIFICANCE: A moderate prevalence of S. haematobium was found among the under-fives conceivably with adverse health events. The infected under-fives could be a source of continuity for transmission in the community. An intervention that covers this group is necessary and should be complemented with regular screening, health education campaigns, and an adequate supply of safe water.

Persistence of Schistosoma haematobium transmission among school children and its implication for the control of urogenital schistosomiasis in Lindi, Tanzania.

BACKGROUND: Despite twelve rounds of school-based preventive chemotherapy for schistosomiasis in endemic areas of Tanzania such as Mtama district, Lindi: the burden of Schistosoma haematobium infection has remained highly conceivable due to re-infections. The factors associated with continuity of S.haematobium transmission in Mtama district, Lindi have not been fully established. This study investigated the burden and factors contributing to the ongoing transmission of S.haematobium infection in the endemic district of Mtama, Lindi. METHODS: A quantitative cross-sectional survey was carried out among 649 school-age children in the Mtama district to determine the burden and factors associated with continuity of S.haematobium infection transmission. A single urine specimen was obtained from each pupil and tested for macro- and microhaematuria, presence of S.haematobium ova, as well intensity of infection; this was complemented with a survey of Bulinus spp snail intermediate hosts and their infectivity. A structured questionnaire was employed to gather information on individual and environmental risk factors for S.haematobium transmission. Summary statistics were computed for individual variables; while a univariate and multivariate logistic regression analysis was performed to assess the association between risk factors with S.haematobium infection. RESULTS: Prevalence of S.haematobium infection by macro- and microhaematuria was 13.1% and 46.2% respectively. The prevalence of S.haematobium ova was 52.7%; intensity of infection was light in 53.1%, and heavy in 46.9%. Snail intermediate hosts were Bulinus globosus and B.nasutus, whose infectivity was 2.2% and 1.3%, respectively. Among the assessed risk factors, long residency (10-13 years) in the area was a significant risk factor for the continuity of S.haematobium transmission (AOR: 21.79, 95% CI: 1.37-346.4). CONCLUSIONS: The observed 52.7% prevalence of S.haematobium infection represents unacceptably high prevalence after 12 rounds of preventive chemotherapy. Therefore, an urgent need for the implementation of integrated multiple control interventions in the Mtama district; is considered to be imperative.

Factors affecting uptake of ≥ 3 doses of Sulfadoxine-Pyrimethamine for malaria prevention in pregnancy in selected health facilities, Arusha region, Tanzania.

BACKGROUND: Tanzania adopted the revised World Health Organization policy in 2013 recommending a minimum of ≥3 doses of Intermittent Preventive Treatment during pregnancy with Sulfadoxine-Pyrimethamine (IPTp-SP) to protect against malaria. A study in Tanzania in 2014 reported low (9%) uptake. We investigated health workers knowledge about IPTp-SP and factors that influenced uptake of > 3 doses of IPTp-SP among pregnant women. METHODS: We conducted a cross-sectional study in 2017 among post-delivery women and health care workers from nine randomly-selected public health facilities in three Districts of Arusha Region. Probability proportional to size methodology was used to determine number of participants per facility. We used a structured questionnaire to collect socio-demographic and obstetric data, information on doses of SP received, and knowledge of SP for IPTp. Health care workers were interviewed about their knowledge for IPTp- SP and challenges encountered in its uptake and use. RESULTS: We interviewed 556 persons (median age 26 years, range 16-42 years) with the response rate of 99.3%. Of these, 484 (87.1%) had > 3 Antenatal Care (ANC) visits. A total of 402 (72.3%) were multigravida with 362 (65.1%) having given birth at least once. Of the 556 participants, 219 (39.4%) made their first ANC booking at < 17 weeks of pregnancy and 269 (48.4%) had received > 3 doses of SP-IPTp. Factors associated with uptake of > 3 doses of IPTp-SP included having secondary or higher education [Adjusted Odds Ratio (AOR) =1.6, 95%CI 1.1-2.4], attending ≥4 ANC visits [AOR = 3.1, 95%CI 2.1-4.6], having first antenatal booking at < 17 weeks [AOR = 1.8, 95%CI 1.4-2.3], and adequate knowledge on IPTp-SP [AOR = 2.7, 95%CI 1.9-3.9]. Among 36 health care workers interviewed, 29(80.6%) had adequate knowledge about IPTp-SP. SP was available in seven (87.5%) of the visited health facilities and was administered under Direct Observed Therapy (DOT) in six (75%) facilities. Health care workers reported that stock outs of SP was a challenge. CONCLUSIONS: Fewer than half of the women interviewed reported uptake of > 3 doses of IPTp-SP. That is below the Tanzania national target of 80%. Making > 4 ANC visits, having secondary or higher education, making an early first ANC visit and having adequate knowledge on IPTp-SP promoted uptake of > 3 doses. Further qualitative studies are needed to explore factors that might contribute to low uptake of SP.

