A Tale of 3 Families: Dengue in Cuba & Mexico

Time for action?
2.5 billion people – two fifths of the world’s population – are now at risk from Dengue every year.
WHO Dengue Fact Sheet

Dengue infections in Merida and the Yucatan beach areas are 4X higher so far in 2010 – present at a rate that may result in over 120,000 new Dengue Virus infections in Yucatan in 2010. Potentially Dengue Hemorrhagic Fever rates are now more than 50% of confirmed Dengue cases in Yucatan, and across Mexico.
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A Tale of Three Families
The Amon’s, the Harrison’s, and the Solis’s  (A Fracture Fairy Tale…)
Picture a slave ship, 300 years ago, crossing the Atlantic to deliver a load of slaves to Cuba, plus a family of Egyptian mosquitoes (Aedes Aegypti = A.ae.), a family named Amon.    The Amon’s lived well in Cuba:    great homes,   plenty of dark places to hide,   lots of small flower pots holding rain-water in people’s jardins for laying eggs,    plus plenty of small pools of standing water in drains and yard-waste & brush piles.   The warm wet climate allowed them to raise a new generation of Amon’s every week.    Imagine it:   hundreds of eggs laid weekly by the female Amon’s,  hatching into hundreds of larvae,    all growing safely in pools too small for the evil predatory fish.   In just a week, a new generation of adult Amon females would leave the tiny pools, hungry for human blood.
Cuba’s great:    lots of humans,   no screens to keep the Amon’s out of human homes,    plus fruit and plants for the male Amon’s to feed from.    Even the females would suck an occasional sugary liquid meal from plants, when no humans were around, but human blood is so tasty.   Unfortunately, the blood meals come at high price.

Humans had learned to kill most kinds of mosquitoes when they bite, but the Amon’s (A. ae.) had some advantages:   Fly silently (no zzzzz);    fly rapidly to avoid swats;   land very gently;    and when they pierce human skin, they also inject a little anesthetic with their saliva when they first bite to mask their activity.  This works really well, pumping a little anesthetic laden spittle in and out, along with enzymes to locally disable the human’s wicked clotting system, keeping the blood flowing smoothly.

Life was good.     So good, that some Amon’s even lived to the ripe old age of 6 months, much longer than a normal 30 days of life in the wild for Aedes aegypti (A. ae.) mosquitoes.

Amon Family Picture Album:

Amon Family Tree.
Great-Grandma ‘Bastet”.

Old Colonial Amon Family Portraits =>

Cuba was little paradise for the Amon’s, and the family grew rapidly, expanding from city to city across Cuba.   They did so well, they moved out of Cuba:   immigrating by boat (not like by airplanes today) over to Progresso and Merida, Yucatan.    The Tropics in the Americas were a paradise for the Amon’s, until the Humans brought Dengue Virus (DV) into the New World.    Dengue virus   from Human blood infected the Amon (A. ae.) females,  making them feel sick and a little lethargic.    The Humans at the ports and beach  towns and ultimately Merida   continued to infect many poor Amon females.  The Amon’s never did well in the small pueblos, because there were never enough Humans around to maintain the Dengue transmission cycle.

Every time a Human had a fever from the Dengue Virus (DV),  the Human blood just teemed with such high levels of the virus  that the poor Amon (A. ae.) mosquitoes were at risk of getting Dengue.    More and more Amon females became sick from biting febrile Humans,  and every time an infected Amon tried to get her next blood meal,  there was a chance of her infecting yet another Human with Dengue.   Sometimes an entire Human familys’ blood became tainted with Dengue Virus.

As the Amon’s fed on one sick feverish Human, they would later feed on a different Dengue-free Human family member just 10 or 12 days later, transferring some of the Dengue Virus to the fresh Human.    Soon, none of the Humans in that family were safe to feed-on.    (The Amon’s relatives in Indonesia report that typical Indonesian Human families would have a 97% chance of another member contracting DV from the first infected Human family member, and 95% of A. ae. mosquitoes in febrile Dengue patient households carry Dengue.)    Even the Dengue Virus Family came up with some new tricks, causing the Amon’s more problems.

