41 research outputs found
Cost implications of improving malaria diagnosis: findings from north-eastern Tanzania.
No full textBACKGROUND: Over diagnosis of malaria contributes to improper treatment, wastage of drugs and resistance to the few available drugs. This paper attempts to estimate the rates of over diagnosis of malaria among children attending dispensaries in rural Tanzania and examines the potential cost implications of improving the quality of diagnosis. METHODOLOGY/PRINCIPAL FINDINGS: The magnitude of over diagnosis of malaria was estimated by comparing the proportion of outpatient attendees of all ages clinically diagnosed as malaria to the proportion of attendees having a positive malaria rapid diagnostic test over a two month period. Pattern of causes of illness observed in a or=5 year age group in the lower transmission site (RR 14.0 95%CI 8.2-24.2). In the low transmission site the proportion of morbidity attributable to malaria was substantially lower in <2 year old cohort compared to children seen at routine care system. (0.08% vs 28.2%; p<0.001). A higher proportion of children were diagnosed with ARI in the <2 year old cohort compared to children seen at the routine care system ( 42% vs 26%; p<0.001). Using a RDT reduced overall drug and diagnostic costs by 10% in the high transmission site and by 15% in the low transmission site compared to total diagnostic and drug costs of treatment based on clinical judgment in routine health care system. IMPLICATIONS: The introduction of RDTs is likely to lead to financial savings. However, improving diagnosis to one disease may lead to over diagnosis of another illness. Quality improvement is complex but introducing RDTs for the diagnosis of malaria is a good start
Epidemiology of Subpatent Plasmodium Falciparum Infection: Implications for Detection of Hotspots with Imperfect Diagnostics.
No full textAt the local level, malaria transmission clusters in hotspots, which may be a group of households that experience higher than average exposure to infectious mosquitoes. Active case detection often relying on rapid diagnostic tests for mass screen and treat campaigns has been proposed as a method to detect and treat individuals in hotspots. Data from a cross-sectional survey conducted in north-western Tanzania were used to examine the spatial distribution of Plasmodium falciparum and the relationship between household exposure and parasite density. Dried blood spots were collected from consenting individuals from four villages during a survey conducted in 2010. These were analysed by PCR for the presence of P. falciparum, with the parasite density of positive samples being estimated by quantitative PCR. Household exposure was estimated using the distance-weighted PCR prevalence of infection. Parasite density simulations were used to estimate the proportion of infections that would be treated using a screen and treat approach with rapid diagnostic tests (RDT) compared to targeted mass drug administration (tMDA) and Mass Drug Administration (MDA). Polymerase chain reaction PCR analysis revealed that of the 3,057 blood samples analysed, 1,078 were positive. Mean distance-weighted PCR prevalence per household was 34.5%. Parasite density was negatively associated with transmission intensity with the odds of an infection being subpatent increasing with household exposure (OR 1.09 per 1% increase in exposure). Parasite density was also related to age, being highest in children five to ten years old and lowest in those > 40 years. Simulations of different tMDA strategies showed that treating all individuals in households where RDT prevalence was above 20% increased the number of infections that would have been treated from 43 to 55%. However, even with this strategy, 45% of infections remained untreated. The negative relationship between household exposure and parasite density suggests that DNA-based detection of parasites is needed to provide adequate sensitivity in hotspots. Targeting MDA only to households with RDT-positive individuals may allow a larger fraction of infections to be treated. These results suggest that community-wide MDA, instead of screen and treat strategies, may be needed to successfully treat the asymptomatic, subpatent parasite reservoir and reduce transmission in similar settings
Safety, efficacy and pharmacokinetics profile of antimalarial drugs in pregnancy : pharmacoepidemiology studies
No full textBackground: Malaria in pregnancy is an important public health problem in sub Saharan Africa. It is known to be the most common and preventable cause of harmful birth outcomes in malaria endemic areas. It is therefore important for a pregnant woman to be treated with safe and effective antimalarial medication. Drug safety in pregnancy is of a greater concern due to limited safety data available in this vulnerable group. This is because pregnant women are not involved in clinical trials related to drug development process due to safety reasons and hence, most of these medicines come to market with limit information available about their safety in pregnancy. Hence, establishing a drug safety monitoring mechanism would be important to generate safety data when a given medicine is already in the market, especially medications against tropical diseases.