Lymphatic filariasis transmission in Rufiji District, southeastern Tanzania: infection status of the human population and mosquito vectors after twelve rounds of mass drug administration.

BACKGROUND: Control of lymphatic filariasis (LF) in most of the sub-Saharan African countries is based on annual mass drug administration (MDA) using a combination of ivermectin and albendazole. Monitoring the impact of this intervention is crucial for measuring the success of the LF elimination programmes. This study assessed the status of LF infection in Rufiji district, southeastern Tanzania after twelve rounds of MDA. METHODS: Community members aged between 10 and 79 years were examined for Wuchereria bancrofti circulating filarial antigens (CFA) using immunochromatographic test cards (ICTs) and antigen-positive individuals were screened for microfilaraemia. All study participants were examined for clinical manifestation of LF and interviewed for drug uptake during MDA rounds. Filarial mosquito vectors were collected indoor and outdoor and examined for infection with W. bancrofti using a microscope and quantitative real-time polymerase chain reaction (qPCR) techniques. RESULTS: Out of 854 participants tested, nine (1.1%) were positive for CFA and one (0.1%) was found to be microfilaraemic. The prevalence of hydrocele and elephantiasis was 4.8% and 2.9%, respectively. Surveyed drug uptake rates were high, with 70.5% of the respondents reporting having swallowed the drugs in the 2014 MDA round (about seven months before this study). Further, 82.7% of the respondents reported having swallowed the drugs at least once since the inception of MDA programme in 2000. Of the 1054 filarial vectors caught indoors and dissected to detect W. bancrofti infection none was found to be infected. Moreover, analysis by qPCR of 1092 pools of gravid Culex quinquefasciatus collected outdoors resulted in an estimated infection rate of 0.1%. None of the filarial vectors tested with qPCR were found to be infective. CONCLUSION: Analysis of indices of LF infection in the human population and filarial mosquito vectors indicated a substantial decline in the prevalence of LF and other transmission indices, suggesting that local transmission was extremely low if occurring at all in the study areas. We, therefore, recommend a formal transmission assessment survey (TAS) to be conducted in the study areas to make an informed decision on whether Rufiji District satisfied WHO criteria for stopping MDA.

Interferon-γ and Interleukin-10 Responses during Clinical Malaria Episodes in Infants Aged 0-2 Years Prenatally Exposed to Plasmodium falciparum: Tanzanian Birth Cohort.

BACKGROUND: Infants born to mothers with placental malaria are prenatally exposed to Plasmodium falciparum antigens. However, the effect of that exposure to subsequent immune responses has not been fully elucidated. This study aimed at determining the effect of prenatal exposure to P. falciparum on Interleukin-10 and Interferon-γ responses during clinical malaria episodes in the first 24 months of life. METHODS: This prospective cohort study involved 215 infants aged 0-2 years born to mothers with or without placental malaria. Enzyme-linked immunosorbent assay (ELISA) was used to determine levels of IL-10 and IFN-γ in infants and detect IgM in cord blood. Data were analyzed using SPSS version 20. FINDINGS: Geometric mean for IFN-γ in exposed infants was 557.9 pg/ml (95% CI: 511.6-604.1) and in unexposed infants it was 634.4 pg/ml (95% CI: 618.2-668.5) (P=0.02). Mean IL-10 was 22.4 pg/ml (95% CI: 19.4-28.4) and 15.1 pg/ml (95%CI: 12.4-17.6), respectively (P=0.01). CONCLUSIONS: Prenatal exposure to P. falciparum antigens significantly affects IL-10 and IFN-γ responses during clinical malaria episodes in the first two years of life.

Hyperparasitaemia during clinical malaria episodes in infants aged 0-24 months and its association with in utero exposure to Plasmodium falciparum.