When the Human immune system came up with new defenses that would protect them from Dengue for 4-5 months, Dengue Virus could mutate (a typically rare event), to create a new Dengue strains of cousins.  Over time, the Dengue Virus mutated to form 4 different strains,   all circulating in Cuba (thanks to Castro),   Yucatan,  and much of the humid tropical regions of the New World.   These strains were eventually identified by genetic testing, and the Humans named them: DV-1, DV2, DV-3, and DV-4.  Human tourists and travelers were key to spreading the new Dengue strains around the world.

These new strains caused even more problems for the poor Amon females…   Every time a Human got one of the four DV strains, the Human’s immune systems only protected them from just that one strain, and the protection lasted for only 4-5 months.  Then, to make it worse, the previously infected Humans would have weaker and weaker immune system defensive reactions with every new Dengue infection,  allowing even more Dengue virus to multiply more rapidly in the previously sick Human.

The problems for the Amon’s were further complicated by the Humans getting sicker and sicker with every successive Dengue infection, so, even healthy humans would get Dengue Hemorrhagic Fever (DHF) symptoms with just their second or third DV infections – bleeding from their  eyes,   gums,     and into their stomachs.    And the Humans have no medicines to fight Dengue Virus,   so,  they can only rest,   drink lots of fluids,   take a pain reliever like Tylenol, and   only use drugs that do not suppress blood clotting – avoiding aspirin and other NSAIDs (Non-Steroidal Anti-Inflammatory Drugs like Advil, Motrin, Aleve, Naproxen, etc.).   Darned Humans…

The Human’s immune systems did fight back some, making antibodies to fight the Dengue Virus.   Later, the Humans in Yucatan built two special laboratories in Merida, to test the Human blood for those antibodies.   Still, many Human’s immune systems would keep most Dengue Virus infected Humans from getting fevers and other symptoms, so, in the past,   only 1 out of 4 DV-infected humans would showed significant symptoms.   As more people have multiple Dengue infections, recent confirmed Dengue virus cases have had over 50% progressing to the potentially fatal DHF.    The symptoms of Dengue Virus included:   no symptoms,    or “Classic Dengue Fever” = very high (risky) fever of 40ºC or 104ºF   and heavy flu-like symptoms   with extreme pains in the joints,   or pain in the eye orbits,   or body rash,   or the sometimes fatal Dengue Hemorrhagic Fever or even Dengue Shock Syndrome.   (A second or third DV infection of any strain greatly increases the Human’s chances of having Dengue Hemorrhagic Fever symptoms, where bleeding occurs from the eyes, nose, gums and other parts of the body.)

Fast forward to two centuries later:     the great-great-great-great-great-(you get the picture)-great granddaughter: Bastet Amon (aka Great-Grandma A.ae. Mosquito) is living in a really nice part of El Centro, in Merida, along with her very large family of children, grand-children, and great-grand-children.

Bastet wakes up hungry early one morning, needing a blood meal, so, she flies through an unscreened window; lurks under a desk for an hour; and bites a dengue-free Human on his ankle:   Jerry Harrison,   a Dengue-free Canadian.     After biting Jerry  3 or 4 different times,   gradually tanking-up on her favorite meal (human blood),   she’s over-loaded & bloated with blood,  barely flying – bumping along the floor – and lumbers back into the dark place under Jerry’s desk to digest her blood meal for several days.

As she digests Jerry’s blood, her belly swells with 100’s of new eggs.    She goes and lays her eggs in a little bit of water that stands in one of Jerry’s floor drains and then goes off to find some plant nectar or plant sap  or to get another Human blood meal.  She doesn’t need any woo-woo now, because she got enough for a lifetime not long after she hatched.  Those boy-mosquitoes were “way-cute”, much more beautiful than the long nosed/big proboscis  female A.ae. mosquitoes.    Just after emerging from the water she found a real hottie: his antennae looked like large dark ostrich plumes,   his palpi (feelers) were long and festooned with feathery hairs,  and he had no long proboscis like the females.   Bastet Amon’ blood meal,   resting,   and egg-laying cycle then starts all over again.  (Hint: break any link of this chain – like killing the resting mosquito or cleaning up standing water,  and Dengue transmission stops.)

