Is a COVID-19 spike on the way for Africa-??- The possible role of the environment

A few weeks ago, I was interviewed about COVID-19 in West Africa with a focus on the upcoming rainy season.

https://voicesfromthefrontlines.com/2020/05/27/voices-radio-this-week-we-are-joined-by-gregory-jenkins-professor-of-meteorology-atmospheric-science-geography-and-african-studies-at-penn-state-about-climate-change-and-covid-19-in-africa-then/

COVID-19 has ravaged most of the world, with the largest number of cases in the United States. South America and Brazil in particular has become the Epicenter of COVID-19 and  India is now becoming a new epicenter and at #4 for the total number of cases behind the US, Brazil, and  Russia.
In the United States, the black community has suffered the burden of COVID-19 mortality, and confounding issues related to hypertension, obesity, diabetes and cardiovascular disease have played a role in mortality.

What is the role of the environment in the increase of COVID-19 and COVID-19 mortality?  Over the past two months, a number of articles and presentations have examined the roles of seasonality and air pollution on COVID-19 in China, Europe, and the United States.  Those results have pointed to pollution as a potential factor in COVID-19 mortality.  Particulate matter and NO2 which is a pollutant often found in urban areas where automobile traffic this short-lived pollutant.  However, particulate matter, especially PM2.5 has also been linked to COVID-19 deaths. a study under review shows that an increase of 1 microgram/meter cubed of particulate matter leads to an eight percent increase in COVID-19 mortality.  Furthermore, earlier studies show the highest mortality in African Americans over 65 due to air pollution; African Americans also live near sites where the burden of pollution is much higher than for whites.  Some of this is definitely tied to historical and environmental racism in the United States.

https://www.nationalacademies.org/event/05-28-2020/basc-session-on-air-quality-climate-variability-and-covid-19

SubSaharan Africa has experienced the smallest number of cases relative to the rest of the globe.   But is this about the change???? 

There are several reasons to be worried:

1.  The hospital infrastructure in much of Africa is much weaker than the US;
2.  Coastal West and Southern Africans share the same DNA pool as the African Americans and Afro-Brazilians with likely similar risk factors leading to COVID-19 mortality;
3.  Many of the noncommunicable diseases such as diabetes, stroke and cardiovascular disease have emerged to outpace to infectious disease in some cases;
4.  Biomass burning and dust pollutes many thousands of square kilometers and exposes tens of millions of people of short periods of time (days);
5.  Megacities in Africa have exploded with too many cars and pollution levels are likely to be high;
6. The wet season, which is similar to the winter season in the United States is likely to lead to influenza which may increases susceptibility to serious health outcomes from COVID-19;
7. Vector-borne and water-borne diseases will arrive with the wet season with has begun in countries like Nigeria and will begin starting in July further north in Sahelian countries;
8.  Many governments have allowed businesses, schools and universities to open;
9.  There is no vaccine.


I am going to focus on what we know about the changes in COVID cases and the Environment (my zone).

How Seasons in Africa Work

Rainfall patterns in Africa (mm/month for winter, spring, summer and Autumn )

The rainfall in Africa (25N-25S)  tends to follow the overhead Sun  leading to the following pattern if you are in West Africa and North of the Equator:
Wet Seasons (May-October), Dry Season-fire (November-April) in West Africa 

If your location is in Nigeria, Ghana, Togo, Benin, you are likely to get rain in March which moves north with a short drier period in August followed by a second wet period.    If you live further north in Senegal, Mali, Niger you get one rainy starting in July and ending in late September.  The entire region will become dry by December in general.  During the dry season, there is the Harmattan with dust from the Sahara desert and lots of fires linked biomass burning.



If you lived south of the Equator in Southern Africa
Wet Seasons (November-April) Dry Season-fire  (May-October), in Southern Africa

If your life in the Republic of Congo, Angola, and Zambia the rainy period begins in November through April.  The rainfall patterns in the Southern Hemisphere are varied and as one goes further eastward the pattern becomes more complex. Beginning in May we see large scale fires in Southern Africa linked to biomass burning.


