Cholera

Concerned that malaria may become untreatable and the vector, mosquito, uncontrollable, scientists have alerted on the dramatic increase in resistance of mosquitoes to five mainstream insecticides.

In a step toward better control of mosquitoes that transmit malaria, researchers have mapped the patterns of insecticide resistance in Anopheles gambiae mosquitoes across Africa. The new study, published June 25, 2020 in the open-access journal PLOS Biology by Catherine Moyes and Penelope Hancock of the University of Oxford, United Kingdom (U.K.), and collaborators, found that resistance to five mainstream insecticides increased dramatically between 2005 and 2017.

There are more than 400,000 deaths due to malaria worldwide each year, with more than half of all cases occurring in just six countries in Sub-Saharan Africa. In recent years, progress in reducing the burden of malaria in these areas has resulted from expanded mosquito control programs. However, field studies have suggested an increase in insecticide resistance among the mosquitoes that transmit malaria. This could lead to a decrease in the effectiveness of interventions such as insecticide-treated bednets, which are a mainstay of malaria prevention across the continent.

In the new study, researchers analyzed a published database of information on mosquitoes collected throughout mainland Sub-Saharan Africa between 2005 and 2017. The study looked at 6,423 observations across 1466 different locations. They used the data to map and model when and where insecticide resistance had arisen in populations of Anopheles gambiae mosquitoes.

According to the study, in West Africa, resistance to pyrethroids, the only class of insecticides used in all treated bednets, increased drastically over the timeframe. For instance, 15 per cent of West Africa had mosquitoes with resistance to deltamethrin in 2005, but by 2017 this had risen to 98 per cent. In East Africa, resistance to pyrethroids increased to a lesser degree, expanding from nine per cent to 45 per cent of the region. Similar increases were seen among populations of mosquitoes resistant to DDT, a chemical often used for indoor spraying to kill malaria-transmitting mosquitoes.

Dichlorodiphenyltrichloroethane, commonly known as DDT, is a colorless, tasteless, and almost odorless crystalline chemical compound, an organochlorine. Originally developed as an insecticide, it became infamous for its environmental impacts.

The authors said: “The rapid spread of resistance across large parts of the Sub-Saharan Africa signals an urgent need to quantify the efficacy of different resistance management strategies, and to understand the impact of resistance on malaria transmission and control.

“Relationships between insecticide resistance and malaria prevalence are currently poorly understood, but there is evidence that resistance can reduce the efficacy of standard pyrethroid-treated bednets which have played a key role in achieving reductions in malaria prevalence in Africa over 2000-2015.”

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No fewer than 701 fresh cases of cholera epidemic were recorded at various Internally Displaced persons ( IDPs) camps in Maiduguri and other local government areas of Borno State between Friday last week to Monday .

Over 4 victims also died within the said period with Muna Garage IDPs camps where the first case of cholera was traced to, recording 1425 cases while Dikwa IDPs camp recorded 600 cases with Monguno IDPs camps recording 607 cases as the remaining 96 cases were recorded in other IDPs camps in Borno between 16th August this year when the first outbreak was reported .

This was disclosed yesterday by the Borno State Commissioner of Health, Dr. Haruna Mshelia during the flag off of the cholera vaccination campaign organised by the Borno state government, in collaboration with the World Health Organization (WHO) which was held at the Muna-garage IDPs camp in Maiduguri, the Borno state capital.

Dr Mshelia,who in his earlier briefing last week Friday , on Cholera situation, put the total cases of Cholera recorded in Borno at 1,925 with 44 deaths noted that the cases jumped up to 2,728 with 48 deaths by Monday this week.

Since the outbreak of Cholera in some of the IDPs camps, the ministry of health, World Health Organization and other partners have been working round the clock to ensure that the epidemic which was caused by poor sanitary facilities at IDPs camps are eradicated.

So far over 1,600 latrines have been evacuated and fumigated while 4 treatment centres were created with 2 in Maiduguri metropolis, one in Dikwa while the remaining one is situated in Mongunu.

Adequate vaccines have been acquired for the vaccination of all persons living in the affected camps and areas which include; MMC, Here , Mongunu , Konduga, Ngala, Kalabarge, Kukawa and Gwoza,” the Commissioner of Health said.

He added that the cholera vaccines acquired are brand new and the first of its kind in the country.