Merida is so humid that the sink drain in the spare bathroom containing Bastet’s eggs doesn’t dry out,  and her eggs hatch into larvae and transform to become adults in just 7 days.   Even if the water did dry-up, she’s a careful mom.   She lays her eggs at the water’s edge,  so, when it rains again (or the maid dumps mop-water into the drain) within the next year,  her eggs can quickly re-hydrate  and hatch-out.  She also sometimes slips outside into the jardin to lay her eggs in the little bit of rain-water residues standing in old tires and flower pots with no drain-holes.

If her squiggling ¼ inch larvae avoid little fish and other predators, they morph (turn) into little mosquitoes.    So, in just seven (7) days after laying the eggs, Bastet has a new batch of  flying juvenile mosquitoes,  as long as the Humans don’t flush the drain or treat the drain with ammonia or bleach or insecticide.    Her newly emerging girl-babies fly-off to look for a little woo-woo and then a blood meal.    Her boy-babies head to the garden to look for fruit or leaves to suck sugary solutions, and a maybe if lucky:    a little woo-woo too.

One of Bastet’s new babies, Halima, has a dilemma – after woo-woo of course:    should she fly far away to a new home, (up to 100 meters),  or stay close to the source of the next easy meal?

Jerry’s next door neighbor’s back yard (owned by the Solis family) seems fine.     The Solis family has screens on their doors and windows, so, Halima lurks with her sisters by the door to the Solis house.   When Don Francisco Solis enters the house, Halima quickly flies inside as he walks through the door,  riding close to him,  pulled along in his trailing wake of air – like a Mini Cooper drafting a semi-truck.   Halima also learns that she can also ride on Don Francisco’s son’s  – Daniel’s – wonderful smelling – sweaty clothes, to get into the cool dark Solis house… Daniel works as a mason and concrete worker out in the hot sun, and comes home tired and sweaty, so his sweaty smell makes it easy for Halima to smell him coming.     She also tracks Humans by the CO2 trails from their breath from long distances, as she gets closer, she homes-in on them from body heat,  and finally she uses Human BO to find & ID them as a tasty meal before landing.  (DEET and other “repellants” don’t actually repel mosquitoes, the DEET blocks the female mosquitoes’ ability to smell Humans.)

Halima’s family heritage has prepared her well for a life of feeding on City Human blood…

Little Halima hides in low or dark places en Casa de Solis for a few days,  sometimes under the bed,  or in with the clothes  in the closet – loving the aroma of Human B.O., just waiting for her chance.

Halima, like her mother, is a “morning person”.    She wakes-up early, hungry for a blood meal.    She loves to bite exposed feet and ankles,  but in a pinch, she will take advantage any uncovered skin.    In the modern vernacular, she’s “keepin’ it on the down-low”. Biting in secret,   down low,  injecting her anesthetic spit, “filling her tank” every 10 or 12 days,  and going back into the dark places to sleep it off and digest her meal,  then heading out to a tablespoon or so of water to lay her eggs – like in palm leaf brush piles, bits of crockery, or sink & floor drains.

Halima has a nice life for the next few weeks,  biting, sleeping it off,   laying eggs,  & then avoiding woo-wooing with the pesky nectar-‘n-sap drinkin’ boys … biting humans, and then off to look for new drains, toilets, tinacos, old tires, and flower pots to lay her eggs.   She really doesn’t much like the nasty swamp water or jungle water or cienaga water  that the Malaria and West Nile Virus carrying mosquitoes enjoy (Anopheles and Culex genus mosquitoes),  she instead prefers staying in town – close to the action – and her food supply.    Yes, the jungle has lots animals she could bite, but Humans are just soooo much more tasty – and  besides,  she’s  a  City-Girl!

One day, Halima bites a sick Human,   little Juanita Solis.    Little Juanita (Don Francisco’s grand-daughter) was bitten three weeks earlier by Halima’s Dengue-infected cousins.    It took several bites by the Amon cousins to infect little Juanita Solis.   Twenty (20) days or so passed (or as little as 4?)  before Juanita showed symptoms.    Juanita becomes feverish with Dengue Virus, and horror of all horrors,    Halima catches Dengue virus from that darned little Human Juanita.

Halima had bitten Dengue Virus infected humans before, and never caught Dengue, but this time, her luck ran out…   The dengue virus circulates through Halima’s system,  multiplying,   making her feel a little under the weather until the virus settles in her saliva glands.   She moves back into Jardin to rest.   Ever the good mother, Halima lays her eggs,  but this time  she heads back to Jerry Harrison’s jardin,   to get away from the the Solis house:  source of her Dengue Virus infection.

