Enhanced health facility surveys to support malaria control and elimination across different transmission settings in The Philippines

Abstract

<jats:p>Following substantial progress in malaria control in the Philippines, new surveillance approaches are needed to identify and target residual malaria transmission. This study evaluated an enhanced surveillance approach using rolling cross-sectional surveys of all health facility attendees augmented with molecular diagnostics and geolocation. Facility surveys were carried out in 3 sites representing different transmission intensities: Morong, Bataan (pre-elimination), Abra de Ilog, Occidental Mindoro (stable-medium risk) and Rizal, Palawan (high risk, control). Only 1 RDT positive infection and no PCR confirmed infections were found in Bataan and Occidental Mindoro suggesting the absence of transmission. In Rizal, inclusion of all health facility attendees, regardless of symptoms, and use of molecular diagnostics identified an additional 313 infected individuals in addition to 300 cases identified by routine screening of febrile patients with RDT or microscopy. Of these, the majority (313/613) were subpatent infections and only detected using molecular methods. Simultaneous collection of GPS coordinates on tablet-based applications allowed real-time mapping of malaria infections. Risk factor analysis showed higher risks in children and indigenous groups, with bednet use having a protective effect. Subpatent infections were more common in men and older age groups. Overall, malaria risks were not associated with patient status and some of non-patient clinic attendees reported febrile illnesses (1.9%, 26/1369) despite not seeking treatment highlighting the widespread distribution of infection in communities. Together, these data illustrate the utility of health-facility based surveys to augment surveillance data to increase the probability of detecting infections in the wider community.</jats:p>

Analytical approaches for antimalarial antibody responses to confirm historical and recent malaria transmission: an example from the Philippines

“…A total of 9132 samples from a health facility-based survey conducted from 2016 to 2018 (Reyes et al, 2021) were available for serological evaluation, with the majority (>70%) from Rizal, Palawan, where the monthly sampling spanned 2 years, while collection in the other sites Morong, Bataan and Abra de Ilog, Occidental Mindoro spanned 1 year. Females comprised more than 60% of the total number of participants, with higher proportions in Bataan and Occidental Mindoro, though individuals from all ages and gender groups were represented (Table 3).…”

The seasonal dynamics and biting behavior of potential Anopheles vectors of Plasmodium knowlesi in Palawan, Philippines

“…flavirostris lies outside the sampling period investigated. However this is unlikely as rainfall and malaria transmission are strongly seasonal in Palawan, with the peak period of rains and malaria transmission (June–August/September) falling within the sampling period [ 42 ]. Notably, the peaks in An.…”

Ataxia with vitamin E deficiency in the Philippines : A case report of two siblings

“…Interestingly, TTPA knockout mice are resistant to cerebral malaria, which could explain the comparatively high prevalence of TTPA pathogenic variants in areas around the Mediterranean Sea (12,24). In the Philippines, 6,604 cases of malaria were reported in 2016 (25). Given that TTPA mutations help protect against malaria, AVED might be more prevalent and underestimated in the Philippines.…”