OBJECTIVE: Existing information has shown that infants who are prenatally exposed to P. falciparum are susceptible to subsequent malaria infections. However, the effect of prenatal exposure to P. falciparum on parasite density during clinical malaria episodes has not been fully elucidated. This study is a component of a prospective cohort study for which initial results have been published. This component was designed to determine the effect of prenatal exposure to P. falciparum on parasite density during clinical malaria episodes in the first 24 months of life. A total of 215 infants were involved and monitored for clinical malaria episodes defined by fever (≥ 37 °C) and parasitaemia. The geometric mean parasite counts between exposed and unexposed infants were compared using independent samples t test. The effect of in utero exposure to P. falciparum on parasite density was assessed using binary logistic regression. RESULTS: The geometric mean parasite count per µl of blood during clinical malaria episodes in exposed infants was 24,889 (95% CI 18,286-31,490) while in unexposed infants it was 14,035 (95% CI 12,111-15,960), P < 0.05. Prenatal exposure to P. falciparum was associated with hyperparasitaemia during clinical malaria episodes (OR 7.04, 95% CI 2.31-21.74), while other factors were not significantly associated (P > 0.05).

Lymphatic filariasis elimination efforts in Rufiji, southeastern Tanzania: decline in circulating filarial antigen prevalence in young school children after twelve rounds of mass drug administration and utilization of long-lasting insecticide-treated nets.

BACKGROUND: Lymphatic filariasis (LF) is a parasitic infection transmitted by mosquito vectors, and in Sub-Saharan Africa it is caused by the nematode Wuchereria bancrofti. The disease has been targeted for global elimination with the annual mass drug administration (MDA) strategy. Vector control is known to play an important complementary role to MDA in reducing the transmission of LF. The effects of an MDA and insecticide-treated net intervention implemented in an endemic area of southeastern Tanzania are reported here. METHODS: A cross-sectional study assessing W. bancrofti circulating filarial antigen (CFA) was conducted in five primary schools in five different villages. Standard one pupils aged 6-9 years were screened for CFA using immunochromatographic test cards (ICT), with a total of 413 screened in 2012 and 659 in 2015. Just after CFA testing, the children were interviewed on their participation in the MDA campaign. Moreover, 246 heads of households in 2012 and 868 in 2015 were interviewed on their participation in MDA and utilization of long-lasting insecticide-treated nets (LLINs). RESULTS: The prevalence of CFA for the 413 children tested in 2012 was 14.3%, while it was 0.0% for the 659 children tested in 2015. The Tanzanian National Lymphatic Filariasis Elimination Programme reported annual treatment coverage for Rufiji District ranging from 54.3% to 94.0% during the years 2002-2014. The surveyed treatment was 51.6% in 2011 and 57.4% in 2014. With regard to LLINs, possession and utilization increased from 63.4% and 59.2%, respectively, in 2012, to 92.5% and 75.4%, respectively, in 2015. CONCLUSIONS: The findings suggest that 12 rounds of MDA complemented with vector control through the use of insecticide-treated nets resulted in a marked reduction in W. bancrofti CFA in young school children.

Prenatal exposure to Plasmodium falciparum increases frequency and shortens time from birth to first clinical malaria episodes during the first two years of life: prospective birth cohort study.

BACKGROUND: Prenatal exposure to Plasmodium falciparum affects development of protective immunity and susceptibility to subsequent natural challenges with similar parasite antigens. However, the nature of these effects has not been fully elucidated. The aim of this study was to determine the effect of prenatal exposure to P. falciparum on susceptibility to natural malaria infection, with a focus on median time from birth to first clinical malaria episode and frequency of clinical malaria episodes in the first 2 years of life. METHODS: A prospective birth cohort study was conducted in Rufiji district in Tanzania, between January 2013 and December 2015. Infants born to mothers with P. falciparum in the placenta at time of delivery were defined as exposed, and infants born to mothers without P. falciparum parasites in placenta were defined as unexposed. Placental infection was established by histological techniques. Out of 206 infants recruited, 41 were in utero exposed to P. falciparum and 165 infants were unexposed. All infants were monitored for onset of clinical malaria episodes in the first 2 years of life. The outcome measure was time from birth to first clinical malaria episode, defined by fever (≥37 °C) and microscopically determined parasitaemia. Median time to first clinical malaria episode between exposed and unexposed infants was assessed using Kaplan-Meier survival analysis and comparison was done by log rank. Association of clinical malaria episodes with prenatal exposure to P. falciparum was assessed by multivariate binary logistic regression. Comparative analysis of mean number of clinical malaria episodes between exposed and unexposed infants was done using independent sample t test. RESULTS: The effect of prenatal exposure to P. falciparum infection on clinical malaria episodes was statistically significant (Odds Ratio of 4.79, 95 % CI 2.21-10.38, p < 0.01) when compared to other confounding factors. Median time from birth to first clinical malaria episode for exposed and unexposed infants was 32 weeks (95 % CI 30.88-33.12) and 37 weeks (95 % CI 35.25-38.75), respectively, and the difference was statistically significant (p = 0.003). The mean number of clinical malaria episodes in exposed and unexposed infants was 0.51 and 0.30 episodes/infant, respectively, and the difference was statistically significant (p = 0.038). CONCLUSIONS: Prenatal exposure to P. falciparum shortens time from birth to first clinical malaria episode and increases frequency of clinical malaria episodes in the first 2 years of life.