Pregnant women are at increased risk of malaria infection and illness than non-pregnant individuals due to physiological, hormonal and immunological changes that occur in their body after conception. The changes are also responsible for various therapeutic challenges that face this vulnerable group. This explains the presence of significant alteration of antimalarial pharmacokinetic (PK) properties in pregnancy and hence lead to a reduced drug blood concentration, which will ultimately lower antimalarial cure rate. Another factor that affects antimalarial effectiveness in pregnancy is parasite resistance against sulfadoxine-pyrimethamine (SP), a drug that is used for intermittent preventive treatment of malaria in pregnancy (IPTp).
The objectives of the thesis were to assess the magnitude of drugs exposure during pregnancy in relation to pregnancy outcomes, to describe the feasibility of establishing active pharmacovigilance system in developing countries using Health Demographic Surveillance System (HDSS) platform, to determine safety of artemether-lumefantrine (AL) exposure in first trimester of pregnancy, to evaluate pharmacokinetics and pharmacodynamics properties of artemether-lumefantrine in pregnant and non-pregnant women, and to determine the effectiveness of IPTp-SP in prevention of placental malaria, maternal anaemia and low birth weight in areas with different malaria transmission intensity.
Method: Three different study designs were used independently to respond to different specific objectives of this thesis; (i) a longitudinal follow up study was conducted to generate artemether/lumefantrine (AL) safety data in first trimester secondary to its inadvertent exposure in two Health Demographic Surveillance System (HDSS) areas in Tanzania. Pregnant women with gestational age ? 20 weeks were enrolled and followed up on monthly bases until delivery. Drugs exposures during the entire pregnancy period were also recorded. The latter was used to document the feasibility of establishing active pharmacovigilance system using HDSS platform in one of the studied HDSS area. (ii) To determine AL PK, a prospective study involving pregnant in second and third trimester and non-pregnant women, both with uncomplicated P falciparum malaria. Plasma samples were collected at pre-defined dates for bioassay to determine drug level. Participants were followed up on pre-defined schedule visits until day 42. Inter- and intra-individual variability was assessed and covariated effects quantified using a nonlinear mixed-effect modeling approach (NONMEM®). (iii) Another prospective study enrolling pregnant women to assess the effectiveness of IPTp in two areas with different malaria transmission intensity. Pregnant women were recruited in the labor ward and structured questionnaire was used for interview. Placental parasitaemia was screened by using both light microscope and real-time quantitative PCR.
Findings
Pharmacovigilance system
91% (994 of 1089) of pregnant women who were piloted to assess feasibility of establishing active PV system completed the follow up until delivery. 98% of pregnant women reported to have taken at least one medication during pregnancy, mainly drugs provided in the antenatal program. Other most reported drugs were analgesics (24%), antibiotics (17%) and antimalarials (15%), excluding IPTp. Iron and folate supplementations were associated with decreased risk of miscarriage/stillbirth (OR 0.1; 0.08 – 0.3).
AL safety
82% (1783 of 2167) of pregnant women who used and not used antimalarial drugs in first trimester were followed until delivery and recorded their pregnancy outcome. 319 (17.9%) used antimalarial drugs in first trimester and AL was the most frequent antimalarial used [53.9% (172 of 319)]. Others were 24.4 % quinine, 20.7% SP and 3.4% amodiaquine. Quinine exposure in first trimester was associated with increased risk of miscarriage/stillbirth (OR 2.5; 1.3 – 5.1) and premature birth (OR 2.6; 1.3 – 5.3). AL, SP and amodiaquine exposure were found not to be harmful.
PK analysis
33 pregnant women and 22 non-pregnant women with malaria were treated with AL (80/480mg) twice daily for 3 days. Lumefantrine (LF) bioavailability and metabolism rate into desmethyl-lumefantrine were respectively 34% lower and 78% higher in pregnant than in non-pregnant patients. Overall PCR uncorrected therapeutic failure was 18% in pregnant and 5% in non-pregnant women (OR 4.0; p value 0.22). A higher median day 7 LF concentration was associated with adequate clinical and parasitological response.