Examples of current COVID Cases in South Africa,  West and Southern Africa

South Africa (approximately 60000 cases)

In the next 10 days, the winter season will begin in South Africa.  The autumn season has seen a steady rise in COVID cases and the situation is likely to get worse as people are more likely to spend more time indoors because of colder temperatures and rainy conditions especially in Cape Town.   While you can recover from COVID, other confounding factors from the flu and poor air quality are likely to increase the risk of dying.    The number of reported daily positive cases in South Africa have increased from 698 cases on May 12 to 3359 cases on June 12.  The number of recorded deaths increased from 12 on May 11 and 70 as of June 12.


The Democratic Republic of Congo (DRC) -(4600) and Angola (160)

The DRC and Angola are near each other but have very different COVID-19 reported loading.   Angola took early pre-emptive action to limit COVID-19 by closing borders and limiting international flights.

https://www.namibian.com.na/199267/archive-read/Angola-closes-borders-for-15-days


This may have helped reduce the numbers of its COVID-19 cases to a current value of 130 positive cases.  However, according to Worldometer, they have only conducted about 10000 tests.

The neighboring DRC on the other hand has an estimated 4700 cases with more than 100 new cases reported per day over the last month.  Both the DRC and Angola are in  the dry season with many active fires

June 12 Satellite estimated Fire in Southern Africa

Because of the fires, we expect that poor air quality is occurring and will continue over the next 3 months.  This is a red flag for those with respiratory or cardiovascular disease to be very careful and to keep face covered if poor air quality is detected.



West Africa 
Similar to Southern Africa, COVID-19 cases have risen since April.  We examine Ghana, Nigeria and Senegal, which have all opened their economies and governments to some degree.  Senegal never really completely shut down but had a night curfew.    Nigeria, Ghana and Senegal all have megacities that are growing and could possibly become epicenters like many cities in the United States.  Nigeria is West Africa's most populated nation with nearly 200 million inhabitants.  Senegal and Ghana are considerably smaller.

Nigeria (approximately 15000 cases).  
Has seen a steady increase in the numbers of COVID cases with more than 15,000 total cases and a steady increase in daily positive cases.

Ghana (approximately 11000 cases) -has more than 11 thousand cases with an earlier peak in early May and a steady number of cases since June.

Senegal (approximately 5000 cases) - has approximately 5,000 positive cases since March with a steady increase of more than 100 cases since early June.


Potential Environmental Impacts for West Africa 

The wet season began along the Gulf of Guinea countries such as  Nigeria and Ghana in mid-to-late March.  Last night there was rain in Senegal --which is a little early. 

With the wet season comes a set of vector-borne and water-borne diseases along with influenza.   In fact, the wet season tends to be the coolest (not very cold) but rain can limit activity and keep more people in the house.   Possible diseases once the rain began to fall (now through October)

- malaria
- yellow fever and Dengue
- influenza
-acute respiratory infection

Influenza and acute respiratory infection (pneumonia)  like mid-latitude countries occur during the coolest and wettest part of the year in West Africa.  A paper lead my colleague Dr. Toure from Senegal shows that the largest numbers of reported cases for adults and children during wet season under normal conditions during 2015-2016.

Influenza, acute respiratory infection, and vector/water-borne diseases could pose a serious threat to patients that come down with COVID-19.

The rainy season and the associated diseases could:

- Increase  transmission because of indoor activity with the wet season;
- Increased susceptibility by weakening immune systems if one is fighting off another disease;
- Produce a much higher burden on hospitals as they cope with COVID-19 patients;
- Make it difficult for people with influenza or acute respiratory disease to distinguish it from COVID-19.

After one or two months of dry weather, West Africa countries will have to deal with the burden of dust and biomass burning and Southern Africa will have to contend with the wet season.  Because the cases of COVID-19 were relatively small during the last dry season in West Africa and wet season in Southern Africa any prediction of what may be expected is highly uncertain.



Key things to remember for the African Continent over the next year:

1.  The virus is in full effect around the World;
2.  Mask, social distancing and hand washing should be followed no matter what the case;
3.  The capacity of the public health care system must be monitored very carefully as the increase in cases in locations such as India, Brazil and now South Africa shows that the number of cases can increase quickly;
4.  The situation will remain dangerous until a vaccine is available (2021-2022).


