Evaluation of the fat-tailed gerbil, Pachyuromys duprasi (Rodentia: Gerbillidae), as a new animal model for studies of Leishmania major infection and transmission.

The fat-tailed gerbil Pachyuromys duprasi is a common burrowing rodent found across the northern Sahara Desert from Morocco to Egypt. There is overlap in the geographical distribution and ecological habitats of P. duprasi, several Old World Leishmania species, and numerous sand fly vectors of Leishmania, but there are no records that document the natural occurrence of this gerbil with any species of Leishmania or phlebotomine sand fly.

Failure of Supervised Chloroquine and Primaquine Regimen for the Treatment of Plasmodium vivax in the Peruvian Amazon.

The widespread use of primaquine (PQ) and chloroquine (CQ), together, may be responsible for the relatively few, isolated cases of chloroquine-resistant P. vivax (CQRPV) that have been reported from South America. We report here a case of P.

Virus isolations and high population density implicate Culex antennatus (Becker) (Diptera: Culicidae) as a vector of Rift Valley Fever virus during an outbreak in the Nile Delta of Egypt.

In June, 2003, Egypt's hospital-based electronic disease surveillance system began to record increased cases of acute febrile illness from governorates in the Nile Delta. In response to a request for assistance from the Egyptian Ministry of Health and the World Health Organization (WHO), the U.S.

Sulfadoxine-pyrimethamine-based intermittent preventive treatment, bed net use, and antenatal care during pregnancy: demographic trends and impact on the health of newborns in the Kassena Nankana District, northeastern Ghana.

Demographics and health practices of 2,232 pregnant women in rural northeastern Ghana and characteristics of their 2,279 newborns were analyzed to determine benefits associated with intermittent preventive treatment (IPTp), antenatal care, and/or bed net use during pregnancy. More than half reported bed net use, 90% reported at least two antenatal care visits, and > 82% took at least one IPTp dose of sulfadoxine-pyrimethamine. Most used a bed net and IPTp (45%) or IPTp alone (38%).

Effects of ivermectin on blood-feeding Phlebotomus papatasi, and the promastigote stage of Leishmania major.

Ivermectin (IVM) is a chemically modified macrocyclic lactone of Streptomyces avermitilis that acts as a potent neurotoxin against many nematodes and arthropods. Little is known of IVM's effect against either blood-feeding Phlebotomus sand flies, or the infective promastigote stage of Leishmania transmitted by these flies. We injected hamsters subcutaneously with two standard IVM treatments (200 and 400 μg/kg body weight) and allowed cohorts of Leishmania major-infected Phlebotomus papatasi to blood-feed on these animals at various posttreatment time points (4 h, 1, 2, 6, and 10 days).

Discordant patterns of genetic variation at two chloroquine resistance loci in worldwide populations of the malaria parasite Plasmodium falciparum.

Mutations in the chloroquine resistance (CQR) transporter gene of Plasmodium falciparum (Pfcrt; chromosome 7) play a key role in CQR, while mutations in the multidrug resistance gene (Pfmdr1; chromosome 5) play a significant role in the parasite's resistance to a variety of antimalarials and also modulate CQR. To compare patterns of genetic variation at Pfcrt and Pfmdr1 loci, we investigated 460 blood samples from P. falciparum-infected patients from four Asian, three African, and three South American countries, analyzing microsatellite (MS) loci flanking Pfcrt (five loci [approximately 40 kb]) and Pfmdr1 (either two loci [approximately 5 kb] or four loci [approximately 10 kb]).

Laboratory demonstration of the acquisition and development of leishmania major in the sand fly Phlebotomus kazeruni (Diptera: Psychodidae).

Phlebotumus kazeruni, a blood-feeding, xerophilic sand fly species found broadly throughout North Africa and Western Asia, is a suspected vector of cutaneous leishmaniasis (CL). Following successful laboratory colonization of this species, we employed the murine (BALB/c) infection model to determine whether our Sinai strain of P. kazeruni was able to successfully acquire, develop, and transmit a Sinai strain of Leishmania major.