Effectiveness of IPTp
350 pregnant women were recruited and screened for placental parasitaemia (175 each from high and low malaria transmission areas). Prevalence of placenta parasitaemia was 16.6% in high transmission area and 2.3% in low transmission area. One or more doses of IPTp in high transmission area had 80% impact against placental malaria (OR 0.2; CI 0.06 – 0.7; p=0.015) and 60% in low transmission (OR 0.4; CI 0.04 – 4.5; p=0.478). Primigravida and residing in high transmission area were significant risk factors for placental malaria (OR 2.4; CI 1.1 – 5.0) and (OR 9.4; CI 3.2 – 27.7), respectively. The numbers needed to treat (NNT) was 4 (CI 2 – 4) women in high transmission area and 33 (CI 20 – 50) low transmission area to prevent one placental malaria. IPTp use was not statistically significant associated with decreased risk of maternal anaemia or low birth weight, regardless are of transmission intensity.
Conclusion:
Overall medicine use in pregnancy period is very high, including AL exposure in first trimester albeit this drug is not the first line treatment for malaria in early pregnancy. AL use in first trimester was safer as opposed to quinine, the first line drug which was associated with adverse pregnancy outcomes. We therefore recommend to consider other options than quinine for standard antimalarial drug in first trimester, and AL could be the best one.
HDSS platforms represent a reliable and feasible support to build on a pharmacovigilance system to assess safety of drugs in pregnancy since it has proved to be feasible. We recommend that pharmaceutical companies and other global financial bodies should invest more on the establishment of active pharmacovigilance system in pregnancy in tropical developing countries. The latter will boost safety data pool of newly marketed medicines and anti-infective agents for treating different illnesses in pregnancy.
LF bioavailability is significantly lowered in pregnant women due to altered PK properties as opposed to non-pregnant women in the same area. This may be responsible for therapeutic failure among pregnant women secondary to the observed low post-treatment prophylaxis. We recommend to evaluate a modified treatment regimen of malaria in pregnancy. ---------- Muhtasari
Utangulizi: Ugonjwa wa malaria kwa mama mjamzito ni tatizo kuu kwenye afya ya jamii hasa Africa kusini mwa jangwa la Sahara. Malaria ni miongoni mwa magonjwa yanayoweza kuzuilika. Ugonjwa huu unasababisha mazara makubwa sana kwa mtoto mchanga tokea akiwa tumboni kwa mama yake hasa sehemu zenye malaria kwa kiwango cha juu. Hivyo basi ni vema mama mjamzito atibiwe na dawa salama na zenye uwezo mkubwa wa kuangamiza vidudu vya malaria. Usalama wa dawa kwa mama mjamzito ni kitu chenye changamoto kubwa kutokana na uhaba wa takwimu muhimu za usalama wa dawa za malaria kwa wajawazito. Sababu kuu inatokana na mama wajawazito kutohusishwa kwenye majaribio ya dawa kipindi cha za mwanzoni pale ambapo dawa husika bado hazijapewa kibali cha kuingia sokoni kwa sababu ya kuhofia usalama wa kiafya hasa kwa mtoto aliyopo tumboni. Hilo linapelekea kwa dawa nyingi kuingia sokoni zikiwa na upungufu wa taarifa muhimu juu ya usalama wake kwa mama mjamzito. Kwa sababu hiyo, ni muhimu kuwa na mfumo wa kipekee wa kumfuatilia mama mjamzito pale atakapotumia dawa ambazo zipo tayari sokoni ili kuboresha taarifa za kiusalama kiafya kutokana na matumizi yake kipindi cha ujauzito.
Mama mjamzito anahatari kubwa ya kuambukizwa ugonjwa wa malaria pamoja na kuuguwa kuliko mama ambaye hana ujauzito. Hili linatokana na mabadiliko kipindi cha ujauzito ambayo yanasababishwa na kupunguwa kwa kinga ya mwili na mabadiliko ya homoni mwilini mwake. Mabadiliko haya yanachangia pia kuathiri ufanisi wa dawa mwilini kwake kupambana na vijidudu vya malaria na hivyo kupunguza uwezo wa uponyaji. Usugu wa dawa dhidi ya vijidudu vya malaria, kwa mfano dawa ya SP huchangia pia kuathiri uwezo wa kumponya mgonjwa wa malaria.