Halima, now hungry from being sick, slips into Jerry’s house.   Jerry Harrison, a Canadian, and his absent gringo neighbors still haven’t clean-up their back yards, and they have standing rain water in their little plunge pool,  and fountain,  so, it’s prime breeding ground.

Jerry plops down with his morning coffee to check out the latest posts on “Yolisto” and “Mexico Connect”.   Halima slips out of the shadows, lights and bites him on his right ankle. While injecting some of her spittle to keep Jerry’s blood flowing,  some of the Dengue viruses move from Halima into Jerry’s blood stream….    Jerry thinks nothing of it, he’s been bitten hundreds of times during past Mexico vacations and even more often since he and Harriet moved here.

He’s a sharp guy,   he’s lived in Merida for couple of years,  and he never knew anyone with Dengue.    He’s reading yet another long, dreary, boring post by one of those virologist, chemist, or engineer guys – you know ‘em:    they like to cite recent fact and figures, talk like experts,    and quote lots of meaningless statistics about the supposed Dengue epidemic spreading through pockets of Merida… yada, yada, yada…    As long as there’s no headline in the Diario about the risks of Dengue, why worry.

Halima? She goes into an absent US neighbor’s backyard to lay more eggs – green pool water works fine and doesn’t leave her eggs high  and dry – and none of that nasty egg-killing chlorine or larvae-killing copper.    Halima returns later that week to the Harrison’s House and bites Jerry’s wife, Harriet.    (Jerry really could install more screens and close the gaps around his doors and screens and remove or cover/seal/treat the standing water in his house, even the unused sink and floor drains.)     But why worry,   no Dengue Epidemic headlines in the Diario,    no news conferences/press releases by Govt. Officials on Sipse 2 or Trece TV?    And didn’t he just hear a spraying truck go down his street last week?   El Gobierno must have things under control…

Three weeks later, Jerry’s not feeling too well.   Later that week, Harriet still feels fine, even though she too has a Dengue virus infection.  In the meantime Halima returns and feeds on little Suzy:  Jerry and Harriet’s daughter,    and Halima keeps crankin’-out hundreds of uninfected new kids…    The newly hatched generations of Dengue-free Amon kids feed on Jerry while he’s feverish,     so, even the recently-born Dengue-free Amon mosquitoes  now catch Dengue   from Jerry, (and later, from little Suzy, too).

Jerry gets a little sicker, until on the second day of feeling crappy, he goes to the Doctor for help and advice.   The doctor says… “blah, blah, blah, …   Drink plenty of fluids, take Tylenol for the pain and fever, but no aspirin or ibuprofen, or other NSAIDs….   Come back in two or three days for a Dengue blood test.     The test doesn’t work until you’ve felt sick for 4-5 days,   but come back around the 5’th or 6’th day of fever or feeling poorly,   cause you (Jerry) might have the DHF symptoms  by Day 6.

If you have DHF symptoms, we may need hospitalize you, to give you IV fluid treatments.” (DHF = Dengue Hemorrhagic Fever)

Jerry gets his blood tested after feeling crappy for 5 days.  Next day,  Doc calls to tell him:  “Yep, You’ve got Dengue 1. Merida’s got Dengue 1 and Dengue 2 circulating this year, and there’s a also chance of getting Dengue 3 or Dengue 4 in Merida,   which means that all four Dengue variants are endemic to the Yucatan – around every year – until we control the Aedes aegypti (A. ae.) mosquitoes.”

Doc goes on to say: “Dengue is only transmitted by being bitten by a Dengue-infected Aedes aegypti mosquito.    It’s safe to hug and kiss your kids,    and it’s safe to have woo-woo with Harriet.    Get lots of rest;   take acetaminophen (Tylenol) or baths   to reduce the eye-popping pain & bone-breaking aches and fever & chills; and drink lots of non-sugary fluids – 5 glasses per day per adult.

Sugary fluids like pop and juice   do little   to rehydrate your body.  In fact, pop and juice act as a mild diuretic, making your already stressed kidneys work harder.     Instead use cool water, or 1 or 2 bottles of special water from the pharmacy  with added electrolytes   to replenish what’s lost from sweating during the fever.”

