Guido Sabatinelli

Malaria in Maremma, Italy.

BACKGROUND In August, 1997, a woman with no history of travel to malarious regions developed Plasmodium vivax malaria. She lived in a rural area of Italy where indigenous Anophyles labranchiae mosquitoes were present. METHODS AND FINDINGS An environmental investigation was done within a 3 km radius of the patients house. Adult mosquitoes and larvae were collected and examined by PCR with the gene for plasmodium circumsporozoite protein as target. About 200 people living in the area were interviewed to detect possible carriers of P. vivax. FINDINGS None of the mosquitoes captured were carrying any malarial organisms. The house-to-house investigation identified a 7-year-old girl who had had a feverish illness a few days after her arrival in Italy from India, and who, 3 months later, still had P. vivax in her blood; she and her mother had antimalarial antibodies. INTERPRETATION These investigations suggest that the index case of malaria was caused by local anopheline mosquitoes infected with exogenous P. vivax.

Malaria epidemiological situation in Italy and evaluation of malaria incidence in Italian travelers

BACKGROUND Malaria was endemic throughout the country until it was eradicated nearly 50 years ago. Since then, mainly imported malaria cases have been reported to the National Health Service, with an increasing trend. The aim of this study was to present a detailed analysis of the current epidemiological situation of malaria in Italy, and to make a first attempt to calculate the incidence of malaria in Italian international travelers. METHODS An archive of confirmed malaria cases is available at the Istituto Superiore di Sanità (ISS), the National Institute of Health of Italy, based on the mandatory report system. Data from each case report reported to the ISS from 1989 to 1997 have been analyzed. An evaluation of malaria incidence in Italian travelers has been also performed for the same period, based on the statistics provided by the Ministry of Transport. RESULTS From 1989 to 1997, a total of 5,898 microscopically confirmed malaria cases have been reported. Of these, 5,773 (97.9%) were imported cases, 106 cases (1.8%) were relapses of Plasmodium vivax or Plasmodium ovale infections, and 19 cases (0.3%) occurred in subjects who had never been out of Italy. During the period of study, 55 deaths due to Plasmodium falciparum malaria were reported, with a mean fatality rate of 1.2%. Malaria incidence in Italians who traveled to Africa was estimated to be 1.5/1000. These figures appeared to be 10-20 and 30-40 times greater than that recorded in travelers to Asia (0.11/1000) and Central-South America (0.04/1000) respectively. CONCLUSIONS From 1989 to 1997, there has been a remarkable increase in the total number of imported malaria cases in Italy, which reached a peak of more than 800 cases/year in 1997. A constant increase in the number of cases affecting foreigners has been reported, while the cases among Italians have remained stable. From 1989 to 1997 the number of Italian intercontinental travelers has nearly doubled, but malaria incidence has remained quite stable.

Compliance and tolerability of mefloquine and chloroquine plus proguanil for long-term malaria chemoprophylaxis in groups at particular risk (the military).

An historical prospective study was performed on 5120 Italian soldiers deployed in Somalia and Mozambique in 1992-94, to determine compliance and tolerability of long-term malaria chemoprophylaxis with chloroquine plus proguanil (C + P) and with mefloquine. Compliance with C + P among 3734 soldiers on duty in Somalia for 3.8 +/- 1.8 months and with mefloquine among 1386 soldiers on duty in Mozambique for 3.4 +/- 1.5 months was 90.3% and 95.7%, respectively (P < 0.01). Chemoprophylaxis curtailment rate due to side-effects was 1.5% among C + P users and 0.9% among mefloquine users (P = NS). Compliance with chemoprophylaxis and medication curtailment rate due to side-effects did not change significantly for either C + P or mefloquine, even after 3 months of continuous prophylaxis. Chemoprophylaxis curtailment rate was significantly lower in subjects aged < or = 25 years than in older subjects (1.3% vs. 2.5% for C + P [P < 0.05] and 0.4% vs. 3.3% for mefloquine [P < 0.01]). These results further support the evidence that both C + P and mefloquine regimens may be safely used in long-term malaria chemoprophylaxis. Moreover, weekly mefloquine seems easier to perform than C + P and not to increase prophylaxis discontinuation due to side-effects. Mefloquine regimen should therefore be considered the elective chemoprophylaxis for groups at particular risk of chloroquine-resistant Plasmodium falciparum malaria and especially for young male subjects.