Dhumini kuu la utafiti huu ni (i) kujuwa wingi wa dawa anazotumia mama mjamzito ukilinganisha na matokeo ya mimba yake, (ii) kuonyesha uwezekano wa kuwa na mfumo pekee wa kudhibitisha matumizi ya dawa ambao utaweza kufuatilia usalama na matumizi ya dawa kwa ujumla kwa mama mjamzito, kwenye nchi inayoendelea kwa kutumia mfumo wa HDSS (Health Demographic Surveillance System), (iii) kuhakiki usalama wa matumizi ya dawa mseto (ALU) ya malaria kipindi cha mimba changa, (iv) kutathimini unyambulisho wa dawa ya mseto mwilini mwa mgonjwa sambamba na kulinganisha ufanisi wake wa kuangamiza vijidudu vya malaria, na (v) kutathimini ufanisi wa dawa ya SP ambayo mama mjamzito anapatiwa kliniki kama inasaidia kuangamiza vijidudu vya malari kwenye kondo la uzazi, kuzuia upungufu wa damu kwa mama na mtoto kutozaliwa na kilo pungufu kwenye maeneo yenye viwango tofauti vya maambukizo ya malaria.
Methodolojia: Njia tatu tofauti zilitumika kupata majibu husika ya malengo ya utafiti huu; (i) Kufuatilia mama wajawazito tokea kipindi cha mwanzo cha ujauzito wao hadi wanapojifungua na kurekodi taarifa za matumizi ya dawa (ikiwemo dawa mseto) na matokeo ya ujauzito. Zoezi hili lilifanyika kwenye vituo vya HDSS huko Rufiji na Kigoma mjini. (ii) Unyambulisho wa ufanisi wa dawa mseto uliwahusisha wanawake ambao ni wajawazito (wenye umri wa mimba kuanzia wiki 13 na kuendelea) na wale wasio wajawazito lakini wote wakiwa wametambulika hawana malaria kali. Walipewa dawa mseto na kutolewa damu kwa kipindi tofauti tofauti ndani ya siku 42 za kuwafuatilia ili kupima kiwango cha dawa kwenye damu na kuhakiki vijidudu vya malaria vinavyo angamia. (iii) Kuhakiki ufanisi wa SP kama kinga ya malaria kwa mama mjamzito (IPTp) ilihusisha kuwatambua akina mama wajawazito wakiwa kwenye hospitali mbili tofauti ambazo zipo kwenye maeneo yanye viwango tofauti vya uambukizaji wa malaria. Utambuzi wa akinamama hawa ulikuwa muda mfupi kabla hawajajifungua na ulihusisha kukusanya damu toka kwenye kondo la uzazi mara tu baada ya kujifungua na kupima kama kuna maambukizi ya vijidudu vya malaria.
Matokea: (i) Mfumo wa ukusanyaji taarifa ya matumizi ya dawa kipindi chote cha ujauzito. Asilimia 90 (994/1089) ya mama wajawazito waliweza kufuatiliwa mpaka walipo jifunguwa. Jumla ya 98% waliripoti kutumia walau aina moja ya dawa kipindi cha ujauzito, hasa zikiwa dawa zinazotolewa kwenye mpango maalumu wa mama na mtoto. Dawa nyingi zikiwa ni dawa za kuzuia maumivu (24%), antibayotiki (17%) na dawa za kutibu malaria (15%). Imeonekana dawa za kuongeza wingi wa dama zinahusiana na kupunguza hatari ya mimba kuharibika na mtoto kuzaliwa njiti.
(ii) Usalama wa dawa mseto: Jumla ya mama wajawazito 1783 kati ya 2167 (82%) waliyotumia na ambao hawajatumia dawa za malaria kipindi cha miezi mitatu ya mwanzo ya ujauzito walifuatiliwa na kurekodi matokeo yao ya ujauzito wao. 319 (17.9%) walitumia dawa za malaria kipindi hicho cha mwanzo cha ujauzito na kati ya hawa 53.9% walitumia dawa mseto. Wengine walitumia quinine (24.4%), SP (20.7%) na amodiaquine (3.4%). Matumizi ya quinine kipindi cha miezi mitatu ya mwanzo ya mimba yalihusishwa na kuharibika kwa mimba na kuzaa mtoto njiti. Dawa ya mseto, SP na amodiaquine zilionyesha kutokuwa na mathara yeyote.
