Rain is a bless­ing, but the wet sea­son brings floods, dengue, lep­tospiro­sis and mould, serv­ing as a re­minder that an un­cov­ered bar­rel can cre­ate a med­ical “hotspot” in a neigh­bour­hood. We should pre­pare for ill­ness by watch­ing what these show­ers leave be­hind.

Lep­tospiro­sis is caused by bac­te­ria spread through the urine of in­fect­ed an­i­mals, es­pe­cial­ly rats, dogs, cat­tle and oth­er mam­mals.

Dur­ing heavy rain and flood­ing, con­t­a­m­i­nat­ed urine can mix with wa­ter and mud. A per­son wad­ing through flood­wa­ter with cuts on the feet, walk­ing bare­foot through a soaked yard, clean­ing a flood­ed home with­out pro­tec­tion or swal­low­ing con­t­a­m­i­nat­ed wa­ter may be ex­posed.

Lep­tospiro­sis may be­gin like any oth­er fever: headache, chills, mus­cle pains, vom­it­ing, red eyes and ex­haus­tion.

That is why it can be mis­tak­en for dengue, in­fluen­za, “a virus” or or­di­nary tired­ness af­ter flood clean-up. Fever af­ter flood­wa­ter ex­po­sure should not be min­imised.

Some cas­es are mild. Oth­ers may in­volve the liv­er, kid­neys, lungs or brain. Jaun­dice, short­ness of breath, re­duced urine out­put, bleed­ing, se­vere weak­ness, or con­fu­sion should send a per­son ur­gent­ly for med­ical care.

Ear­ly treat­ment can save lives, but de­lay gives the in­fec­tion time to do dam­age.

The prac­ti­cal ad­vice is unglam­orous. Avoid walk­ing through flood­wa­ter if you can. If you must, wear boots or pro­tec­tive footwear. Cov­er cuts with wa­ter­proof dress­ings. Wash ex­posed skin with clean wa­ter and soap. Do not let chil­dren play in flood­wa­ter. It is rain­wa­ter mixed with what­ev­er the rain has col­lect­ed.

Dengue is the oth­er great vis­i­tor.

The mos­qui­to that spreads dengue, Aedes ae­gyp­ti, is a rest­less house-and-yard mos­qui­to. It breeds in clean stand­ing wa­ter, of­ten close to where peo­ple live. A bot­tle cap, a vase, a gut­ter, a bar­rel, a tyre, a pet bowl or a ne­glect­ed plant saucer can be­come a nurs­ery.

Dengue usu­al­ly presents with fever, headache, pain be­hind the eyes, body pains, joint pains, rash or pro­found tired­ness. Many re­cov­er, but some de­vel­op warn­ing signs af­ter the fever be­gins to set­tle. Se­vere ab­dom­i­nal pain, per­sis­tent vom­it­ing, bleed­ing from the gums or nose, black stool, marked drowsi­ness, rest­less­ness, faint­ness or dif­fi­cul­ty breath­ing are dan­ger sig­nals.

If dengue is sus­pect­ed, avoid as­pirin, ibupro­fen and oth­er an­ti-in­flam­ma­to­ry painkillers un­less a doc­tor ad­vis­es oth­er­wise, be­cause they may in­crease the risk of bleed­ing. Parac­eta­mol is usu­al­ly the safer op­tion for fever, along with flu­ids and med­ical re­view when “red flags” ex­ist.

The war against dengue is fought around the home. Emp­ty con­tain­ers. Turn over any­thing that can col­lect wa­ter. Cov­er tanks and bar­rels prop­er­ly. Clean gut­ters. Change wa­ter in vas­es and pet bowls. Dis­pose of old tyres. Re­pair screens where pos­si­ble. Use re­pel­lents. Pro­tect ba­bies, old­er peo­ple and those al­ready ill. Fog­ging may help, but it can­not com­pen­sate for a yard full of breed­ing sites.

The im­me­di­ate health im­pacts of floods in­clude drown­ing, in­juries, dan­ger­ous­ly low body tem­per­a­tures and an­i­mal bites. Health risks are al­so as­so­ci­at­ed with the evac­u­a­tion of pa­tients, the loss of health work­ers and dam­age to in­fra­struc­ture, in­clud­ing es­sen­tial sup­plies. In­fect­ed wounds, poi­son­ing, com­mu­ni­ca­ble dis­eases and a tot­ter­ing agri­cul­tur­al in­dus­try are in­di­rect ef­fects of flood­ing.

If the wa­ter sup­ply is dis­rupt­ed or sus­pect­ed to be con­t­a­m­i­nat­ed, fam­i­lies should use safe bot­tled, boiled or prop­er­ly treat­ed wa­ter. Food that has sat un­re­frig­er­at­ed for too long af­ter a pow­er cut should not be res­cued out of guilt. When in doubt, throw it out.

Flood­ing al­so finds the weak points in chron­ic dis­ease man­age­ment. In­sulin spoils when stor­age fails. Tablets are lost or soaked. Dial­y­sis be­comes hard­er when roads are blocked. Preg­nant women miss ap­point­ments. Old­er per­sons run out of blood pres­sure med­ica­tion. Peo­ple with di­a­betes may walk through dirty wa­ter with numb feet and dis­cov­er an in­fect­ed wound on­ly days lat­er.

This is why emer­gency prepa­ra­tion is about pre­scrip­tions, in­halers, in­sulin, glu­cose me­ters, dress­ings, blood pres­sure tablets, spec­ta­cles, phone charg­ers and the name of some­one who will check on the el­der­ly neigh­bour liv­ing alone.

Anx­i­ety, de­pres­sion and post-trau­mat­ic stress dis­or­der (PTSD) are trag­ic se­que­lae among those who ex­pe­ri­ence such cat­a­stroph­ic events. Af­ter flood­ing, peo­ple may sleep poor­ly, be­come ir­ri­ta­ble, feel con­stant­ly on edge when clouds gath­er, or ex­pe­ri­ence sad­ness that oth­ers min­imise be­cause “at least no­body died.” Men­tal health ser­vices must be a pri­or­i­ty in dis­as­ter re­sponse ef­forts as com­mu­ni­ties re­build lives.

Telemed­i­cine pro­vides re­mote con­sul­ta­tions and med­ical ad­vice when phys­i­cal ac­cess to health­care fa­cil­i­ties is com­pro­mised. This en­sures con­ti­nu­ity of care and al­le­vi­ates the bur­den on over­taxed health fa­cil­i­ties.

The rain will come, and it is not with­in our con­trol. How­ev­er, the mos­qui­to breed­ing in the old tyre, the child play­ing bare­foot in flood­wa­ter, the in­sulin left un­re­frig­er­at­ed, the fever ig­nored for four days, the blocked drain no­body cleared and the el­der­ly neigh­bour no­body checked are with­in reach.

That is where pre­ven­tion lives.