COVID-19 and the Caribbean and SE US

Poor air quality from the Saharan Air Layer (SAL) has already been detected in Senegal and Cabo Verde (see figure).  Over the next 2 months, millions of tons of dust will be transported across the Atlantic degrading air quality.  This will make people with respiratory, cerebrovascular, and cardiovascular diseases more susceptible to poor outcomes from COVID-19.  In addition, the Caribbean will have to prepare for rain associated with easterly waves and potentially tropical cyclones. 

Dust leaving the African Coast on June 12, 2020

The number of hurricanes is projected to be higher than normal, but let us hope that their impact is limited and not capable of becoming major storms like Hurricane Dorian.

https://cimss.ssec.wisc.edu/satellite-blog/wp-content/uploads/2019/09/190901_190902_goes16_infrared_Dorian_anim.gif

4th large Bodele outbreak since Saturday -- impact on human health likely but unknown. Monitoring/communication required!!

Tuesday noon dust identification over North Africa.  

This morning, the 4th large dust outbreak erupted from Chad this morning and has entered eastern Niger, Chad and soon Nigeria and Cameroon.   As mentioned earlier, the anomalous flow across the desert has triggered these dust events.  Nearly all of Nigeria, Benin, Togo, Ghana and Ivory Coast have been impacted.   Millions have been under unhealthy to hazardous air quality from high concentrations of PM2.5.   In the next two days, the dust will move westward and emerge off the coast of West Africa.  In the process, many more people from Mali to Cabo Verde may experience very poor air quality and airports will be subject to poor visibiity.

Identification of dust outbreaks on Sat (Red), Sunday (Green) and Monday (Purple)

Communicating these large and long-exposure hazards is required, especially that many countries having low public health capacity, a growing population and limited access to income.  It has been estimated that there are 780,000 premature deaths due to pollution and desert dust is the primary contributor.  Recently we published a paper (https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019GH000214)  showing that desert dust is very high in Senegal and respiratory disease is also very high.   My good friend Karin recently published a paper showing how lung cells are destroyed in dusty environments (https://www.sciencedirect.com/science/article/pii/S0013935119306887?via%3Dihub)

and it may be the reason why lung-cancer is relatively high in Senegal, even for non-smokers.  

Communication requires real-time access to data for the public.  Currently, the amount of surface data available for any decisionmaker including an asthmatic person is not sufficient in Africa.   If you go to http://aqicn.org/map/world/ you would only see one station with real-time data in West Africa which is Bamako.  My colleagues in Senegal put out a daily bulletin about air quality conditions each day for the Dakar region.  But there are far too many places that receive no information.  

Over the past year, there are some in the community that using low-cost sensors (200-300 USD) to try and provide real-time data.  While these instruments cannot be compared to 100,000 USD state of the art equipment, they provide a measure of air quality and are used all around the globe.   The purple air sensors are a great example of this (https://www.purpleair.com/map). 

Since, June we are trying to build a network in West Africa (Senegal, Cape Verde, Angola...) but simple things such as continuous wifi and electricity make it a challenge.  We are working on solutions for those.  When there are dust events such as the current one, there is a need to know locally what happening.  But really it is hospitals, decisionmakers and the public that really need the information locally.    So the most populous nation in West Africa, Nigeria does not have enough local monitoring of PM to protect its population during the dry season.  

Purple Air Network, Tuesday, February 11, 2020

If this is 2020 and we really want to have clear vision, we need to use innovation to help solve the current set of environmental problems.  But communication and protecting the public against predictable hazards such as dust outbreaks is within reach.  We just need to commit to the right action.

Large dust outbreak threatens the respiratory health of more than 100 million over next 10 days

Over the next few days, large quantities of millions of pounds of dust from the Sahara desert will enter into Nigeria, Benin, Ghana, Togo and Cote d-Ivorie.   It will pose a serious health hazard to more than 100 million in this region, especially those with existing respiratory disease, the young and elderly.   While this may seem like the typical garden variety type of dust event it is not.  Why????

1.  Duration.  This event is expected to last at least 5 days followed by another dust event.

2.  Intensity.  Dust levels will reach hazardous levels

3.  Scale.  The dust will cover thousands of miles and impact large cities such as Lagos (18 million), Ibadan, Cotonou, Accra and Kumasi.  Additional dust sites will be activated and impact Niamey and eventually Ouagadougou, Bamako and Dakar.