(iii) Unyambulisho wa ufanisi ya dawa mseto: Utafiti huu ulihusisha wajawazito 33 na wanawake wasio wajawazito 22 waliyo na malaria na kutibiwa na dozi kamili ya dawa mseto mara mbili kutwa kwa siku 3. Sehemu ya dawa ya mseto ilionekana kuwa pungufu kwa wajawazito ukilinganisha na wale wasiyo wajawazito. Kwenye kipindi cha kuwafuatiliya wagonjwa (ndani ya siku 42), 18% ya wajawazito na 5% ya wasiyo wajawazito waligundulika kuwa bado wana vijidudu vya malaria. Kuwa na kiwango kikubwa cha dawa ya mseto kwenye mzunguko wa damu ulihusishwa na kupona malaria kwa ufasaha.
(iv) Ufanisi wa SP kama kinga ya malaria kwa mama mjamzito. Jumla ya mama wajawazito 350 walihusiswa kwenye utafiti huu, 175 toka kila sehemu yenye malaria ya kwa kiwango cha juu na pia toka kwenye sehemu ya malaria kwa kiwango cha chini. Maambukizo ya malaria kwenye kondo la uzazi ilikuwa 16.6% kwenye eneo la malaria cha kiwango cha juu na 2.3% kwenye eneo lenye malaria kwa kiwango cha chini. Matumizi ya SP yalionyesha uwezekano wa kuzuia maambukizi ya kondo la uzazi hasa eneo lenye malaria ya juu. Kuwa na ujauzito wa kwanza na kuishi eneo lenye malaria ya juu ni kiambata hatarishi cha kupata maambukizo ya kondo la uzazi
Hitimisho: Kwa ujumla matumizi ya dawa kipindi cha ujauzito yapo kwenye kiwangu cha juu, ikiwemo matumizi ya dawa mseto kwenye kipindi cha mimba changa, japokuwa dawa hii siyo chaguo la kwanza kwenye tiba ya malaria kwenye kipindi hichi. Dawa mseto imeonekana kuwa salama zaidi kuliko quinine hivyo ni bora kuanza kufikiria jinsi itakavyoweza kupendekezwa kwa matumizi kipindi cha mimba changa.
Kupitia HDSS imeonyesha inaweza kusaidia kuwa na mfumo wa uhakika na kuaminika wa kukusanya taarifa muhimu za matumizi ya dawa kwa mama mjamzito kwenye nchi masikini. Hivyo ni bora makampuni ya dawa, wafadhili kwa kushirikiana na taasisi za afya ndani na nje ya nchi wafikirie jinsi ya kufadhili mfumo huu ili kusaidia kuboresha takwimu za usalama wa dawa kwa mama wajawazito.
Imethibitika kuwa dawa mseto inapunguwa kwa kiasi kikubwa mwilini mwa mwanamke mjamzito ukilinganisha na mwanamke asiyo mjamzito. Hili huenda ikapelekea mama mjamzito kutopona kwa ufasaa na kupungukiwa uwezekano wa kukabiliyana na maambukizo mapya ya malaria kipindi cha usoni hasa baada ya kumaliza dozi ya malaria. Hivyo tunapendekeza kupitiwa upya dozi ya malaria inayotumika sasa na mama mjamzito na kushauri upatikanaji wa dozi mpya kwa hili kundi la wajawazito
Textual construction of domestic violence: examples from Kiswahili novels
No full textThis article discusses dominant discourses in the field of violence against women1 as articulated in Kiswahili novel. Using Foucauldian discourse analysis, the article illustrates the discursive strategies employed by Kiswahili novelists to explain the problem of violence against women. It reveals that the novelists foregrounded dominant discourses which exonerate abusive men from responsibility while placing responsibility on women. The author argues that this perspective plays a vital role in resisting feminist efforts to situate the social problem in patriarchal framework and strategically holds back efforts for ending violence against women in Tanzanian society. The main implication of this perspective is to normalize violence against women and the patriarchal system that sustain the abuse
Susceptibility Status of Malaria Vectors to Insecticides Commonly used for Malaria Control in Tanzania.