Doc continues: “ Heck, exercise physiologists have found that even drinking coffee with a little sugar is 80% as effective as drinking water for re-hydration – better than pop or juice.”

Jerry was floored… he was sure that drinking juice must be more healthy than pop or beer or coffee… Doc suggests diluting any juice 1:2 or 1:4 with garafon-water. “Skip the pop – it’s just liquid candy = about 7 teaspoons of white sugar per can….”

Doc tells Jerry: “Good new and bad news, which do you want first??”

“Jerry, you’re protected from catching Dengue 1 for the next 4 months, but you really must spray your house with insecticide for mosquitoes, clean up your property and maybe even your neighbor’s properties, ‘cause while you’ve got a fever, you’re now a Dengue carrier, and you can potentially infect new mosquitoes, and those mosquitoes will be trying to bite Harriet, Suzy, and Don Francisco and Doña Deena and their little grandchildren Robertito and Juanita next door…”

“Don Francisco has already had Dengue twice in his life, and he gets worse symptoms every time, and his next Dengue infection may progress into DHF and make him really sick or even kill him.   None of us would want that  ‘on our conscience.’ ”

In the meantime,    both Harriet and little Suzy also have Dengue 1.  Harriet still feels fine, and even Jerry’s feeling a little better. … but Little Suzy feels lousy. … On Day 5 of symptoms:  Suzy’s mild fever spikes up 3 degrees into a wicked fever (40ºC or 104ºF),  and Harriet realizes it’s time to take action!    She knows that Tylenol really is a pretty lousy anti-pyretic.   ( = Tylenol/Acetaminophen really isn’t effective at lowering fever… Sidelight: my Pharmacist buddies quietly gave their kids aspirin during the 1980’s and 1990’s to reduce fever, since the risks of harm from a high fever are much greater than the “almost negligible” chance of getting Reyes Syndrome… but no aspirin if Dengue is suspected.)

Harriet remembers Doc’s guidance about no aspirin or NSAIDs or blood thinner medications  if Dengue is a possibility.    Harriet remembers her First Aid training:   High fevers of 104ºF or higher can be dangerous,  (risking seizures, etc),  and the patient should be treated immediately to reduce the fever by either a cool bath,  a shower,   or an isopropyl alcohol rubdown.     She starts filling the tub with cool – tepid water, and  quickly grabs the isopropanol (isopropyl alcohol) that she bought at the grocery store… (Harriet’s prepared! She has a stash of:  Acetone (fingernail polish remover) to remove/un-stick Super Glue (Cola Loka), (Super glue used to glue-shut wicked cuts), Hydrogen Peroxide (Agua Oxigenada) to remove blood stains and non-toxically disinfect things,   Isopropanol (Alcohol Isopropilico) to remove ink stains and relieve fevers, and a good First Aid Kit.

She wets a wash-cloth generously with the Isopropanol and begins gently wiping down Suzy – cooling her fever with the evaporating alcohol… Once the tub is partly full, she helps Suzy into the tub, to soak and further reduce the dangerous fever to a reasonable 101ºF or 102ºF (38.5ºC).

Doc says: “A little fever is good.   Helps the body fight viruses and infections.    The fever also keeps the patient quiet… make’s ‘em rest,   and not get up and run around….”

On day 6 of symptoms, Suzy spikes yet another wicked fever, and Harriet repeats the fever-reducing First Aid and calls the doctor. Doc says, “Bring her in right-away for testing, and we’ll check her out.”

Harriet takes Suzy into the UADY Hideo Noguchi lab, across from Merida’s Zoo on Avenida Izaes & Calle 59, for a free doctors evaluation, free advice, and free Dengue testing.

Doc determines that Suzy’s Dengue Virus infection has proceeded from a body rash, eye pain, and fever, instead  shifting into full-blown DHF (Dengue Hemorrhagic Fever) symptoms.    Harriet worries that she should have brought Suzy in for testing and treatment earlier.     Doc says: “You did fine, Harriet. The DHF symptoms don’t show up until the 6’th or 7’th day of symptoms. Plus, the test doesn’t work until you’ve had symptoms for about 5 days,   and  getting the test results  does not  change the treatment.”