4. Health Impacts.  Based on what we have seen this year, the dust particles are PM2.5 which is about 25 times smaller than a human hair.  These particles reach deep into the lung system causing problems for those who have COPD, Asthma or other respiratory problems.

5. Prior Exposure.  Most Guinea locations in Nigeria, Ghana, Togo, Benin and Cote d'Ivoire have experienced many hours of bad air quality since December.  The negative health effects are likely
evident even if not well reported.

What is at the root of this event and the earlier ones. 

Positive Phase of the North Atlantic Oscillation (NAO) - which yields a strong Azores high that migrates into North Africa.  This year, the NAO has been locked in a positive phase leading to dust transport across most of West Africa.

Depiction of Azores high moving over North Africa and transporting dust 

The positive NAO has also been responsible for very warm temperatures across Europe this winter.

washingtonpost.com/weather/2020/02/03/warmth-is-really-unheard-much-eastern-europe-including-helsinki-moscow-saw-warmest-january-record/


Over the next 14 days, the area of high pressure is expected remain strong as depicted in the GFS model for 72 hours.   This pattern will send dust from Chad into Nigeria.

GFS Sunday morning (Feb 9) forecast of sea level pressure and Anomaly. Red represents higher than normal pressure

This pattern is forecasted to persist over North Africa as shown by the ECMWF model for next Wednesday, Feb 12

ECMWF Wednesday (Feb 11, 2020) Afternoon forecast of sea level pressure and anomalies.

What this means, is that dust will continue to flow strongly from Chad into the Guinea coast and westward toward Niger, Mali and Senegal.  I have run the WRF regional model with dust and the forecast from Wednesday depicts lots 

of dust moving first into Nigeria tomorrow but eventually making its way across much of West Africa.  The model underpredicts the amounts of dust coming into locations like Accra, Lagos and Abidjan and these values will be much higher than shown.

Caption:  WRF depiction of PM10 dust concentration on Sat Feb 8 and Tuesday, Feb 11 2020.

Those colors in orange or red represent hazard dust levels and as a short term hazard represent a certain level of mortality (> 12 %).  By reference, the World Health Organization (WHO) recommends no more than 50 microgram per meter cubed in a 24 hour period.  It is likely that people will see 4-10 times this amount and for the smallest particles of PM2.5 will see greater 50 micrograms per meter cubed;  WHO recommends no more than 25 50 microgram per meter cubed in a 24 hour period.   Because the exposure may be significant it is recommended that 

1. Limit outdoor activity 

2. Close windows 

3.  Monitor the young, elderly and those with existing respiratory conditions

4.  WEAR a mask if you have one.

5.  Go to the hospital if you are feeling acute symptoms such as shortness of breath or chest pains.

Poor Air Quality across West Africa-- negative health outcomes expected.

Caption:  Satellite images of dust loading (Red) across West Africa afternoon Jan 3, 2020

Each winter, the Harmattan winds begin to blow from the Sahara Desert.  It carries dry air but also dust into large populations of West Africa.   We link dust concentrations to particulate matter and focus on PM2.5 which penetrates deep into the lungs.  The consequences are serious if you are asthmatic, have COPD and can cause strokes and heart attacks.   When the values of PM begin to increase, studies have shown that there will be an increase in mortality associated with listed diseases above (see chart).

PM concentrations and Air Quality along with mortality risk

Since January 1, high Particulate Matter ( dust concentrations) have occurred across West Africa. Senegal and Cabo Verde have seen the heaviest reported values in the north.   Some of the airports in Cabo Verde closed because of low visibility.  However, in the south, Ghana, Ivory Coast, Nigeria, Togo, Benin, have experiences high PM values since Christmas.  I am 100% sure that there have been morbidity and mortality in these locations in the past.