No full textThe aim of the study was to monitor the insecticide susceptibility status of malaria vectors in 12 sentinel districts of Tanzania. WHO standard methods were used to detect knock-down and mortality in the wild female Anopheles mosquitoes collected in sentinel districts. The WHO diagnostic doses of 0.05% deltamethrin, 0.05% lambdacyhalothrin, 0.75% permethrin and 4% DDT were used. The major malaria vectors in Tanzania, Anopheles gambiae s.l., were susceptible (mortality rate of 98-100%) to permethrin, deltamethrin, lambdacyhalothrin and DDT in most of the surveyed sites. However, some sites recorded marginal susceptibility (mortality rate of 80-97%); Ilala showed resistance to DDT (mortality rate of 65% [95% CI, 54-74]), and Moshi showed resistance to lambdacyhalothrin (mortality rate of 73% [95% CI, 69-76]) and permethrin (mortality rate of 77% [95% CI, 73-80]). The sustained susceptibility of malaria vectors to pyrethroid in Tanzania is encouraging for successful malaria control with Insecticide-treated nets and IRS. However, the emergency of focal points with insecticide resistance is alarming. Continued monitoring is essential to ensure early containment of resistance, particularly in areas that recorded resistance or marginal susceptibility and those with heavy agricultural and public health use of insecticides
ОСОБЛИВОСТІ СПІЛЬНОГО ФУНКЦІОНУВАННЯ ПОВИТУХИ ТА АКУШЕРКИ В РОДИЛЬНІЙ ОБРЯДОВОСТІ УКРАЇНСЬКОГО ТА РУМУНСЬКОГО НАСЕЛЕННЯ БУКОВИНИ / SPECIFICS OF THE CONCURRENT FUNCTIONING OF A MIDWIVES AND OBSTETRICIANS IN MATERNITY RITES OF UKRAINIAN AND ROMANIAN POPULATION IN BUKOVYNA
No full textМойсей Антоний. Особенности совместного функционирования повитухи и
акушерки в родильной обрядности украинского и румынского населения Буковины.
В предлагаемом вниманию читателя исследовании, на основе этнографических и статистических данных, характерных для Буковины, отслеживается процесс исчезновения одного
из действующих персонажей родильной обрядности повитухи (моши) под давлением новых
реалий, созданных официальной медициной. Проблема рассматривается в компаративном
ключе, с учетом многовекового сосуществования украинского и румынского населения в
буковинской этнографической зоне.
Ключевые слова:
повитуха, Моша, акушерка, Буковина, Черновицкая
область, родильная обрядность
Moysey Antoniy. Specifics of the concurrent functioning
of a midwives and obstetricians in maternity rites
of Ukrainian and Romanian population in Bukovyna.
The proposed research deals with the process of disappearance
of the one of characters in maternity rituals - the midwife
(Mosha) under the pressure of new realities created by
official medicine. The article is based on ethnographic and
historical data of the Bukovyna region. Historiography and
Source investigate presented topics in comparative perspective,
shows how it was described theese problems by Romanian
and Ukrainian ethnographers. Some attention was paid
to terminology midwife name and its etymology. For insight
into the problem by using a building material obtained during
field research. It allows to the author to indicate midwifes and
obstetricians function in a traditional century’s period: medical,
social and magical activities. The word Midwife is used
for indication the person, who used own empirical knowledge
before, during and after accouchement; performed special
magical effect on the whole process of childbirth. As a result
of her activities midwife acquired high social status in rural
communities. Church cooperated with her and recognizes all
midwife magical actions. Respect her job the village citizen
have been protected and she enjoyed uncommon love their
patients. She was one of the most respected persons for all
village families, bathing, christenings, weddings and even
burials.
Along with the development of the official medicine,
this became progress especially in the second half of the nineteenth
century. Bukovyna as a part of the Austro-Hungarian
Empire and its Bessarabian part (today’s Chernivtsi region),
which administratively belonged to the Russian Empire, began
a noticeable pressure on midwives as communities character.
The article presents a statistical analysis of the growth
of special medical establishmentsin the Bukovinian region
during XIX - early XX centuries, until the complete disappearance
of the midwife (Mosha) in public family rituals. At
the same time the process followed to reduce the influence of
this important character, and transformation its function and
some elements of its activities.