Accuracy of clinical diagnosis and malaria rapid diagnostic test and its influence on the management of children with fever under reduced malaria burden in Misungwi district, Mwanza Tanzania.

INTRODUCTION: Malaria diagnosis is known to be non-specific because of the overlap of symptoms of malaria with other infectious diseases that is made worse with declining malaria burden. Though the use of malaria rapid diagnostic test (mRDT) for malaria confirmation has universally been adopted, malaria decline may alter performance of mRDT. This study examined accuracy of clinical diagnosis and mRDT and its influence on prescription for febrile underfives. METHODS: A cross-sectional study of 600 underfives was carried out in 6 randomly selected health facilities in Misungwi district, Mwanza; from November - December 2014. Consecutive underfives with a fever consultation were recruited: for each fever and the clinical diagnosis entertained were recorded. Parasitological confirmation of malaria was done by mRDT and microscopic examination of finger prick blood samples. Treatment was based on mRDT results, drugs prescribed recorded. Accuracy of clinical diagnosis and mRDT in predicting malaria was assessed by performance indices against microscopy. Antimalarial and antibiotics prescriptions were assessed against parasitological findings. RESULTS: Clinically, 37.2% had malaria; 32.8% were mRDTpositive and 17.0% microscopically positive. Sensitivity of clinical diagnosis was very high (97.0% [95%CI: 91.0-99.2]); specificity 66.7% [95%CI: 62.3-70.8], and positive predictive value 37.4% (95%CI: 31.6-43.5). Sensitivity of mRDTwas very high (99.0% [95%CI: 93.9-99.9]), specificity (80.7% [95%CI: 76.9-84.0]), positive predictive value 51.3% [95% CI: 44.1-58.4]) and negative predictive 99.75% [95%CI: 99.4-100.0]. Those receiving antimalarial prescription, 75.0% were mRDT positive; 39.4% microscopically positive. Those receiving antibiotic, 78.8% were mRDT negative; 90.1% microscopically negative. CONCLUSION: Decline in malaria lowered specificity of mRDT to < 95% against WHO recommendation. Though adherence to mRDT results was high, there was over prescription of antibiotics.

Community Knowledge and Perceived Effectiveness of Interventions to Reduce Malaria: Implications for Sustained Use of Malaria Interventions in Rufiji District, Southeastern Tanzania.

Insecticides treated-nets (ITNs) and artemether-lumefantrine (ALu), crucial for malaria elimination, depend on perceived effectiveness in reducing malarial fevers. We examined community knowledge and perceived effectiveness of ITNs and ALu for reducing malaria in Rufiji district. Heads of households were interviewed on causes of fever in underfives, fever history, and antimalarial use during the last 2 weeks, perceived effectiveness of, and willingness to continue using ALu and ITNs. A total of 1,885 respondents were interviewed, a majority (88.2%) females. Illnesses with fever (malaria-76.1% and respiratory conditions-58.9%) were major health problems. There was a very high recognition of fever as malaria symptom (95.1%). There were mixed perceptions on effectiveness of ALu and ITNs: ALu (52.8%) and on ITNs as highly effective (48.1%). Both ALu and ITNs were judged partially effective. Reorientation of social marketing to increase demand for ALu and ITNs for malaria control consolidation is crucial.