High Effective Coverage of Vector Control Interventions in Children After Achieving Low Malaria Transmission in Zanzibar, Tanzania.

\ud \ud Formerly a high malaria transmission area, Zanzibar is now targeting malaria elimination. A major challenge is to avoid resurgence of malaria, the success of which includes maintaining high effective coverage of vector control interventions such as bed nets and indoor residual spraying (IRS). In this study, caretakers' continued use of preventive measures for their children is evaluated, following a sharp reduction in malaria transmission. A cross-sectional community-based survey was conducted in June 2009 in North A and Micheweni districts in Zanzibar. Households were randomly selected using two-stage cluster sampling. Interviews were conducted with 560 caretakers of under-five-year old children, who were asked about perceptions on the malaria situation, vector control, household assets, and intention for continued use of vector control as malaria burden further decreases. Effective coverage of vector control interventions for under-five children remains high, although most caretakers (65%; 363/560) did not perceive malaria as presently being a major health issue. Seventy percent (447/643) of the under-five children slept under a long-lasting insecticidal net (LLIN) and 94% (607/643) were living in houses targeted with IRS. In total, 98% (628/643) of the children were covered by at least one of the vector control interventions. Seasonal bed-net use for children was reported by 25% (125/508) of caretakers of children who used bed nets. A high proportion of caretakers (95%; 500/524) stated that they intended to continue using preventive measures for their under-five children as malaria burden further reduces. Malaria risk perceptions and different perceptions of vector control were not found to be significantly associated with LLIN effective coverage While the majority of caretakers felt that malaria had been reduced in Zanzibar, effective coverage of vector control interventions remained high. Caretakers appreciated the interventions and recognized the value of sustaining their use. Thus, sustaining high effective coverage of vector control interventions, which is crucial for reaching malaria elimination in Zanzibar, can be achieved by maintaining effective delivery of these interventions

From high to low malaria transmission in Zanzibar-challenges and opportunities to achieve elimination.

BACKGROUND: Substantial global progress in the control of malaria in recent years has led to increased commitment to its potential elimination. Whether this is possible in high transmission areas of sub-Saharan Africa remains unclear. Zanzibar represents a unique case study of such attempt, where modern tools and strategies for malaria treatment and vector control have been deployed since 2003. METHODS: We have studied temporal trends of comprehensive malariometric indices in two districts with over 100,000 inhabitants each. The analyses included triangulation of data from annual community-based cross-sectional surveys, health management information systems, vital registry and entomological sentinel surveys. RESULTS: The interventions, with sustained high-community uptake, were temporally associated with a major malaria decline, most pronounced between 2004 and 2007 and followed by a sustained state of low transmission. In 2015, the Plasmodium falciparum community prevalence of 0.43% (95% CI 0.23-0.73) by microscopy or rapid diagnostic test represented 96% reduction compared with that in 2003. The P. falciparum and P. malariae prevalence by PCR was 1.8% (95% CI 1.3-2.3), and the annual P. falciparum incidence was estimated to 8 infections including 2.8 clinical episodes per 1000 inhabitants. The total parasite load decreased over 1000-fold (99.9%) between 2003 and 2015. The incidence of symptomatic malaria at health facilities decreased by 94% with a trend towards relatively higher incidence in age groups > 5 years, a more pronounced seasonality and with reported travel history to/from Tanzania mainland as a higher risk factor. All-cause mortality among children < 5 years decreased by 72% between 2002 and 2007 mainly following the introduction of artemisinin-based combination therapies whereas the main reduction in malaria incidence followed upon the vector control interventions from 2006. Human biting rates decreased by 98% with a major shift towards outdoor biting by Anopheles arabiensis. CONCLUSIONS: Zanzibar provides new evidence of the feasibility of reaching uniquely significant and sustainable malaria reduction (pre-elimination) in a previously high endemic region in sub-Saharan Africa. The data highlight constraints of optimistic prognostic modelling studies. New challenges, mainly with outdoor transmission, a large asymptomatic parasite reservoir and imported infections, require novel tools and reoriented strategies to prevent a rebound effect and achieve elimination

Aiming at malaria elimination in Zanzibar [Elektronisk resurs]