Mefloquine treatment for uncomplicated falciparum malaria in young children 6-24 months of age in northern Ghana.

Mefloquine (MQ) single dose 20 mg/kg treatment of falciparum malaria was evaluated in 186 children of 6-24 months of age in northern Ghana. There were 15 RII/RIII-type parasitologic failures, all with Day 2 MQ blood levels significantly lower than children whose parasitemias cleared before Day 7 and remained clear through 28 days. Predictors of RII/RIII parasitologic response were vomiting after MQ dosing, Day 2 MQ levels < 500 ng/mL, and undetectable Day 2 levels of the carboxymefloquine metabolite.

Bionomics of phlebotomine sandflies at a peacekeeping duty site in the north of Sinai, Egypt.

A longitudinal entomological survey for sandflies was conducted from 1989 to 1991 at a focus of enzootic cutaneous leishmaniasis in Northeast Sinai, Egypt, within the border region monitored by multinational peacekeepers. Standardized sampling with CDC light traps, oiled paper "sticky traps", and human landing collection was employed to determine monthly trends in species composition, density, sex ratio, and reproductive status of vector sandflies. Each collection method independently defined sandfly seasonality as the period May-November in 1990, and March-October in 1991.

Use of bioassay and microplate assay to detect and measure insecticide resistance in field populations of Culex pipiens from filariasis endemic areas of Egypt.

Insecticide and resistance bioassays and microplate assays were performed on Culex pipiens mosquitoes to determine the level and mechanisms of resistance. Culex pipiens larvae were collected from three filariasis-endemic areas of Egypt and reared to adults for subsequent production and testing of F1 generation larvae and adults. Bioassays were performed using World Health Organization (WHO) methods with the diagnostic doses of 6 organophosphate insecticides for larvae and 1 organochlorine (OC), 4 pyrethroid, 2 organophosphate, and 2 carbamate insecticides for adults.

Hepatitis E virus infection in work horses in Egypt.

Hepatitis E virus (HEV) is an important cause of hepatitis among young Egyptian adults with high seroprevalence rates seen in both rural areas of the Nile Delta and in suburban Cairo. Because natural antibodies to HEV have been detected in animals and zoonotic transmission is postulated, we surveyed work horses in Cairo for evidence of HEV exposure and viremia. Sera from 200 Cairo work horses were tested by ELISA for the presence of IgG anti-HEV antibody revealed a seropositivity of 13%.

Mefloquine is highly efficacious against chloroquine-resistant Plasmodium vivax malaria and Plasmodium falciparum malaria in Papua, Indonesia.

Background: During the period of 1996-1999, we prospectively monitored 243 Javanese adults and children after arriving in Papua, Indonesia, and microscopically documented each new case of malaria by active surveillance.

Methods: In a randomized, open-label, comparative malaria treatment trial, 72 adults and 50 children received chloroquine for each incident case of malaria, and 74 adults and 47 children received mefloquine.

Results: Among 975 primary treatment courses, the cumulative 28-day curative efficacies were 26% and 82% for chloroquine against Plasmodium falciparum malaria and Plasmodium vivax malaria, respectively.

Malaria transmission dynamics at a site in northern Ghana proposed for testing malaria vaccines.

We studied the malaria transmission dynamics in Kassena Nankana district (KND), a site in northern Ghana proposed for testing malaria vaccines. Intensive mosquito sampling for 1 year using human landing catches in three micro-ecological sites (irrigated, lowland and rocky highland) yielded 18 228 mosquitoes. Anopheles gambiae s.

Short report: in vivo sensitivity of Plasmodium falciparum to halofantrine in southern central Vietnam.

Drug-resistant Plasmodium falciparum is present in Vietnam. We assessed the in vivo sensitivity of P. falciparum to halofantrine in two villages in the southern part of central Vietnam.

Primaquine for prevention of malaria in travelers.

An expanding risk and range of endemic malaria threatens travelers. Primaquine is an old drug recently demonstrated to offer effective prophylaxis. Clinical trials conducted in Indonesia, Kenya, and Colombia showed that a primaquine base (30 mg per day) had protective efficacy against Plasmodium falciparum and Plasmodium vivax of 85%-93%.

