Category: Science

My Journey to Rio De Janeiro: Exploring the Clinical Side of TB Care and Prevention

As a preclinical researcher working in a lab environment, my day-to-day work focuses on developing new treatments, diagnostics, and vaccines for tuberculosis (TB). However, I recently had the opportunity to participate in a site visit during the 7th Global Forum on TB Vaccines in Rio De Janeiro, which gave me a glimpse into the clinical side of public health relating to TB.

I believe it’s essential for preclinical researchers like myself to be exposed to the clinical side of TB care and prevention. After all, we are developing new tools that will eventually be used in the “real world”. It’s crucial for us to understand the requirements of the healthcare system and local communities, as well as engage with them about potential new vaccines and delivery systems.

The site visit took me to three different locations: a Family Health Centre, a Surveillance Centre, and a Vaccination Centre. Each location provided valuable insights into the clinical side of TB care and prevention in Rio De Janeiro.

Family Health Centre

Catchment areas for the Family Health Centre
Health information for patients
View of a favela from the Family Health Centre
Preparation of first-line TB drugs for patients

The first site I visited was the Clínica da Família Estácio de Sá in Rio De Janeiro. What struck me was the clinic’s impressive 90% treatment success rate, significantly higher than the national average of around 70%. The main reason for this success is the clinic’s ability to track patients and ensure they complete their treatment. Patients are registered at the front desk according to their community, and health agents from the same community deliver TB drugs on weekdays.

The clinic uses a range of diagnostic tools, including X-ray, TST, sputum smear, and culture. I was impressed by the clinic’s infrastructure and the health agents’ deep understanding of the local community’s needs. The fact that multidrug-resistant TB (MDR-TB) is relatively uncommon in Brazil may be due to the national health system’s control over first-line TB drugs. You can’t buy TB drugs over the counter in Brazil, so everyone, even if they’re millionaires, collect their TB medication from the clinic.

Surveillance Centre

The control centre is highly integrated and allows for monitoring of traffic, energy and other utilities within Rio de Janeiro

The second site I visited was at the Centro De Operaçoes Rio Prefeitura, a centralised monitoring system for outbreaks and disease surveillance. The centre’s implementation is designed to minimise additional friction on busy healthcare workers, allowing them to focus on patient care. The data is grouped by municipality, and healthcare centres and government agencies can access it.

I was impressed by the centre’s ability to predict outbreaks up to four weeks in advance, using data on temperature, humidity, and other factors. The centre also monitors traffic, temperature, and power distribution, providing a comprehensive view of the city’s public health situation.

Vaccination Centre

Zé Gotinha
Cooler box used to transport vaccines to community members who are unable to travel to the clinic
“I took a vaccine and I was brave!”

The final site I visited was a Vaccination Centre in CMS Rocha Maia, Rio De Janeiro. This centre serves the local community, offering vaccinations from 8am to 10pm, allowing people to visit after work or school. The centre has an outreach program that delivers vaccines directly to those who cannot attend the centre.

I was heartened by the low levels of vaccine hesitancy in the area and the enthusiasm for vaccination among people living in favelas. The centre’s use of a SUS mascot, Zé Gotinha, a character modelled after the “drop” of polio vaccine, has become a beloved symbol of vaccination in Brazil. Who says vaccines can’t be fun?

My site visit to Rio De Janeiro was an eye-opening experience that highlighted the importance of understanding the clinical side of TB care and prevention. As preclinical researchers, we must engage with local communities and healthcare systems to ensure our work is relevant and effective. I left Rio De Janeiro inspired by the dedication of healthcare workers and the commitment of local communities to public health.

Role of Plants in the Nitrogen Cycle (in the Home Aquaria)

Possibly the most persistent myth in the aquarium hobby is the belief that the primary role of aquatic plants in the nitrogen cycle is to uptake nitrates. This has been repeated many times in older aquarium literature, but frustratingly many recently published sources (including books) incorrectly describe the role of plants in the nitrogen cycle. Understanding the “correct” nitrogen cycle in an aquarium has important implications to planning and maintaining a planted aquarium.

Nitrification

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Nitrification Simplified

It is widely accepted that nitrification (converting harmful ammonia into nitrites and then nitrates) is carried out by nitrosomonas and nitrobacter, aerobic bacteria which are present in the soil and water attached to surfaces. The chemical process from converting ammonia into nitrites and then to nitrates releases energy, which the bacteria use for their metabolism.

The Role of Aquatic Plants in the Nitrogen Cycle

Aquatic plants require nitrogen to synthesise proteins, and can only use nitrogen in the form of ammonia. Indeed, plants can uptake nitrates, although they must convert nitrates into ammonia before they can use the nitrogen, a process which requires significant energy (the same amount of energy nitrifying bacteria have gained from the opposite reaction).

Experiments have shown that when given both ammonia and nitrates, aquatic plants will only uptake nitrates when ammonia has been depleted. When aquatic plants are given a choice between ammonia and nitrates, most aquatic plants vastly prefer the uptake of ammonia over nitrates even if this means “competing” with nitrifying bacteria.

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Bacteria gain energy from nitrification, while plants must spend energy to obtain ammonia

Implications for the Home Aquarium

The uptake of ammonia by aquatic plants has practical implications for the aquarist. Most importantly, it de-emphasises the importance of a “biological” filter in aquaria with healthy fast growing plants. Although essential in aquariums without plants or with very little plant growth, many would argue that the biological filter is an unreliable way of dealing with ammonia in an aquarium. Nitrifying bacteria require plenty of flow and oxygen, can be sensitive to changes in water chemistry and their growth is very slow (division ~18 hours), during which time ammonia “spikes” can occur if there are any rapid changes to stocking or feeding levels. Nitrification also causes nitrate levels to increase and pH to fall, two reasons why frequent water changes are necessary in aquariums relying on the biological filter for ammonia control.

Using fast growing (especially emergent) plant growth in an aquarium is a considerably better way of controlling ammonia than a biological filter. Most aquatic plants prefer the uptake of ammonia directly compared to nitrates, and by competing with nitrifying bacteria, can prevent the buildup of nitrates in the aquarium. Competition with nitrifying bacteria for ammonia, rather than the direct uptake of nitrates may be the reason why aquariums with plants have lower nitrate levels than those relying on the biological filter. Acidification of aquarium water due to nitrification can also be prevented by using plants for ammonia control, as they compete with nitrifying bacteria for ammonia and consume H+ ions in photosynthesis.

As Diana Walstad said in her book, Ecology of the Planted Aquarium, “let the plants do the work for you!”.

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Letting the plants do the work for me in my no-maintenance planted Walstad Bowl