What is different now is that we are using cost-effective sensors to get a look at what is happening across West Africa in real-time.  This allows us to link the environment to health outcomes.   We have been developing a network (measurements) in Senegal, Gambia, Cabo Verde, Ivory Coast while others have been developing low-cost networks in Ghana, and Togo.  Together we get a sense of the air quality from good to hazardous, where the real-time colors correspond to air quality on the maps.
https://www.purpleair.com/map?opt=1/mAQI/a10/cC0#4.15/12.99/-22.89

US EPA Air Quality Standards for PM2.5 and PM10

Purple Air estimates of Air Quality for the morning of 3 January 2020

Causes of Dust Storms in West Africa. 
What is driving force behind the current set of dust events?  There are large sources of dust over Northern Africa.  Two of the biggest dust sources are Bodele (the largest in the World) located in Chad, and the Adrar region of Southern Algeria and northeast Mali.   The Azores high-pressure system which exists over the subtropical ocean and is part of the North Atlantic Oscillation (NAO).
During the winter, the Azores high moves into North Africa across the Sahara and while high pressure normally means sunny weather, over North Africa it also brings strong winds over the desert which then starts the sandblasting process.

Depiction of how the Azores high to drive a dust storm

What is happening now, is that high pressure is currently in place for all of North Africa.  The figure from GFS forecast strong high pressure in play.

GFS sea level pressure and anomalies across Africa 0000 UTC

This means winds will flow across Chad and drive westward flowing winds that send dust from East to West.   The dust will flow into Nigeria and lead to poor air quality over the next few days to week.

January 4, 2020 Visible and AOD position of dust.  Circled in red are Adrar and Bodele dust regions

What to do when there is poor air quality?
So what are the proper actions to take if you suspect or see that the air quality is poor (unhealthy to hazardous)?

1.)  If air quality is poor, limit your time outdoors and your physical activity.

2.)  Wear a mask if you have one until conditions get better.  This may not seem cute, but you are not sick!! You are trying not to get sick. 

3.) Pay attention to the elderly, and young children. 

4.)  If breathing problem begin or you feel chest pain go to the Emergency Room to be checked
by a doctor.


Other Sources of Poor Air Quality 

On the continent, there are multiple sources of pollution that can make air quality poor.  In rural areas, seasonal biomass burning which is tied to agricultural practices can create very poor quality. Large megacities are now becoming problematic because of traffic, waste, and industry.   The waste that is being generated is burned in large waste sites or locally leading poor air quality.  Traffic has become worse with no end in sight.  Many of the cars use low-quality diesel fuel with high sulfur content making pollution horrible in places like Dakar, Senegal.  The so-called modernization of Africa is leading to pollution-causing industries, like cement and coal-burning power plants. 

Sources of pollution including Traffic, Industrial pollution and burning of trash

Finally, there is indoor pollution from cooking.  We know this is bad for family members who use biomass or charcoal, especially in poorly ventilated buildings. 

We need to predict, communicate and protect individuals from air pollution for success.  Ultimately, government policy is required to address pollution issues.  Everyone who has a friend or family member has something to gain from improving air quality.

Tropical Storm expected to impact Cabo Verde tomorrow rain begin tonight.. Residents of Cabo Verde should Take necessary Precautions tonight!

Over the next 24 hours expect potentially hazardous conditions over the country of Cabo Verde along with the possibility of heavy rain in Senegal tonight and rough seas along coastal Senegal and the Gambia.  As of 5 PM the National Hurricane Center has upgraded the disturbance to TD #15.   This may be a tropical storm tomorrow bringing winds and possible flooding.

Caption:  Tropical disturbance off the coast of Senegal at 1700 UTC

BULLETIN
Tropical Depression Fifteen Advisory Number   1
NWS National Hurricane Center Miami FL       AL152019
500 PM AST Mon Oct 14 2019

...NEW TROPICAL DEPRESSION FORMS SOUTHEAST OF THE CABO VERDE
ISLANDS...
...HEAVY RAINS EXPECTED ACROSS EASTERN CABO VERDE ISLANDS TONIGHT...


SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...13.2N 20.2W
ABOUT 320 MI...515 KM SE OF THE CABO VERDE ISLANDS
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...NW OR 310 DEGREES AT 8 MPH...13 KM/H
MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES


WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.

However, interests in the Cabo Verde Islands should closely monitor
the progress of the depression since a Tropical Storm Warning may be
required for portions of the islands later tonight or early Tuesday.

