Doi:10.1016/s0140-6736(05)64844-

malaria among international travellers. Can Comm Dis Rep 1995; probably a change in living conditions. Even in the poorest 21, S3: 1–18.
US communities, most people now live and work in air- Krogstad DJ. Plasmodium species (malaria). In: Mandell, Douglas, conditioned buildings, or are at least protected by insect and Bennett’s principles and practice of infectious diseases. 4th ed.
screens. In addition, the spacing of houses and other New York: Churchill Livingston, 1995: 2415–27.
buildings has increased because modern urban areas haveevolved around the motor vehicle. As a result, populationdensity is much lower than in the past, a major impediment Global warming and mosquito-borne disease to transmission. Events such as the dengue pandemic that affected the Caribbean, Central America, and Mexico in1995 support this explanation. 74 000 cases were reported SIR—In your June 8 editorial1 you raise the issue of the from the region (Pan-American Health Organisation, impact of global warming on health. Speculations on the unpublished data), including 4479 from Tamaulipas state, effect of global warming in the USA frequently include on the Texas border. Of these, 2361 were from Reynosa, a discussion of mosquito-borne diseases such as malaria, city contiguous with Hidalgo, Texas, but only seven yellowfever, and dengue.2 Some have suggested that rising autochthonous cases were reported in the entire state of temperatures will expand the geographical range of vector Texas.5 Thus, unless living conditions are drastically mosquitoes, increase their rate of development, and reduce changed, global warming is unlikely to give rise to major the extrinsic incubation time of their pathogens. The epidemics of tropical mosquito-borne disease in the USA.
implication is that both the mosquitoes and the diseases willemerge from the tropics and give rise to epidemics in the USA. Such predictions ignore the complex dynamics of Dengue Branch, Division of Vector-Borne Infectious Diseases, National Centre forInfectious Diseases, Centers for Disease Control and Prevention, San Juan mosquito-borne infections: climate and weather are Laboratories, San Juan, Puerto Rico 00921, USA important variables, but other factors are of equal or greaterimportance.
Editorial. Climate-and-health debate warms up. Lancet 1996; 347:
Several efficient malaria vectors are indigenous to North America, and are common in many areas. The disease was Patz JA, Epstein PR, Burke TA, et al. Global climate change and once endemic and widespread in the USA (figure). In 1934, emerging infectious diseases. JAMA 1996; 276: 217–23.
the year after systematic reporting began, 125 556 cases were Zucker JR. Changing patterns of autochthonous malaria transmissionin the United States: a review of recent outbreaks. Emerging Infectious recorded.3 Transmission was also recorded in Canada. When Diseases 1996; 2: 37–43.
it was founded in 1946, the main function of the Centers for Ehrenkranz NJ, Ventura AK, Cuadrado RR, et al. Pandemic dengue in Disease Control and Prevention (CDC) was malaria control, Caribbean countries and the southern United States—past, present and it was based in Atlanta because the city was in a and potential problems. N Engl J Med 1971; 285: 1460–69.
malarious region. The disease was finally eradicated from the Centers for Disease Control and Prevention. Dengue at the US-Mexico border, 1995. MMWR (in press).
USA in the 1950s. Aedes (Stegomyia) aegypti (L), theprincipal urban vector of yellowfever and dengue, is alsocommon throughout the southern USA. From the 17thcentury onwards, frequent epidemics of yellowfever killedtens of thousands of people as far north as New York. In a Isotretinoin and azathioprine: a synergy that single year (1878), there were 100 000 cases and 20 000 deaths. Dengue fever was also common, eight majorpandemics occurring between 1827 and 1946.4 In 1922, SIR—Acne is common after organ transplantation.1 Steroids dengue spread east from Texas (500 000 cases) through are usually blamed but recently cyclosporin has also been Louisiana, Georgia, and Florida, and then south into the reported to be associated with severe acne.2 Systemic Caribbean islands. Savannah, Georgia, reported 30 000 treatment with antibiotics may interact with cyclosporin cases, 28% of which had haemorrhagic manifestations.
metabolism and absorption. Severe acne responds to Summer temperatures in the USA were clearly conducive isotretinoin. Transplant physicians have been reluctant to to the transmission of these diseases. Indeed, in the southern prescribe this drug because of concern about enhancing states they are higher than in many tropical countries. So why rejection, although several cases have now been reported on did epidemic transmission cease? The principal factor was the use of isotretinoin with no deleterious effects on thegrafts.2 A rare side-effect of isotretinoin is curling hair.3 We report three simultaneous pancreas-kidney (SPK) transplantrecipients, who developed curling hair after isotretinointherapy. The first patient is a 49-year-old man who was puton isotretinoin 100 mg/day 13 months after transplantationbecause of severe acne which did not respond to topicaltherapy. 2 months later he developed extremely curly hair(figure). The second patient was a 46-year-old man whostarted 60 mg isotretinoin 12 months after transplantation,and developed curls in his hair after 60 days. The thirdpatient started isotretinoin 60 mg/day 13 months aftertransplantation and developed curling hairs 3 months later.
All patients had an improvement in their acne and nodeleterious effects on pancreas and kidney graft functionwere seen. Cyclosporin dosage had to be increased in two patients, based on trough levels. Concurrent medication was Figure: Areas of the USA where malaria was thought to be prednisone (10 mg/day), cyclosporin (Neoral), and azathioprine. Furthermore, nifedipine (2/3 patients), sodium Reproduced from Emerging Infectious Diseases with permission bicarbonate (3/3), omeprazole (1/3), distigmine bromide (1/3), atenolol (1/3), hydrochlorothiazide (1/3), and enalapril

Source: http://planet.botany.uwc.ac.za/NISL/Gwen's%20Files/GeoCourse/Climate%20Change/Verification/P%20Reiter/USAMosquitoReiter.pdf