Tropical Health Matters

Several reports and studies aim to help understand the malaria parasite and the human behavior surrounding its control. Cultural perceptions in Benin influence treatment seeking. Tracking cases in India aid in elimination efforts. The contrasts between in vivo and in vitro studies are examined. The factors associated with anemia among children and women in Ghana are traced to malaria and other factors. Finally both human and mosquito immunity are discussed. Click the links in each section to read details.

Demonstration of indigenous malaria elimination through Track-Test-Treat-Track (T4) strategy in a Malaria Elimination Demonstration Project in Mandla, Madhya Pradesh

Using the current intervention and prevention tools along with optimum utilization of human resources,This project has revealed about 91% reduction of indigenous cases of malaria during the period from June 2017 to May 2020, through case management and vector control strategies. A total 357,143 febrile cases were screened, out of which 0.19% were found positive.

The reduction was similar in the three high prevalence blocks of the district. These results reveal that malaria elimination is achievable in India within a stipulated time frame. The reduction of malaria at the community level was further validated when zero malaria cases were diagnosed during hospital and community-based studies in Mandla. Prompt detection and treatment of imported/migratory cases may have prevented outbreaks in the district. This project has demonstrated that field programmes backed by adequate technical, management, operational, and financial controls with robust monitoring are needed for achieving malaria elimination.needed for achieving malaria elimination.

Risk factors for anaemia among Ghanaian women and children vary by population group and climate zone

Anaemia has serious effects on human health and has multifactorial aetiologies. This study aimed to determine putative risk factors for anaemia in children 6-59 months and 15- to 49-year-old non-pregnant women living in Ghana. Data from a nationally representative cross-sectional survey were analysed for associations between anaemia and various anaemia risk factors. National and stratum-specific multivariable regressions were constructed separately for children and women to calculate the adjusted prevalence ratio (aPR) for anaemia of variables found to be statistically significantly associated with anaemia in bivariate analysis. Nationally, the aPR for anaemia was greater in children with iron deficiency (ID; aPR 2.20; 95% confidence interval [CI]: 1.88, 2.59), malaria parasitaemia (aPR 1.96; 95% CI: 1.65, 2.32), inflammation (aPR 1.26; 95% CI: 1.08, 1.46), vitamin A deficiency (VAD; aPR 1.38; 95% CI: 1.19, 1.60) and stunting (aPR 1.26; 95% CI: 1.09, 1.46).

In women, ID (aPR 4.33; 95% CI: 3.42, 5.49), VAD (aPR 1.61; 95% CI: 1.24, 2.09) and inflammation (aPR 1.59; 95% CI: 1.20, 2.11) were associated with anaemia, whereas overweight and obese women had lower prevalence of anaemia (aPR 0.74; 95% CI: 0.56, 0.97). ID was associated with child anaemia in the Northern and Middle belts, but not in the Southern Belt; conversely, inflammation was associated with anaemia in both children and women in the Southern and Middle belts, but not in the Northern Belt. Anaemia control programmes should be region specific and aim at the prevention of ID, malaria and other drivers of inflammation as they are the main predictors of anaemia in Ghanaian children and women.

From Circulation to Cultivation: Plasmodium In Vivo versus In Vitro

Research on Plasmodium parasites has driven breakthroughs in reducing malaria morbidity and mortality. Standard in vitro culture environments differ dramatically from in vivo conditions in nutrient levels, hematocrit, and rheology and have lower variability in gas levels and temperature.

Nutritional and physical differences lead to pronounced, and often rapid, changes in phenomenon, important for understanding virulence in Plasmodium. Parasite drug sensitivity may be altered due to culture adaptation selection, supraphysiological metabolite concentrations, and in vitro media formulations. Parasites propagated in vitro, versus in vivo, show altered transcriptomic and genomic patterns related to virulence factors, metabolism, gametocytogenesis, and more.

Direct-from-host methodologies avoid the impacts of in vitro culture adaptation but limit the types of assessments that can be performed as many experiments either require equipment not readily available in endemic settings or necessitate long-term manipulation….