Anopheles sacharovi (Diptera: Culicidae): A Reemerging Malaria Vector in the Ararat Valley of Armenia

Abstract In 1994, the first indigenous case of malaria since the 1960s was reported in Armenia, and the number of cases quickly increased in the ensuing years. In 1998, a roll-back malaria program was developed to eliminate the recently established foci of malaria infection and to prevent the reestablishment of malaria in Armenia. As part of this program, we carried out entomological surveys to identify the potential malaria vectors in the Ararat Valley, the area where most of the indigenous malaria cases had been reported. In particular, we attempted to ascertain the presence of Anopheles sacharovi Favre, which is historically the most important malaria vector in Armenia yet which had not been reported since 1965. In 1998–2000, we collected adult mosquitoes and larvae in the city of Masis and in three rural villages of the Ararat Valley. Species identification of the members of the Anopheles maculipennis complex was performed through egg and larval morphology, heteroduplex analysis, and sequencing of the second internal transcribed spacer of ribosomal DNA. Two species of the complex were identified: An. sacharovi, found in all of the study sites, and An. maculipennis s.s. Meigen, the most common species in the area. The reemergence of An. sacharovi in the study sites shows that the receptivity for malaria is still high in the Ararat Valley and, likely, in other regions of Armenia.

Prevention and morbidity of malaria in non-immune subjects; a case-control study among Italian troops in Somalia and Mozambique, 1992–1994

The impact of malaria on Italian troops taking part in 1992-1994 in the United Nations Organization humanitarian missions in Somalia and Mozambique is discussed. In Somalia, 18 cases of Plasmodium falciparum malaria occurred among 11,600 soldiers; the overall attack rate was 0.4 cases/1000/month of exposure and the risk of malaria was effectively reduced by chemoprophylaxis with chloroquine plus proguanil (C+P) (odds ratio [OR] = 0.05, 95% confidence limits [95% CL] 0.02-0.16). In Mozambique, 119 cases of P.falciparum malaria occurred among 4800 soldiers; most cases (100) occurred in the first months of deployment (late March-June 1993), with an attack rate of 17 cases/1000/month, when C+P was the recommended chemoprophylactic regimen; the remaining 19 cases occurred subsequently, with an attack rate of 1.8 cases/1000/month, after C+P was replaced by mefloquine in July 1993. Protection achieved by C+P was unsatisfactory (OR = 0.37, 95% CL 0.21-0.67), while chemoprophylaxis with mefloquine effectively reduced the risk of malaria in Mozambique (OR = 0.03; 95% CL 0.01-0.10). A significant number of malaria infections was also detected among soldiers following their return home from Somalia (147 cases) and Mozambique (40 cases); these were due mainly to P. vivax. Fifteen of 113 P. vivax primary infections imported from Somalia (13.3%) relapsed 2-13 months after the primary attack. Because of the small proportion of relapsing P. vivax tropical strains, primaquine may be limited to radical treatment of relapses or, more extensively, of all P. vivax infections, but it should not be necessarily given to all asymptomatic subjects returning from tropical endemic areas, as is generally suggested for particular groups at risk.

Malaria epidemiological trends in Italy

Based on the official reports received from local health laboratories, an epidemiological analysis of malaria cases reported in Italy from 1989 to 1992 is presented. A total of 1,941 cases were reported, 1,287 among Italians and 654 among foreigners. The incidence of cases was on average 500 per year with a maximum in 1990. A slight, but constant decrease of incidence of malaria cases was recorded in this period among Italian citizens (−21.5%), while the incidence among foreigners increased (+80%).Plasmodium falciparum accounted for 74.2% of total infections, followed byP. vivax (19%). The highest number of cases was imported from Africa (86.5%), followed by Asia, South America, and Oceania. 11 cases were contracted in Europe (transfusion, airport and cryptic malaria). 26 people died from malaria during the four years, with a fatality rate of 2.3% among Italians. Other epidemiological features concerning incidence in the different categories of travellers, countries of infection, clinical and therapeutic aspects of cases, are also discussed.