The model uncertainty is unclear about the exact track but intensification is possible as waters are above normal along the track.

I hope that the government will issue a Tropical Storm Watch shortly for Tomorrow.  

Vulnerable Areas and threats 

Coastlines

Caption: Airplane approach to the Capital City of Praia

The shape of many coastlines across the islands of  Cabo Verde has open parabolic shapes which can

produce coastal flooding.  The tropical disturbance does not need to cross a particular island but a fetch (water pushed by the winds for many hours) can occur from persistently strong winds producing coastal flooding.    

Flash Flooding

People should not go out tomorrow for work as the roads could be dangerous and flooded.  Please check the TV or Radio if you have to go out

Cape Verde has very steep terrain and many houses that are elevated on hills and so flash flooding could be problematic.   Santiago, Sao Nicolau, Santo Antao, Fogo, and Sao Vicente have some steep terrain with mountains exceeding 3000 feet that falls off rapidly.  

Even in the Capital city of Praia, the houses sit on pretty steep hills which promote fast runoff and potential flash flooding.  Take care near these areas.

Houses in Praia that are elevated on hills 

Preparation Items 

-Make sure that you have flashlight, candles and charge cell phones in the event of loss of power

- Fill your car with gas in the event of power loss

- Take Cash from Bank

- Check-in with family members on other Islands 

Hopefully, things will not be too bad, but better safe than sorry.

Senegal 

Strong storms continue to impact Senegal tonight.  The ocean will remain rough and some coastal flooding is possible with a southerly fetch.  

Coastal disturbance expected to bring rain and unsettled seas from Guinea to Mauritania Tomorrow through Tuesday

Sunday Midnight IR image of disturbance with convection over Guinea

A potent African Easterly Wave is expected to emerge over the Eastern Atlantic on late Sunday night through early Monday morning.  Potential heavy rain is expected from Guinea north through Senegal beginning tomorrow night.  While the disturbance has the potential to develop into a tropical depression, the steering currents at 15000 feet are expected to steer the storm north along a path between Senegal and Cape Verde from Monday through Wednesday.      Given the path of the storm, it may pose a threat to coastal fishermen and shipping through Wednesday.   The eastern Islands of Cabo Verde could be impacted but it is too early to also tell.   The rain threat in Senegal should begin tomorrow afternoon and continue through Monday.    Lets hope that this is the last rain event in Senegal this year but this storm is worth watching. 

Is the October the new July in West Africa? -- Rainy season continues in Senegal with significant damage in Dakar (Oct. 2-3)

Caption:  CHRS iRain estimated rainfall over the past 72 hours (October 9) in West Africa

In a typical year, the rainy season in the Sahel (north of 10 N) begins in June and runs through September.  Then the rain will shut off for the next 8 months and crystal blue skies unless there are dust storms or biomass burning (another story)  However, this year has been very different, especially in the Western Sahel... Senegal in particular.   June and most of July were very dry causing major concerns for farmers, however, August and September turned very wet.  Sometime about September 20th it appeared the dry season was making its entrance, but then around October 1st rain began falling again.  The rain has not stopped and it has rain as far north at Mauritania (very unusual).    For example, satellite estimates show that heavy rain has fallen over both Senegal and Mauritania in just the last 72 hours and for the past 3 days in parts of Senegal and the past 24 hours in Mauritania.

Caption: CHRS Satellite estimated Rainfall in Senegal 

Caption: Satellite estimated rainfall in Mauritania (Oct 6-9, 201)

On the night of October 2 through October 3, 2019 a very strong Mesoscale Convective system moved through Senegal and caused a significant amount of damage in Dakar, the capital.   We might expect this in July or August but not in October.   The damage was documented on Facebook by La Meteo Dakaroise de Riad and is pretty incredible. 

https://www.facebook.com/meteodakaroise/videos/530636927765427/


There are real implications for vector-borne disease (especially Malaria) of being wetter in Senegal and warmer than normal across most of Africa during this wet season.  September was the warmest month on record..

https://www.washingtonpost.com/weather/2019/10/04/earth-just-experienced-its-hottest-september-heads-record-books/

Hopefully, the rain will break soon, but the models are suggesting several strong easterly waves over the next 10 days which could bring more rain.  Stay tuned.