Detection of malaria sporozoites by standard ELISA and VecTestTM dipstick assay in field-collected anopheline mosquitoes from a malaria endemic site in Ghana.

We compared the VecTestTM dipstick assay for detection of Plasmodium sporozoites in Anopheles vectors of malaria with standard circumsporozoite (CS) microplate ELISA for detection of Plasmodium falciparum circumsporozoite protein (PfCSP) in Anopheles mosquitoes. Mosquitoes were collected from a malaria endemic site (Kassena Nankana district) in northern Ghana. Of 2620 randomly sampled mosquitoes tested, the standard CS-ELISA gave a sporozoite rate of 10.

Seasonal profiles of malaria infection, anaemia, and bednet use among age groups and communities in northern Ghana.

We conducted all-age point prevalence surveys to profile the severity and seasonality of malaria and anaemia in Kassena-Nankana District of northern Ghana. Random cross-sectional surveys were timed to coincide with the end of low (May 2001) and high (November 2001) malaria transmission seasons and to yield information as to the potential value of haemoglobin (Hb) levels and parasitaemia as markers of malaria morbidity and/or malaria vaccine effect. Parasitaemia was found in 22% (515 of 2286) screened in May (dry-low transmission), and in 61% of the general population (1026 of 1676) screened in November (wet-high transmission).

Age-dependent impairment of IgG responses to glycosylphosphatidylinositol with equal exposure to Plasmodium falciparum among Javanese migrants to Papua, Indonesia.

Immune responses directed at glycosylphosphatidylinositol (GPI) anchors of Plasmodium falciparum may offer protection against symptomatic malaria. To independently explore the effect of age on generation of the anti-GPI IgG response, we measured serum anti-GPI IgGs in a longitudinal cohort of migrant Javanese children (6-12 years old) and adults (> or = 20 years old) with equivalent numbers of exposures to P. falciparum in Papua, Indonesia.

Serologic evidence of infection with ehrlichiae and spotted fever group rickettsiae among residents of Gag Island, Indonesia.

The causative agents of scrub and murine typhus are considered endemic to Indonesia. However, the presence of spotted fever group rickettsiae and ehrlichiae have not been previously described in this country. During an investigation of arthropod-borne diseases on Gag Island, located northwest of the island of New Guinea in eastern Indonesia, the prevalence of antibody to the etiologic agents of monocytic ehrlichiosis, spotted fever rickettsiosis, and scrub and murine typhus were determined.

Very high risk of therapeutic failure with chloroquine for uncomplicated Plasmodium falciparum and P. vivax malaria in Indonesian Papua.

Chloroquine remains the first-line therapy for uncomplicated malaria in Indonesia. Among a series of trials of chloroquine for malaria on this archipelago conducted since 1990, we now report the highest risk of therapeutic failure yet observed. A clinical trial of standard chloroquine therapy for uncomplicated malaria at Arso PIR V in northeastern Indonesian Papua was conducted during 1995.

New haplotypes of the Plasmodium falciparum chloroquine resistance transporter (pfcrt) gene among chloroquine-resistant parasite isolates.

Mutations in the Plasmodium falciparum chloroquine resistance transporter (pfcrt) gene were examined to assess their associations with chloroquine resistance in clinical samples from Armopa (Papua) and Papua New Guinea. In Papua, two of the five pfcrt haplotypes found were new: SVIET from Armopa and CVIKT from an isolate in Timika. There was also a strong association (P < 0.

Tolerability of azithromycin as malaria prophylaxis in adults in northeast papua, indonesia.

Drug tolerability affects compliance. We evaluated the tolerability levels of azithromycin (750-mg loading dose plus 250 mg/day; n = 148 subjects), doxycycline (100 mg/day; n = 75), and placebo (n = 77) as prophylaxis against malaria in Indonesian adults over 20 weeks. Self-reported and elicited symptoms, health perception, hearing, hematology, and biochemistry were assessed.