Following the increase of the international funding for implementation of the combined malaria control strategies in the past decade, a significant reduction of malaria attributed morbidity and mortality has been achieved. Yet, malaria is still a severe threat to global health. In 2013, more than 200 million malaria cases causing the death of over 600 000 people were reported. Zanzibar was among the first to implement artemisinin-based combination therapy (ACT) for malaria treatment, strengthened vector control measures including long lasting insecticide treated nets (LLINs) and indoor residual spraying (IRS) as well as rapid diagnostic test (RDT) for malaria diagnosis at peripheral health care facilities. We assessed the effectiveness of malaria control tools and interventions for achieving malaria elimination in Zanzibar by studying the temporal trends of different malariometric indices in two districts of Zanzibar (Micheweni and North A) with a population of approximately 100,000 people each, between 1999 and 2013. Moreover, we conducted a health facility based study in the same districts for evaluation of RDT for malaria diagnosis including its performance within the integrated management of childhood illness (IMCI) algorithm as well as its field applicability as a source of parasite DNA for DNA extraction for molecular surveillance. The interventions, with high sustained community uptake, were associated with major decline in malaria transmission most pronounced from 2004 to 2007, after which there appears to be a steady state. The cross-sectional survey in 2013 revealed a 97.0% reduction of Plasmodium falciparum prevalence when compared to 2003. Health facility data showed 96.0 % reduction of parasitologically confirmed malaria infections. All cause mortality among children under five decreased by 70%. Moreover, the general perception of reduced malaria burden by the caretakers was not associated with reduced adherence to the vector control measures. RDT sensitivity against PCR and blood smear microscopy was relatively low (76.5% and 78.6%, respectively). Adherence to the RDT results was excellent (99.9%) and RDT performed well in the IMCI algorithm with equally high adherence among children under five as compared with other age groups. Further, RDT showed to be a good and reliable source of parasite DNA, useful for malaria case detection, molecular surveillance and RDT quality control. During the conduct of the studies in this thesis, malaria elimination was not achieved in Zanzibar. However, following implementation of effective and sustainable tools and interventions with high coverage and uptake, Zanzibar has reached a state of malaria preelimination. Additional tools and interventions are necessary for further reduction of malaria transmission towards malaria elimination

Effect of antiretroviral treatment and counselling on disclosure of HIV-serostatus in Johannesburg, South Africa

This prospective non-randomized study of clinic attendees, compares self-reported HIV disclosure patterns in relation to access to antiretroviral access and counselling. It was carried out in public sector hospital HIV clinics in Johannesburg, South Africa, and 144 HIV-positive men and women attending the HIV clinics participated in the study.The results showed that there was no correlation between being on antiretroviral therapy and disclosure of HIV status. There was also no correlation between disclosure of HIV status and with different levels of counselling and access to support groups. Disclosure levels were high (92% told at least one person), however, there was a high level of delayed (15% greater than a year) or non-disclosure (21%) to partners. Family members and partners provided most moral support after disclosure. Having access to antiretroviral therapy and support groups and available counselling did not seem to affect disclosure patterns. It is possible that a patients beliefs about their treatment plays a more important role for disclosure than the actual treatment itself. Other factors are also likely important for disclosure, such as the patient's social network especially with their families, and knowledge of the disease

Rapid Clearance and Frequent Reinfection With Enteric Pathogens Among Children With Acute Diarrhea in Zanzibar

Background. Acute infectious gastroenteritis is an important cause of illness and death among children in low-income countries. In addition to rotavirus vaccination, actions to improve nutrition status, sanitation, and water quality are important to reduce enteric infections, which are frequent also among asymptomatic children. The aim of this study was to investigate if the high prevalence of these infections reflects that they often are not cleared properly by the immune response or rather is due to frequent pathogen exposure. Methods. Rectal swabs were collected at time of acute diarrhea and 14 days later from 127 children, aged 2-59 months and living in rural Zanzibar, and were analyzed by real-time polymerase chain reaction targeting multiple pathogens. Results. At baseline, detection rates >20% were found for each of enterotoxigenic Escherichia coli, Shigella, Campylobacter, Cryptosporidium, norovirus GII, and adenovirus. At follow-up, a large proportion of the infections had become cleared (34-100%), or the pathogen load reduced, and this was observed also for agents that were presumably unrelated to diarrhea. Still, the detection frequencies at follow- up were for most agents as high as at baseline, because new infections had been acquired. Neither clearance nor reinfection was associated with moderate malnutrition, which was present in 21% of the children. Conclusions. Children residing in poor socioeconomic conditions, as in Zanzibar, are heavily exposed to enteric pathogens, but capable of rapidly clearing causative and coinfecting pathogens