Women attending antenatal care as a sentinel surveillance population for malaria in Geita region, Tanzania: feasibility and acceptability to women and providers

Prevalence of non-falciparum malaria infections among asymptomatic individuals in four regions of Mainland Tanzania

BACKGROUND

Recent studies point to the need to incorporate the detection of non-falciparum species into malaria surveillance activities in sub-Saharan Africa, where 95% of the world's malaria cases occur. Although malaria caused by infection with Plasmodium falciparum is typically more severe than malaria caused by the non-falciparum Plasmodium species P. malariae, P. ovale spp. and P. vivax, the latter may be more challenging to diagnose, treat, control and ultimately eliminate. The prevalence of non-falciparum species throughout sub-Saharan Africa is poorly defined. Tanzania has geographical heterogeneity in transmission levels but an overall high malaria burden.

METHODS

To estimate the prevalence of malaria species in Mainland Tanzania, we randomly selected 1428 samples from 6005 asymptomatic isolates collected in previous cross-sectional community surveys across four regions and analyzed these by quantitative PCR to detect and identify the Plasmodium species.

RESULTS

Plasmodium falciparum was the most prevalent species in all samples, with P. malariae and P. ovale spp. detected at a lower prevalence (< 5%) in all four regions; P. vivax was not detected in any sample.

CONCLUSIONS

The results of this study indicate that malaria elimination efforts in Tanzania will need to account for and enhance surveillance of these non-falciparum species.

Genomic malaria surveillance of antenatal care users detects reduced transmission following elimination interventions in Mozambique

Routine sampling of pregnant women at first antenatal care (ANC) visits could make Plasmodium falciparum genomic surveillance more cost-efficient and convenient in sub-Saharan Africa. We compare the genetic structure of parasite populations sampled from 289 first ANC users and 93 children from the community in Mozambique between 2015 and 2019. Samples are amplicon sequenced targeting 165 microhaplotypes and 15 drug resistance genes. Metrics of genetic diversity and relatedness, as well as the prevalence of drug resistance markers, are consistent between the two populations. In an area targeted for elimination, intra-host genetic diversity declines in both populations (p = 0.002-0.007), while for the ANC population, population genetic diversity is also lower (p = 0.0004), and genetic relatedness between infections is higher (p = 0.002) than control areas, indicating a recent reduction in the parasite population size. These results highlight the added value of genomic surveillance at ANC clinics to inform about changes in transmission beyond epidemiological data.

Accessibility of malaria commodities in Geita District Council, mainland Tanzania: the experiences from healthcare providers and clients

Background

Access to essential malaria commodities is a cornerstone in malaria control. However optimal availability and access to essential malaria commodities remain a challenge in Tanzania. Therefore, this study aimed to explore the factors affecting the accessibility of malaria commodities in Tanzania.

Methods

This was a mixed-method cross-sectional study using both quantitative and qualitative approaches. Data were collected between February and March 2023 from health facilities, health facility staff, and patients.

Results

Availability of malaria commodities in government health facilities was 100% for all items while in the private and faith-based facilities, this ranged from 10% to 80%. The reasons for stockouts in Government facilities were related to delayed and inadequate quantity delivery while in private facilities the main reason was the lack of cash for procurement. Both private facilities' clients and healthcare providers concurred that most people do not access complete treatment due to the high costs of prescribed medicines and poor stocking levels.

Conclusion

The availability, hence the accessibility, of malaria commodities in private and faith-based health facilities is still sub-optimal. Logistic management needs to be improved to eliminate stockouts and malaria commodities high costs need a permanent solution.

Genomic malaria surveillance of antenatal care users detects reduced transmission following elimination interventions in Mozambique

Routine sampling of pregnant women at first antenatal care (ANC) visits could make Plasmodium falciparum genomic surveillance more cost-efficient and convenient in sub-Saharan Africa. We compared the genetic structure of parasite populations sampled from 289 first ANC attendees and 93 children from the community in Mozambique between 2015 and 2019. Samples were amplicon sequenced targeting 165 microhaplotypes and 15 drug resistance genes. Metrics of genetic diversity and relatedness, as well as the prevalence of drug resistance markers, were consistent between the two populations. In an area targeted for elimination, intra-host genetic diversity declined in both populations (p=0.002-0.007), while for the ANC population, population genetic diversity was also lower (p=0.0004), and genetic relatedness between infections were higher (p=0.002) than control areas, indicating a recent reduction in the parasite population size. These results highlight the added value of genomic surveillance at ANC clinics to inform about changes in transmission beyond epidemiological data.