Key words: the midwife, “mosha”, the obstetrician, Bukovyna,
Chernivtsi region, puerperal rites
Foot-and-mouth disease in Tanzania from 2001 to 2006.
No full textFoot-and-mouth disease (FMD) is endemic in Tanzania, with outbreaks occurring almost each year in different parts of the country. There is now a strong political desire to control animal diseases as part of national poverty alleviation strategies. However, FMD control requires improving the current knowledge on the disease dynamics and factors related to FMD occurrence so control measures can be implemented more efficiently. The objectives of this study were to describe the FMD dynamics in Tanzania from 2001 to 2006 and investigate the spatiotemporal patterns of transmission. Extraction maps, the space-time K-function and space-time permutation models based on scan statistics were calculated for each year to evaluate the spatial distribution, the spatiotemporal interaction and the spatiotemporal clustering of FMD-affected villages. From 2001 to 2006, 878 FMD outbreaks were reported in 605 different villages of 5815 populated places included in the database. The spatial distribution of FMD outbreaks was concentrated along the Tanzania-Kenya, Tanzania-Zambia borders, and the Kagera basin bordering Uganda, Rwanda and Tanzania. The spatiotemporal interaction among FMD-affected villages was statistically significant (P≤0.01) and 12 local spatiotemporal clusters were detected; however, the extent and intensity varied across the study period. Dividing the country in zones according to their epidemiological status will allow improving the control of FMD and delimiting potential FMD-free areas
Automatic detection of potentially illegal online sales of elephant ivory via data mining
No full textIn this work, we developed an automated system to detect potentially illegal elephant ivory items for sale on eBay. Two law enforcement experts, with specific knowledge of elephant ivory identification, manually classified items on sale in the Antiques section of eBay UK over an 8 week period. This set the “Gold Standard” that we aim to emulate using data-mining. We achieved close to 93% accuracy with less data than the experts, as we relied entirely on metadata, but did not employ item descriptions or associated images, thus proving the potential and generality of our approach. The reported accuracy may be improved with the addition of text mining techniques for the analysis of the item description, and by applying image classification for the detection of Schreger lines, indicative of elephant ivory. However, any solution relying on images or text description could not be employed on other wildlife illegal markets where pictures can be missing or misleading and text absent (e.g., Instagram). In our setting, we gave human experts all available information while only using minimal information for our analysis. Despite this, we succeeded at achieving a very high accuracy. This work is an important first step in speeding up the laborious, tedious and expensive task of expert discovery of illegal trade over the internet. It will also allow for faster reporting to law enforcement and better accountability. We hope this will also contribute to reducing poaching, by making this illegal trade harder and riskier for those involved
Nutritional zinc deficiency, immune capacity and malaria : a study on mediators of immunity to malaria caused by Plasmodium falciparum in African children
No full textThis thesis aimed at investigating the role of genetic and nutritional factors that affect the immune response to malaria in Tanzanian children. The introductory chapter (Chapter 1) reviews the importance of nutritional deficiencies, particularly of zinc, and presents the hypothesis that such deficiencies lead to impaired immunity and contribute to the burden of malaria. The chapter also describes current efforts to prevent malaria through intermittent preventive treatment, both in infants (IPTi) and pregnant women (IPTp). Sulfadoxinepyrimethamine is still used for first-line treatment of uncomplicated malaria, or, in many countries, to prevent malaria and anaemia in pregnancy. In malaria endemic areas, development of resistance to previously valuable antimalarial drugs has been continuously reported for decades. Thus our initial longitudinal study aimed at measuring the prevalence of resistance-associated mutations on dihydrofolate reductase (DHFR) and dihydropteroate synthase (DHPS) genes (dhfr and dhps) that confer parasite resistance to sulphadoxinepyrimethamine (SP) that was used as an interim antimalarial drug after chloroquine resistance. Although SP resistance-associated point mutations were highly prevalent, we observed an adequate parasite response to SP (Chapter 2). We speculated that the impact of the dhfr and dhps mutations on SP resistance may be dependent at least in part on the protective immunity that has developed in response to frequent exposure to infection and may be weighed down by host immunity in endemic areas and thus impacts in the continued use of the drug for treatment