Widespread misuse of antibiotics giving WHO a headache

Antibiotics misuse and misunderstanding fuel resistance globally, the World Health Organisation has warned.

Over-use and misuse of the drugs increase the development of resistant bacteria, and WHO points out some of the practices, gaps in understanding and misconceptions that contribute to this headache.

“The rise of antibiotic resistance is a global health crisis, and governments now recognise it as one of the greatest challenges for public health today. It is reaching dangerously high levels in all parts of the world,” says Dr Margaret Chan, WHO director-general.

Antibiotic resistance is compromising ability to treat infectious diseases and undermining many aances in medicine.

The findings point to the urgent need to improve understanding around antibiotic resistance. The WHO warning comes at a time another study has shown that overuse of antibiotics in animal feeds is making it harder for doctors to treat life-threatening infections in young children.

The report by paediatricians says the widespread practice of giving antibiotics to healthy livestock to promote growth and prevent disease in animals is making the drugs ineffective when they are needed to treat people.

African countries have also been asked to change how tests for malaria drug resistance are conducted.

To determine whether malaria parasites have developed resistance toward drugs intended to destroy them, researchers usually monitor the rate at which the parasites are declining in the blood of the sick.

Based on current WHO recommendations, presence of parasites in more than 10 per cent of malaria patients — three days after completing treatment — indicates a likelihood of drug resistance which researchers need to investigate.

The 10 per cent threshold was informed by data from Asian populations, which, according to the researchers, does not, therefore, reflect realities on the African continent.

Compared to the Asians, they note that Africans have a higher immunity towards malaria, hence when they become sick and receive treatment, they are likely to clear parasites much faster and recover more quickly.

Therefore, by the time Africa attains the 10 per cent limit, the resistance problem may already be bigger on the continent than in Asia.

One for all

“A one-size-fits-all approach does not take into account the differences in populations from different regions,” said Grant Dorsey, infectious disease researcher at the University of California who participated in the study.

The researchers, therefore, recommended that the benchmark for assessing drug resistance in Africa be decreased from the current 10 per cent to five per cent.

The researchers argued that this reduction will enable malaria experts to identify areas at high risk of drug resistance at an early stage so that appropriate measures to address it are taken.

“Quickly identifying areas where malaria treatments are becoming less effective is critical if we are to optimally respond to the emergence of anti-malarial resistance,” added Umberto d’Alessandro, director at the Gambia Medical Research Unit who was also involved in the study, published in BMC Medicine journal.

Dr Ambrose Talisuna, head of Malaria Case Management and Drug Evaluation Unit at the Kemri-Wellcome Trust stated that Africans tend to have a higher immunity against malaria due to high transmission rates in the region.

After repeated attacks, those infected usually develop some immunity against malaria to help the body ward off the dire consequences of the disease.
These people can still get malaria, experts said.

But when they do symptoms will be less severe as the body will be prepared to fight the disease, borrowing from the memory of previous infections.

Half-a-million people

Drug resistance occurs when a particular medicine loses its ability to kill disease-causing germs that it was intended to destroy.

When this happens, patients will religiously take recommended drugs for certain ailments but thy will still be unwell. And the organisms causing the disease will continue to multiply in their bodies.

Malaria is one of the world’s most devastating killers, claiming lives of close to half a million people globally — mainly young children and pregnant mothers.

The impact is felt more in Sub-Saharan Africa, which is home to 89 per cent of malaria cases and 91 per cent deaths.

To avert these deaths, the WHO has recommended the use of artemisinin-based combination therapy (ACT), which drug effectively treats the disease and cuts transmission.

But resistance to this drug has begun in Asia, with cases reported in Cambodia and Thailand.

Studies conducted in both countries showed that patients were taking longer to recover even after receiving the recommended treatment — an indication that malaria parasites are beginning to develop resistance to ACT there.

This could seriously threaten global malaria control and elimination programmes.

Because resistance to previous malaria drugs — such as chloroquine and fansidar — also began in Asia before spreading to Africa, malaria experts are concerned that without appropriate measures, history could repeat itself.

Monumental gains

“If the resistance were to emerge in Africa, as we’ve seen in the past, it could place millions of lives at risk of treatment failure and threaten the monumental gains we’ve made against malaria over the past decade,” said Dr Talisuna.

Drug development processes usually take years. Thus, researchers caution that if resistance to ACT is not forestalled, the world could wait for long before new malaria treatments are released. In the meantime, those with the diseases will continue to die helplessly.

Resistance to drugs often develops in different phases.

During the initial stage, the recommended drug is still able to kill the malaria parasites but it takes longer than expected.

In the second stage, parasites die but reappear two to three weeks after treatment. The third stage is the worst.

Parasites remain alive even after patients take malaria drugs.

Major driver

Continuous monitoring of patients and assessing the effect of ACT to malaria parasites in their body is thus usually recommended in all malaria endemic nations — including Kenya — to enable researchers detect emerging drug resistance early and prevent it from escalating to catastrophic levels.

A major driver of resistance is misuse of medicines.

This occurs when patients fail to complete recommended malaria drug doses, or when they take the medicine before test are done to confirm malaria infection.

People that are infected with drug-resistant malaria can easily transmit the diseases to thousands more, especially in areas where malaria interventions like bed net use and indoor residual sprays are low.

SOURCE: BUSINESS DAILY