Between traditional remedies and pharmaceutical drugs: prevention and treatment of “Palu” in households in Benin, West Africa

In Benin, malaria clinical cases, including the larger popular entity called “Palu” are evoked when people get fever. “Palu” is often self-diagnosed and self-medicated at home. This study aimed to describe the use of herbal medicine, and/or pharmaceutical medicines for prevention and treatment of malaria at home and the factors associated with this usage.

Methods. A cross-sectional survey was conducted in Benin in an urban and in a rural area in 2016. Around 600 households in each place were selected by using a random sampling of houses GPS coordinates of the families. The association between socio demographic characteristics and the use of herbal medicine was tested by using logistic regression models.

Results. In Cotonou (urban), 43.64% of households reported using herbal or pharmaceutical medicine to prevent “Palu”, while they were 53.1% in Lobogo (rural). To treat “Palu” in Cotonou, 5.34% of households reported using herbal medicine exclusively, 33.70% pharmaceutical medicine exclusively and 60.96% reported using both. In Lobogo, 4% reported using herbal medicine exclusively, 6.78% pharmaceutical medicine exclusively and 89.22% reported using both. In Cotonou, the factors “age of respondent”, “participation to a traditional form of savings” and “low socioeconomic level of the household” were associated with the use of herbal medicine.

Conclusions. This study shows the strong use of herbal medicine to prevent “Palu” or even treat it, and in this case it is mostly associated with the use of pharmaceutical medicine. It also highlights the fact that malaria control and care seeking behaviour with herbal medicine remain closely linked to household low-income status but also to cultural behaviour. The interest of this study is mostly educational, with regards to community practices concerning “Palu”, and to the design of adapted behaviour change communication strategies. Finally, there is a need to take into account the traditional habits of populations in malaria control and define a rational and risk-free use of herbal medicine as WHO-recommended.

Malaria parasite fools body with protein to dodge immune system

By SHIGEKO SEGAWA: OSAKA- The parasite responsible for malaria generates a look-alike of a human protein to suppress the workings of the immune system, leaving humans “defenseless” against infection, according to Japanese and British researchers.
A team comprised mainly of researchers from Osaka University and the University of Oxford said they hope the finding will help lead to new therapies for the mosquito-borne tropical disease.

As plasmodium is resistant to the immune system, the body’s self-defense system, humans can become infected repeatedly. Three years ago, the researchers realized that when plasmodium infects human red blood cells, it generates proteins called RIFINs, which send out signals for suppressing immunity. During the latest study, the researchers analyzed the structure of RIFIN in detail and found it closely resembles part of the structure of a specific human protein, which is involved in the mechanism for preventing the immune system from staging an attack on the body by mistake.

That protein combines with a molecule that suppresses the workings of the immune system. The scientists found the RIFIN that closely imitates the human protein in shape also combines with the same molecule and dodges attacks of the immune system. “We hope our findings will help develop vaccines and therapeutic drugs for malaria,” said Hisashi Arase, a professor of immunology with Osaka University, who is part of the research team. The research results were published in Nature, the British scientific journal.

Why Do Insect Vectors Not Get Ill from the Microbes They Transmit?

Some Evidence from Malaria-carrying Mosquitos by Kevin Noonan. The conservation of diverse and molecularly well-defined hemocyte types between distantly related mosquito genera and the apparent absence of megacytes in our Ae. aegypti mosquito dataset raise questions as to how the immune systems of these mosquito species have evolved to limit their capacity to transmit parasites and arboviruses to humans. This knowledge will ultimately underpin immunological strategies aimed at interrupting disease transmission by rendering mosquitoes resistant to such pathogens.

The conservation of diverse and molecularly well-defined hemocyte types between distantly related mosquito genera and the apparent absence of megacytes in our Ae. aegypti mosquito dataset raise questions as to how the immune systems of these mosquito species have evolved to limit their capacity to transmit parasites and arboviruses to humans. This knowledge will ultimately underpin immunological strategies aimed at interrupting disease transmission by rendering mosquitoes resistant to such pathogens.