of malaria. The impact of other drugs with similar mechanisms of action used as antibiotics in selecting mutations responsible for SP resistance needs therefore to be studied for their modulating activity of the immune response. These findings underscore the relevance to further study the crucial involvement of the immune system in the development of protection against malaria but also affecting the efficacy of treatment modalities of malaria in various African conditions. In the subsequent cross-sectional studies, we assessed the effect of deficiencies of zinc and magnesium as well as iron deficiency anaemia on malaria-specific cytokine responses indicative of innate immunity to Plasmodium falciparum (Chapter 3). In this study, we used Plasmodium falciparum-parasitised red blood cells (pRBCs) as antigens for in vitro stimulation of peripheral blood mononuclear cells (PBMCs). Cytokines were measured in the supernatant of cultured PBMCs after 24 hours of stimulation. Zinc deficiency was associated with a marked increase in monocyte-derived TNF-α concentration in children with malarial infection but not in their uninfected peers. In children with malarial infection, iron deficiency anaemia was associated with elevated concentrations of TNF-α, whereas magnesium deficiency in children without malaria seemed to be associated with increased concentrations of IL-10. Our findings reflected plasticity in cytokine profiles of monocytes reacting to malaria infection under conditions of different nutrient deficiencies. Following the observation of the variable impact of micronutrients on innate cytokines, we evaluated the profile of both type I and type II cytokines and whether they were influenced by nutritional and malaria status (Chapter 4). The cytokine measurements were performed at day 7 of stimulation anticipating that this timing was optimal for measuring effects on these cytokines mainly derived from activated T-cells. The results indicated a variable influence of nutrient deficiencies on increased cytokine response with zinc deficiency and iron deficiency anemia having greater impact on type I and magnesium deficiency on type II cytokines. The subsequent study evaluated the plasma levels of naturally acquired antimalarial antibodies of variousIgG subclasses plus the total IgG and IgM levels and whether they were associated with zinc deficiency based on preceding chapters (Chapter 5). The results indicated a high variability in antibody levels with zinc deficiency, varying with age of the affected child. IgG3 appeared to be predominant across all age subgroups within These studies demonstrate that despite antimalarial drug resistance, there is a potential for optimizing the immunological protective capacity in the population to confer parasite clearance that can be variably influenced by micronutrient status. Improving nutritional status in this population could be rewarding not only to increase protection to malaria but possibly also to other infections. <br/
Trends in chloroquine resistance marker, Pfcrt-K76T mutation ten years after chloroquine withdrawal in Tanzania.
No full textBACKGROUND: Plasmodium falciparum resistance to anti-malarial drugs remains a major obstacle to the control of malaria. In 2001 Tanzania replaced chloroquine (CQ) with sulphadoxine-pyrimethamine (SP) as first-line drug, which in turn was replaced by artemisinin combination therapy in 2006. SP has however, continued to be used in intermittent preventive treatment of malaria in pregnancy (IPTp) despite reports of high levels of resistance to SP due to the lack of alternatives to SP for IPTp. Recent reports have indicated recovery of CQ-susceptibility in Malawi, Kenya, Mozambique, and Tanzania based on the prevalence of wild types at codon 76 of the Pfcrt gene in indigenous P. falciparum populations. The current prevalence of this Pfcrt-76 CQ resistance marker from six regions of Tanzania mainland is hereby reported. METHODS: DNA extracted from filter-paper dried blood spots and rapid diagnostics kit strips collected from finger-prick blood were used to genotype the Pfcrt-76 resistance marker using PCR-RFLP. Data from previously published studies were used to generate CQ susceptibility recovery trends using logistic regression model. RESULTS: Seven hundred and forty one (741) samples were genotyped. The current frequency of the CQ-susceptible Pfcrt-K76 was above 92% and did not differ between regions in Tanzania (χ(2) = 2.37; p = 0.795). The K76 allelic prevalence was between 85.7 and 93% in regions (χ(2) = 7.88, p = 0.163). The CQ resistance recovery trends showed regional variability that may be caused by differences in malaria transmission intensity, but overall the trends converge as the susceptibility levels in all regions approach >90%. CONCLUSIONS: CQ withdrawal in Tanzania has resulted into >90% recovery of susceptibility in ten years of withdrawal. These findings are in support of the search for CQ-based combination drugs as a possible future alternative to SP for IPTp in places where full recovery of CQ-susceptibility will be evident