Doc chooses to give Suzy an IV and hospitalize her, because  Suzy’s previously mild Dengue Fever has bloomed into full-blown DHF, and Suzy has begun to bleed heavily from her eyes and gums,   and later vomits lots of congealed blood.   Harriet can hardly bear to look at the vomit loaded with coffee-ground-like small clots of black blood.

Jerry’s not feeling to good about his previously  slightly-cocky  mostly-casual   attitude about reports of Dengue in Merida…   He wishes he had sprayed his house for mosquitoes at the first sign of Dengue, and plans to clean up his property of even small bits of plastic holding thimbles-full of standing water,    cover his drains,  flush his toilets regularly – even the ones in the guest bathroom –  put some little fish in his fountain,   and  he even started going around, urging his neighbors and friends  to do likewise.

He and his family plan  to wearing long pants & socks when outside in the mornings,   or apply their choice of mosquito repellent to clothing or exposed skin when outside.   He sprays the entire house, focusing on clothes closets and low, dark, cool, areas,  and closes it up for 1-2 hours – to kill all inside mosquitoes.    He realizes he should have thoroughly sprayed his house with Mata Mosko at the first sign of Dengue symptoms in his family.

He thinks about getting Swiss-made pesticide-treated curtains for his screen-less windows and possibly buying the somewhat expensive Swiss-made bed netting with a pesticide treatment that stays bound to the net and stays active for the next 3-5 years (depending on sun-exposure and # of washings).   He buys a small but effective $700 peso mosquito trap with UV bulb & fan to keep his bedroom clear of mosquitoes – and even treats his drains once a week with ammonia (to kill larvae) until he has no more mosquitoes in the house.

Jerry and Harriet talk about it, and decide to carefully screen all the doors and windows, and to wave a towel before sliding-back the screen doors to disrupt and temporarily chase away Halima and her Amon kin that lurk by their doors,   and to burn mosquito coils when they’re on the patio.    Halima and her kin still love to sit on the door screen,  and slip inside into the Harrison’s house quickly when the screen is opened even a little bit.

Halima never did live that long, just 30 days, her daughter lived only 10 days,   but her grand-daughter Layla lived a long life of 175 days, and since Layla had bitten Suzy during Suzy’s feverish period (high viremia), Layla was also infected…

Layla went on bite the kindly abuelito Don Francisco, and with DHF recently running at over 50% of Dengue cases, he  just didn’t make it.

Suzy recovered nicely.    With Harriet’s careful mothering, Suzy never got Dengue again.   Jerry still loved his shorts ‘n sandals,  used mosquito repellent for a while,    and ultimately got bitten again while drinkin’-beer one evening at a gringo-buddy’s house.

Jerry…? Since his immune system was compromised by his previous infection,  he got way-sick the next time,  sick enough that he changed his casual sometimes-inattentive ways,  and started posting strongly worded long but descriptive messages about Dengue and Aedes aegypti mosquito control on the various web Forums….

Odds and Ends
The  silent female A.ae. mosquito may be the only silent female in the animal/insect world.
A.ae. mosquito bites are the only way you can get the Dengue virus. The Dengue-infected mosquito got the dengue virus from a Dengue virus infected human while they had a fever.

Question: A mosquito bit you a few weeks ago:   Do you have Dengue?
 If you have the distinctive eye pain, bone pain, or body rash, and possibly a fever and you have been in the Tropics, then you likely have Dengue …

 Have you had a dengue infection in the last 4 months? If so, and  if the dengue type you had (e.g. Type 1) is the same as the current bite’s virus, then your immune system should protect you.    If it’s a different strain of the 4 Dengue viruses (called DV-1 – DV-4), then you may be infected.

Time for action?
2.5 billion people – two fifths of the world’s population – are now at risk from Dengue.
WHO Dengue Fact Sheet

This year:  Dengue infections in Merida and the Yucatan beach areas are 4X higher so far in 2010 – present at a rate that may result in over 120,000 new Dengue Virus infections in Yucatan in 2010.

Potentially Dengue Hemorrhagic Fever rates are now more than 50% of confirmed Dengue cases in Yucatan – Progresso/Chelem/Chicxulub,  Merida   and across Mexico. . . .to be continued

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Feel free to copy while giving proper attribution: YucaLandia/Surviving Yucatan. © Steven M. Fry

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