Violet Okech, Georgina Kirunda, Remy S M Muhire and Paschal Ssebbowa posted this blog at SBFPHC Policy Advocacy. We have added more information on malaria and traditional medicine in Uganda.

It is estimated that over 60% of Ugandans seek medical attention from Traditional Healers. This pattern cuts across all social classes and educational levels.  With a medical doctor: patient ratio of 1:20,000 compared to traditional healer: patient ratio of 1:200-400, high poverty levels and a poor health system, the traditional healers’ services are the most accessible to the majority of Ugandans. With such statistics, it is inconceivable that the country has no national policy to regulate the activities of the traditional healers.  It is possible that their services may be causing more harm than good to their clients.

[Photo: Traditional Medicine man selling herbs courtesy of disabledtravelersguide.com]
The World Health Organization encourages sharing of information about Traditional Medicine/ Alternative medicine policy formulation because they acknowledge the complexity of the process.  The traditional healers in Uganda have mobilized themselves under The National Council of Traditional Healers and Herbalists Associations of Uganda (NACOTHA). They seek to unite and to push for their field of Traditional Medicine to be given greater consideration by the government.  It is reported that the Ministry of Health in Uganda drafted a Policy so as to regulate and improve research in Traditional Medicine in 2008. This policy has not been finalized to date.

There is need to formulate a policy to track, regulate traditional medicine in Uganda and  conduct intensive research in traditional medicines so as to ensure proper determination and monitoring of drug safety. There is also need for preservation of the medicinal plants against extinction. Relevant medical training should also be offered to traditional healers.

A look into the literature on herbal medicine for malaria in Uganda found a 1999 report on a trial in the southwest on one indigenous herb. “No severe adverse reactions were observed, although about 50 per cent experienced minor side-effects. Although complete parasite clearance was achieved in only one case, the geometric mean of parasite counts had declined significantly by day 7. There was also a marked symptomatic improvement in 17 of the 19 patients.”

Another study in eastern Uganda documented that, “Twenty-seven species distributed between 24 genera  and 16 families were reportedly used in herbal preparations for the treatment of malaria. The most frequently mentioned species were Vernonia amygdalina Delile, Momordica foetida Schumach., Zanthoxylum chalybeum Engl., Lantana camara L. and Mangifera indica L.” As Okech and colleagues note, much more research is needed on the efficacy and safety of this valuable herbal resource.

Azusa Sato raises an important question in a research article on health service choices by Ghanaians – why do individuals turn to traditional medicine only as a second recourse?

In general, Sato’s review of literature on health care choices cite the maxim that indigenous medicine is easily accessible, affordable, available and acceptable. The irony in this study is that indigenous medicine is a more popular second choice than first.  Sato shows that “The most common acute complaint was ‘fever, headache and hot body’ (334/460, or 72.6%),” which people may interpret as possible malaria in a local context.  Interestingly, only 45 respondents used indigenous medicines first whether they sought acute care from outside or found/made it at home.

When a second or additional recourse was added, the number using indigenous medicine rose to 103 people for acute illnesses. Respondents who chose indigenous medicine at some point overwhelmingly had a favorable opinion (77%) of this form of medicine.

Ghana has a dynamic health system that is attempting to bring more people into the orthodox care orbit.  The national health insurance scheme to which over 60-70% of people subscribe, make care seeking at orthodox health facility (either public or private) more attractive and affordable.  Ghana is also working on expanding primary health care through establishing community health compounds – a local building donated by the community and staffed by government trained community health officers. Although these measures are a ways from attaining universality, they may in part explain a tendency to choosing orthodox care first.

Another interesting irony of Ghana’s pharmacy system is the the health authorities have actually approved some indigenous malaria medicines (see picture). These are sold alongside Coartem and artesunate-amodiquine in licensed shops and pharmacies.

Pharmacy stocks and consumer care seeking choices support Sato’s recommendations for seeking more evidence to develop an integrated system of care in Ghana.  With global health funding in seeming decline, any effort to find additional efficacious local resources to expand malaria treatment are most welcome.